CN105510977B - Towed marine seismic survey vertical cable data collecting system - Google Patents

Abstract

A towed vertical cable data acquisition system for marine seismic exploration, including a workboat equipped with an excitation system and a vertical cable for towed marine seismic exploration. The vertical cable includes auxiliary steel cables and cable parts, and the cable parts are front-connected from top to bottom. section, the first working section, the tail working section and the tail connecting section, an inclinometer and a pressure sensor group are installed between the front connecting section and the first working section, and 8 hydrophone combinations are arranged sequentially along the length direction of the head and tail working sections , There is an expandable 8-channel digital package between the first working section and the tail working section, and an inclinometer and a pressure sensor group are installed between the tail working section and the tail connecting section. The digital-to-analog conversion is realized on the vertical cable of the present invention, which truly realizes the digitalization of the cable; the working water depth is large, and the vertical cable can still work normally when the water depth is 1000m; Reasonable separation; deep detection depth, by adjusting the front connection section and tail connection section, the vertical cable sinking depth can be controlled in real time.

Description

Towed Vertical Cable Data Acquisition System for Marine Seismic Exploration

technical field

The invention relates to a data acquisition system used in geophysical exploration, in particular to a towed vertical cable data acquisition system for marine seismic exploration.

Background technique

Marine seismic exploration data acquisition system is an important part of marine seismic exploration. At present, domestic marine seismic exploration systems use horizontal cables (Horizon Cable) or submarine cables (Ocean Bottom Cable). In recent years, with the advancement of technology, some high-resolution multi-channel horizontal cables have been developed in China. However, due to their proximity to the sea level, the accuracy of the data obtained is low, and their resolution can only meet the needs of medium-deep or shallow layers. The needs of engineering seismic exploration cannot meet the requirements of high-precision seismic exploration. At present, the working water depth of domestic horizontal cables or submarine cables is mostly within 30m. When the working water depth exceeds 30m, the cables cannot work normally, which brings great restrictions to marine seismic exploration. At present, there is no good domestic precedent for carrying out high-precision detection closer to the seabed. The towed vertical cable data acquisition system for marine seismic exploration is a good way to solve this problem.

In addition, the foreign vertical cable system is connected with the Ocean Bottom Seismometer (Ocean Bottom Seismometer) in Haiti. There is no vertical cable that works alone, and there is no direct-reading vertical cable that is towed by a working ship. To a certain extent, the cost of work. And because of its technical monopoly, the construction cost is greatly increased, which cannot meet the actual domestic demand.

Contents of the invention

The purpose of the present invention is to provide a towed vertical cable data acquisition system for marine seismic exploration to make up for the deficiencies in the prior art.

The invention is based on the existing excitation system and differential GPS navigation, and is an innovation to the collection system, especially the vertical cable part.

A towed vertical cable data acquisition system for marine seismic exploration, including a working boat, which is equipped with a PC control host, a vertical cable control unit, a differential GPS, and is equipped with an excitation system. The excitation system includes a seismic source host on the deck and An electrode located in the water, and a towed vertical cable for marine seismic exploration for receiving seismic data are characterized in that the electrodes and the vertical cable for towed marine seismic exploration are towed by a workboat to work, and the PC control host passes the vertical cable a control unit to receive and analyze data collected by the towed marine seismic vertical cable;

The towed marine seismic exploration vertical cable includes an auxiliary steel cable and a cable part fixed on the auxiliary steel cable through a snap ring, and the auxiliary steel cable and the cable part are vertically arranged, and the cable part is from top to bottom It is the front connecting section, the first working section, the tail working section and the tail connecting section in turn, and a watertight joint is provided at the upper end of the front connecting section, and an inclinometer and a pressure sensor group are arranged between the front connecting section and the first working section. In addition, there are multiple groups of cables inside the first and last working sections, and the first and last working sections are provided with hydrophone combinations in sequence along the length direction, and an expandable 8-channel digital package is provided between the first and last working sections (the The 8-channel digital package is used to process the analog signals received by each of the four channels in the front and rear working sections), the polyurethane solid material is filled between the cable and the hydrophone combination, and the tail working section and the tail connecting section 7 are provided There are an inclinometer and a pressure sensor group, and a titanium alloy metal joint is connected at the end of the tail connecting section, and a plurality of buckles for hanging heavy objects are also arranged on the auxiliary steel cable.

