CN106567706B - Interwell stratum parameter information acquisition system based on phase identification - Google Patents

Abstract

The invention discloses an interwell stratum parameter information acquisition system based on phase identification, which comprises a ground transmitting subsystem, a ground receiving subsystem, a wireless communication module for realizing clock synchronization of the ground transmitting subsystem and the ground receiving subsystem, an underground transmitting subsystem, an underground receiving subsystem and an underground clock module, wherein the underground transmitting subsystem, the underground receiving subsystem and the underground clock module respectively return time information and send acquisition pulses. The ground transmitting subsystem and the ground receiving subsystem are used for respectively transmitting clock information to the underground transmitting subsystem and the underground receiving subsystem. And the downhole clock module marks the time of the acquired pulse according to the clock information. And the ground transmitting subsystem and the ground receiving subsystem respectively calculate transmission delay according to the time information, and simultaneously carry out phase identification on a received signal and a transmitted signal at the same moment according to the transmission delay and the time mark so as to obtain the information of the interwell stratum parameters through inversion.

Description

A system for obtaining interwell formation parameter information based on phase identification

technical field

The invention belongs to the related technical field of inter-well electromagnetic logging devices, and more particularly relates to an inter-well formation parameter information acquisition system based on phase identification.

Background technique

Although conventional wireline logging has the advantages of high resolution and accuracy, the measurement scale is small, and the information provided is only a large number of heterogeneous bodies and very limited partial sampling, which cannot accurately describe the reservoir characteristics in a large range around the wellbore . The interwell electromagnetic logging technology is a new logging method developed on the basis of a single well: the transmitter is placed at a fixed position in the launching well to transmit electromagnetic waves (called the transmitted signal) to the formation, and the receiver in the receiving well is placed at a fixed position. Receive electromagnetic waves (referred to as received signals) propagating through the formation at different locations, and the received signals undergo a series of processing to obtain received data. In this way, the measurement of one profile is completed, the position of the transmitter is changed, and the measurement of the next profile is performed. This is repeated until the measurement point covers the entire measurement well section. By inverting the received data, two-dimensional to three-dimensional resistivity imaging reflecting the inter-well reservoir structure and oil and gas distribution can be obtained, so as to directly measure and describe the electrical properties of the inter-well formation, which is the best way to detect the inter-well formation information. and the most direct logging method.

The phase difference between the received signal and the transmitted signal of the interwell electromagnetic logging is closely related to the formation conductivity, which is expressed as

In the formula, r is the straight-line distance between the transmitter and the receiver, z is the distance between the transmitter and the receiver in the Z-axis direction of the space rectangular coordinate system, and P is the propagation coefficient, which can be expressed as

In the formula, ω=2πf, f is the frequency of the transmitted signal, μ is the magnetic permeability, and σ is the formation conductivity. In order to accurately calculate the inter-well formation conductivity distribution, it is necessary to identify the phase of the transmitted signal and the received signal. In actual logging, the phase identification is performed by comparing the transmitted signal and the received signal at the same time, and then the inter-well formation parameter information is obtained by inversion; if the transmitted signal corresponding to the phase identification and the received signal are not at the same time, the calculated conductance The accuracy of the rate distribution is poor and has no practical reference significance. However, most of the phase identification of the received signal and the transmitted signal cannot be guaranteed to be performed at the same time. Correspondingly, there exists in the art to develop an inter-well formation parameter information acquisition system capable of phase identification of the transmitted signal and the received signal at the same time.

SUMMARY OF THE INVENTION

In view of the above defects or improvement needs of the prior art, the present invention provides a phase identification-based inter-well formation parameter information acquisition system, which is based on the working characteristics of inter-well electromagnetic logging, and is designed for the inter-well formation parameter information acquisition system. design. The analysis and calculation of the inter-well formation parameter information acquisition system are all completed in the ground transmitting subsystem and the ground receiving subsystem, and the ground personnel can monitor in real time; the ground transmitting subsystem and the ground receiving subsystem respectively calculate the The transmission delay and the transmission delay in the receiving well; the downhole clock module time stamps the acquisition pulse; through the time stamp, the transmitter and the receiver can be respectively found in the acquisition pulse output by the downhole transmitter subsystem and the downhole receiver subsystem. The rising edge of the terminal at the same time can be compared with the transmitted signal and the received signal at this time, and the phase identification of the transmitted signal and the received signal at the same time can be realized, and then the distribution of formation conductivity between wells can be calculated. The structure is simple and the accuracy is high. It has practical reference significance.

