RU2431868C1 - Method for seismic exploration when searching for hydrocarbons and seismic system for realising said method - Google Patents

Abstract

FIELD: physics. ^ SUBSTANCE: in the disclosed engineering solution, determination of the dispersion curve of microseismic waves typical for the investigated territory is carried out via synchronous detection of microseismic signals using not less than three seismic station by picking up seismic noise at frequencies 0.008-20 Hz at the water-soil boundary, wherein odd harmonics 0.003 and 0.005 Hz are picked up from the spectrum of horizontal components and even harmonics 0.002, 0.004, 0.006 and 0.008 Hz are picked up from the spectrum of vertical components; variation of the magnetic field is measured at frequencies 0.01-1.0 Hz, magnetic induction of the electromagnetic field at frequencies 1-200 Hz, the electric component of the electromagnetic field at frequencies 1-500 Hz, acoustic noise at frequencies 5-5000 Hz, hydrodynamic noise of the sea at frequencies 0.01-100 Hz in tectonic zones; based on the measured parameters, factoral analysis is performed at the levels of natural geophysical background and geophysical background by plotting a graph of amplitude of gradients of seismic, geodeformation, geochemical and hydrophysical indicators based on measurements which do not exceed 50-100 km in average latitudes of 8-10 km in high and equatorial latitudes respectively; short-term variation of the magnetic field caused by sea disturbance is also taken into account; magnetic survey errors are minimised by detecting the thin structure of magnetic irregularities and determining parameters thereof; arrival of a seismogenetic acoustic wave is determined from the value of the frequency shift of the scattered radiation. Detecting devices placed at a distance from the coastal area enable to analyse low-frequency components of the scattered signal using quasiharmonic high-frequency ship noise signals as reference signals, and detecting devices placed in the coastal zone enable to determine onset and direction of arrival of seismic waves via narrow-band filtration and spectral analysis of the waves through recursive Butterworth filters, wherein input filtration is carried out using recursive filters with integral coefficients, and signals with sampling frequency 100 Hz and lower are filtered with coefficients in form of floating point numbers; hydroacoustic signals are picked up using wide-band ocean-bottom seismographs with not less than three seismic channels, wherein signals are analysed using three independent detectors, and the detection signal is generated when signals coincide in at least two channels from three; spectral analysis is performed for volume waves with phases PP and S, and for Love, Rayleigh and Stonely surface waves; plotting the map of amplitude variations of the microseismic signal for each spectral frequency of spatial variations, as well as associating each obtained map with its corresponding depth is carried out by approximating the profile of the vertical relief relative the coastal line, and the basic spline used is a cubic spline with zero boundary derivatives, wherein construction of a two-dimensional spline - function is executed through the tensor product of one-dimensional splines; the measured base at the sea floor is formed by placing seismic receivers at a distance of not more than 5 km from each other to form an isosceles triangle in the underwater space, at the vertices of which seismic receivers are put. Seismic vibration receivers are placed in a shelf zone, along the line of the foot of the continental slope and along the axis of the perpendicular Gardiner lines on fault boundaries; detection of local structures with oil-and-gas bearing potential is carried out via seismic profiling using a mobile seismic station with multiple overlapping of reflecting boundaries. The seismic system for seismic survey which consists of stationary seismic receivers and a mobile multichannel seismometric module, each of which consists of a block of highly sensitive seismic sensors, a recoding module with a block of filters and amplifiers, a board of analogue-to-digital converters, digital-to-analogue converters, a computer, a GPS receiver, a power supply, a calibration unit, a unit for processing and analysing signals and spectral characteristics thereof, MathLab 6.0 or higher type software, is characterised by that it includes a floating apparatus, a flight device, a standalone ocean bottom seismic station, a near-bottom seismic station and a floating seismic station; the mobile seismic module is in form of a controlled underwater vehicle; the floating apparatus is fitted with an underwater probe; the recording apparatus of the seismic system additionally includes a methane detector, a hydrophysical module, an ocean bottom seismometre, a magnetic field sensor with a control unit, a penetrometre, a gravimetre, a pneumatic radiator, an ocean bottom pressure sensor, a hydroacoustic communication channel modem, a satellite communication channel modem, a spatial orientation unit, an acoustic Doppler measuring device for measuring flow contour and a unit for hydrochemical measurements. ^ EFFECT: high reliability of seismic surveys when searching for and exploring hydrocarbon deposits. ^ 2 cl, 13 dwg

Description

The invention relates to the field of seismic research and can be applied in the search for hydrocarbon deposits on the continental shelf.

Known methods for seismic exploration usually use the registration of the passage of seismic vibrations with a frequency of more than 10.0 Hz. During the use of such frequencies in seismic exploration, hardware design for generating and recording such oscillations, as well as a mathematical apparatus for processing data, have been quite widely developed. Either vibrators or explosions are predominantly used to generate such vibrations. For blasting, it is necessary to drill holes for laying explosives. This technique sharply negatively affects the state of the environment in the search area. In addition, the success rate of prediction using known methods and techniques of seismic exploration does not exceed 0.5. Therefore, at least every second well drilled according to the conclusions of traditional seismic exploration of oil and gas deposits, is erroneously laid. In addition to funds spent in vain for drilling a well, irreparable and unreasonable damage to the environment is caused, especially when performing similar work on the shelf of the seas.

There is a method of vibro-seismic exploration when searching for a hydrocarbon deposit [1], in which seismic vibrations are excited by a vibrator, a seismic signal is recorded by three-component seismic receivers and mathematically processed, and seismic vibrations are excited in a frequency range of 2-5 Hz for at least 3 minutes, registration of seismic the signal is carried out for at least 20 minutes before the excitation of seismic vibrations and no more than 5 minutes after the end of the generation of seismic vibrations , the seismic background of the Earth is used as a seismic signal, and the presence of a deposit is judged by the increase in the area under the curve of the mutual spectrum of the same components when recording a seismic background after excitation of seismic vibrations compared with recording a signal before generating oscillations.

The disadvantage of this method is the low information content, which does not allow to determine the depth of the reservoir, as well as the complexity of the mathematical analysis of the received signals due to the inability to isolate the recorded interference.

There is also a method of searching for hydrocarbon deposits [2], in which seismic vibrations are generated by a seismic vibrator in the range from 2 to 5 Hz, an information signal is recorded using three-component seismic oscillation receivers capable of recording an information signal in the infrasonic range and located at a distance of no more than 500 m from each other and no further than 500 m from the seismic vibrator, in the frequency range from 2 to 5 Hz simultaneously for three components both before and during the generation of the seismic signal, and the presence of hydrocarbon deposits is judged by the appearance of the spectral anomaly of the information signal on at least one of the components when recording the information signal during the generation of seismic vibrations compared with the information signal measured before generation.

The disadvantage of this method is the low information content, which does not allow to determine the depth of the reservoir, as well as the complexity of the mathematical analysis of the received signals due to the inability to isolate the recorded interference.

A known method of seismic exploration [3], including the formation of zones of emission and reception of seismic signals, registration of an information signal, followed by mathematical processing of the obtained data, and the signal is recorded by at least two three-component seismic installations located at some distance from each other.

To implement this method, it is necessary to use seismic emitters and conduct a preliminary study of the geological section in the search area. In addition, the method is burdened with computational operations.

Also known is a method of seismic exploration in the search for oil and gas fields.

[4], based on the determination of the wavelength L of the prevailing seismic background in the unpromising section, in which the correlation between the same components is weakened by more than two times. In the area under study, at least two three-component installations are located at a distance L / 4. The natural seismic background is recorded for all components at frequencies of 1-20 Hz. The presence of a field is judged by the shift towards low frequencies of the maximum frequency spectrum of the seismic signal recorded in the study area.

However, this method is time-consuming due to the need to carry out seismic studies on a prospectless field, which requires preliminary work to identify such a site, and then perform seismic studies on a promising field that can be detected by comparing the recorded signals over both sites. At the same time, obtaining objective estimates of research results is possible only with synchronous registration of signals over both sections.

There is also a known method of seismic exploration in the search for groundwater [5]. The specified method consists in placing at least three electric probes in the Earth in separate positions in a straight line, passing through the studied area of the Earth between the first and second electric current probes and measuring the potential difference between the first and third probes, as well as between the third and second a probe. The indicated potential differences are compared with each other and based on this comparison, the presence of groundwater is determined.

This method is also time-consuming due to the need to perform drilling operations necessary for the equipment of the mines for the placement of electric probes, and allows you to achieve the required degree of reliability of determining the site with a promising field, provided that a significant number of mines for the placement of electric probes are equipped.

There is also a method of searching for hydrocarbons (options) and a method for determining the depth of productive formations [6], in which the technical task to be solved is to increase the accuracy of determining productive hydrocarbons in formations, including determining the depth of their occurrence.

The technical result obtained as a result of the implementation of the method consists in reducing the number of erroneously drilled wells, as well as providing the ability to control the operation of production wells and gas storages during oil and gas production.

To achieve the technical result according to the first embodiment, it is proposed to use a hydrocarbon search method characterized by recording seismic vibrations of the Earth’s surface using seismic vibrations receivers capable of recording seismic vibrations in the range from 0.1 to 20 Hz, and seismic vibrations receivers located at a distance of 50 m to 500 m from each other, registration is carried out simultaneously for all measured components, dividing the time range of registration of the measured n and the prospective area of the information signal for discrete sections synchronized in time for all seismic receivers, they calculate the spectral characteristics corresponding to each discrete section with the formation of a discrete sequence, analyze each discrete section for interference of anthropogenic nature, and for the presence of an event associated with the arrival signal from the reservoir, exclude from further consideration those discrete sections that do not contain events associated with the signal from the reservoir in each of the records of the corresponding components of the seismic receivers, as well as discrete sections containing the indicated interference, and analyze the remaining discrete sections with a judgment on the presence or absence of hydrocarbons. When implementing the method, seismic oscillations are additionally measured in a place that is obviously not containing hydrocarbons, and the presence of oil or gas is judged by the appearance of deviations in the spectral characteristics, compared with a place that is obviously not containing hydrocarbons. The method can be implemented both on land and in the water area, with seismic receivers respectively being located on land, in the bottom of the water area, or deepened in the surface layer, in the aquatic environment, and / or on watercraft in places minimally prone to natural vibrations of the body of the craft moreover, the watercraft are removed at equal distances from the source of oscillation generation.

According to the second variant, in order to achieve the indicated technical result, the Earth’s microseismic noise is additionally measured and the presence of hydrocarbons is judged by the appearance of changes in the spectral characteristics of at least one of the components when recording a signal during oscillation generation and / or after oscillation generation compared to the information signal measured before generating. The proposed method can also be implemented both on land and in the water area; therefore, seismic receivers are located on land, in the bottom of the water area and / or on watercraft in places that are minimally prone to natural vibrations of the body of the craft, and the craft are removed at equal distances from the source of oscillation generation. In all cases of the implementation of the proposed method, usually the receivers of seismic vibrations are grouped and also synchronized. In addition, in the process of mathematical processing of the recorded results, the information signal is mainly divided into temporary sections of at least 2-3 signal periods of the lowest frequency range.

As part of the implementation of the first and second options, the task of controlling the operation of a hydrocarbon deposit can be solved. To do this, control points are selected over the reservoir, preferably located near production wells. At selected points, receivers of seismic vibrations are located, capable of detecting seismic vibrations in the infrasonic frequency range of at least one of the components. The microseismic noise of the Earth is periodically recorded. By the disappearance of the anomaly in the spectral characteristics at frequencies of 0.1–20 Hz, the passage of the water – hydrocarbon contact under the control point is judged.

The anomalous behavior of the spectral characteristics is determined by any of the above options - without applying external influences, by analyzing the behavior of the spectral characteristics of each discrete section of the time range partition, or with respect to the spectral characteristic of the information signal recorded for the section that obviously does not lie above the reservoir, as well as in the variant using external influence, using the same oscillation processing algorithms, but applying them to the recorded signal during / after air The action of the source of seismic vibrations, or the transition of the water-hydrocarbon contact, is judged by the appearance of changes in the spectral characteristics of at least one of the components when recording a signal during oscillation generation and / or after oscillation generation compared to the spectral characteristics of the information signal measured before generation. It is preferable to record the spectral characteristics of the microseismic noise of the Earth for each point for 40-60 minutes.

When controlling the degree of filling of the underground natural gas storage, points on the Earth's surface are selected that roughly determine the different degrees of filling of the gas storage, seismic vibration detectors are placed at the selected points, capable of recording infrasonic vibrations by at least one component, and the spectral characteristics of the Earth’s microseismic noise are periodically recorded, moreover the absence of an abnormal change in the spectral characteristics of the information signal at frequencies of 0.1-20 Hz stvuet the absence of natural gas under the control point. For comparison, a microseismic noise of the Earth is recorded by a similar receiver above a place obviously located outside the gas storage. It is preferable to select control points during the first filling of the gas storage, determining in which places above the gas storage the presence of natural gas is noted at various amounts of gas supplied. However, in any case, control points are determined empirically. It is possible to generate seismic vibrations during the registration process. In this case, registration is carried out both before the start of generation and during generation.

