Resistivity logging system based on transient electromagnetics

Abstract

A resistivity logging system based on transient electromagnetics. The system comprises: a measuring instrument (101), which is used for simultaneously measuring a logging curve with a flaw detection function and a logging curve with a through-casing resistivity measurement function by means of a transient electromagnetic method when the instrument reaches a well depth position; a transmission module (102), which is used for transmitting casing and formation measurement information to the surface; and a surface module (103), which is used for receiving and parsing the casing and formation measurement information. The system provides a high-capacity data channel with a stable performance, and simultaneously completes casing resistivity measurement and casing damage detection in steel-cased production wells.

Description

A transient electromagnetic resistivity logging system TECHNICAL FIELD

[0001] The present application relates to the technical field of casing production well logging, in particular to a transient electromagnetic resistivity logging system. BACKGROUND

[0002] The transient electromagnetic method is a method of using a transmitting coil to emit a primary pulse magnetic field, using a receiving coil to observe a secondary eddy current field during the intermittent period of the primary pulse magnetic field, recording the change characteristics of the secondary field voltage signal over time, extracting the electrical information of the surrounding medium, and finally obtaining the formation resistivity. In the implementation process of the production well, the transmitted waveform is a bipolar rectangular wave, and a steady-state primary magnetic field is established in the casing and the formation during the pulse transmission period. During the transmission interval, the primary magnetic field disappears, and eddy currents are generated in the casing and the formation. With the increase of time, the eddy current consumes as a kind of heat energy and finally disappears. Measuring the change characteristics of the eddy current secondary field over time can further extract the formation resistivity information, thereby realizing the casing resistivity logging.

[0003] The secondary field waveform received by the transient electromagnetic casing resistivity logging instrument is a time spectrum curve. During the entire receiving time period, the early waveform has a large amplitude and is easy to be measured by the observation system; the late waveform has a small amplitude, and the effective signal superimposed noise signal gradually becomes the main received information with the extension of time, and the effective signal is gradually buried by the noise signal, so it is not easy to be measured by the observation system. Since the formation information is distributed in the entire receiving time period, in order to meet the needs of late data mining and data interpretation, it is necessary to collect the full spectrum of the transient electromagnetic downhole instrument, so that the amount of downhole logging data is large.

[0004] For conventional cable logging downhole measuring instruments, such as pulse counting type gamma logging data, the data amount is usually only a few bytes; for energy spectrum type or wave train type, such as lithology density spectrum or acoustic logging data, the data amount is generally several hundred bytes; and for the transient electromagnetic resistivity logging instrument, one measurement point at one logging depth includes multiple logging curves, and the logging data amount can reach thousands of bytes. The conventional cable logging data transmission system cannot effectively transmit such a large amount of data.

[0005] In addition, when performing transient electromagnetic resistivity detection in a casing well, the steel pipe wall of the casing well has a large attenuation effect on the electromagnetic signal. In order to obtain a high signal-to-noise ratio and make the transmitted signal penetrate the pipe wall and reach the formation, a large transmission power is required, which is also beyond the capability of the conventional cable logging data transmission system.

[0006] Therefore, the prior art not only cannot realize the uplink transmission of the transient electromagnetic resistivity curve through cable logging, but also cannot simultaneously obtain the casing resistivity and flaw detection resistivity curves measured based on the transient electromagnetic method. SUMMARY

[0007] The present application aims to provide a data transmission technology for resistivity logging instruments implemented in production wells, to achieve long-distance, large-capacity and high-speed communication of downhole data, to transmit logging data measured by various downhole instruments to the ground in real time and to perform logging interpretation and display, so as to solve the problems in the background art.

[0008] To solve the above technical problems, the present application provides a transient electromagnetic resistivity logging system, comprising: a measuring instrument for measuring logging curves with a flaw detection function and logging curves with a through-casing resistivity measurement function; a transmission module for transmitting casing and formation measurement information to the ground; and a ground module for receiving and analyzing the casing and formation measurement information.

[0009] Preferably, the measuring instrument comprises at least one detection instrument for transmitting bipolar rectangular waves and receiving two-way receiving signals detected respectively at different pulse transmission intervals, obtaining flaw detection logging curves by subtractively processing the two-way receiving signals, and obtaining resistivity measurement logging curves by additively processing the two-way receiving signals.

[0010] Preferably, the measuring instrument comprises: a shallow detection instrument comprising a set of shallow transmitting coils and two sets of shallow receiving coils, for transmitting bipolar rectangular waves by the shallow transmitting coils, and obtaining first flaw detection logging curves and first resistivity measurement logging curves by the first shallow receiving coil and the second shallow receiving coil respectively detected at forward pulse transmission intervals, and obtaining second flaw detection logging curves and second resistivity measurement logging curves by the first shallow receiving coil and the second shallow receiving coil respectively detected at reverse pulse transmission intervals; and / or a deep detection instrument comprising two sets of deep transmitting coils and two sets of deep receiving coils, for transmitting bipolar rectangular waves by the deep transmitting coils, and obtaining third flaw detection logging curves and third resistivity measurement logging curves by the first deep receiving coil and the second deep receiving coil respectively detected at forward pulse transmission intervals, and obtaining fourth flaw detection logging curves and fourth resistivity measurement logging curves by the first deep receiving coil and the second deep receiving coil respectively detected at reverse pulse transmission intervals.

[0011] Preferably, the first shallow receiving coil, the second shallow receiving coil, the first deep receiving coil and the second deep receiving coil are all coil groups with comparative winding, wherein the shallow detection instrument is configured to detect a first near receiving signal and a second near receiving signal by two sub-coils in the first shallow receiving coil respectively during a forward / reverse pulse transmission interval, so as to obtain the first / probe detection well curve by subtracting the first near receiving signal from the second near receiving signal, and detect a third near receiving signal and a fourth near receiving signal by two sub-coils in the second shallow receiving coil respectively during the forward / reverse pulse transmission interval, so as to obtain the first / second resistivity measurement well curve by adding the third near receiving signal and the fourth near receiving signal; the deep detection instrument is configured to detect a first far receiving signal and a second far receiving signal by two sub-coils in the first deep receiving coil respectively during the forward / reverse pulse transmission interval, so as to obtain the third / fourth probe detection well curve by subtracting the first far receiving signal from the second far receiving signal, and detect a third far receiving signal and a fourth far receiving signal by two sub-coils in the second deep receiving coil respectively during the forward / reverse pulse transmission interval, so as to obtain the third / fourth resistivity measurement well curve by adding the third far receiving signal and the fourth far receiving signal.