In order to achieve the above purpose, the present invention provides a phase identification-based interwell formation parameter information acquisition system, which includes a wireless communication module, a ground transmitter subsystem, a ground receiver subsystem, and downhole transmitters housed in the transmitter well and the receiver well, respectively. The subsystem, the downhole receiving subsystem and the downhole clock module are characterized by:

The wireless communication module is used to realize clock synchronization between the ground transmitting subsystem and the ground receiving subsystem;

The ground transmitting subsystem and the ground receiving subsystem are configured to transmit clock information to the downhole transmitting subsystem and the downhole receiving subsystem respectively after synchronizing local clocks;

The downhole transmitting subsystem and the downhole receiving subsystem are respectively used for receiving the clock information and returning time information to the ground transmitting subsystem and the ground receiving subsystem. At the same time, the downhole transmitting subsystem and The downhole receiving subsystem respectively sends out acquisition pulses;

The downhole clock module is used to receive the clock information, and time stamp the acquisition pulses sent by the downhole transmitting subsystem and the downhole receiving subsystem according to the clock information, even if the received signal and the transmitted signal are separate. has a corresponding time scale;

The ground transmitting subsystem and the ground receiving subsystem are also respectively used to calculate the transmission delay in the transmitting well and the transmission delay in the receiving well according to the received time information. The transmission delay and the time scale process the received signal and the transmitted signal, so as to realize the phase identification of the transmitted signal and the received signal at the same time, and then invert to obtain the formation parameters between wells information.

Further, the system for acquiring formation parameter information between wells further includes a cable, and the ground transmitting subsystem and the ground receiving subsystem are respectively connected to the downhole transmitting subsystem and the downhole receiving subsystem through the cable.

Further, the number of the wireless communication modules is two, and the two wireless communication modules are adjacent to the ground transmitting subsystem and the ground receiving subsystem, respectively, and are arranged at intervals.

Further, the wireless communication module is a radio frequency smart card.

Further, the number of the downhole clock modules is two, and the two downhole clock modules are located in the transmitting well and the receiving well, respectively, and are respectively connected to the downhole transmitting subsystem and the Downhole receiving subsystem.

In general, compared with the prior art through the above technical solutions conceived by the present invention, the phase identification-based interwell formation parameter information acquisition system provided by the present invention, its analysis and calculation are performed in the ground transmitting subsystem and the ground receiving subsystem. After completion, the ground personnel can monitor in real time; the ground transmitting subsystem and the ground receiving subsystem respectively calculate the transmission delay in the transmitting well and the transmission delay in the receiving well; the downhole clock module time stamps the acquisition pulse; The time scale can be found in the acquisition pulses output by the downhole transmitting subsystem and the downhole receiving subsystem, respectively, to find the rising edge of the transmitting end and the receiving end at the same time. The phase identification of the signal and the received signal is used to calculate the distribution of the formation conductivity between the wells. The structure is simple and the accuracy is high.

Description of drawings

FIG. 1 is a schematic diagram of the application of a system for obtaining inter-well formation parameter information based on phase identification provided by a preferred embodiment of the present invention.

FIG. 2 is a schematic diagram of the transmission delay between the receiving end and the transmitting end of the phase identification-based inter-well formation parameter information acquisition system in FIG. 1 .

FIG. 3 is a schematic diagram of the processing of marking time information by the ground transmitting subsystem and the ground receiving subsystem of the phase identification-based inter-well formation parameter information acquisition system in FIG. 1 .

In all the drawings, the same reference numerals are used to denote the same elements or structures, wherein: 1-wireless communication module, 2-ground transmitting subsystem, 3-ground receiving subsystem, 4-cable, 5-downhole transmitting Subsystem, 6-downhole receiving subsystem, 7-downhole clock module.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

Referring to FIGS. 1 to 3 , a system for obtaining inter-well formation parameter information based on phase identification provided by a preferred embodiment of the present invention utilizes time synchronization to realize phase identification of a transmitted signal and a received signal. The interwell formation parameter information acquisition system includes a wireless communication module 1 , a ground transmitting subsystem 2 , a ground receiving subsystem 3 , a cable 4 , a downhole transmitting subsystem 5 , a downhole receiving subsystem 6 and a downhole clock module 7 . In this embodiment, the number of the wireless communication modules 1 is two, and the two wireless communication modules 1 are adjacent to the ground transmitting subsystem 2 and the ground receiving subsystem 3 respectively, and the two are arranged at intervals; The wireless communication module 1 may be ZigBee (low power consumption personal area network protocol), a radio frequency smart card, or the like.