Using, in particular, the second option (with generation), it is possible to determine the depth of the reservoir productive for hydrocarbons. To do this, use at least 4 receivers of seismic vibrations, capable of detecting infrasonic vibrations by 3 mutually perpendicular components, placing them at the vertices of the quadrangle.

In all of the above embodiments of the invention, a fundamental and important step is the process of filtering the recorded time series from surface noise and extracting the information signal. For this purpose, a grouping (arrangement) of seismic oscillation receivers and cross-correlation processing of the recorded signal are used.

To implement the above options, a seismic oscillation detector is used that is capable of detecting vibrations in the infrasonic range, containing at least one seismic oscillation sensor capable of detecting infrasound vibrations, all the sensors used are located on a rigid base so that the sensitivity axes of the sensors are located at fixed angles relative to flat rigid base and relative to each other, with each sensor connected to the registration unit, and the main The sensors are housed in a rigid, sealed enclosure. Angular and / or linear vibration sensors capable of detecting vibrations in the infrasonic frequency range can be used. Advantageously, the recording unit of each sensor comprises a pre-connected signal amplifier, an amplitude-frequency response driver and a terminal amplifier, each terminal amplifier being configured to be connected to a common recorder.

However, the known method [6] is based on the hypothesis of oil deposits as the only possible source of the observed anomaly in the low-frequency range of the seismic spectrum. At the same time, practice shows [7] that anomalous signals are observed in the presence of other significant heterogeneities in the section, in particular in the form of active tectonic disturbances or in the presence of underground rivers. An abnormal signal is also observed in the target range with a shallow basement at the point of study, commensurate with the depth of hydrocarbons.

In addition, when placing seismic oscillation receivers on boats or at deep horizons, it is necessary to exclude from the observation results the signal component due to noise of navigation and the speed of underwater currents. In this case, all the sensors used must be located on a rigid base in such a way that the sensitivity axes of the sensors are located at fixed angles with respect to the flat rigid base and with respect to each other, which is practically impossible to provide under the hydrosphere.

In the known method of low-frequency seismic sensing for the search and exploration of hydrocarbon deposits (options) [7], the problem is solved by the method of low-frequency seismic sensing for the search and exploration of hydrocarbon deposits, which includes determining at least one observation point on the search area, placing seismic vibrations at the observation point of the receiver conducting registration of information signals by their measured components for a period of time sufficient to record statistically noise signal in the infra-low-frequency range, calculating the spectral characteristics using the Fourier transform of the received signals, analyzing them for the presence of false signals and signals from the reservoir with natural hydrocarbons, excluding false signals from the analysis, analyzing the remaining signals with a judgment on the presence or the absence of hydrocarbons, in which, in contrast to the known method, registration and recording are carried out on the vertical components of information signals, Fur l-conversion of the vertical components of information signals is carried out according to their first derivative, the maximum is determined on the obtained spectra, which is characterized by the location on the spectrum in the frequency range

Vs / H <F <Vp / H,

where Vs is the average sedimentary cover velocity of transverse seismic waves at the observation point;

Vp - average sedimentary cover velocity of propagation of longitudinal seismic waves at the observation point;

H is the known depth of the foundation at the observation point,

a signal with this maximum is taken as a false signal corresponding to the resonance between the day surface and the foundation — a signal from the foundation, a point with a spectrum that contains a signal from the foundation with a monotonic decrease in the spectrum amplitude towards high frequencies from the maximum of the signal from the foundation is recognized as a hopeless observation point observations, in the signal spectra of which there are maxima at frequencies greater than the frequency of the maximum signal from the foundation, with their uniform arrangement with an offset relative to other measurements less than half the width of its maximum, is taken as promising for the presence of hydrocarbons from natural reservoirs. In this case, when identifying a uniform arrangement of signals, it is possible to compare them relative to signals of other measurements from one observation point, or relative to signals from other channels of their recording from this observation point with a multi-channel observation method, or relative to signals from their recordings from neighboring observation points with a single-channel observation method. If there are more observation points in the study area, the signal from the foundation additionally characterizes its presence at most observation points.

The problem is also solved by the second variant of the method of low-frequency seismic sounding for the search and exploration of hydrocarbon deposits [8], which includes determining at least one observation point on the search area, placing seismic vibrations at the observation point of the receiver, recording information signals from their measured components during the interval enough time to record a statistically significant noise signal in the infra-low-frequency range, the calculation of the spectral characteristics Istik using the Fourier transform of the received signals, its analysis for the presence of false signals and signals from the reservoir with natural hydrocarbons, exclusion of false signals from the analysis, analysis of the remaining signals with a judgment on the presence or absence of hydrocarbons, which, unlike the known method registration and recording are carried out on the vertical components of information signals, the Fourier transform of the vertical components of information signals is carried out according to their first production one, on the obtained spectra reveal the maximum, which is characterized by the location on the spectrum in the frequency range

Vs / H <F <Vp / H,

where Vs is the average sedimentary cover velocity of transverse seismic waves at the observation point;

Vp - average sedimentary cover velocity of propagation of longitudinal seismic waves at the observation point;

H is the known depth of the foundation at the observation point,

a signal with this maximum is taken as a false signal corresponding to the resonance between the day surface and the foundation — the signal from the foundation, the point with the spectrum, in which there is a signal from the foundation with a monotonic decrease in the spectrum amplitude towards large frequencies from the maximum of the signal from the foundation, is recognized as a hopeless observation point spectra of signals in which there are maxima at frequencies greater than the frequency of the maximum signal from the foundation, these spectra are classified into two groups: 1) spectra with equal by the uneven arrangement of signal maxima with an offset of relative to other measurements by less than half the width of their maximum, 2) spectra with an uneven arrangement of signal maximums with an offset of other measurements by at least half the width of their maximum; the observation point with signals with a spectrum of the first group is defined as promising for the presence of deposits from natural hydrocarbons, signals with a spectrum of the second group are defined as false signals - signals from the zone of possible tectonic disturbances. In this case, when identifying a uniform or uneven arrangement of signals, it is possible to compare them relative to signals of other measurements from one observation point, or relative to signals from other channels of their recording from this observation point with a multi-channel observation method, or relative to signals from their recordings from neighboring observation points with a single-channel observation method observations. If there are more observation points in the study area, the signal from the foundation additionally characterizes its presence at most observation points.

This method allows you to distinguish between false signals from signals from the reservoir and thereby dramatically increase the reliability of decisions. The registration and recording of signals is carried out in a wide frequency range of 0.5-50 Hz, corresponding to the range of the depths of the basement.

Search and reconnaissance methods are implemented using well-known hardware, for example, using the Express-4 mobile digital seismometric complex developed by the Geofizpribor Design Bureau of the Russian Academy of Sciences (Moscow). The block diagram of a mobile multi-channel seismometric complex includes the following main modules:

- a set of highly sensitive seismic sensors of the type SM-ZKV ADNR;

- remote distributor with cable communication lines;

- a recording module with a block of filters and amplifiers, a board of analog-to-digital converters, digital-to-analog converters, a computer;

- GPS-receiver GARMIN 12 XL;

- Power Supply;

- calibration block.

The sensors are magnetoelectric pendulum geophones that convert the speed of mechanical vibrations into electric current, while the voltage excited at the ends of the receiver’s working winding is proportional to the speed of the soil. The recording module of the Express-4 complex provides reception of seismic signals, their conversion to digital code, registration of data in various formats, binding of recorded data to a single time, visualization of input data, calibration of seismic channels, preliminary assessment of the quality of recorded data. When processing and analyzing signals and their spectral characteristics, standard software tools such as Mathlab version 6.0 and higher are used.

For specific studies and field tests, three seismic receivers were used - a set of highly sensitive seismic sensors of the SM-ZKV type ADNR of the Express-4 mobile digital seismometric complex with 4 recording channels located at a distance of 50-100 meters from each other, in the frequency range 0 5-50 Hz, corresponding to a foundation depth of 6-8 km, seismic signals were recorded simultaneously for all recording channels for at least 400 s, as a result of signal reception and processing, they were obtained with spectral characteristics, including false signals from the foundation, signals from disturbances, a signal from the reservoir.

The disadvantage of this method is the relatively low reliability, because to generate a signal in the range of 05, -1.0 Hz using three seismic receivers of the same type, with the same measuring base, is a difficult technical task, especially in marine conditions.

The known method [8] solves the technical problem of increasing the efficiency of seismic exploration for great depths. The technical result is to increase the depth of seismic exploration while increasing the reliability and efficiency of seismic exploration at various depths through the use of the entire frequency range of the microseismic signal, including ultra-low frequencies.

In this case, the technical result is achieved due to the fact that in the seismic survey method, which includes preliminary determination of the dispersion curve of microseismic waves characteristic of the study area by synchronously recording microseismic signals with at least three seismic stations with vertical seismic sensors with subsequent evaluation of the apparent velocity dependences based on the obtained data the propagation of microseismic waves from the signal frequency, the determination of wavelengths and the frequency range based on e analysis of apparent velocities, in which the microseismic signal consists of Rayleigh waves, placing seismic sensors in the study area so that the distance between them is no more than half the shortest Rayleigh wavelength, determining the amplitude non-identity of the measuring channels of the seismic sensors in the microseismic signal frequency band by simultaneously recording microseismic signal by all seismic sensors at one point for a time sufficient to establish the stationarity of the spectrum the power of the microseismic signal, with the subsequent determination of the logarithmic difference of the spectra of all measuring channels of the seismic sensors, the registration of the microseismic signal by at least two seismic stations, one of which is installed stationary in the central part of the study area, and the rest move across the study area, accumulation of the power spectrum of the microseismic signal at each point measurements for a time sufficient to establish the stationarity of the spectrum, the calculation of the spectrum of spaces variations of the microseismic signal for each measurement point by determining the logarithmic difference of the power spectrum for each measurement point and the power spectrum of the microseismic signal stored at the seismic station installed stationary for an equivalent time in the same time period, taking into account the amplitude non-identity of the measuring channels of the seismic sensors, map amplitude variations of the microseismic signal for each frequency of the spectrum of spatial variations, the binding of each gender scientific map corresponding to its depth H according to the ratio:

H = λ _p K,

where K is the experimentally established numerical coefficient depending on the constituent rocks,

λ _p - Rayleigh wavelength, determined by the dispersion curve, m

The distinguishing features of the known method is the determination of the dispersion curve of microseismic waves with the subsequent assessment of the dependence of the apparent propagation velocities of microseismic waves on the signal frequency, the determination of wavelengths and the frequency range consisting of Rayleigh waves, the placement of seismic sensors by the above method, the determination of the amplitude non-identity of the measuring channels of seismic sensors with the subsequent determination of the logarithmic spectral difference, seismic microseismic signal recording stations, one of which is stationary, the accumulation of the power spectrum of the microseismic signal until the spectrum is stationary, the calculation of the spectrum of spatial variations of the microseismic signal for each measurement point, the construction of a map of the amplitude variations of the microseismic signal for each frequency of the spectrum of spatial variations, the binding of each received map to its corresponding depth according to the above ratio, which allows to increase the depth of seismic exploration while increasing The reliability and effectiveness of seismic exploration at various depths through the use of the entire frequency range of the microseismic signal, including ultra-low frequencies. Microseismic signals are represented in the general case by the sum of body and surface waves of the Love and Rayleigh type. Moreover, the energy of surface waves in a microseismic signal is much higher than the energy of body waves and are not taken into account when implementing the method. The use of vertical sensors makes it possible to isolate only Rayleigh waves from the surface waves that contain the zero mode even in the absence of bright reflecting boundaries, in contrast to Love waves. Placing seismic sensors at a distance from each other of no more than half the shortest Rayleigh wavelength allows you to achieve maximum horizontal resolution of the method. Taking into account the amplitude non-identity of the measuring channels of seismic sensors allows you to exclude the individual characteristics of the measuring channels when building maps. The accumulation of the power spectrum of the microseismic signal at each measurement point before establishing the stationarity of the spectrum must be done due to the duality of the nature of the microseismic signal, which consists of deterministic trains with random initial phases, random frequencies, amplitudes and directions of arrival. At sufficiently large times, these deterministic trains are a random stationary signal. It is these stationary characteristics, including the power spectrum, that are determined during measurements. The calculation of the spectrum of spatial variations of the microseismic signal for each measurement point is necessary in order to exclude the influence of sources forming the microseismic signal. The mapping of amplitude variations of the microseismic signal and their binding to the depth are made to obtain the mechanical characteristics of the medium at various depths.