The above-mentioned towed marine seismic exploration vertical cable data acquisition system is characterized in that each hydrophone combination in the head and tail working sections adopts an equidistant and unequal weight combination composed of 16 hydrophones, and the hydrophones The intergroup distance is 0.3m, and the weight design is: 1, 2, 3, 4, 3, 2, 1.

The above-mentioned towed vertical cable data acquisition system for marine seismic exploration is characterized in that one or more working sections are added between the head and tail working sections, and the structure of said working sections is the same as that of the head and tail working sections; There is an 8-channel digital package between the first working section and the adjacent working section, and an 8-channel digital package between the last working section and the adjacent working section. When there are multiple working sections, the adjacent two There is also an 8-channel digital package between the two working sections; the 8-channel digital package is respectively combined with the 8-channel hydrophone above it and the 8-channel hydrophone below it through a 56-pin cable connector. The upper four channels of the combination are connected to convert the continuous analog signal into a discrete digital signal, realizing the digitization of the cable, and realizing the expansion of the vertical cable.

The above-mentioned towed vertical cable data acquisition system for marine seismic exploration is characterized in that the 8-channel digital package and the working section are independent of each other, and the 8-channel digital package includes a columnar titanium alloy metal protective cover. There are multiple circuit boards, and the 8-channel digital package is connected to the working section at the upper and lower ends of the 8-channel digital package through the 56-pin cable connector inside the protective cover. The circuit boards inside the 8-channel digital package include: digital board A, digital board B, Seismic data acquisition board, signal gain control board, inclination data acquisition board, pressure data acquisition board, current data acquisition board; Among them, the digital board B19 is used to collect the output data of the seismic data acquisition board, and control the signal gain control board to the data Perform signal gain; digital board A is used to collect the output data of the inclination data acquisition board, pressure data acquisition board and current data acquisition board. Power conversion and acquisition of real-time status information during vertical cable transmission; the seismic data acquisition board is connected to the 4-channel hydrophone combination at the upper end and the 4-channel hydrophone combination at the lower end, and is responsible for the transmission of each hydrophone combination The analog signal is sampled and converted from digital to analog, and output to electronic board B.

The above-mentioned towed marine seismic exploration vertical cable has an inclinometer and a pressure sensor group at the top of the head section and the bottom of the tail section, which can record the depth, position and attitude of the cable in real time when it is working. The water depth is 1000 meters; and the high-performance deep-water hydrophone is adopted, and the vertical observation method is adopted. By adjusting the length of the elastic front connection section, it can still work normally at a water depth of 1000 meters, which can be used for military target tracking.

The above-mentioned towed marine seismic exploration vertical cable uses auxiliary steel cables, so that the cable part does not have to adopt a rigid structure but can adopt an elastic structure. When the cable part is suspended on the auxiliary steel cable, the hydrophone can be adjusted by bending and hanging the cable part. The distance between the detector combinations can be arranged in a non-fixed track spacing, which is convenient for flexible adjustment of different goals and easy for separation of wave fields. It can separate upgoing waves (such as reflected waves) and downgoing waves (such as direct waves), and it is also easy to identify scattered waves and multiple waves.

The above towed vertical cable data acquisition system for marine seismic exploration, combined with the values of the inclinometer and pressure sensor, can control the inclination angle and depth of the vertical cable in real time by adjusting the speed of the ship and the length of the connecting section.

Advantages of the present invention: a. The digital-to-analog conversion is realized on the vertical cable, and the digitalization of the cable is really realized, so that the cable can reach the expansion of the maximum channel number under the corresponding sampling rate; b. The working water depth is large, and when the water depth is 1000m, the vertical The cable can still work normally; c. The arrangement of non-fixed track spacing is adopted to facilitate the flexible adjustment of different goals; d. The time sampling rate is high, up to 1/8ms, and there are many optional sampling rates: 1/8ms, 1/ 4ms, 1/2ms, 1ms, 2ms, 4ms; e. There is an auxiliary steel cable outside the vertical cable, which realizes the reasonable separation of functions; f. The frequency bandwidth of the receiving signal: 10Hz-8kHz; g. The detection depth is deep, with 6000J The electric spark seismic source can meet the detection of the seabed sedimentary strata greater than 1000 meters in water depths greater than 1000 meters; h. By adjusting the front connecting section and the tail connecting section, the sinking depth of the vertical cable can be controlled in real time.