[0012] Preferably, the second shallow receiving coil, the first deep receiving coil and the second deep receiving coil are internally provided with magnetic cores; the duty ratio of the transmission pulse width to the transmission interval time is 1:1, wherein the forward pulse transmission width and the reverse pulse transmission width are T / 4, T representing a measurement period; and there are a plurality of time channel curve sampling points in a time period during the transmission interval of the measurement instrument.

[0013] Preferably, the near detection instrument further comprises a near signal processing unit corresponding to the first shallow receiving coil and the second shallow receiving coil, and the far detection instrument further comprises a far signal processing unit corresponding to the first deep receiving coil and the second deep receiving coil, wherein the near signal processing unit / far signal processing unit is configured to, after obtaining the receiving signals of the sub-coils, sequentially sample, add or subtract, amplify and digital-analog convert the receiving signals of a corresponding pair of sub-coils to obtain a corresponding well curve.

[0014] Preferably, the transmission module is further configured to connect with the measuring instrument through a first type of bus, integrate the inspection logging curve and the resistivity measurement logging curve to obtain casing and formation measurement information, and convert the casing and formation measurement information from the first type of bus communication mode to a second type of bus communication mode, so as to transmit the casing and formation measurement information to the ground through the second type of bus.

[0015] Preferably, the first type of bus is a CAN bus, and the transmission speed of the CAN bus is not less than 800 Kbps; and the second type of bus is an AMI bus, and the transmission speed of the AMI bus is not less than 100 Kbps.

[0016] Preferably, the transmission module comprises: a well depth associated feature acquisition unit configured to acquire associated features at a current well depth position, including casing well liquid temperature, casing coupling magnetic positioning and casing outer formation gamma value; a first bus mode packaging unit configured to package the shallow inspection complete package and / or the deep inspection complete package and the associated features into a first bus mode complete data stream; a mode conversion unit configured to convert the first bus mode complete data stream into a second bus mode data stream; and a second bus mode packaging unit configured to package the second bus mode data stream and transmit the packaged second bus mode packaged data stream to the ground through a second bus.

[0017] Preferably, the measuring instrument further comprises: a measuring instrument packaging unit configured to individually package the inspection logging curve and the resistivity measurement logging curve according to the number of curves, respectively, and package the logging curves of the shallow inspection instrument into the shallow inspection complete package and / or package the logging curves of the deep inspection instrument into the deep inspection complete package.

[0018] Preferably, the measuring instrument packaging unit is further configured to transmit the shallow inspection complete package and / or the deep inspection complete package to the transmission module through a frame packet in a timing mode, wherein the first bus is in an idle state after transmitting a standard frame packet until the next standard frame packet is transmitted.

[0019] Preferably, the second bus mode packaging unit is configured to transmit the second bus mode packaged data stream containing logging data in a data frame format, and each second bus data frame contains a data header, a data bit, a check bit and an end bit, wherein the data bit can package 4 bytes of logging data, and the second bus is not idle during continuous transmission of data frames.

[0020] Preferably, the first type of bus is a CAN bus, and the transmission speed of the CAN bus is not less than 800 Kbps; and the second type of bus is an AMI bus, and the transmission speed of the AMI bus is not less than 100 Kbps.

[0021] Preferably, the ground module comprises: a ground panel module for decoding the casing and formation measurement information to obtain standard logging data, and combining the standard logging data with the corresponding correlation features at different logging depths or logging times to form record standard logging data; a data processing module connected with the ground panel module through a third bus, for realizing display of current logging information, formation interpretation and oil well analysis and evaluation according to the record standard data.

[0022] Preferably, the second bus is a seven-core cable, wherein the middle core is used as a signal transmission line, and the surrounding six cores are used as power lines, the six power lines include two groups of first power supply groups with a first direct current voltage and a group of second power supply groups with a second direct current voltage, one group of power supply groups includes two power lines, the first power supply groups are used for providing power supply for the measuring instrument, the second power supply groups are used for providing power supply for the transmission module, and the first direct current voltage is higher than the second direct current voltage.

[0023] Preferably, in each group of power supply groups, the cable core of the power line is used as the positive pole of the corresponding power supply group, and the steel outer sheath of the power line is used as the negative pole of the corresponding power supply group.

[0024] Compared with the prior art, one or more embodiments in the above scheme can have the following advantages or beneficial effects:

[0025] The application provides a transient electromagnetic resistivity logging system. The transient electromagnetic resistivity logging instrument is used for measuring and calculating the formation resistivity in a cased well, and has higher accuracy. The measured data is transmitted to the ground in real time, and accurate resistivity measurement values are provided for subsequent reservoir saturation calculation. In addition, the transient electromagnetic resistivity logging instrument adopts a comparative receiving electromagnetic probe, uses the received waveform in a period of time to describe the resistivity, and significantly improves the utilization rate of the measured original signal. Meanwhile, by increasing the number of transmitting coils and receiving coils and by different combinations of the transmitting coils and the receiving coils, a large amount of logging data can be obtained. When the data is analyzed on the ground, resistivity logging curves of two different detection depths, i.e., near detection and far detection, can be provided simultaneously, and cased hole resistivity measurement and casing damage detection can be completed simultaneously.

[0026] In addition, since the logging data generated by the transient electromagnetic resistivity logging instrument has a large amount of information, the capacity is particularly large, and the capacity of each depth measurement point has reached nearly 5000 bytes, which is far beyond the data transmission capacity of the conventional casing logging, and the transient electromagnetic resistivity logging data transmission system of the present application forms a data stream suitable for different data transmission modes by reasonably setting the ground, transmission and downhole three modules, constructs the CAN bus and AMI bus, and provides a stable large-capacity data channel by designing different data transmission cycles, synchronizing the data communication between the modules and setting the cable power supply mode, etc., which provides a strong guarantee for the real-time and accurate uploading of massive data.

[0027] In addition, in order to not lose valuable logging data, the storage logging instrument has to temporarily store in the large-capacity downhole memory, and after the measurement is completed, the instrument is taken to the ground to play back the data, but increasing the downhole memory also means that more circuit space and circuit design difficulty need to be increased, which causes greater logging risk in the harsh high temperature and high pressure downhole operation environment, the transient electromagnetic resistivity logging data transmission system of the present application utilizes the large-capacity cache of the downhole instrument itself, and simultaneously utilizes the stable and reliable data transmission channel and the ground interpretation software, so that the downhole measurement data can be extracted and displayed in real time according to the set mode, which significantly releases the storage space of the downhole information, reduces the hardware cost and the logging risk caused thereby.