The known method of seismic exploration [8] is as follows. The dispersion curve of microseismic waves characteristic of the study area is preliminarily determined by performing synchronous registration of microseismic signals by at least three seismic stations with vertical seismic sensors, followed by an assessment of the dependence of the apparent propagation velocity of microseismic waves on the signal frequency. The wavelengths and frequency range of the microseismic signal are determined based on an analysis of the apparent velocities in which it consists of Rayleigh waves. Seismic sensors are placed in the study area so that the distance between them is no more than half the shortest Rayleigh wavelength. Then, the amplitude non-identity of the measuring channels of the seismic sensors in the microseismic signal frequency band is determined by simultaneously recording the microseismic signal by all seismic sensors at one point for a time sufficient to establish the stationarity of the power spectrum of the microseismic signal, followed by determining the logarithmic difference of the spectra of all the measuring channels of the seismic sensors. A microseismic signal is recorded by at least two seismic stations, one of which is installed stationary in the central part of the study area, and the rest move around the study area. The power spectrum of the microseismic signal is accumulated at each measurement point for a time sufficient to establish the stationarity of the spectrum. The spectrum of spatial variations of the microseismic signal for each measurement point is calculated by determining the logarithmic difference of the power spectrum for each measurement point and the power spectrum of the microseismic signal accumulated at a stationary seismic station for an equivalent time in the same time period, taking into account the amplitude non-identity of the measurement channels of the seismic sensors. Maps of amplitude variations of the microseismic signal are constructed for each frequency of the spectrum of spatial variations. Make a binding of each received card corresponding to its depth.

The value of the coefficient K is established experimentally in the course of mathematical modeling on the basis of the finite element method for the propagation of Rayleigh waves in an inhomogeneous half-space composed of rocks close to rocks of volcanic origin.

Using the proposed method of seismic exploration allows to increase the reliability of seismic exploration, provides a fundamental opportunity to conduct seismic surveys in places inaccessible to the use of artificial sources, allows seismic exploration at great depths, allows seismic exploration in monitoring mode without using sources. The method is technically simple to implement, environmentally friendly, cost effective.

However, the determination of the value of the coefficient K from experimental data by mathematical modeling is carried out on the assumption that the value of the coefficient K corresponds to the value of the coefficient in an inhomogeneous space composed of rocks close to rocks of volcanic origin. If the rocks of the heterogeneous space are composed of rocks of non-volcanic origin, then the value of the coefficient will be different from the accepted one, which will entail a significant error in the final research results.

In addition, when constructing maps of the amplitude variations of the microseismic signal, the triangulation method is used, when applying which the results of calculating differentials of various orders are not reliable.

The objective of the proposed technical solution is to increase the reliability of seismic studies in the search and exploration of hydrocarbon deposits.

The problem is solved due to the fact that in the method of seismic exploration when searching for hydrocarbons, which includes recording the natural seismic background and seismic signal in the studied space, measured by one or more seismic complexes, followed by mathematical processing of the measured values, preliminary determination of the dispersion curve of microseismic waves, characteristic for the study area, by conducting synchronous registration of microseismic signals by at least three seismic stations with vertical seismic sensors, followed by the assessment of the dependence of the apparent propagation velocity of microseismic waves on the signal frequency, the determination of wavelengths and the frequency range based on the analysis of apparent velocities, in which the microseismic signal consists of Rayleigh waves, placing seismic sensors in the study area in this way so that the distance between them is no more than half of the shortest Rayleigh wavelength, the determination of the amplitude non-identity ism signal channels of seismic sensors in the microseismic signal frequency band by simultaneously registering the microseismic signal with all seismic sensors at one point for a time sufficient to establish the stationarity of the power spectrum of the microseismic signal, with the subsequent determination of the logarithmic difference of the spectra of all measuring channels of the seismic sensors, accumulating the power spectrum of the microseismic signal at each measurement point for a time sufficient to establish stationary spectrum, calculating the spectrum of spatial variations of the microseismic signal for each measurement point by determining the logarithmic difference of the power spectrum for each measurement point and the power spectrum of the microseismic signal accumulated at a seismic station installed stationary for an equivalent time in the same time period, taking into account the amplitude the identity of the measuring channels of seismic sensors, building a map of the amplitude variations of the microseismic signal for each th frequency of the spectrum of spatial variations, the binding of each received map to its corresponding depth; at the same time, information signals are recorded by their measured components for a period of time sufficient to record a statistically reliable noise signal in the infra-low-frequency range, spectral characteristics are calculated using the Fourier transform of the received signals, and they are analyzed for the presence of false signals and signals from the reservoir with natural hydrocarbons, false signals are excluded from consideration, an analysis of the remaining signals is carried out with a judgment on the presence of whether there are no hydrocarbons, registration and recording are carried out on the vertical components of the information signals in the frequency range 0.5-50 Hz, corresponding to the range of the basement depths, the Fourier transform of the components of the information signals is carried out according to their first derivative, the maximum that is taken as a false signal corresponding to the resonance between the day surface and the foundation - a signal from the foundation, the point with the spectrum at which the presence there is a signal from the foundation with a monotonic decrease in the amplitude of the spectrum towards higher frequencies from the maximum of the signal from the foundation, an observation point in the signal spectra of which there are maxima at frequencies greater than the frequency of the maximum of the signal from the foundation, with their offset relative to other measurements by less than half its width maximum, taken as promising for the presence of deposits from natural hydrocarbons, the presence of hydrocarbons is judged by the change in the spectral power of the information signal at the measured frequency In contrast to the known methods, the determination of the dispersion curve of microseismic waves characteristic of the study area by synchronously recording microseismic signals by at least three seismic stations is carried out by recording seismic noise at frequencies of 0.008-20 Hz at the water-ground boundary, from the spectrum of the horizontal components, the odd harmonics are 0.003 and 0.005 Hz, and even harmonics of 0.002, 0.004, 0.006, and 0.008 Hz are extracted from the spectrum of the vertical component, while magnetic field oscillations at frequencies of 0.01-1.0 Hz, magnetic induction of an electromagnetic field at frequencies of 1-200 Hz, electric component of an electromagnetic field at frequencies of 1-500 Hz, acoustic noise at frequencies of 5-50000 Hz, hydrodynamic noise of the sea at frequencies 0.01-100 Hz in the zones of tectonic faults, according to the measured parameters, they perform factor analysis at the levels of the natural geophysical background and geophysical background during the phase of the sun and moon being on the same celestial line, by plotting the amplitudes of the seismic gradients, geode formation, geochemical, hydrophysical indicators with a measurement base not exceeding 50-100 kilometers in the middle latitudes and 8-10 kilometers in the high and equatorial latitudes, respectively, while taking into account short-period variations in the magnetic field caused by sea waves, minimize magnetic imaging errors by detecting fine structure of magnetic inhomogeneities and determination of their parameters, registration of hydroacoustic signals is performed with the separation of phases such as PP, S and T, the arrival of an acoustic wave of seismic origin driving is determined by the magnitude of the frequency shift of the scattered radiation, while using the recording devices located at a distance from the coastal zone, the low-frequency components of the scattered signal are analyzed using the noise of navigation as reference quasi-harmonic high-frequency signals, and using registration devices located in the coastal zone, the moment of appearance and direction of arrival of seismic waves by narrow-band filtering and spectral analysis of waves, the separation of phases such as PP, S and T is carried out by narrow-band filtering using Butterford recursive filters, while input filtering is performed by recursive filters with integer coefficients, and signals with a sampling frequency of 100 Hz and below are filtered with coefficients in the form of floating point numbers; sonar signals are recorded by means of broadband bottom seismographs with at least three seismic channels, while the signals are analyzed by three independent detectors, and the detection signal is generated when the signals coincide in at least two of the three channels; Spectral analysis is performed both of the body waves of the PP and S phases, and of the Love, Rayleigh, and Stoneley surface waves, the mapping of the amplitude variations of the microseismic signal for each frequency of the spectrum of spatial variations, and the mapping of each received map to its corresponding depth is performed by approximating the profile of the relief along the section relative to the coastline, and as the base spline, a cubic spline with zero boundary derivatives is used, while the construction of a two-dimensional spline function is performed by em-dimensional tensor product spline; the measuring base on the seabed is formed by placing seismic receivers at a distance of not more than 5 km from each other, with the formation of an isosceles triangle in the underwater space at the tops of which seismic receivers are placed, while the seismic oscillation receivers are placed in the shelf zone, along the foot line of the continental slope and along the axis perpendicular to the Gardiner line along the fault boundaries, the identification of local structures, perspective in the oil and gas bearing, is carried out by seismic profiling by means of a mobile seismic station with multiple overlapping reflecting boundaries, and a seismic complex for seismic exploration, consisting of stationary seismic receivers and a mobile multi-channel seismometric module, each of which consists of a block of highly sensitive seismic sensors, a recording module with a block of filters and amplifiers, an analog- digital converters, digital-to-analog converters, computer, GPS-receiver, power supply, calibration unit, unit processing, analysis of signals and their spectral characteristics, software such as Mathlab version 6.0 and higher, in contrast to known devices, a seismic complex includes a floating means, an aircraft, an autonomous seismic bottom station, a bottom seismic station, a float seismic station, and a mobile seismic one the module is made in the form of a controlled underwater vehicle, the swimming means is equipped with an underwater probe, the recording equipment of the seismic complex additionally contains methane detection sensor, hydrophysical module, bottom seismometer, magnetic field sensor with control unit, penetrometer, gravimeter, device for exciting elastic vibrations in the marine environment, bottom pressure sensor, hydro-acoustic communication channel modem, satellite communication channel modem, spatial orientation unit, acoustic Doppler flow profile meter, hydrochemical measurement unit.

The essence of the proposed technical solution is illustrated by drawings.

Figure 1. Placement of seismic signal recording means.

The drawing shows: coastline 1, water surface 2, continental shelf 3, slope 4, foot of the continental shelf 5, Gardiner line 6, fault 7, swimming facility 8, aircraft 9, autonomous seismic bottom station 10, bottom seismic station 11, a seismic float station 12, a controlled underwater vehicle 13, an underwater probe 14, artificial Earth satellites 15.

Figure 2. The scheme of test measurements along the profile to identify the boundaries of gas hydrate deposits and the boundaries of its fault. The diagram shows: the boundary of the gas hydrate formation zone 16, the fault boundary 17, the reflecting horizon of the gas hydrate zone 18, the measurement profile 19, the direction of gas diffusion 20, as well as the water surface 2, the continental shelf 3, fault 7, a swimming vehicle 8, an aircraft 9, autonomous seismic bottom station 10, bottom seismic station 11, float seismic station 12, guided underwater vehicle 13, underwater probe 14, artificial Earth satellites 15.

Figure 3. The design of an autonomous seismic bottom station.

The design of an autonomous seismic bottom station 10 includes an underwater spectrum analyzer 21, a frame 22, a power supply unit 23 for autonomous operation, a radioactive contamination control unit 24, a robust housing 25, a cable line modem 26, a recording and control unit 27, a power arc 28, and underwater sonar equipment remote control 29, farm 30, hydrophysical module 31, bottom seismometer 32, control unit 33 of the magnetic field sensor, precession coil 34, junction box 35, penetrometer 36, gravimeter 37, device for exciting vibration in the marine environment 38, bottom pressure sensor 39.

Figure 4. The design of the bottom seismic station. The design of the bottom seismic station consists of a frame 40, on which a spherical titanium strong case 41 is installed, inside of which hardware units are installed. The housing 41 is connected by a cable 42 to a disconnector 43, which is connected by an anchor cable 44 with an anchor 45. On the upper part of the frame 40, a remote unit 46 is installed, inside of which there are devices designed to connect the bottom station with the ship complex. A hydrophysical module 47, nodes and elements of satellite 48 and hydroacoustic 49 communication channels are also installed on the upper part of the frame 40. The frame 40 is articulated with an anchor device 50, on which the bottom seismometer 51 is fixed, in the working position, placed by means of the anchor device 50 on the seabed 3.

Figure 5. Block diagram of the bottom seismic station.

The block diagram of the bottom seismic station includes a seismic module 52, seismic acoustic module 53, hydrophysical module 54, magnetic field sensor 55, recording and control unit 56, modem 57 sonar communication channel 49, modem 58 satellite communication channel 48, spatial orientation unit 59, sonar disconnector 60, acoustic Doppler current profile meter 61, hydrochemical measurement unit 62, methane sensor 63, bottom pressure sensor 64, beacon 65, flashing beacon 66, power supply 67.

6. The block diagram of the hydrophysical module 54. The block diagram of the hydrophysical module 54 includes a flow velocity sensor 68, a temperature sensor 69, an electrical conductivity sensor 70, a hydrostatic pressure sensor 71, a microprocessor 72.

7. The block diagram of the magnetic field sensor 55. The block diagram of the magnetic field sensor 55 includes a fluxgate sensor 73, a key phase sensing amplifier 74, a three-channel ADC 75, a temperature sensor 76, an output port 77, a DAC 78, 79, a microcontroller 80, an interface 81, a voltage-to-current converter 82, a low-pass filter 83, a compensation winding 84, a microcomputer 85. A phase sensitive amplifier 74, a DAC 78, 79 and a voltage-to-current converter 82 form a signal processing channel along the horizontal component of the magnetic field 8644. Similar elements s form channels 87 and 88 for processing the signals in the longitudinal and vertical component of the magnetic field, respectively.

Fig. 8. Type of input voltage to the ADC 75.

Fig.9. Data processing algorithm when receiving a single magnetic field value.

Figure 10. The pattern of the horizontal components of a three-component vector seismometer.