The downhole transmitting subsystem 5 and the downhole receiving subsystem 6 are respectively arranged in the transmitting well and the receiving well, and both are connected to the ground transmitting subsystem 2 and the ground receiving subsystem 3 through the cable 4 respectively. . In this embodiment, the number of the downhole clock modules 7 is two, and the two downhole clock modules 7 are located in the transmitting well and the receiving well, respectively, and are respectively connected to the downhole transmitters. System 5 and said downhole receiving subsystem 6 .

The wireless communication module 1 is used for data transmission between the ground transmitting subsystem 2 and the ground receiving subsystem 3 to realize clock synchronization between the ground transmitting subsystem 2 and the ground receiving subsystem 3 .

After synchronizing local clocks, the ground transmitting subsystem 2 and the ground receiving subsystem 3 respectively send clock information to the downhole transmitting subsystem 5 and the downhole receiving subsystem 6 through the cable 4 . The surface transmitter subsystem 2 and the surface receiver subsystem 3 respectively receive the time information returned by the downhole transmitter subsystem 5 and the downhole receiver subsystem 6, and calculate the transmission in the launch shaft (surface to downhole) Delay and transmission delay in the receiving well (surface to downhole). At the same time, the ground transmitting subsystem 2 and the ground receiving subsystem 3 respectively process the transmitting signal and the receiving signal according to the transmission delay obtained by calculation, so as to realize the transmitting signal and the receiving signal at the same time. Phase identification of the signal.

The downhole transmitting subsystem 5 and the downhole receiving subsystem 6 are respectively used to receive the clock information sent by the ground transmitting subsystem 2 and the ground receiving subsystem 3 and send back time information. The subsystem 5 and the downhole emission subsystem 6 output acquisition pulses. In this embodiment, after receiving the clock information, the downhole transmitting subsystem 5 and the downhole receiving subsystem 6 generate acquisition pulses through frequency division of a high-frequency crystal oscillator according to the clock information shown.

The two downhole clock modules 7 are respectively used to receive the clock information sent by the ground transmitter subsystem 2 and the ground receiver subsystem 3, and to update the downhole transmitter subsystem 5 and all the clock information according to the clock information. The acquisition pulse output by the downhole receiving subsystem 6 is time-marked, so that each rising edge of the pulse has a corresponding time scale, even if the received signal and the transmitted signal are marked with a time scale. The ground transmitting subsystem 2 and the ground receiving subsystem 3 process the received signal and the transmitted signal according to the transmission delay and the time scale obtained by calculation, so as to process the transmitted signal at the same time. The signal and the received signal are phase marked.

When the inter-well formation parameter information acquisition system works, firstly, the wireless communication module 1 realizes the clock synchronization between the ground transmitting subsystem 2 and the ground receiving subsystem 3; secondly, the ground transmitting subsystem 2 and the ground receiving subsystem 3 respectively transmit the clock information to the downhole transmitting subsystem 5, the downhole receiving subsystem 6 and the downhole clock module 7 through the cable 4; The system 5 and the downhole receiving subsystem 6 respectively receive the clock information from the ground transmitting subsystem 2 and the ground receiving subsystem 3, and return time information to the ground transmitting subsystem 2 and the ground receiving subsystem 3. The ground receiving subsystem 3, at the same time, the downhole transmitting subsystem 5 and the downhole receiving subsystem 6 output acquisition pulses respectively, and the downhole clock module 7 receives the clock information, and according to the clock information The acquisition pulses output by the transmitting subsystem 5 and the downhole receiving subsystem 6 are time-marked, so that the rising edge of each pulse has a corresponding time scale; finally, the ground transmitting subsystem 2 and the ground receiving subsystem 3 The transmission delay of the transmitting well and the transmission delay of the receiving well are calculated respectively according to the received time information. At the same time, the ground transmitting subsystem 2 and the ground receiving subsystem 3 The transmission delay and the time scale are used to process the received signal and the transmitted signal, so as to realize the phase identification of the transmitted signal and the received signal at the same time.