[0028] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the present application. The objects and other advantages of the present application can be realized and achieved by the structure particularly pointed out in the specification, claims and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0029] The accompanying drawings are included to provide a further understanding of the present application, and constitute a part of the specification, illustrate the embodiments of the present application, and are used to explain the present application together with the embodiments of the present application, and do not constitute a limitation on the present application. In the drawings:

[0030] Fig. 1 is a schematic diagram of the overall structure of the transient electromagnetic resistivity logging system according to the embodiment of the present application.

[0031] Fig. 2 is a schematic diagram of the detailed structure of the transient electromagnetic resistivity logging system according to the embodiment of the present application.

[0032] Fig. 3 is a data encapsulation principle diagram of the specific structure of the transient electromagnetic resistivity logging system according to the embodiment of the present application.

[0033] Fig. 4 is a data encapsulation principle diagram between the single resistivity detection instrument and the transmission module in the transient electromagnetic resistivity logging system according to the embodiment of the present application.

[0034] Fig. 5 is a schematic diagram of a principle of generating a CAN mode complete data stream in the transient electromagnetic resistivity logging system according to the embodiment of the present application.

[0035] Fig. 6 is a schematic diagram of a principle of generating two time spectral logging curves in one receiving period by a single probe instrument in the transient electromagnetic resistivity logging system according to the embodiment of the present application.

[0036] Fig. 7 is a schematic diagram of a principle of data encapsulation of a single probe instrument in the transient electromagnetic resistivity logging system according to the embodiment of the present application.

[0037] Fig. 8 is a schematic diagram of a principle of data encapsulation of a measuring instrument in the transient electromagnetic resistivity logging system according to the embodiment of the present application.

[0038] Fig. 9 is a schematic diagram of time spectral logging curves generated in a unit measuring period and a unit receiving period in the transient electromagnetic resistivity logging system according to the embodiment of the present application.

[0039] Fig. 10 is a schematic diagram of time spectral logging curves based on time traces in the transient electromagnetic resistivity logging system according to the embodiment of the present application.

[0040] Fig. 11 is a schematic diagram of a principle of forming time spectral logging curves based on time traces in the transient electromagnetic resistivity logging system according to the embodiment of the present application.

[0041] Fig. 12 is a schematic diagram of a frame packet transmission mode timing and a standard frame format of a CAN bus in the transient electromagnetic resistivity logging system according to the embodiment of the present application.

[0042] Fig. 13 is a schematic diagram of a frame packet transmission mode timing of an AMI bus in the transient electromagnetic resistivity logging system according to the embodiment of the present application.

[0043] Fig. 14 is a schematic diagram of a data transmission timing in the transient electromagnetic resistivity logging system according to the embodiment of the present application.

[0044] Fig. 15 is a schematic diagram of a module structure of a surface module in the transient electromagnetic resistivity logging system according to the embodiment of the present application.

[0045] Fig. 16 is a schematic diagram of an armored cable structure of an AMI bus in the transient electromagnetic resistivity logging system according to the embodiment of the present application. DETAILED DESCRIPTION

[0046] The embodiments of the present application will be described in detail hereinafter, with reference to the drawings and examples, so that the technical means by which the present application solves the technical problems and achieves the technical effects can be fully understood and implemented. It should be noted that, unless there is a conflict, each embodiment in the present application and each feature in each embodiment can be combined with each other, and the technical solutions formed thereby are within the protection scope of the present application.

[0047] In addition, the steps shown in the flowchart of the drawings can be executed in a computer system such as a set of computer-executable instructions. Moreover, although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that here.

[0048] The terms used herein are merely used to describe specific embodiments and are not intended to limit exemplary embodiments. Unless the context clearly indicates otherwise, as used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well. It will be further understood that the terms "comprises" and / or "comprising," when used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0049] The transient electromagnetic method is a method of transmitting a primary pulse magnetic field by a transmitting coil, observing a secondary eddy current field during an intermittent period of the primary pulse magnetic field by a receiving coil, extracting electrical information of a surrounding medium by recording the change characteristics of the secondary field voltage signal over time, and finally obtaining the formation resistivity. In the production well implementation process, the transmitted waveform is a bipolar rectangular wave, and a steady-state primary magnetic field is established in the casing and the formation during the pulse transmission period. During the transmission interval, the primary magnetic field disappears, and eddy currents are generated in the casing and the formation. With the increase of time, the eddy current consumes as a kind of heat energy and finally disappears. By measuring the change characteristics of the eddy current secondary field over time, the formation resistivity information can be further extracted, so as to realize the through-casing resistivity logging.

[0050] The secondary field waveform received by the transient electromagnetic through-casing resistivity logging instrument is a time spectrum curve. In the entire receiving time period, the early waveform has a large amplitude and is easy to be measured by the observation system; the late waveform has a small amplitude, and the effective signal superimposed noise signal gradually becomes the main received information with the continuation of time, and the effective signal is gradually buried by the noise signal, so it is not easy to be measured by the observation system. Since the formation information is distributed in the entire receiving time period, in order to meet the needs of late data mining and data interpretation, the full spectrum of the transient electromagnetic downhole instrument is usually collected, and thus the amount of downhole logging data is large.

[0051] For the downhole measuring instrument of conventional cable logging, for example, the gamma logging data of pulse counting type, the data amount is usually only several bytes; for the spectral type or wave train type, for example, the lithology density spectrum or acoustic logging data, the data amount is generally several hundred bytes; and for the transient electromagnetic resistivity logging instrument, one measuring point at one logging depth contains multiple logging curves, and the logging data amount can reach thousands of bytes, and the conventional cable logging data transmission system is difficult to effectively transmit such a huge data amount.

[0052] In addition, when the transient electromagnetic resistivity detection is performed in the cased well, the steel pipe wall of the cased well has a large attenuation effect on the electromagnetic signal, and in order to obtain a higher signal-to-noise ratio, a larger transmission power is required to make the transmitted signal penetrate the pipe wall and reach the formation, which is also unable to be completed by the conventional cable logging data transmission system.

[0053] In order to solve the problems of the prior art, the embodiment of the present application proposes a transient electromagnetic resistivity logging system. The system comprises a ground module, a transmission module and a downhole measuring instrument module, wherein the high-speed AMI mode transmission is adopted between the ground module and the transmission module, and the high-speed CAN mode transmission is adopted between the transmission module and the downhole measuring instrument module. The present application can not only measure the resistivity change of the formation outside the well casing, but also measure the damage of the well casing, and at the same time, the measured logging data is transmitted to the ground in a cable mode at a high speed, the transmission distance can reach more than 5000 meters, the average transmission rate reaches 100 Kbps, at least two sets of resistivity logging instrument measurement data can be transmitted at the same time, and the demand of logging is met.