11. General view of a controlled underwater vehicle. The controlled underwater vehicle consists of a hull 89, a marching mover 90, vertical tunneling movers 91, horizontal tunneling movers 92. Antennas 93 and 94, respectively, of a sonar and satellite communication channel are installed on body 1. Inside the body there are navigation and motion control systems 95, positioning system 96, sonar complex 97 (sounding fish finder, profilograph, side-scan sonar, sound velocity meter), seismic signal receiver 98, gravimeter 99 and magnetometer 100).

Fig. 12. Block diagram of a device for exciting elastic vibrations in a marine environment.

The device consists of a housing 101, a nozzle 102, a spark plug 103, an excitation coil 104, a power source 105.

Fig.13. Fragments of records of seismic waves.

On figa presents a fragment of an earthquake in the south of Lake Baikal.

On figb shows an example of recording the vertical component of the Sichuan earthquake, which is clearly visible arrivals of bulk P and S waves. The distance to the epicenter of the earthquake is about 5600 km.

On figv presents a fragment of the recording of the vertical components of the earthquake seismic receiver on about. Honshu.

The underwater probe 14 consists of geophysical equipment, which includes measuring sensors for geophonic and hydrophone types, modules for receiving, recording, converting and storing registered signals, interface units with an onboard module of a swimming means, sonar measuring instruments - a multi-beam echo sounder, profiler, side-scan sonar, meter speed of sound.

Methane Detection Sensor 63 is a METS ("CAPSUM") type sensor that measures the concentration of methane in the water column. The sensor is a semiconductor device, the principle of which is that the diffusion of hydrocarbon molecules from water through a special silicone membrane is transmitted to the sensor chamber. Adsorption of carbohydrate molecules on the active layer of the sensor leads to electronic exchange with oxygen molecules, thus changing the resistance of the active layer, which is converted into output (measured) voltage.

Main characteristics of the sensor:

- 10 μm silicone membrane;

- working depth 0-3500 m;

- operating temperature 2-20 ° C;

- measurement time from 1 to 3 s;

- diffusion stabilization time up to 5 minutes, depending on turbulence;

- input voltage 9-36 V;

- power consumption 160 mA / h;

- output signal - analog 0-5 V and digital RS - 485;

- methane 50 nmol / L - 10 μm mol / L.

The block of hydrochemical measurements 62 is intended for measuring Raman spectra of optical radiation in an underwater observatory by means of a spectrum analyzer. From the Raman spectra, information is obtained on the composition of sea water. The main technical characteristics of the spectrum analyzer are: a spectral range of 0.52-0.78 microns, a passband of 0.54 nm by 0.783 microns, a positioning accuracy of 0.2 nm in the spectrum, and a number of spectral channels of 4096.

The spectrum analyzer 21 is designed to measure the Raman spectra of optical radiation as part of an underwater station. From the Raman spectra, information is obtained on the composition of sea water. The main technical characteristics of the spectrum analyzer 1: the spectral range of 0.52-0.78 μm, the passband of 0.54 nm to 0.783 μm, the accuracy of positioning in the spectrum of 0.2 nm, the number of spectral channels 4096.

Penetrometer 36 is a probe mounted on a telescopic device, and is designed to perform marine ground survey. A penetrometer is a cone-shaped projectile equipped with sensors that are buried under the influence of gravity into the ground. An analogue of penetrometer 36 is a CPT Fugro penetrometer with a penetration depth of the probe into the ground up to 20 m. The strength characteristics of the soil are determined from the measured drag and friction coefficients.

An analogue of the gravimeter 37 is a BGM-3 gravimeter, which provides accurate measurements at high noise.

The radioactive contamination control unit 24 contains a radiation contamination control module, which is designed to determine in situ the content of gamma-emitting radionuclides (both technogenic and natural origin) in sea water.

The main technical characteristics of the radiation pollution control module are: the range of recorded energies is 0.2-3.0 meV, the energy resolution along the cesium line is 137 13%, the number of quantization levels of the spectrum is 256, the maximum number of samples in the channel is 65,000, the maximum recording speed is at least 1000 1 /from.

The block of hydrochemical measurements 62 contains a classifier for classifying seawater contaminants according to the spectral characteristics and molecular composition of seawater. The analogs of the sensors of the hydrochemical measurements unit are the devices shown in the sources (1. Basic processes and equipment of chemical technology. Edited by Yu. N. Dytnersky, M., Chemistry, 1983. 2. Chemical analytical complexes of Agilent Technologies (US), http://www.chem.agilent.com 3. Chemical and analytical complexes of SRI Instruments (US), http://www.perichrom.com 4. Chemical and analytical complexes of CJSC Chromatek (RU), http : //www.chronomatec.ru.).

The hydrophysical module 47 consists of two main components: a three-component acoustic current meter of the 3D-ACM type 3ACM-CBP-S type and a conductivity and temperature meter based on the CTS-C-1ED type velocity meter.

The current velocity sensor is an acoustic current meter and measures the three components of the current velocity on one horizon and includes a three-component magnetic compass for measuring the Earth’s magnetic field in three projections, a two-axis electrolytic inclinometer for measuring deviations from the vertical, and a solid-state temperature sensor. The principle of measuring the flow velocity is based on measuring the difference in the time of flight of the acoustic pulse in the forward and reverse directions (“time-of-flight” meter). It can also be equipped with a pressure sensor to measure the depth of setting of the current velocity sensor. It also has an interface for connecting a salinity and temperature sensor and two DC input channels for connecting external sensors. The measurement results are transmitted in real time in ASCII format via the RS-232 or RS-485 serial interface at a speed of 19200 bit / s, or written to a standard static RAM of 0.5 MB in size, powered by a lithium battery for subsequent reading. It has a setting depth of up to 7000 m and a “coastal” setting of up to 1000 m of depth (depending on the design of the body and the measuring range of the pressure sensor),

The software (3DACM97 program) allows you to configure and configure the sensor using the standard Windows user interface. Data can be transmitted in real time or read from the internal memory of the device. Real-time data can be displayed graphically on the display screen. The software in real time receives and stores data on the velocity vector, data from a three-component compass, inclinometer, data from additional sensors, including a salinity, temperature, pressure sensor.

Data on the velocity vector and inclinometer readings are averaged using the vector averaging algorithm over a time interval from 15 seconds to 60 minutes. ACMPost program allows you to graphically display the read data on the display and save data on measurements of salinity, temperature, pressure in a file of standard DAT C00 and HDR. These formats can also be read by ACMPost.

The temperature sensor and the electrical conductivity sensor are made in the form of a single module, which provides the possibility of high-precision measurement of electrical conductivity and temperature.

An electronic interface provides DC voltage output in proportion to electrical conductivity and temperature. Voltage output control is achieved through two user-controlled logic lines.

Conductivity and temperature sensors are based on an inductively coupled conductivity sensor. Inductive sensors demonstrate natural stability, unlike sensors based on unprotected electrodes, when their geometry changes, which is caused by biofouling. The large internal diameter of the conductivity sensor eliminates the need for a pump or other artificial means of conducting water flow through the sensor. The use of a high-quality platinum resistance thermometer leads to linear temperature measurements characterized by high stability. The electronic signal is very linear, which eliminates the need to use complex equations to convert output signals to physical quantities.

The communication protocol of the module includes an advanced command system that allows you to organize work with the module in the most convenient way for the user.

The module can operate in one of four modes:

- RUN MODE (normal) mode.

In this mode, the module measures all parameters.

- RUN MODE mode (fast pressure)

In this mode, measurements are made only for the pressure sensor and only the pressure value is transmitted.

The OPEN MODE (change of calibration constants) and CAL MODE (calibration) modes are auxiliary and are used during metrological maintenance of the device. The measured values are automatically converted into physical values and in this form (in ASCII codes) are transmitted to the user, as well as recorded in memory, from where they can be read later at an arbitrary point in time.

The spatial orientation unit 59 is a spatial orientation sensor and is intended for use as part of the seismic module to determine the exact position in space of the seismic module 52 and the seismic acoustic module 53.

As the sensor of the spatial orientation unit 59, an electronic compass module of the TCM 2.50 type is used, which is a three-axis directional compass with a tilt compensator, structurally made on the same board with the electronics unit. The compass is equipped with an electronic compensation system, which allows you to make accurate calculations of azimuth, side tilt (roll) and keel tilt (pitch) at angular positions of ± 50 degrees.

The magnetic field sensor 55 (Fig. 7) is made on the basis of a sensitive element of a flux-gate magnetometer of the LEMI-018B type and is designed to measure 3 components of the Earth's magnetic field induction and their variations, as well as temperature.

The composition of the magnetic field sensor includes: a sensor unit, which contains the primary measuring transducers of the magnetic field, and an electronics unit, which has a built-in thermometer to measure the temperature inside the unit. The electronics unit and the sensor unit are housed in rugged enclosures and connected by a special cable.

The flux-gate magnetometer is a fully autonomous automatic device controlled by a microprocessor system based on a microcontroller.

Microcontroller 80 controls the magnetometer and transmits magnetic field and temperature data via the UART port. The magnetic field is measured by a fluxgate sensor 73, which is located at a distance of 1 m or more from the electronics. The flux-gate sensor 73 and the electronics are interconnected by a special test cable.

The flux-gate sensor 73 is excited by an excitation voltage with a frequency f1 = 5236 Hz. The output signals of the sensor are amplified and filtered using phase-sensitive amplifiers (PSFs) 74 of the key type. A signal is generated at their outputs with a frequency of the second harmonic of the excitation voltage f2 = 10472 Hz. The filtered signal comes from the output of each frequency converter to one of the channels of the three-channel analog-to-digital converter ADC 75.

The program for processing and digitizing data on the example of one channel of the magnetometer is shown in Fig. 8, which shows the signal supplied to the input of the ADC 375, and also shows the times at which the amplitude of the signals is read. To calculate one value of the magnetic field, formula (1) is used.

The calculation of the measured values of U _J by this formula eliminates the influence of the temperature offset of the zero of the selective amplifier, as well as the ADC 75.

Next, the values of U _j (j = 1 ... n) measured n times are averaged over a time period that is a multiple of 20 ms (frequency period 50 Hz). This allows you to reduce noise along the input signal circuit, as well as significantly weaken the influence of the network with a frequency of 50 Hz. The selection of the measured signal U _c averaged over this period is performed according to formula (2).

Due to the large value of n, the obtained average value of U _c for each channel is very resistant to random failures and is used to create a compensation signal using digital-to-analog converters DAC 78 and DAC 79, which are then summed and converted into compensation current using the voltage-current converter unit (U / I) 82. This current is supplied to the compensation winding W _c , creating with it a magnetic field in the sensor volume, equal and opposite in direction to the measured field. The output voltage of the same DACs 78 and 79, after passing through a second-order low-pass filter with a cutoff frequency of 0.5 Hz (not shown), is fed to the analog output of the magnetometer.

The codes that are installed on the DAC 78 and DAC 79 after completion of the compensation process are proportional to the measured values of the magnetic field. They then go through the control microcontroller 80 and the UART / RS-232 converter 77 to the microcomputer 82. By means of which the registered data is visualized, which are also written to a file on the hard disk.

Figure 9 shows the algorithm for obtaining one value at the output of the magnetometer.

The algorithm is executed in the following sequence:

1. Initial settings. The necessary magnetic channel is switched, the working registers of the microcontroller are reset, i = 1, n is selected from the condition T = 20 ms.

2. Synchronization by a slice of a pulse of the excitation frequency f1 of the magnetometer.

3. Synchronization along the slice of the pulse of the second harmonic of the excitation frequency of the magnetometer f2.

4. Reading from the ADC of the i-th voltage value.

5. Repeat steps 3, 4, 5 until i = 4.

6. The accumulation of data and the calculation of U _j according to the formula (1).

7. Remembering U _j .

8. Checking that j = n, if not, repeat steps 2 to 8, if so, go ahead.

9. At the end of the 20 ms cycle, calculate the average value of U _c according to the formula (2).

10. Spend the correction of the value of the DAC.

After the magnetometer is turned on, its ADC 75 is saturated and an initial compensation algorithm is implemented with a linearly increasing signal at the outputs of DAC 78, which provides a sufficiently efficient compensation algorithm in which the difference between the compensating and measured fields will constantly decrease. If this difference decreases to a value less than ± 2 nT, the ADC 75 will go out of saturation and the compensation algorithm will change: the necessary value of the compensation signal is calculated by the microprocessor 82 from the ADC 75 and corrects the value of the DAC compensation code 78. After that, another compensation algorithm is switched on, in which the value of the DAC 78 code remains unchanged (it provides gross compensation for this component of the magnetic field), and only the compensation code of the DAC 79 is adjusted according to the ADC 75. At the maximum value field ± 60,000 nT, the price of 1 bit of DAC 36 is 1.8 nT, and the price of 1 bit of DAC 37 is 0.01 nT.

The output reading of the magnetometer for each channel is presented in the form of a 32-bit code, which consists of 16 bits removed from the DAC 78, and 16 bits that are removed from the DAC 79 (the output codes of these DACs overlap).