Description of drawings

Fig. 1 is a schematic diagram of the overall structure of the present invention.

Fig. 2 is a schematic diagram of the construction structure of the present invention.

Fig. 3 is a schematic diagram of the overall structure of the towed marine seismic exploration vertical cable of the present invention.

Fig. 4 is a schematic diagram of the extension of the vertical cable for towed marine seismic exploration according to the present invention.

Fig. 5 is a schematic diagram of the combined structure of the vertical cable hydrophone for towed marine seismic exploration according to the present invention.

Fig. 6 is a schematic diagram of the internal structure of the digital packet of the present invention.

Among them, 1 watertight joint, 2 front connection section, 3 pressure sensor and inclinometer group, 4 first working section, 5 digital package, 6 tail working section, 7 tail connecting section, 8 auxiliary steel cable, 9 snap ring, 10 card Buckle, 11 hydrophone combination, 12 hydrophone, 13 cable connector, 14 signal gain control board, 15 digital board A, 16 seismic data acquisition board, 17 pressure data acquisition board, 18 inclination data acquisition board, 19 electronic board B , 20 current data acquisition board, 21 working section, 22 two connected working sections, 23 working boat, 24pc control host, 25 vertical cable control unit, 26 differential GPS, 27 source host, 28 electrodes, 29 towed marine seismic exploration vertical cable.

detailed description

As shown in Figure 1-3, a towed vertical cable data acquisition system for marine seismic exploration includes a workboat 23, which is equipped with a PC control host 24, a vertical cable control unit 25, and a differential GPS26, and is equipped with an excitation system , the excitation system includes a seismic source main engine 27 located on the deck and an electrode 28 located in the water, and a towed vertical marine seismic exploration cable 29 for receiving seismic data, which is characterized in that the electrode 28 and the towed vertical marine seismic exploration cable 29 is towed by the workboat to work, and the PC control host 24 receives and analyzes the data collected by the towed marine seismic exploration vertical cable 29 through the vertical cable control unit 25;

The towed marine seismic exploration vertical cable includes an auxiliary steel cable 8 and a cable part fixed on the auxiliary steel cable 8 through a snap ring 9, and the auxiliary steel cable 8 and the cable part are vertically arranged, and the cable part From top to bottom are the front connecting section 2, the first working section 4, the tail working section 6 and the tail connecting section 7, and a watertight joint 1 is provided at the upper end of the front connecting section 2, and the front connecting section 2, the first working section 4 An inclinometer and a pressure sensor group 3 are arranged between them, and multiple sets of cables are arranged inside the first and last working sections 4 and 6, and eight hydrophone combinations 11 are sequentially arranged along the length direction of the first and last working sections 4 and 6, Between the first working section 4 and the tail working section 6, there is an expandable 8-channel digital package 5 (the 8-channel digital package 5 is used to process the analog signals received by each of the four channels in the front and rear working sections), the described Polyurethane solid material is filled between the cable and the hydrophone combination, an inclinometer and a pressure sensor group 3 are arranged between the tail working section 6 and the tail connecting section 7, and a titanium alloy metal joint is connected at the end of the tail connecting section 7. The auxiliary steel cable 8 is also provided with a plurality of buckles 10 for hanging heavy objects.

As shown in Figure 5, each hydrophone combination 11 in the first and last working sections 4 and 6 adopts an equidistant and unequal weight combination composed of 16 hydrophones 12, and the group inner distance of the hydrophones 12 is 0.3m. The design with weights is: 1, 2, 3, 4, 3, 2, 1.

As shown in Figure 3, one or more working sections 21 are also added between the first and last working sections 4,6, and the described working section 21 has the same structure as the first and last working sections 4,6; An 8-channel digital package 5 is provided between adjacent working sections 21, and an 8-channel digital package 5 is provided between the tail working section 6 and the adjacent working section 21. When a plurality of working sections 21 are added, adjacent An 8-channel digital package 5 is also arranged between the two working sections 21; the 8-channel digital package 5 is respectively combined with the 8-channel hydrophone 11 above it through a 56-pin cable connector, and the 8-channel digital package 5 is located below it. The upper four channels of the 8-channel hydrophone combination 11 are connected to each other, thereby converting the continuous analog signal into a discrete digital signal, realizing the digitization of the cable, and realizing the expansion of the vertical cable.