Specifically, on the basis that the ground local clock has been synchronized, set the ground time as T, the transmission delay of the launch silo measured by the ground transmitter subsystem 2 is Δt', and the ground receiver subsystem 3 measured the The transmission delay of the receiving well is Δt", and it is assumed that Δt=Δt"-Δt'; the downhole transmitting subsystem 5 is T0 after the delay Δt', and the downhole receiving subsystem 6 is after the delay. The time after Δt" is T1, then the ground launch subsystem 2 can find the same time as T1 in the acquisition pulse generated in the launch silo after calculating T0 and T1, that is, T0+Δt, at this time T0+ Δt is taken as the starting time, discarding the transmitted signal and the received signal before this time, and retaining and comparing the transmitted signal and the received signal after this time, so that the transmission signal and the received signal at the same time can be compared. The phase identification of the received signal is then used to invert and calculate the corresponding conductivity distribution.

In the phase identification-based interwell formation parameter information acquisition system provided by the present invention, the analysis and calculation are completed in the ground transmitter subsystem and the ground receiver subsystem, and the ground personnel can monitor in real time; the ground transmitter subsystem and the ground receiver subsystem can be monitored in real time; The system calculates the transmission delay in the launch well and the transmission delay in the receiving well respectively; the downhole clock module marks the acquisition pulse; through the time stamp, the acquisition pulse output by the downhole transmitting subsystem and the downhole receiving subsystem can be Find the rising edge of the transmitting end and the receiving end at the same time, and compare the transmitting signal and the receiving signal at this time, so as to realize the phase identification of the transmitting signal and the receiving signal at the same time, and then calculate the distribution of the formation conductivity between wells, the structure Simple and accurate.

Those skilled in the art can easily understand that the above are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention, etc., All should be included within the protection scope of the present invention.

Claims (4)

1. The utility model provides an interwell stratum parameter information acquisition system based on phase place sign, its includes wireless communication module (1), ground emission subsystem (2), ground receiving subsystem (3), respectively accept in the well emission subsystem (5) in the pit of emission well and receiving well, receive subsystem (6) in the pit and clock module (7) in the pit, its characterized in that:

the wireless communication module (1) is used for realizing clock synchronization between the ground transmitting subsystem (2) and the ground receiving subsystem (3);

the ground transmitting subsystem (2) and the ground receiving subsystem (3) are used for respectively transmitting clock information to the underground transmitting subsystem (5) and the underground receiving subsystem (6) after synchronizing a local clock;

the underground transmitting subsystem (5) and the underground receiving subsystem (6) are respectively used for receiving the clock information and returning time information to the ground transmitting subsystem (2) and the ground receiving subsystem (3), and meanwhile, the underground transmitting subsystem (5) and the underground receiving subsystem (6) respectively send out acquisition pulses;

the downhole clock module (7) is used for receiving the clock information and marking the acquisition pulses sent by the downhole transmitting subsystem (5) and the downhole receiving subsystem (6) with time marks according to the clock information, namely, the received signals and the transmitted signals respectively have corresponding time scales;

the ground transmitting subsystem (2) and the ground receiving subsystem (3) are respectively used for calculating transmission delay in the transmitting well and transmission delay in the receiving well according to the received time information, and processing the receiving signal and the transmitting signal according to the transmission delay and the time scale so as to realize phase identification of the transmitting signal and the receiving signal at the same moment and further invert to obtain interwell stratum parameter information; the wireless communication module (1) is a radio frequency smart card;

the time mark is used for respectively finding the rising edge of the transmitting end and the receiving end at the same moment in the acquisition pulse output by the underground transmitting subsystem (5) and the underground receiving subsystem (6), and comparing the transmitting signal and the receiving signal at the moment, so that the phase identification of the transmitting signal and the receiving signal at the same moment can be realized.

2. The phase identification based interwell formation parameter information acquisition system of claim 1, wherein: the system for acquiring the parameter information of the interwell stratum further comprises a cable (4), and the ground transmitting subsystem (2) and the ground receiving subsystem (3) are connected to the underground transmitting subsystem (5) and the underground receiving subsystem (6) through the cable (4) respectively.

3. The phase identification based interwell formation parameter information acquisition system of claim 1, wherein: the number of the wireless communication modules (1) is two, the two wireless communication modules (1) are respectively adjacent to the ground transmitting subsystem (2) and the ground receiving subsystem (3), and the two wireless communication modules are arranged at intervals.

4. The phase identification based interwell formation parameter information acquisition system of claim 1, wherein: the number of the underground clock modules (7) is two, the two underground clock modules (7) are respectively positioned in the transmitting well and the receiving well, and the two underground clock modules are respectively and correspondingly connected to the underground transmitting subsystem (5) and the underground receiving subsystem (6).

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