Excitation of the flux-gate sensor is carried out by a special excitation circuit, which creates a signal with a minimum content of the second harmonic. In parallel, the voltages from the outputs of DAC 78 and DAC 79, proportional to the values of the measured components of the magnetic field induction, after summing and filtering, go to the analog outputs of the magnetometer.

In the event of a temporary power failure or a malfunction of the microcontroller, an automatic restart of the system is initiated. After restarting, the magnetometer enters the operating mode, the external magnetic field is compensated, and recording continues without operator intervention.

The placement of magnetometers at different depth horizons and a low-speed controlled underwater vehicle makes it possible to take into account the short-period variations of the magnetic field that are observed at all latitudes, significantly complicating the Arctic Circle, and their gradients in time and amplitude are such that the field can change by more than 1 second 0.1 gamma. In addition, it becomes possible to take into account variations caused by sea waves, which minimizes the errors of magnetic surveying, which is achieved by revealing the fine structure of magnetic inhomogeneities and determining their parameters.

Considering that geological reference sections are usually located far from the areas of work, the general requirement for integration is to obtain data with the maximum number of methods for a more confident subsequent geological interpretation. This makes it possible to identify the structures of the sedimentary stratum, gravitational and magnetic fields with the aim of tectonic zoning, as well as to map the structures of the second order, to identify local structures that are promising in the oil and gas bearing.

Seismic, gravimetric and hydromagnetic profiling is performed with multiple overlapping reflective boundaries.

The registration and control unit 27 is intended for synchronous digitization and registration of signals from seismic and other sensors of various types. Signals are digitized using an 8-channel delta-sigma ADC with a resolution of 24 bits. It has a non-volatile memory of 16 GB, as well as an additional non-volatile memory for storing service information and time calibration data with a quantization frequency of 100 Hz, a memory capacity of 16 GB and a continuous recording time of 160 days.

Preparation of the registration and control unit 27 for operation, namely: checking the operability, the presence of the necessary signals, cleaning and checking the memory, installing and checking the internal real-time clock, is carried out by the ship complex via a serial interface of the RS-232 type. Reading registered data is carried out using a special additional device via USB.

The transmission of digital telemetric information from seismic stations is carried out in 256 Byte blocks by means of underwater telecontrol equipment 29.

To increase the reliability of the transmission of digital telemetric information in the equipment, redundant coding with a cyclic code (2072,2048) is used in combination with the principle of retransmission of information blocks with detected errors by auto-request.

The transmission of digital information is controlled remotely via a radio modem.

Signals are exchanged between the vessel and the seismic devices in sequential form by start-stop combinations at a speed of 14400 baud.

The algorithm of the main mode of operation of dispatching stations (installed on a ship or aircraft) when servicing a network of several autonomous seismic bottom stations 10, bottom seismic stations 11, float seismic stations 12 and a controlled underwater vehicle 13, before setting them up in the marine environment, consists in providing information communication between them and the dispatch station, which is carried out via a hydroacoustic communication channel using the access method with time division of the subscriber in. Up to 8 submarine stations operating in stand-alone maintenance-free mode can simultaneously be connected to one dispatch station.

The number of measuring channels in each underwater station depends on the problem being solved at a particular place of its formulation. In principle, the maximum number of digital measuring channels can be up to 30, and analog - up to 6.

The control computer of the dispatching station and the software and software, the real-time service are designed to control the equipment of the underwater station, diagnose its malfunctions, receive data received from the underwater station and place the received data on the information storage devices. The functioning of the entire hardware and software complex is determined by the configuration file, which is created by a special program and sets the presence of underwater stations, the type of geophysical channels used, channel parameters, as well as the presence or absence of time synchronization equipment (GPS receiver).

When starting the registration program, the configuration of the entire network of the submarine station is read out and the Greenwich time is referenced to within a few tens of microseconds and the corrections are calculated to the frequency of the computer’s quartz to maintain the functioning of the complex in the event of a short-term GPS receiver failure. Time synchronization is carried out every second from the GPS receiver.

Following synchronization, there is a survey, programming, synchronization and start-up of equipment of individual underwater stations. The state of equipment of each underwater station is requested (its serviceability, availability of channels, serviceability of channels, etc.). In case of problems, an appropriate message is displayed on the screen (it is also recorded in the operation protocol file). The program of work for each measuring channel, the interrogation frequency, and the gain are transmitted to the registration and control unit of the submarine station.

Before starting, each control and registration unit is synchronized by the time of the dispatch station computer (in the future, synchronization is carried out every 10 s). During synchronization, the time taken to pass the signal from the computer of the control station to the synchronized registration and control unit 27 is taken into account. After that, the registration and control unit 27 starts and starts collecting data from the measuring channels. The registration and control unit in each underwater station operates independently and compresses all information and adds it to the buffer memory.

The control computer of the dispatching station cyclically requests from the corresponding control and registration unit 27 data on the signals registered by the sensors and, if available, receives them and writes them to their buffers in the main memory. After accumulating a sufficient amount of data for the channel, they are overwritten into a file corresponding to the type of channel. Usually these files are located on another computer and are accessible on a local network, although for short-term experiments the system can be configured in such a way that a local disk will be used. With short-term communication breaks (up to 10 minutes), data is not lost due to the presence of each control unit and registration 27 sufficiently large own buffer. In the process of exchanging data, the operator can calibrate any measuring channel that is part of the control station network. In the event of an emergency (communication breakdown with the underwater station, its breakdown, failure of individual channels, or restoration of the above), as well as some normal situations - the occurrence of an event or the calibration of the corresponding measuring channel is triggered, a message is displayed on the screen, including the GMT time of the onset of the situation, names submarine stations and channel and the message itself. Messages are also written to a buffer of 100 lines and to the log file. The buffer can be viewed by the operator at any time.

A device for exciting elastic vibrations in the marine environment 38 comprises a housing 101, a nozzle 102, a spark plug 103, an excitation coil 104, and a power source 105.

The housing 101 is cylindrical. The cylinder is made of double-walled anticorrosive metal, consisting of two cases (outer case and inner case). Between the outer and inner bodies forming the cavity, a macrolon is placed to give the body 101 rigidity. A power source 105 and an excitation coil 104 are located in the cavity. In the upper part, the housing 1 is articulated with a nozzle 102, the inner surface of which is provided with vertical ribs to enhance acoustic properties. The placement of the power source 105 and the excitation coil 104 in the cavity with the macrolon is due to the damping of acoustic signals that occur during operation of the power source 105 and the excitation coil 104.

The device operates as follows. When the device is immersed, sea water through the nozzle 102 enters the cylinder and fills the internal volume of the cylinder. From a power source 105, a voltage of the order of 27 V is supplied to the excitation coil 104, with which an electric signal is supplied to the spark plug 103, on which an electric discharge of the order of 1000 A is formed. In this case, an electrochemical reaction occurs between oxygen and hydrogen ions, resulting in an acoustic wave . An acoustic wave propagates through the nozzle 102, the inner surface of which is provided with vertical ribs, in seawater. An acoustic wave is recorded by receivers of acoustic signals located both directly in the zones of installation of devices for the excitation of elastic vibrations, and in the coastal zone.

The bottom pressure sensor 39 is a quartz pressure meter.

Known similar devices based on the use of deep-sea tsunami wave recorders are installed, as a rule, along the protected coast. Such recorders measure the pressure or thickness of the water layer and must have a very high sensitivity. The height of the tsunami wave in the open ocean of 10 cm can increase many times in shallow water and pose a significant danger. Therefore, when setting to a depth of, for example, 3 km, registrars should have a sensitivity no worse than 3 × 10 ^-5 .

This sensitivity is provided only by quartz pressure meters. At the same time, bottom echo sounders are used to measure the thickness of the water layer, which is necessary to compensate for the error due to the uneven distribution of the speed of sound in water.

In this case, the recorded signals, in the form of sinusoidal oscillations, of the measured parameter when superimposed on them by anthropogenic acoustic and hydrodynamic noises, can be both periodic and aperiodic, which requires multiple arrays of the measured parameter to identify the amplitude that is statistically significantly different from the background to achieve positive technical result.

In addition, the appearance of microseismic storms (sharp and relatively short-term increases in the level of microseismic at the bottom) caused by strong sea storms, bottom currents and seismic activity, both from distant earthquakes, and seismoacoustic vibrations from a group of local earthquakes and seiche, negatively affects the reliability of the forecast. fluctuations in the surface of the water that occur during tides and are caused by tidal currents.

Moreover, at very low frequencies (below 0.01 Hz) due to the negligibly small thickness of the ocean layer compared to the wavelength, oscillations caused by microseisms can last several hours (10 or more), which are not detected by known devices.

The seismic acoustic module 53 includes a block of highly sensitive seismic sensors, a recording module 12 with a block of filters and amplifiers, an analog-to-digital converter board, a digital-to-analog converter board, a computer, a calibration block, a processing unit, signal analysis and spectral characteristics, software tools such as Mathlab version 6.0 and above.

The seismic module 52 is made in the form of a block of broadband transducers, which includes three sensors oriented along three planes. Each sensor is made in the form of a sealed cylindrical vessel, divided by a partition into two compartments filled with electrically conductive liquid, the partition is equipped with an opening. Mesh electrodes are located in the middle and sides of the cylindrical vessel, the ends of the cylinder are made in the form of elastic membranes.

The broadband converter unit consists of primary sensors and a processing unit. Each primary sensor is a sealed cylindrical vessel, divided by a thick partition into two compartments filled with a special electrically conductive liquid (aqueous solution of potassium iodide and iodine). To allow fluid to flow from one compartment to another, a thin hole is made in the center of the partition, and the ends of the cylinder are made in the form of elastic membranes (in a different design, instead of membranes, each compartment has cavities filled with inert gas). Mesh platinum electrodes are located in the middle and sides of the hole, to which a weak constant voltage is applied: plus to the central anode and minus to the cathodes. As a result, an equilibrium redox reaction occurs. With increasing direct voltage, the current through the cell grows rapidly at first, then when the equilibrium state of the ions is reached at a voltage U _us , a saturation current I _us occurs, which changes quite slowly. Upon reaching the breakdown voltage U _{us, the} current through the cell increases sharply. With a reverse polarity voltage, a small reverse current flows. The work area lies in the range from U _us to U _ave . The operating point is usually set in the middle part of this region at U _p ≈0.5 V. To compensate for the initial current I, _we used two electrolytic cells in one housing, which form a differential circuit that allows providing zero output voltage. When mechanical vibrations are applied along the axis of the cylinder, the inertial fluid flows through the hole to the beat of the vibrations. Due to the mechanical transport of ions, the equilibrium state is violated, and a current proportional to the mechanical action appears between the electrodes. Primary sensors are installed in horizontal and vertical planes. The main advantages of the sensors are low shock sensitivity (up to 30g), the ability to register signals in the vertical, horizontal and azimuthal directions, as well as small dimensions and weight, economical power supply.

The processing unit collects, digitizes and accumulates signals from sensors. The subsystem is a hardware-software complex for an Intel-compatible processor family and is equipped with debugging and testing tools. In this case, there are three modes of signal registration: continuous, start-stop according to a given program and start-stop with control by signal level. The parameters of the processing unit are controlled by the results of express signal processing based on the analysis of the energy level and spectral composition using fast real-time algorithms.

The hardware of the subsystem for collecting and recording data consists of the following basic elements: a digital recorder, an accurate time storage unit, a communication channel, a central microcomputer with a hard disk drive.

The digital recorder of the registration and control units 27 and 56 is a micromodule controller based on an Intel-compatible NEC V25 processor with a PCMCIA flash drive and a standard output communication tool based on the RS232 interface. The microcontroller contains a built-in multi-channel ADC with a serial interface, programmable timers, real-time clocks, digital I / O ports, external hardware interrupt channels and a direct memory access channel. Distinctive features of the controller used are miniature dimensions (100 × 70 × 30 mm), low consumption (0.5 W), high reliability and low cost,

The accurate time storage unit is designed using energy-saving technologies, entirely on CMOS elements. It is used as a generator of reference minute (second) marks for synchronizing the clock of the microcontroller of the central microprocessor.

Seismic module 52 is also functionally combined with seismic-acoustic module 53 to provide simultaneous measurements by several sensors of various designs, which leads to increased accuracy and reliability of measurements.

Seismic module 52 is designed to provide continuous seismic monitoring of the seabed in a wide frequency range.

Seismic module 52 includes sensors:

- an electrochemical cycle meter, type СМЕ-ЗПО-3, which is a three-component seismic sensor designed to record seismic vibrations of the bottom surface along three orthogonal directions;

- a strong motion sensor, which is a three-component vector seismometer;

- spatial orientation sensor.

The strong motion sensor is equipped with a sensor, which consists of a magnetoelastic crystalline transducer, a high-energy permanent magnet, three independent electrical windings and a single inert mass, as well as a pre-amplifier. The strong motion sensor converts the three components of the vector of acoustic vibrations of the bottom surface in three orthogonal directions into electrical signals. The sensor of strong movements has a velocity characteristic, which, in comparison with the characteristics of traditional instruments for measuring vibration displacements, has a high frequency-dependent sensitivity to displacements. The sensitivity of the sensor of strong movements with an increase in frequency by 10 times increases by 1000 times.