As shown in Figure 6, the 8-channel digital package 5 and the working section are independent of each other. The 8-channel digital package 5 includes a columnar titanium alloy metal protective cover. There are multiple circuit boards inside the protective cover. The 8-channel digital package 5 passes through the protective cover. The internal 56-pin cable connector 13 is respectively connected to the working section located at its upper and lower ends. The circuit boards inside the 8-channel digital package 5 include: digital board A15, digital board B19, seismic data acquisition board 16, signal gain control board 14, Inclination data acquisition board 18, pressure data acquisition board 17, current data acquisition board 20; Wherein, digital board B 19 is used to collect the output data of the acquisition board 16 of seismic data, and control signal gain 14 control boards carry out signal gain to data; Digital board A 15 is used to collect the output data of inclination data acquisition board 18, pressure data acquisition board 17 and current data acquisition board 20, there is no circuit connection between digital board A 15 and digital board B19, but adopt parallel distribution combination, respectively Carry out power conversion in the vertical cable transmission process and obtain real-time status information; the seismic data acquisition board 16 is connected to the 4-channel hydrophone combination 11 at its upper end and the 4-channel hydrophone combination at its lower end, and is responsible for monitoring each hydrophone Combine the transmitted analog signals for sampling and digital-to-analog conversion, and output to the electronic board B19.

As shown in Fig. 2, the electrode 27 and the towed marine seismic exploration vertical cable 28 are towed by the workboat to work, wherein the PC control host receives and analyzes the data collected by the towed marine seismic exploration vertical cable through the vertical cable control unit.

As shown in Figure 3, the towed type marine seismic exploration vertical cable (8 tracks, expandable) 28 of the present invention is divided into front connecting section 2 (at least 30m), first working section 4 (at least 60m), and tail working section 6 (at least 60m) , the tail connection section 7 and the auxiliary cable 8. The working sections 4 and 6 are all solid cables. The auxiliary steel cable 8 and the cable part are fixed together by the snap ring 9, the auxiliary steel cable 8 and the cable part are arranged vertically, and the two are relatively free, by adjusting the snap ring 9, the flexible arrangement of the track spacing can be realized.

A watertight joint 1 is provided at the upper end of the front connecting section 2, and the vertical cable control unit 24 supplies power and transmits data to the cable through the watertight joint 1. An inclinometer and a pressure sensor group 3 are provided between the front connecting section 2 and the first working section 4, and between the tail working section 6 and the tail connecting section 7, which can record the attitude and sinking depth of the cable in real time.

As shown in Figure 5, eight hydrophone combinations 11 are respectively provided in the towed marine seismic exploration vertical cable head working section 4 and the tail working end 4 of the present invention, and each hydrophone combination 11 adopts 16 hydrophones, The arrangement of the 16 hydrophones 12 in each hydrophone combination 11 is 1, 2, 3, 4, 3, 2, 1 equidistant and unequal weight combination, and the spacing of each hydrophone combination It is a non-fixed track spacing to suppress random interference and achieve flexible adjustment under different objectives.

When using the present invention, as long as the vertical cable is wound on the winch, the pc main control machine, the vertical cable control unit, the towed marine seismic exploration vertical cable and the exciting source are connected. During construction, the working ship sails at low speed (less than 2 knots), slowly puts the vertical cable into the sea, and controls the sinking depth of the working section of the vertical cable by adjusting the elastic sections at both ends of the working section of the cable, and can sink to the maximum water depth 1000m. During the construction work, the seismic reflection wave signal received by the vertical cable is converted into a digital signal through 8 digital-to-analog conversion digital packets, and then transmitted to the pc main control unit for collection and recording. The inclinometers and pressure sensors at both ends of the working section are real-time Record information such as the attitude and position of the cable, and display the inclination and water pressure in real time on the PC control host, which is convenient for flexible adjustment of ship speed and sinking depth.