[0054] Fig. 1 is a schematic diagram of the overall structure of the transient electromagnetic resistivity logging system according to the embodiment of the present application. As shown in Fig. 1, the resistivity logging system according to the embodiment of the present application comprises a measuring instrument 101, a transmission module 102 and a ground module 103. The measuring instrument 101 and the transmission module 102 are arranged downhole. The ground module 103 is arranged at the ground end. The transmission module 102 is connected with the measuring instrument 101 through a first type bus 104. The ground module 103 is connected with the transmission module 102 through a second type bus 105.

[0055] The measuring instrument 101 is used to lower the cable to the corresponding well depth position through the logging winch, and simultaneously measure the (transient electromagnetic resistivity) logging curve with the flaw detection function and the (transient electromagnetic resistivity) logging curve with the through-casing resistivity measurement function through the transient electromagnetic method.

[0056] The transmission module 102 is used to transmit casing and formation measurement information to the surface. In one embodiment, the transmission module 102 integrates the flaw detection logging curve and the (through-casing) resistivity measurement logging curve to obtain casing and formation measurement information, and converts the casing and formation measurement information from a first type of bus communication mode to a second type of bus communication mode, thereby transmitting the converted casing and formation measurement information to the surface via the second type of bus 105. The surface module 103 is used to connect to the transmission module via the second type of bus, and is used to receive and parse the casing and formation measurement information via the second type of bus.

[0057] Overall, the measuring instrument 101 completes the acquisition of well logging data, the transmission module 102 completes the long-distance uploading of well logging data, and the surface module 103 completes the collection and display of well logging data, forming an oil well database, thus providing data support for oil well interpretation and evaluation.

[0058] In this embodiment of the invention, the measuring instrument 101 contains various types of resistivity detection instruments. These instruments utilize transient electromagnetic technology to not only detect the formation outside the casing in the casing well and use the through-casing resistivity measurement logging curve to describe the formation resistivity characteristics along the wellbore direction, but also continuously monitor the environment in the casing and use the flaw detection logging curve to detect casing damage.

[0059] As oilfields undergo development over a period of time, casing damage may occur in oil and water wells. Severe casing deformation and damage can affect the normal production of oil and water wells. Therefore, a comprehensive, accurate, and efficient system is needed to monitor the integrity of casing wells. This system can accurately identify casing deformation, misalignment, bending, porosity, cracks and contamination, as well as casing corrosion or defects, providing accurate information for well workover plans and further ensuring normal oilfield production.

[0060] In one embodiment, the measuring instrument 101 includes at least one detection instrument. The detection instrument has a transmitting mechanism and at least one receiving mechanism. The detection instrument is used to transmit a bipolar rectangular wave and receive two received signals obtained from different pulse transmission intervals (e.g., each receiving mechanism generates two received signals). A flaw detection logging curve is obtained by subtracting these two received signals, and a resistivity measurement logging curve is obtained by adding these two received signals.

[0061] Figure 2 is a detailed structural schematic diagram of the transient electromagnetic resistivity logging system according to an embodiment of this application. As shown in Figure 2, the measuring instrument 101 described in this embodiment includes at least one transient electromagnetic resistivity detection instrument (or "downhole instrument"). Further, the measuring instrument 101 includes a shallow detection instrument 201 and / or a deep detection instrument 202.

[0062] The shallow-probing downhole instrument 201 comprises a set of shallow transmitting coils and two sets of shallow receiving coils with different source distances from the shallow transmitting coils. The source distance between the first shallow receiving coil and the shallow transmitting coil is smaller than the source distance between the second shallow receiving coil and the shallow transmitting coil. The second shallow receiving coil is provided with a magnetic core.

[0063] The deep-probing downhole instrument 202 comprises two sets of deep transmitting coils and two sets of deep receiving coils. The first shallow receiving coil, the second shallow receiving coil, the first deep receiving coil and the second deep receiving coil are all formed by coils with comparative winding. The first deep receiving coil and the second deep receiving coil are both provided with a magnetic core.

[0064] The transmitting distance of the shallow-probing downhole instrument 201 is short, and only the far receiving coil is provided with a magnetic core, so the decay time is short and the received signal amplitude is weak, and the probing depth is shallow. Compared with the shallow-probing downhole instrument 201, the transmitting distance of the deep-probing downhole instrument 202 is far, more magnetic lines are generated, and the two sets of receiving coils are both provided with a magnetic core, so the received signal amplitude is large and the probing depth is deep.

[0065] Because the structure of the deep-probing downhole instrument 202 is different from that of the shallow-probing downhole instrument 201, the number of coils, the number of turns, the spacing, the wire diameter, the cross-sectional area and other parameters are different, which leads to the increase of the probing depth of the deep-probing downhole instrument 202, but the design precision, the processing difficulty and the power supply requirement are also increased, which requires higher manufacturing process, high-power power supply system and high maintenance cost. Therefore, in order to balance the factors of the resistivity logging system in terms of manufacturing cost, maintenance cost and power supply demand, the resistivity logging system provided by the embodiment of the present application can separately configure the shallow-probing downhole instrument 201 or the deep-probing downhole instrument 202 according to the requirements of the actual application scene, or can simultaneously configure the shallow-probing downhole instrument 201 and the deep-probing downhole instrument 202.

[0066] When one of the following conditions is met, the deep-probing downhole instrument 202 can be separately configured in the resistivity logging system: 1. When it is necessary to deeply understand the existence of ore bodies in the formation: because if there is a metal ore body far away from the borehole in the formation, deep probing is easier to detect, while shallow probing cannot detect it; 2. When it is necessary to determine the oil-water contact surface in advance: the oil layer in the oil field is displaced by oil and gas through water injection, etc. During the displacement process, there is an oil-water progressive surface, i.e. the contact surface. The resistivity of oil is higher, and the resistivity of water is low, so deep probing is easier to obtain the oil-water progressive surface (compared with shallow probing), which helps geologists understand the oil displacement process and degree, and analyze the remaining oil saturation of the reservoir; 3. When it is necessary to probe a reservoir with large thickness.

[0067] When it is necessary to detect reservoirs with small thickness, the embodiment of the present application can configure the shallow detection downhole instrument 201 in the resistivity logging system alone, so that the later logging interpretation is easier.