For comparison, it should be noted that with the same increase in frequency, the sensitivity of conventional bicycles increases 10 times, and that of conventional accelerometers increases 100 times.

The intrinsic noise of the magnetoelastic sensor is less than the intrinsic noise of the seismometer and much less than the intrinsic noise of the accelerometer.

The magnetoelastic sensor of the strong motion sensor with a steep amplitude-frequency characteristic can simultaneously detect displacements in a significant range of more than 240 dB, which allows simultaneous measurement of displacement amplitudes of less than 10 ^-15 m at frequencies of more than 1000 Hz and more than 10 ^-3 m at frequencies of less than 1 Hz .

The central microprocessor of each submarine station is assembled on the basis of PC-compatible equipment for industrial automation using a processor board such as MicroPC from Octagon Sistems (USA). The applied design meets the stringent requirements of industrial operation, in particular, it is able to withstand large overloads during impacts and has increased MTBF. Having saved the computing power of a modern personal computer, it has small dimensions, weight and power consumption (several units of watts). Moreover, which is especially important for a sealed bottom station, additional cooling (fan) is not required. The presence of a 16-bit IDE interface for a hard disk drive allows the use of modern high-capacity drives and, accordingly, to increase the battery life of the station using the continuous registration mode. The registration system as a whole is fully compatible with PC and runs on ROM-DOS (DOS 6.22).

To expand the dynamic range of the recorded signals, two gain channels are allocated for each registered component, sensitive and coarse, with a ratio of gain K ₁ / K ₂ = 2 ⁿ , where n is selected from the level of the real seismic background at the station installation site. Thus, it is possible to bring the dynamic range of the station under low noise conditions to 130 dB using an inexpensive and reliable 12-bit ADC.

The exact time service is implemented on the basis of periodic synchronization of the internal clock of the PCR microcontroller with standard minute marks from the exact time storage unit.

Since the data of the real-time clock registers of the microcontroller can be updated with some delay, to achieve the required accuracy of the time service, the second marks of the exact time storage unit or a mixture of second and minute marks are used, which are entered through one of the digital inputs of the microcontroller to the clock with the analog signal conversion frequency and ADC words are written to the low-order bit. Thus, the digitized data contains a pilot bit, the front of which is tied to the front of the reference mark with an accuracy not worse than one reference.

Most of the time, the central microprocessor of the station is in "Sleep" mode and is turned on only for the time of transferring data from the flash card to the hard disk and to perform control functions for servicing the station. Using the "Sleep" mode can dramatically reduce the energy consumption of the station as a whole.

The software of the submarine station is entirely written in the high-level C language, which, at the same time, allows for fine control of the hardware up to bitwise operations in their registers specific to assembler. The use of Borland's C language compilers allows the generation of codes that are largely invariant to the type and class of the IBM-compatible computer used by appropriately adjusting the compiler environment. As a result, the program is operational for all types of processors, starting with the 8086/8088 family and ending with 80486 and Pentium.

The version of the program is located in the EPROM microcontroller. The launch of the program for execution and, accordingly, the start of work occurs automatically when power is supplied to the microcontroller.

The seismic signals are digitized using the external interrupt mechanism by the signals of the programmable internal timer of the microcontroller. Digitization and data collection are carried out with pre-processing elements to improve the metrological characteristics of the registration channels. Analog signals are digitized at a higher frequency, then digitally filtered and averaged by triples and fives, followed by discharge to obtain the desired sampling frequency. All filtering procedures in the system are performed in real time using Butterworth's fast recursive filters. Two types of filters are used. It is advisable to use recursive filters with integer coefficients at the characteristic points of a program with a high data canalization rate (for example, with input filtering). Such filters do not require floating point calculations and are much faster than their counterparts with "exact" coefficients. However, it should be noted that the procedure of rounding the coefficients causes a number of known problems and, in particular, can lead to instability of the filter. In other characteristic nodes of the program, where samples with a sampling frequency of 100 Hz and below are subject to digital filtering, it is possible to use recursive filters with "exact" coefficients, presented in the form of floating point numbers. Such filters are more stable, functionally closer to their analog prototype, but they lose in speed. Recursive filters of this type are used, in particular, in the algorithm of the detector of seismic signals. Typically, in analog and digital devices, Butterworth high-order filters obtained by cascading second-order links give the best result.

In order to increase the station’s autonomy time, in addition to the continuous operation mode, a standby recording mode with a brief record of the history of the event is provided. To organize the standby mode, the system uses the so-called STA / LTA, which is most often used for the purpose of detecting seismic signals, a detector that uses the algorithm for the ratio of signal energies with short-period and long-period averaging. The disadvantage of such a detector, as you know, is to skip the first entry when working on a strongly coherent signal. To improve the characteristics of the detector, a three-channel version was developed using the group coincidence attribute “2 of 3”. This means that the data of the three seismic channels are analyzed by three independent detectors, and the detection signal is generated only when the alarms coincide in at least two of the three channels. This method increases the reliability of the system in standby mode. If an event is detected in the system, a signal is generated that allows you to save the previous data file in external memory, otherwise it is erased. Thus, the standby mode of registration is carried out with the recording of the background before the event.

The digital recorder program contains a telecommunication driver that supports half-duplex communication with the central computer of the bottom station. Communication is based on a high-performance binary communication protocol using separate RS232 interface signals. Communication and data storage are controlled by the central microprocessor of the station. The management program supports the file organization adopted in DOS. Arrays of data are stored on the hard disk in files whose format meets the accepted station requirements, and if necessary, using the simplest software supervisor, the formats can be integrated into any of the seismological data exchange formats existing in the world practice.

Unlike known devices that use a separate analog recorder with a frequency range from 0.1 to 15 Hz, the device used uses a recorder with a lower frequency range from 0.003 Hz.

The operation of the entire station is controlled using a central microprocessor such as MicroPC, and the main accumulation of signals is carried out on the hard disk. All this made it possible to expand the frequency range of the digital recorder to 15 Hz from above, the dynamic range to 120 dB (with automatic switching of sensitivity to 2 sub-bands) and completely eliminate analog recording.

When registering seismic signals at the bottom, one of the important areas of using broadband bottom seismographs is the study of microseismic noise excited by sea and ocean waves. Microseisms appear in a wide range of frequencies and serve as a natural background that determines the sensitivity threshold of seismographs. By means of the proposed device, characteristic microseisms with a period of about 6 s are also recorded, microseisms with periods of 20 and 100 s are also detected, which makes it possible to isolate both volume P and S waves and Love surface waves (oscillations in the frequency range 0.0125-0, 05 Hz) and Rayleigh.

At the same time, the excitation of seismic waves in a compressible fluid is accompanied by the generation of hydroacoustic fields in a wider frequency range, and their energy can exceed the energy, for example, tsunami waves. In this case, low-frequency fields (F <1 Hz), like tsunami waves, are excited mainly due to vertical movements of the bottom in the epicenter of an earthquake. Excitation of high-frequency hydroacoustic fields (phase T) occurs over a much larger area and substantially depends on the topography of the bottom. Therefore, high-frequency hydroacoustic fields contain relatively less information per se about the forms of bottom movement in the epicenter of an earthquake.

The presence of intense low-frequency acoustic fields, for example, in the tsunami focus, is observed in the range 0.05-0.4 Hz, while the main energy of elastic vibrations exceeds the tsunami wave energy by about 300 times (Levin B.V., Nosov M.A. Physics tsunami. M.: Janus - K. 2005.360 p.).

At very low frequencies (below 0.01 Hz), due to the negligibly small thickness of the ocean layer compared to the wavelength, anemobaric waves are directly excited due to atmospheric pressure drops (Rabinovich AB Long gravitational waves in the ocean: capture, resonance, radiation S.P.: Gidrometeoizdat, 1993, 325 p.). Part of the energy of microseisms propagating at small angles to the vertical is scattered in the interior of the Earth in the form of body waves in accordance with the law 1 / R ² . Another part of the microseism due to refraction or reflection from the underlying layers returns to the upper boundary and undergoes repeated reflections and transformations of longitudinal waves into transverse and vice versa. In this case, surface waves of various types can form, which can propagate over long distances with low attenuation (the energy attenuation coefficient is proportional to 1 / R). In this case, Rayleigh, Stoneley and Love waves are formed. The speed of Rayleigh waves is always greater than the speed of sound in water. Therefore, at sufficiently high frequencies, when the wavelength in the water layer is commensurate with the depth of the ocean, part of the energy of the Rayleigh waves passes into the water. The amplitude of the waves decreases. Estimates show that the effect of the water layer at an ocean depth of 4 km begins to affect frequencies of about 0.01 Hz. At a frequency of about 0.1 Hz, the wave reflected from the surface of the liquid passes to the bottom in antiphase, i.e. maximum suppression of the Rayleigh wave occurs. In this case, the main mode undergoes the greatest attenuation, since its antinode is located at the water – ground interface. Higher modes attenuate less because there are a number of antinodes of these modes in the underlying layers. Due to the exchange of acoustic energy between the liquid and the elastic base at a sufficient depth of the ocean, a surface Stoneley wave can arise and propagate along the bottom. At the same time along the vertical on both sides of the boundary are inhomogeneous damped waves. With an ocean depth of 4 km, the formation of Stoneley waves is possible at frequencies starting from about 1 Hz, and at frequencies above 10 Hz the limiting effect of the depth of the ocean can be neglected. The speed of a Stoneley wave is less than the speed of waves in water and soil, so there is no energy loss due to "leaky" waves. It follows that Stoneley waves can propagate along the seabed over long distances at high frequencies, in contrast to Rayleigh waves. Love surface waves are transverse vibrations with horizontal polarization. Therefore, they cannot be directly excited by waves incident on the boundary from an aqueous medium or due to drops in anemobaric pressure. Their appearance in the microseism is associated with the transformation of Rayleigh waves on the inhomogeneities of the earth's crust, as well as with seismic emission from the crust and upper mantle.

The nodes and elements, which are a frame 22 and 40, a power arc 28, a cable 42, a disconnector 43, an anchor rope 44, an anchor 45, an anchor device 50, a beacon 65 and a flashing beacon, are intended for setting up underwater stations and raising them.

The method is implemented as follows.

The means for recording hydroacoustic signals are placed, which are broadband bottom seismographs directly at the water - soil boundary in the coastal zone and at a distance from the coastal zone, as well as at different depth horizons using autonomous seismic bottom stations 10, bottom seismic stations 11, and float seismic stations 12.

Broadband seismographs of the G.Streckeisen Messgeratebau type (Switzerland) and Guralp (England), STS-1 and CMG-3 type, or EHP-17 and EHP-20 broadband seismographs are installed on coastal mobile stations.

The measuring base on the seabed is formed by placing seismic receivers at a distance of not more than 5 km from each other, with the formation of an isosceles triangle in the underwater space, at the tops of which seismic receivers are located, while the hydroacoustic antennas of seismic receivers include four transceivers of acoustic signals mounted on a perforated bracket, with the formation of two single-channel and one two-channel transceivers, with the placement of antennas of single-channel receivers transmitters at a distance of 1000 mm from each other in the end zones of the perforated bracket; the two-channel transceiver is formed of two transceivers that are 50 mm apart, one of which is located 200 mm from the first single-channel transceiver, and the second single-channel transceiver is located at a distance of 800 mm from the second single-channel transceiver, the transceivers are located on a perforated bracket with the formation two measuring bases having a common center; seismic oscillation receivers are located in the shelf zone, along the foot of the continental slope and along an axis perpendicular to the Gardiner line along the fault boundaries.

By means of magnetometers and gravimeters installed at underwater stations, magnetotelluric surveys are performed. According to the results of the survey, when processing synchronous recordings using algorithms that make it possible to obtain several independent solutions for impedance and admittance estimates at each frequency, they find the frequency characteristics that connect the electric and magnetic fields in field and base points in the target range of periods, and in nodal points over a wide range of periods. Then, the initial corrections for the frequency samples t and m are performed, the error of the parameters for all samples is calculated and compared, and the samples are recorded with the minimum errors and the corresponding current and average values of the parameters. Based on these average values, graphs of the frequency characteristics t and m are plotted, graphs by profiles, and maps on fixed periods within the target range. The current values of t and m in the frequency samples with minimal errors calculate the current values of the corresponding parameters according to the formulas, at each frequency, find their average values and frequency errors. The average values of the parameters build their frequency characteristics. Similarly, the current values of the impedances and impedance values given in the reference curves obtained point P _m and the other impedance transformation also in valuation embodiments for a complete and the internal magnetic field and their errors. The most informative periods in the target range are selected and graphs are constructed by profiles or maps of the indicated informative parameters for the entire investigated area. For a more reliable detection of weak anomalies t and m, their integral characteristics are calculated according to the corresponding formulas and their graphs or maps for the entire area and for individual sections of the area are also constructed.