Claims (3)

1. a towed marine seismic survey vertical cable data collecting system, including workboat (23), on this workboat (23) It is provided with PC and controls main frame (24), vertical cable control unit (25), differential GPS (26), and be equipped with activating system, activating system bag Include the focus main frame (27) being positioned on deck and the electrode (28) being positioned in water, and for accepting the pull-type sea of geological data The ocean vertical cable of seismic prospecting (29),

It is characterized in that described electrode (28) cable vertical with towed marine seismic survey (29) is operated by workboat towing, Described PC control main frame (24) by vertical cable control unit (25) receive with analyze by towed marine seismic survey vertical The data that cable (29) gathers；

The vertical cable of described towed marine seismic survey includes assisting wirerope (8) and being fixed on described auxiliary by snap ring (9) Cable section on wirerope (8), and assist wirerope (8) to be all vertically arranged with cable section, described cable section is from top to bottom It is followed successively by front linkage section (2), first active section (4), tail active section (6) and tail linkage section (7), and in front linkage section (2) upper end It is provided with watertight connector (1), between front linkage section (2), first active section (4), is provided with inclinometer and pressure transducer group (3), and Internal being provided with of initial and end active section (4,6) organizes cable more, and initial and end active section (4,6) sets gradually 8 road hydrophone along its length Combination (11), is provided with expandable type 8 road digital packets (5) between first active section (4) and tail active section (6), described cable with Filled polyurethane solid material between hydrophone combination, is provided with inclinometer and pressure between tail active section (6) and tail linkage section (7) Force transducer group (3), has titanium alloy metal joint to connect at tail linkage section (7) end, described auxiliary wirerope (8) is additionally provided with many The individual buckle (10) for hanging weight；

8 described road digital packets (5) are separate with active section, and 8 road digital packets (5) include the titanium alloy metal coating of column Set, protection set is internal is provided with multiple circuit board, and 8 road digital packets (5) are by 56 pin cable connectors (13) within protection set respectively Being connected with the active section being positioned at its upper and lower two ends, the circuit board of 8 road digital packets (5) inside includes: digiboard A (15), numeral Plate B (19), earthquake data acquisition board (16), signal gain panel (14), inclination data collection plate (18), pressure data collection Plate (17), current data collection plate (20)；Wherein, digiboard B (19) is for collecting the output of the collection plate (16) of geological data Data, and control signal gain (14) panel carries out signal gain to data；Digiboard A (15) is used for collecting inclination data and adopts Collection plate (18), pressure data collection plate (17) and the output data of current data collection plate (20), digiboard A (15), digiboard B (19) connect without circuit between, but use parallel distributed combination, carry out respectively Power convert in vertical cable transmitting procedure and Obtain real time status information；Earthquake data acquisition board (16) combines (11) and 4 roads of its lower end with 4 road hydrophone of its upper end Hydrophone combination be connected, be responsible for the analog signal sampling of per pass hydrophone combination of transmitted and digital-to-analogue conversion, output is arrived Electron plate B (19).

2. towed marine seismic survey vertical cable data collecting system as claimed in claim 1, it is characterised in that initial and end work Per pass hydrophone combination (11) in the section of work (4,6)) use the equidistant differential weights combination being made up of 16 hydrophone (12), water is listened (element interval of 12 is 0.3m to device, being designed as of employing flexible strategy: 1,2,3,4,3,2,1.

3. towed marine seismic survey vertical cable data collecting system as claimed in claim 1, it is characterised in that at initial and end Also increase between active section (4,6) and have one or more active section (21), described active section (21) and initial and end active section (4, 6) structure is identical；It is provided with 8 road digital packets (5), tail active section (6) between first active section (4) and adjacent active section (21) And it is provided with (8) road digital packets (5) between adjacent active section (21), when increase has multiple active section (21), adjacent two 8 road digital packets (5) it also are provided with between individual active section (21)；This 8 road digital packets (5) by 56 pin cable connectors respectively with position 8 road hydrophone combination (11) Xia tetra-roads of side, 8 hydrophone combination (11) Shang tetra-roads, road of being disposed below are connected thereon Connect, thus continuous print analogue signal is converted into discrete digital signal, it is achieved that the digitized of cable, and to achieve vertically The extension of cable.