[0068] Further, when one of the following conditions is met, the deep detection downhole instrument 202 and the shallow detection downhole instrument 201 need to be configured in the resistivity logging system at the same time: 1. In the case of complex downhole geological conditions and uneven layer thickness distribution of the reservoir, deep detection and shallow detection data are needed to interpret the same reservoir at the same time to increase the accuracy of logging interpretation; 2. In the case of high requirement for fine logging interpretation and no loss of small layers, deep detection and shallow detection instruments are also needed to be shared.

[0069] The transmission module 102 includes a data processing board 203 and an armored cable 204. As shown in FIG. 3, the data processing board 203 in the transmission module 102 further includes: a well depth associated feature acquisition unit 304, a first bus mode packaging unit 305, a mode conversion unit 306, and a second bus mode packaging unit 307.

[0070] The well depth associated feature acquisition unit 304 is used to acquire associated features at the current well depth position, including casing well liquid temperature, casing collar magnetic positioning, and casing outer formation gamma value, and integrate and package each associated feature to form an associated parameter data stream.

[0071] The first bus mode packaging unit 305 is used to integrate and package the shallow detection complete package and / or the deep detection complete package, and the associated parameter data stream, to form a first bus mode complete data stream. Specifically, the first bus mode packaging unit 305 is used to integrate and package the shallow detection complete package and the associated parameter data stream to form a first bus mode complete data stream, or integrate and package the deep detection complete package and the associated parameter data stream to form a first bus mode complete data stream, or integrate and package the shallow detection complete package, the deep detection complete package, and the associated parameter data stream to form a first bus mode complete data stream.

[0072] The mode conversion unit 306 is connected with the first bus mode packaging unit 305, and is used to convert the first bus mode complete data stream output from the first bus mode packaging unit 305 into a second bus mode data stream. The second bus mode packaging unit 307 is connected with the mode conversion unit 306. The second bus mode packaging unit 307 is used to package the second bus mode data stream output from the mode conversion unit 306 to form a second bus mode packaging data stream (i.e. casing and formation measurement information), and transmit the packaged second bus mode packaging data (casing and formation measurement information) stream to the surface module 103 through the second bus 105.

[0073] In the embodiment of the present application, the first type of bus is a high-speed CAN bus, and the second type of bus is a high-speed AMI bus. The transmission speed of the CAN bus is not less than 800 Kbps, and the transmission speed of the AMI bus is not less than 100 Kbps.

[0074] The data processing board 203 is configured to receive the measurement data of the shallow detection downhole instrument 201 and the deep detection downhole instrument 202 in the measurement instrument 101, and convert the data mode of the measurement data into an AMI mode which is easy to be transmitted at a high transmission rate over a long distance, so as to be transmitted to the ground by the armored cable 204.

[0075] The ground module 103 comprises a ground panel module 205 and a data processing module 207. The data processing module 207 is connected with the ground panel module 205 through a third type of bus 206. The third type of bus is a high-speed USB bus.

[0076] The ground panel module 205 is configured to decode the casing and formation measurement information from the AMI bus to obtain standard logging data, and combine the current standard logging data with corresponding (described below) associated features at different logging depths or logging times to form record standard data. The data processing module 207 is configured to realize the display of the current logging information, the formation interpretation and the analysis and evaluation of the oil well according to the record standard data.

[0077] Further, the ground panel module 205 receives the casing and formation measurement information uploaded by the transmission module 102 in the AMI mode through the high-speed AMI bus 105, and performs data processing such as filtering, noise elimination, abnormal point elimination, interpolation and the like, so as to become standard data which is easy to be displayed and read, and then is transmitted to the data processing module 207 through the USB high-speed bus 206 for data display and interpretation analysis. The data processing module 207 comprises data interpretation algorithms such as curve fitting, scale chart and influence factor correction, so as to complete the accurate display of data, the formation interpretation and the oil well evaluation.

[0078] In the embodiment of the present application, the shallow detection downhole instrument 201 is configured to emit a bipolar rectangular wave by the shallow transmitting coil, and detect the first defect detection logging curve and the first resistivity measurement logging curve by the first shallow receiving coil and the second shallow receiving coil respectively during the interval of the forward pulse transmission, and detect the second defect detection logging curve and the second resistivity measurement logging curve by the first shallow receiving coil and the second shallow receiving coil respectively during the interval of the reverse pulse transmission.

[0079] Specifically, the shallow detection downhole instrument 201 is configured to detect, during the forward pulse transmission interval, the first near receiving signal and the second near receiving signal by the two sub-coils in the first shallow receiving coil, so as to obtain the first defect detection well curve after subtracting the current first near receiving signal and the second near receiving signal, and then, during the reverse pulse transmission interval, the first near receiving signal and the second near receiving signal are detected by the two sub-coils in the first shallow receiving coil, so as to obtain the second defect detection well curve after subtracting the current first near receiving signal and the second near receiving signal. Meanwhile, the shallow detection downhole instrument 201 is also configured to detect, during the forward pulse transmission interval, the third near receiving signal and the fourth near receiving signal by the two sub-coils in the second shallow receiving coil, so as to obtain the first resistivity measurement well curve after adding the current third near receiving signal and the fourth near receiving signal, and then, during the reverse pulse transmission interval, the third near receiving signal and the fourth near receiving signal are detected by the two sub-coils in the second shallow receiving coil, so as to obtain the second resistivity measurement well curve after adding the current third near receiving signal and the fourth near receiving signal.

[0080] The deep detection downhole instrument 202 is configured to transmit a bipolar rectangular wave by the deep transmitting coil, and during the forward pulse transmission interval, the third defect detection well curve and the third resistivity measurement well curve are detected by the first deep receiving coil and the second deep receiving coil, respectively, and during the reverse pulse transmission interval, the fourth defect detection well curve and the fourth resistivity measurement well curve are detected by the first deep receiving coil and the second deep receiving coil, respectively.

[0081] Specifically, the deep detection downhole instrument 202 is configured to detect, during the forward pulse transmission interval, the first far receiving signal and the second far receiving signal by the two sub-coils in the first deep receiving coil, so as to obtain the third defect detection well curve after subtracting the current first far receiving signal and the second far receiving signal, and then, during the reverse pulse transmission interval, the first far receiving signal and the second far receiving signal are detected by the two sub-coils in the first deep receiving coil, so as to obtain the fourth defect detection well curve after subtracting the current first far receiving signal and the second far receiving signal. Meanwhile, the deep detection downhole instrument 202 is also configured to detect, during the forward pulse transmission interval, the third far receiving signal and the fourth far receiving signal by the two sub-coils in the second deep receiving coil, so as to obtain the third resistivity measurement well curve after adding the current third far receiving signal and the fourth far receiving signal, and then, during the reverse pulse transmission interval, the third far receiving signal and the fourth far receiving signal are detected by the two sub-coils in the second deep receiving coil, so as to obtain the fourth resistivity measurement well curve after adding the current third far receiving signal and the fourth far receiving signal.