Based on the complex of data obtained, taking into account the errors of parameters and their confidence intervals (accuracy) of the constructions, the presence, nature, size and depth of geoelectric heterogeneities within the target interval of the geological section are judged with an assessment of the accuracy and reliability of their identification.

When performing magnetotelluric surveys, the corresponding hydrosphere parameters are also measured by means of a methane sensor 63, a radioactive contamination control unit 24, a hydrochemical measurement unit 62, and a hydrophysical module 47.

In the presence of geoelectric inhomogeneities, hydroacoustic signals are recorded with phases of the PP, S, and T type being separated. In this case, seismic noise is recorded at frequencies of 0.008-20 Hz, hydrodynamic noise of the sea at frequencies of 0.01-100 Hz, tsunami wave pressure at the bottom at frequencies 0,01-0,01 Hz and perform the survey of the soil through the penetrometer 36.

The phase T signal received in the coastal wedge is determined in the frequency range 34 ... 75 Hz at a quantization frequency of 160 Hz using the pseudo-differential parabolic equation, which provides sound fields in a two-dimensional inhomogeneous ocean with variable bottom topography and sound velocity profile with a given accuracy for any angle range slip of local normal waves, taking into account the interaction between them. Since the observed signal S (t) is the sum of signals from successively excited layers, representing the signal as a vector of a column of time samples and denoting column vectors of signals from successively excited layers by s _i , we have S (S ₁ , S ₂ , ... S _n ), (a ₁ , a ₂ , ... a _n ), a _i - the essence of the amplitude of the scatterers. As the decisive statistics, the sum of the squared amplitudes is used, which has the maximum value for the signal of the expected structure. The estimate is obtained by the least squares method, since the system of linear equations is uncertain.

Performing an assessment for each point in time, get its time dependence. The presence of a maximum in it means the presence in the source of the expected structure of the excitation of the sound field. When plotting the critical statistics of the abscissa of the global maximum, it corresponds to the time of arrival of the total scattered signal.

The arrival of an acoustic wave of seismic origin is determined by the magnitude of the frequency shift of the scattered radiation, while using the recording means located in the near zone of the fault at the signal receiving and processing dispatch stations, the low-frequency components of the scattered signal are analyzed, and noise is used as reference quasi-harmonic high-frequency signals shipping, and by means of registration tools located in the coastal zone, determine the moment of appearance and direction of arrival with acoustic waves through narrow-band filtering and spectral analysis. Phase separation of the PP, S, and T phases is carried out by narrow-band filtering using Butterford recursive filters, while the input filtering is performed by recursive filters with integer coefficients, and signals with a sampling frequency of 100 Hz and below are filtered with coefficients in the form of floating point numbers. Acoustic signals are recorded by means of broadband bottom seismographs with at least three seismic channels, the signals being analyzed by three independent detectors, and the detection signal is generated when the alarms coincide in at least two out of three channels. Spectral analysis is performed as body waves of the phases PP and S, and surface waves of Love, Rayleigh and Stoneley.

When registering seismic signals at the bottom, one of the important areas of use of broadband bottom seismographs is the study of microseismic noise excited by sea and ocean waves. Microseisms appear in a wide range of frequencies and serve as a natural background that determines the sensitivity threshold of seismographs. By means of the proposed device, characteristic microseisms are also recorded with a period of about 6 seconds, microseisms with periods of 20 and 100 seconds are also detected, which makes it possible to isolate both volume P and S waves and Love surface waves (oscillations in the frequency range 0.0125-0, 05 Hz), Rayleigh and Stoneley (1-10 Hz). At coast stations, the Rayleigh wave is recorded in the zero mode.

Known methods allow to achieve a technical result, which consists in increasing reliability, only in an isotropic field, since the nature of the decrease in the intensity of the sound signal with distance from the source in a horizontally inhomogeneous field (especially in the ocean) differs sharply from the same dependence in an isotropic field. Mesoscale inhomogeneities of the ocean (fronts, rings) dramatically rearrange the sound field, causing fluctuations in signal intensity up to 5 dB when predicting their range (D) up to 10 km. Therefore, for an effective forecast of hydroacoustic conditions in abnormal areas, a clear establishment of centers and boundaries, as well as determination of the parameters of disturbing formations, are necessary. Uncertainty in the calculation of the sound field by climatic data or the reference field is expressed in standard deviations of the real level from the reference at 4-9 dB, at D = 90 km, which corresponds to an error in the forecast of the expected range of hydroacoustic systems by 60-90%. The use of a single curve of the vertical distribution of the speed of sound for acoustic calculations is permissible only at short distances (up to 10 km), which is extremely rare in real conditions. By the magnitude and direction (sign) of the horizontal gradient along the signal propagation path, one can judge the degree of variability of the intensity of the sound field at the receiving horizon relative to a fixed source. For calculations of the acoustic field, the parameter is the sound velocity profile, which exactly matches the actual profile at the source location. However, when using regime information, the mean-square profile, as a rule, does not coincide with the actual one, which leads to additional random errors in the final result.

In the proposed technical solution, by means of an underwater probe 14, a profile of the speed of sound in the volume of the studied hydrosphere is determined, and reconnaissance of the studied underwater area and geodetic reference of underwater stations are performed.

Acoustic seismic sensors for recording acoustic signals, proton or quantum variometers and magnetometers for measuring the electric and magnetic components of the Earth’s natural electromagnetic field can be used as measuring tools installed by means of anchor devices, with the separation of the magnetotelluric component against a background of separation of electric and magnetic sensors by the value Δr≤ (0,013 ... 0,025) r, (where r is the distance between the receiver and the source). In this case, the separation of the magnetotelluric component against the background of interference is significantly simplified, since the interference in the electric and magnetic channels is caused by various sources (they are uncorrelated) due to the spacing of the sensors by Δr. Moreover, the magnetic components of the natural magnetic field are smaller than the electric ones, depending on the nature of the geoelectric section far from horizontal inhomogeneities.

In a specific embodiment, the acoustic measuring means installed by means of anchor devices are a set of sonar antennas.

Each receiving hydroacoustic antenna consists of four hydrophones. The antenna section consists of two single-channel and one two-channel module, located on a linear carrier bracket. The distance between the receiving hydrophones of the two-channel module is 50 mm. The maximum spacing of the extreme receivers on the bracket is 1000 mm. The bracket is perforated, which allows the receivers to be located in close proximity to each other for phase calibration and with arbitrary spacing for measuring the direction of arrival of the acoustic signal. Piezoceramic spheres with a diameter of 30 mm were used as receiver antennas, inside which preliminary amplifiers with a gain of 30 dB were placed. The spheres are placed on a steel plate measuring 145 × 145 × 10 mm, equipped with fasteners and an acoustic plug on the back side. The suppression ratio of the audio signal from the back is at least 30 dB.

The antenna complex consists of an 8-channel 2-section receiving hydroacoustic antenna and a hydroacoustic emitting antenna.

Each section of the receiving antenna is a 4-element non-equidistant hydrophone module designed to measure the projection of the acoustic signal arrival vector onto one of the horizontal axes in the ultrashort base mode, in the direction finding mode, or for receiving signals in the long base mode at 4 operating frequencies. Sections of the receiving antenna are located in a horizontal plane perpendicular to each other.

Thus, when all hydrophones receive at the same working frequency, the mode of determining the delay and direction of arrival of the response from a fixed point of the soil is implemented in the ultrashort base mode, and when each of the hydrophones is tuned to its working frequency, the measurement mode of delays from several points of soil in the long base mode.

The recorded signals are processed for each particular point in time to obtain a time dependence within the boundaries characterizing the state levels of the natural geophysical field and hydrophysical fields.

The control unit of the dispatching station (swimming means) analyzes the level of signals received through the hydroacoustic communication channel from the sensors of weak seismic signals, and in the case of raising the threshold level, includes sensors of strong movements and, in the case of significant vertical or inclined displacement velocities of the bottom movement elements, generates a message packet that via satellite radio channel is transmitted to the reference point. Since the control device operates with inertia, to eliminate the loss of the first introductory strong bottom motions, the signals from the outputs of the weak signal sensors are continuously recorded in the buffer memory, which are then used to determine the vessel's motion elements and recorded in a digital multi-channel information storage device. The threshold level is determined by averaging over a long period of time the seismic noise coming from the outputs of the sensors of weak seismic signals.

The signals received by the receiving antenna of the hydroacoustic communication channel of the swimming means are formed into information packets for transmission to strong points via artificial Earth satellites or aircraft, which can be used as a relay means. Analogs of the data conversion algorithm are the data conversion methods described in the source: Ilyin A.A., Marinich A.N. et al. Digital terminals of satellite communication systems. SPb. Deau. 2005, p. 77-78, 89.

A linear polarization antenna in the form of an asymmetric half-wave pin vibrator, which provides the best energy characteristics in the region of small elevation angles of satellite devices, is installed on the boat as a satellite communication antenna.

The hydro-acoustic communication channel provides a range of up to 8000 m with a frequency range of signal transmitters commands 7-10 kHz.

When processing signals, the sum of the squared amplitudes having the maximum value for the signal of the expected structure is used as the decisive statistic. Calculations are performed for each point in time to obtain a time dependence for each field. The presence of a maximum in it means the presence in the source of the expected structure of the excitation of a field. The global maximum corresponds to the arrival time of the cumulative received signal. Upon reaching a global maximum equal to the average value between the amplitudes characterizing the state levels of the natural geophysical and hydrophysical fields, the possibility of the presence of hydrocarbons within the boundaries of the examined formation is judged.

Separation from the spectrum of horizontal components of odd harmonics of 0.003 and 0.005 Hz, and from the spectrum of vertical components of even harmonics of 0.002, 0.004, 0.006 and 0.008 Hz with sea level recording at coastal stations, it is possible to exclude the influence of microseic components, mainly due to the influence of tidal fluctuations.

The dynamic noise of the sea is determined in the frequency range from 5 to 10 Hz by means of a measuring module, including a series-connected hydrophone, pre-amplifier, communication line, broadband amplifier, spectrum analyzer. The received signals about the dynamic noise of the sea are discretized and quantized, and then they undergo spectral processing using the modified periodogram algorithm in the following sequence. From a sequence of signals X ₂ (m) of length L samples, for each sequence X ₂ (m), the fast Fourier transform coefficients are calculated

where W (m) is the corresponding window.

- энергия окна.Next, calculate the periodogram I ₂ (f _k ) = 1 / V | X ₂ (k) |, where f _k (k / L) is the frequency of the discrete Fourier transform,

- window energy.

выполняется какEnergy Spectrum Assessment

runs as

The dynamic noise of the sea coincides with a frequency of about 5 dB. To solve such problems, it is necessary to discretize a continuous area of the water area using nodes of a regular grid. Then the graph is determined by setting the connection (edges of the graph) on this grid. Possible relationships are determined by special indexing of the nodes of the regular grid using the Farey-Cauchy tree. Moreover, the approximation coefficients for the fluctuation fields are expressed analytically through the integrals over the fragments of the reference field in individual grid cells.

The recorded signals characterizing the variations of the magnetic field at frequencies of 0.01-1.0 Hz, the magnetic induction of the electromagnetic field at frequencies of 1-200 Hz, the electrical component of the electromagnetic field at frequencies of 1-500 Hz, acoustic noise at frequencies of 5-50000 Hz, seismic noises at frequencies of 0.01–20 Hz, hydrodynamic noise of the sea at frequencies of 0.01–100 Hz, in the zones of tectonic faults are processed for each specific point in time to obtain a time dependence within the boundaries characterizing the levels of the state of natural ge of the official field and hydrophysical field during the phase of the sun and moon being on the same celestial line, as a geophysical field subject to the greatest maximum disturbances in all components of geophysical and hydrophysical fields in a given period.

When processing signals, the sum of the squared amplitudes having the maximum value for the signal of the expected structure is used as the decisive statistic. Calculations are performed for each point in time to obtain a time dependence for each field. The presence of a maximum in it means the presence in the source of the expected structure of the excitation of a field. The global maximum corresponds to the arrival time of the cumulative received signal. When reaching a global maximum equal to the average value between the amplitudes characterizing the state levels of the natural geophysical and hydrophysical fields and the geophysical field and the hydrophysical field during the phase of the sun and moon being on the same celestial line, by excluding acoustic signals of natural and man-made origin, they judge the possibility of hydrocarbon deposits.

The proposed method implements the technology for constructing a cartographic image based on NURBS in the form of an iterative expert automated procedure. The programming language used is the MatLab language. In this system, the quality of map construction is determined by expert comparison of the position of contours calculated according to NURBS with the position of the corresponding isohypses (isobaths) on the original map.

In a specific implementation of the proposed method, raster maps serve as a source of information about the bottom topography.

In the general case, when approximating the profile of the relief with one-dimensional splines, one should specify the values of the first two derivatives at the end points of the section. However, such information is unknown, and it is impossible to obtain it in practice. Therefore, the simplest cubic spline with zero boundary derivatives was used as the base spline for approximating the relief profile along the section. Due to the fact that there are no explicitly defined two-dimensional splines, since it is impossible to construct an infinite system of algebraic equations for matching the first two derivatives in all directions at the adjacent boundaries of two pieces of a spline surface, the construction of a two-dimensional spline function is performed using the tensor product of one-dimensional splines. The matching of the first two differentials for adjacent rectangular map sections is ensured by overlapping task areas of adjacent NURBS.