[0082] In addition, the shallow-probing downhole instrument 201 comprises, in addition to a set of shallow transmitting coils and two sets of shallow receiving coils with different source distances from the shallow transmitting coils, a near signal processing unit corresponding to the first shallow receiving coil, and a near signal processing unit corresponding to the second shallow receiving coil. Each near signal processing unit is configured to, after obtaining the receiving signals of the sub-coils, sequentially perform sampling, addition or subtraction operation, signal amplification and digital-to-analog conversion on the receiving signals of the current pair of sub-coils, to obtain corresponding logging curves (first defect detection logging curve, first resistivity measurement logging curve, second defect detection logging curve and second resistivity measurement logging curve).

[0083] Similarly, the deep-probing downhole instrument 202 comprises, in addition to two sets of deep transmitting coils and two sets of deep receiving coils, a far signal processing unit corresponding to the first deep receiving coil, and a far signal processing unit corresponding to the second deep receiving coil. Each far signal processing unit is configured to, after obtaining the receiving signals of the sub-coils, sequentially perform sampling, addition or subtraction operation, signal amplification and digital-to-analog conversion on the receiving signals of the current pair of sub-coils, to obtain corresponding logging curves (third defect detection logging curve, third resistivity measurement logging curve, fourth defect detection logging curve and fourth resistivity measurement logging curve).

[0084] In the embodiment of the present application, one measurement cycle of one set of downhole instruments 201 (or 202) of the measuring instrument 101 is T, that is, the measurement cycle of one depth measurement point (which can also be regarded as the signal transmission cycle). Preferably, the forward pulse transmission width and the reverse pulse transmission width are both T / 4, and the duty ratio of the transmission pulse width to the transmission intermittent time is 1:1, and the duty ratio of the receiving pulse width to the receiving intermittent time is 1:1. That is, one measurement cycle T is evenly divided into four time periods, each time period is T / 4, the transmission cycle of the transmitting coil of one set of downhole instruments 201 (or 202) of the measuring instrument 101 is T / 4, and the receiving cycle of the receiving coil is also T / 4.

[0085] Further, the two sets of downhole instruments 201 and 202 of the measuring instrument 101 can work simultaneously or individually. Taking the shallow-probing downhole instrument 201 as an example, the principle of generating two time-spectrum logging curves in one receiving cycle is described below.

[0086] FIG. 6 is a schematic diagram of the principle of generating two time-spectrum logging curves in one receiving cycle by a single-probing instrument in the transient electromagnetic resistivity logging system according to the embodiment of the present application.

[0087] The measuring instrument 101 comprises a shallow detection downhole instrument 201 and / or a deep detection downhole instrument 202. The shallow detection downhole instrument 201 comprises a set of transmitting coils, two sets of receiving coils, i.e., a B set and a C set, and the B set of coils is free of a magnetic core, and the C set of coils is provided with a magnetic core. The deep detection downhole instrument 202 comprises two sets of transmitting coils, two sets of receiving coils, i.e., a B set and a C set, and the B set and the C set of coils are both provided with a magnetic core.

[0088] The two sets of receiving coils, i.e., the B set and the C set, of the downhole instrument 201 or 202 are both in a comparative winding mode. For example, for two sub-coils of the B set of comparative winding receiving coils, time channel sampling is respectively performed in one receiving period (T / 4), and the sub-coil receiving signals obtained after sampling are subjected to addition operation, so as to eliminate casing information, obtain a secondary field signal reflecting original pure formation, and then generate a typical time spectral logging curve ζ (first or second or third or fourth resistivity measurement logging curve) mainly characterized by formation resistivity signal, through signal amplification processing and A / D conversion processing. For two sub-coils of the C set of comparative winding receiving coils, time channel sampling is respectively performed in one receiving period (T / 4), and the sub-coil receiving signals obtained after sampling are subjected to subtraction operation, so as to enhance casing signal to 2 times and enhance formation information, and then generate a typical time spectral curve ε (first or second or third or fourth defect detection logging curve) mainly characterized by casing signal, through signal amplification processing and A / D conversion processing.

[0089] Specifically, data interpretation and description obtained from the typical time spectral curve ζ mainly characterized by formation resistivity signal is resistivity variation characteristics of formation outside the casing, and the purpose is to realize casing resistivity detection. Data obtained from the typical time spectral curve ε mainly characterized by casing signal is to interpret and describe variation characteristics of casing internal environment and the whole casing, and the purpose is to realize casing damage detection.

[0090] FIG. 9 is a schematic view of time spectral logging curves generated in a unit measurement period and a unit receiving period in the transient electromagnetic resistivity logging system according to the embodiment of the present application.

[0091] As shown in FIG. 9(a), the process of time spectral logging curves generated in a unit measurement period (T) and a unit receiving period (T / 4) is described below by taking the shallow detection downhole instrument 201 working alone as an example. First, the transmitting pulse width and the transmitting interval time of the downhole instrument 201 are set, and the ratio of the transmitting pulse width to the transmitting interval time is called the duty cycle. Preferably, the transmitting pulse width is T / 4, the transmitting interval time is also T / 4, and the duty cycle is 1:1.

[0092] In the first T / 4 period, i.e. in the time period of 0~T / 4, it is a forward transmission time period, the downhole instrument 201 is forward excited, the transmitting coil transmits a bipolar rectangular wave to the surroundings, and the transmission amplitude is U.

[0093] In the second T / 4 period, i.e. in the time period of T / 4~2T / 4, it is a transmission pause time period, which is set as a signal acquisition time period of the downhole instrument 201, the receiving coil of the downhole instrument 201 performs curve acquisition, and two transient electromagnetic resistivity logging curves with the same excitation and shallow detection depth are generated, which are a time spectrum curve ζ s (the first resistivity measurement logging curve) mainly characterized by the formation resistivity signal and a time spectrum curve ε s (the first defect detection logging curve).

[0094] In the third T / 4 period, i.e. in the time period of 2T / 4~3T / 4, it is a reverse transmission time period, the downhole instrument 201 is reverse excited, the transmitting coil transmits a reverse bipolar rectangular wave to the surroundings, and the transmission amplitude is U.

[0095] In the fourth T / 4 period, i.e. in the time period of 3T / 4~T, it is a second transmission pause time period, which is set as a signal acquisition time period of the downhole instrument 201, the receiving coil of the downhole instrument 201 performs curve acquisition, and two transient electromagnetic resistivity logging curves with reverse excitation and shallow detection depth are generated, which are a time spectrum curve ζ s (the second resistivity measurement logging curve) mainly characterized by the formation resistivity signal and a time spectrum curve ε s (the second defect detection logging curve).

[0096] From the fifth T / 4 period, i.e. in the time period of T~5T / 4, it is a forward transmission time period of the second measurement point, the downhole instrument 201 is forward excited, the transmitting coil transmits a bipolar rectangular wave to the surroundings, and the transmission amplitude is U.

[0097] Similarly, if another deep detection downhole instrument 202 of the downhole module 101 also works at the same time, the transmission pulse width, transmission pause time, receiving period and the like of the deep detection downhole instrument 202 are set to be the same as those of the shallow detection downhole instrument 201, and the time sequence is the same. That is, in the first T / 4 period, the downhole instrument 202 is forward excited and transmits a bipolar rectangular wave, in the second T / 4 period, the receiving coil is received and acquired, and two transient electromagnetic resistivity logging curves with the same excitation and deep detection depth are generated (the third defect detection logging curve and the third resistivity measurement logging curve), in the third T / 4 period, the downhole instrument 202 is reverse excited, and in the fourth T / 4 period, the receiving coil is received and acquired, and two transient electromagnetic resistivity logging curves with reverse excitation and deep detection depth are generated (the fourth defect detection logging curve and the fourth resistivity measurement logging curve).

[0098] This shows that if the two downhole instruments 201 and 202 of the downhole module 101 work simultaneously, eight logging time spectrum curves will be generated within one measurement cycle T. These curves are: a time spectrum curve ζ of deep exploration with co-directional excitation and formation resistivity signal as the main feature. d (Third resistivity measurement logging curve) and time spectrum curve ε, characterized primarily by casing signal. d (Third flaw detection logging curve); Time spectrum curve ζ of deep-penetration reverse excitation, characterized mainly by formation resistivity signal. d (Fourth resistivity measurement logging curve) and time spectrum curve ε, which is mainly characterized by casing signal. d '(Fourth flaw detection logging curve); Time spectrum curve ζ of shallow exploration co-excitation with formation resistivity signal as the main feature.' s (First resistivity measurement logging curve) and time spectrum curve ε, characterized primarily by casing signal. s (First flaw detection logging curve); Time spectrum curve ζ of shallow exploration reverse excitation, characterized mainly by formation resistivity signal. s '(Second resistivity measurement logging curve) and time spectrum curve ε, which is mainly characterized by casing signal' s (Second flaw detection logging curve).

[0099] Figure 9(b) shows two time-spectrum logging curves generated within a single reception period T / 4. The circled curve is the time-spectrum logging curve ζ, characterized primarily by formation resistivity signals, while the triangular curve is the time-spectrum logging curve ε, characterized primarily by casing signals; t1, t2, t3, t m t n t k t p These are respectively represented as time channels 1, 2, 3, m, n, k, p; ζ1, ζ2, ζ3, ζ m Then, these are respectively represented as t1, t2, t3, t m Voltage amplitudes acquired at the time channel, primarily characterized by formation resistivity signals; ε1, ε2, ε3, ε n ε k ε p Then, these are respectively represented as t1, t2, t3, t n t k t p Voltage amplitude acquired at the time track, characterized primarily by bushing signals.

[0100] As can be seen from Figure 9(b), both the circled time spectrum curve ζ and the triangular time spectrum curve ε exhibit a monotonically decreasing characteristic, that is, as time increases, specifically the time channels t1, t2, t3…t… msignal voltage amplitude ζ1, ζ2, ζ3, ζ m decreases, when the signal decreases to ζ m , the signal contribution from the formation resistivity in ζ m becomes less and less, and is gradually overwhelmed by noise or other interference signals, and cannot be extracted from ζ m . Therefore, after the time trace t m , for example, the signal collected at time trace t m+1 will no longer be used for the calculation of the through casing resistivity. The range of signal voltage amplitude used for the calculation of the through casing resistivity in Fig. 9(b) is simply marked as "through casing ζ" with a circle.

[0101] Similarly, the time spectrum curve ε mainly characterized by the casing signal also has similar signal characteristics with the time spectrum curve ζ mainly characterized by the formation resistivity signal, when the signal decreases to ε n , the signal contribution from the casing signal in ε n becomes less and less, and is gradually overwhelmed by noise or other interference signals. The range of signal voltage amplitude used for the calculation of the casing inspection in Fig. 9(b) is simply marked as "inspection ε" with a triangle.

[0102] In addition, for the time spectrum curve ε mainly characterized by the casing signal, between the time traces t n ~ t p , the information characterized by the through casing resistivity can also be calculated from the casing inspection signal voltage amplitude ε n ~ ε p obtained therefrom. The range of signal voltage amplitude used for the calculation of the through casing resistivity in Fig. 9(b) is simply marked as "through casing ε" with a circle. The present application preferably uses the time trace t k as the last acquisition time trace, i.e., the signal voltage amplitude of the time spectrum curve ε collected after the time trace t k , for example, at time trace t k+1 , will no longer be used for the calculation of the through casing resistivity.

[0103] Fig. 10 is a schematic diagram of the time spectrum logging curve based on the time trace in the transient electromagnetic resistivity logging system according to the embodiment of the present application.

[0104] As shown in Fig. 10, the abscissa axis of the logging curve is the time t of data acquisition, and the T / 4 time of data acquisition of one depth measurement point is t n , which is evenly divided into n equal parts within the time t n , and each equal part is called a time trace, which is the most basic data acquisition time unit, such as t1, t2…t nThe greater the value of the number of time channels is, the more intensive the data collection of the receiving coil is, and thus the more data is calculated, and the more real and accurate the time spectral logging curve is described, but at the same time, the problem of a larger amount of data to be stored or transmitted is caused, which leads to the risk of unstable transmission system, data card blocking or missing code, and the need for more downhole storage space, and also easily causes the instrument to be too long and the risk to be increased. Therefore, it is not advisable to one-sidedly pursue a large number of time channels, and under the premise of ensuring the data collection accuracy, there are a plurality of time channel curve sampling points in the time period during the transmitting interval of the measuring instrument 101, and the appropriate number of time channel curve sampling points in the time period during the transmitting interval ranges from 200 to 400. In the embodiment, the number of time channels is preferably 200.