Thus, the technology for constructing maps in an analytical form based on NURBS allows you to exclude the triangulation stage and thereby eliminate the disadvantages of existing technologies used in well-known technical solutions. The proposed implementation of the technology can be adapted to other types of source information, and more complex types of basic splines can be included in it.

The construction of a map of amplitude variations of a microseismic signal for each frequency of the spectrum of spatial variations, as well as the binding of each received map to its corresponding depth, is performed by approximating the relief profile along the section relative to the coastline, and a cubic spline with zero boundary derivatives is used as the base spline, with the construction of a two-dimensional spline functions are produced by the tensor product of one-dimensional splines. In this case, the legitimacy of identifying hydrocarbon deposits is carried out by identifying the main geographical patterns of the location of geophysical fields within the study region. Since many shelves are a continuation of the lowlands confined to large platform deflections or syneclises, the sequences performing these deflections are tilted towards the shelf and reach maximum power within it. The high power of terrigenous sediments in oil and gas regions is a favorable condition for oil and gas.

To confirm the obtained research results within the section, in particular to confirm the appearance of the spectral anomaly of the information signal, seismic vibrations are generated by means of a device for exciting elastic vibrations in the marine environment 38 against the background of a natural seismic field in the research area.

During the test tests, in order to detect earthquakes, the measurements were carried out using weak seismic signal sensors (seismic module 52), measuring three components (horizontal, vertical and inclined components) in the range of 0.008-0.1 Hz and strong bottom motion sensors (seismic acoustic module 53) in the range of 0.01–20 Hz, which also measure three components, signals were recorded at the interface between sea water and sea soil.

Proton and quantum variometers and magnetometers were also used as measuring sensors to measure the electric and magnetic components of the natural electromagnetic field of the earth with the separation of the magnetotelluric component against the background of interference with the separation of electric and magnetic sensors by the value Δr≤ (0.013 ... 0.025) r, (where r - distance between receiver and source). In this case, the separation of the magnetotelluric component against the background of interference is significantly simplified, since the interference in the electric and magnetic channels is caused by various sources (they are uncorrelated) due to the spacing of the sensors by Δr. Moreover, the magnetic components of the natural magnetic field are smaller than the electric ones, depending on the nature of the geoelectric section far from horizontal inhomogeneities.

The recorded signals were processed for each specific point in time to obtain a time dependence within the boundaries characterizing the state levels of the natural geophysical field and hydrophysical fields.

The control and recording unit 27 analyzed the level of signals coming from the seismic-acoustic module 53, and in the case of increasing the threshold level, turned on the seismic module 52 and in the case of significant vertical or inclined velocities of the movement of the bottom elements formed a message packet that was transmitted through the hydroacoustic communication channel to the control station .

Since the control and recording unit 27 operated with inertia, to eliminate the loss of the first introductory strong bottom motions, the signals from the outputs of the sensors of the seismic module 52 were continuously recorded in the buffer memory of the control and recording unit 27, which were then used to determine the elements of the bottom movement and recorded in digital multi-channel information storage unit of the control and registration unit 27. In this case, the threshold level was determined by averaging over a long period of time seismic w mov output from the seismic sensor unit 52.

The hydro-acoustic communication channel provided a range of up to 8000 m with a frequency range of signal transmitters commands 7-10 kHz.

When processing the signals, the sum of the squared amplitudes having the maximum value for the signal of the expected structure was used as the decisive statistic. Calculations were performed for each moment in time to obtain the time dependence for each field. The presence of a maximum in it means the presence in the source of the expected structure of the excitation of a field. The global maximum corresponds to the arrival time of the cumulative received signal. When a global maximum is reached equal to the average value between the amplitudes characterizing the state levels of the natural geophysical and hydrophysical fields, the possibility of a catastrophic phenomenon is judged.

The separation from the spectrum of horizontal components of odd harmonics of 0.003 and 0.005 Hz, and from the spectrum of vertical components of even harmonics of 0.002, 0.004, 0.006 and 0.008 Hz with registration of sea level at coastal stations, it is possible to exclude the influence of microsexing components, mainly due to the influence of tidal fluctuations.

The proposed technical solution can be used to solve the following problems:

• study of the structure of the earth's crust in the waters of the oceans;

• studies of the totality of the manifestation of geophysical fields in the zones of tectonic faults directly at the bottom of the ocean;

• studies of the state of the marine environment in the bottom zone and its interaction with tectonic processes;

• geophysical and geoecological monitoring of complex hydraulic structures;

• operational assessment of the seismic and hydrodynamic conditions of the regions and the forecast of possible seismic and environmental consequences;

• early warning with a significant increase in the accuracy of forecasting earthquakes and tsunamis;

• identification of precursors of seismic, geodeformation, geochemical, hydrophysical precursors of catastrophic earthquakes, the sources of which are under the ocean floor, the implementation of medium-term and short-term forecast of earthquakes with magnitude 5.5 and higher;

• control of changes in the stress-strain state of the sections of the earth’s crust of shelf zones near the developed oil and gas fields caused by hydrocarbon recovery, bypass water injection and other artificial influences on the hydrocarbon reservoir;

• selection of environmentally sound modes of field exploitation;

• forecasting the development of crustal deformations and induced seismicity;

• prediction of small local earthquakes hazardous to damage to wells, oil platforms / subsea pipelines.

• research of deposits of marine gas hydrates.

The application of the proposed technical solution allows monitoring changes in the stress-strain state of sections of the earth’s crust of shelf zones near developed oil and gas fields caused by hydrocarbon recovery, bypass water injection and other artificial influences on the hydrocarbon layer, and predicting small local earthquakes that can damage wells and oil platforms / subsea pipelines, predict emergencies, thereby helping to reduce environmental danger during the operation of marine industrial facilities.

The implementation of the device is not of technical complexity, since the device is implemented on commercially available sensors and elements of microelectronics, which allows us to conclude that the claimed technical solution meets the patentability condition "industrial applicability".

Information sources

1. Patent RU No. 2045079.

2. Patent RU No. 2161809.

3. Copyright certificate SU No. 949574.

4. Patent RU No. 2054697.

5. Patent WO No. 98/37439.

6. Patent RU No. 2251716.

7. Patent RU No. 2336541.

8. Patent RU No. 2271554.

Claims (2)

1. A method of seismic exploration when searching for hydrocarbons on the continental shelf, including the registration of the natural seismic background and seismic signal in the studied space, measured by one or more seismic complexes, followed by mathematical processing of the measured values, preliminary determination of the dispersion curve of microseismic waves characteristic of the study area, by conducting synchronous registration of microseismic signals by at least three seismic stations from the vertical seismic sensors with subsequent assessment of the dependence of the apparent propagation velocity of microseismic waves on the signal frequency, the determination of wavelengths and the frequency range based on the analysis of apparent velocities, in which the microseismic signal consists of Rayleigh waves, placing seismic sensors in the study area so that the distance between them was no more than half of the shortest Rayleigh wavelength, the determination of the amplitude non-identity of the measuring channels of seismic sensors in the microseismic signal frequency band by simultaneously recording the microseismic signal by all seismic sensors at one point for a time sufficient to establish the stationary power spectrum of the microseismic signal, followed by determining the logarithmic difference of the spectra of all measuring channels of the seismic sensors, accumulating the power spectrum of the microseismic signal in each a measurement point for a time sufficient to establish stationarity spectrum, calculation of the spectrum of spatial variations of the microseismic signal for each measurement point by determining the logarithmic difference of the power spectrum for each measurement point and the power spectrum of the microseismic signal accumulated at a stationary seismic station for an equivalent time in the same time period, taking into account the amplitude non-identity of the measurement channels of seismic sensors, building a map of the amplitude variations of the microseismic signal for each frequency of the spectrum strange variations, the binding of each card received to its corresponding depth; at the same time, information signals are recorded by their measured components for a period of time sufficient to record a statistically reliable noise signal in the infra-low-frequency range, spectral characteristics are calculated using the Fourier transform of the received signals, and they are analyzed for the presence of false signals and signals from the reservoir with natural hydrocarbons, false signals are excluded from consideration, an analysis of the remaining signals is carried out with a judgment on the presence of whether there are no hydrocarbons, registration and recording are carried out on the vertical components of the information signals in the frequency range 0.5-50 Hz, corresponding to the range of the basement depths, the Fourier transform of the components of the information signals is carried out according to their first derivative, the maximum that is taken as a false signal corresponding to the resonance between the day surface and the foundation - a signal from the foundation, the point with the spectrum at which the presence there is a signal from the foundation with a monotonic decrease in the amplitude of the spectrum towards higher frequencies from the maximum of the signal from the foundation, an observation point in the signal spectra of which there are maxima at frequencies greater than the frequency of the maximum of the signal from the foundation, with their offset relative to other measurements by less than half its width maximum, taken as promising for the presence of deposits from natural hydrocarbons, the presence of hydrocarbons is judged by the change in the spectral power of the information signal at the measured frequency otach, characterized in that the determination of the dispersion curve of microseismic waves characteristic of the study area is carried out by conducting synchronous registration of microseismic signals by at least three seismic stations, while recording seismic noise at frequencies of 0.008-20 Hz at the water-ground boundary, while from the spectrum of horizontal components, the odd harmonics are 0.003 and 0.005 Hz, and even harmonics of 0.002, 0.004, 0.006 and 0.008 Hz are isolated from the spectrum of the vertical component, while the variations are additionally measured the magnetic field at frequencies of 0.01-1.0 Hz, the magnetic induction of the electromagnetic field at frequencies of 1-200 Hz, the electrical component of the electromagnetic field at frequencies of 1-500 Hz, acoustic noise at frequencies of 5-50000 Hz, the hydrodynamic noise of the sea at frequencies 0 , 01-100 Hz in the zones of tectonic faults, according to the measured parameters, they perform factor analysis at the levels of the natural geophysical background and geophysical background by plotting the amplitudes of the gradients of seismic, geodeformation, geochemical, hydrophysical indicators at the base and measurements not exceeding 50-100 km at middle latitudes and 8-10 km at high and equatorial latitudes, respectively, while taking into account short-period variations in the magnetic field caused by sea waves, minimize magnetic imaging errors by revealing the fine structure of magnetic inhomogeneities and determining their parameters, the arrival of an acoustic wave of seismic origin is determined by the magnitude of the frequency shift of the scattered radiation, while using registration devices located at a distance from the coastal zone, an analysis of the low-frequency components of the scattered signal, using the noise of navigation as the reference quasiharmonic high-frequency signals, and using the recording devices located in the coastal zone, determine the moment of arrival and direction of arrival of seismic waves by narrow-band filtering and spectral analysis of waves using recursive Butterfort filters, while the input filtering is carried out by means of recursive filters with integer coefficients, and signals with a sampling frequency 100 Hz and below are subjected to filtering with coefficients in the form of floating point numbers; sonar signals are recorded by means of broadband bottom seismographs with at least three seismic channels, while the signals are analyzed by three independent detectors, and the detection signal is generated when the signals coincide in at least two of the three channels; Spectral analysis is performed both of the body waves of the PP and S phases, and of the Love, Rayleigh, and Stoneley surface waves, the mapping of the amplitude variations of the microseismic signal for each frequency of the spectrum of spatial variations, and the mapping of each received map to its corresponding depth is performed by approximating the profile of the relief along the section relative to the coastline, and as the base spline, a cubic spline with zero boundary derivatives is used, while the construction of a two-dimensional spline function is performed by em-dimensional tensor product spline; the measuring base on the seabed is formed by placing seismic receivers at a distance of not more than 5 km from each other with the formation of an isosceles triangle in the underwater space, at the tops of which seismic receivers are placed, while seismic oscillation receivers are placed in the shelf zone along the foot of the continental slope and along the axis of the perpendicular Gardiner line along the fault boundaries. 2. A seismic complex for seismic exploration when searching for hydrocarbons on the continental shelf, consisting of stationary seismic receivers and a mobile multi-channel seismometric module, each of which consists of a block of highly sensitive seismic sensors, a recording module with a block of filters and amplifiers, a board of analog-to-digital converters, digital-to-analogue converters, computer, GPS receiver, power supply, calibration unit, processing unit, signal analysis and their spectral characteristics software, type Mathlab version 6.0 and higher, characterized in that the seismic complex includes a swimming means, an aircraft, an autonomous seismic bottom station, a bottom seismic station, a float seismic station, while the mobile seismic module is designed as a controlled underwater vehicle, a swimming the tool is equipped with an underwater probe, the recording equipment of the seismic complex additionally contains a spectrum analyzer, methane detection sensor, hydrophysical mode ul, bottom seismometer, magnetic field sensor with control unit, penetrometer, gravimeter, pneumatic transducer, bottom pressure sensor, hydroacoustic communication channel modem, satellite communication channel modem, spatial orientation unit, acoustic Doppler current profile meter, hydrochemical measurements unit connected to the unit registration and management.

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