[0105] Referring to FIG. 10, the vertical coordinate axis of the logging curve is the voltage amplitude V of the data collection point, which is a 24-bit digital signal generated by the receiving coil of the transient electromagnetic resistivity logging instrument 201 or 202 after a series of signal processing as shown in FIG. 6. In FIG. 10, for the first time channel t1, the voltage amplitude collected and output by the receiving coil of the transient electromagnetic resistivity logging instrument is marked as ε1, and correspondingly, for the second time channel t2, the voltage amplitude collected and output by the receiving coil of the transient electromagnetic resistivity logging instrument is marked as ε2, and so on, for the nth time channel t n , the voltage amplitude collected and output by the receiving coil of the transient electromagnetic resistivity logging instrument is marked as ε n .

[0106] As can be seen from FIG. 10, at the first time channel t1, the voltage amplitude ε1 collected and output by the receiving coil of the transient electromagnetic resistivity logging instrument is the largest, at the second time channel t2, the voltage amplitude ε2 collected and output by the receiving coil of the transient electromagnetic resistivity logging instrument is smaller than the voltage amplitude ε1 collected at the first time channel, and at the third time channel t3, the voltage amplitude collected and output by the receiving coil of the transient electromagnetic resistivity logging instrument is smaller than the voltage amplitude ε2 collected at the second time channel, and in summary, with the extension of time, that is, the time channel moves forward, the voltage amplitude collected and output by the receiving coil of the transient electromagnetic resistivity logging instrument gradually decreases, that is, the curve gradually decays from high to low, and when at the nth time channel t n , the voltage amplitude ε n collected and output by the receiving coil of the transient electromagnetic resistivity logging instrument is the smallest. Therefore, ε n is also regarded as a threshold value of the voltage amplitude that can be collected and output by the receiving coil of the transient electromagnetic resistivity logging instrument, that is, when the voltage amplitude of the signal that can be collected by the receiving coil is lower than ε n , it will not be read as a valid value.

[0107] The voltage amplitude collected by each time channel is plotted to obtain a time spectrum logging curve as shown in Fig. 10. The time spectrum curve is a standard logging curve characterized by transient electromagnetic resistivity variation, the amplitude of the front section is higher, and the amplitude of the rear section is lower, and in an ideal state, it is a monotonically decreasing curve.

[0108] Further, in any time channel t of Fig. 10, the voltage amplitude ζ or ε collected by the receiving coil of the transient electromagnetic resistivity logging instrument is a 24-bit voltage amplitude digital signal (referred to as time spectrum data). k The voltage amplitude ζ or ε collected by the receiving coil of the transient electromagnetic resistivity logging instrument is a 24-bit voltage amplitude digital signal (referred to as time spectrum data). k The time spectrum data obtained by each time channel number curve sampling point is 3 bytes, and the storage amount of each logging curve is at least 600 bytes. Preferably, if the time channel n = 200, the storage amount of each stored ζ or curve ζ is at least 600 bytes. Correspondingly, the storage amount of 4 time spectrum logging curves is at least 2400 bytes, and the storage amount of 8 time spectrum logging curves is at least 4800 bytes.

[0109] In the embodiment of the application, the time spectrum data obtained by each time channel number curve sampling point is 3 bytes, and the storage amount of each logging curve is at least 600 bytes. Preferably, if the time channel n = 200, the storage amount of each stored ζ or curve ζ is at least 600 bytes. Correspondingly, the storage amount of 4 time spectrum logging curves is at least 2400 bytes, and the storage amount of 8 time spectrum logging curves is at least 4800 bytes.

[0110] Further, the measuring instrument 101 also includes a measuring instrument packaging unit 303. The measuring instrument packaging unit is used to individually package each flaw detection logging curve and each resistivity measurement logging curve according to the number of curves, and then package the logging curves of the shallow detection instrument 201 as a shallow detection complete package and / or package the logging curves of the deep detection instrument 202 as a deep detection complete package.

[0111] Fig. 11 is a schematic diagram of the principle of forming a time spectrum logging curve based on a time channel in a transient electromagnetic resistivity logging system according to an embodiment of the application. As shown in Fig. 11, during the transmission interval, the receiving coil of the downhole instrument 201 or 202 obtains time spectrum data of different time channels. For the first time channel t1, the voltage amplitude ζ1 or ε1 collected and output by the receiving coil of the transient electromagnetic resistivity logging instrument is labeled as 1101 time channel 1; the measurement value 1 is labeled as 1102, and a three-byte unit is allocated for storage; the byte number is labeled as 1103, which is used for buffering; and the storage 1 is labeled as 1110.

[0112] Similarly, for the second time channel t2, the voltage amplitude ζ2 or ε2 collected and output by the receiving coil of the transient electromagnetic resistivity logging instrument is labeled as 1104 time channel 2; the measured value 2 is labeled as 1105, and a three-byte unit is allocated for storage; the number of bytes is labeled as 1106, which is used for buffering; and storage 1 is labeled as 1110;

[0113] The voltage amplitude collected and output by the receiving coil of the transient electromagnetic resistivity logging instrument is sequentially stored for each subsequent time channel;

[0114] For the nth time channel t n , the voltage amplitude ζ n or ε n collected and output by the receiving coil of the transient electromagnetic resistivity logging instrument is labeled as 1107 time channel n; the measured value n is labeled as 1108, and a two-byte unit is allocated for storage; the number of bytes is labeled as 1109, which is used for buffering; and storage 1 is labeled as 1110.

[0115] Finally, the entire table of stored data in 1110 storage 1 is encapsulated into encapsulation 1 data labeled as 803 according to a preset encapsulation strategy.

[0116] Fig. 3 is a data encapsulation principle diagram of the specific structure of the transient electromagnetic resistivity logging system according to the embodiment of the present application. As shown in Fig. 3, the shallow detection measurement unit 301 in the shallow detection downhole instrument 201 included in the measurement instrument 101 generates four transient electromagnetic resistivity logging curves with shallow detection depth. The deep detection measurement unit 302 in the deep detection downhole instrument 202 generates four transient electromagnetic resistivity logging curves with deep detection depth. The above-mentioned four transient electromagnetic resistivity logging curves with shallow detection depth and / or the four transient electromagnetic resistivity logging curves with deep detection depth can be data encapsulated in the data encapsulation unit 303 (also referred to as the “measurement instrument encapsulation unit” 303) according to a corresponding encapsulation algorithm. After data encapsulation is completed, a data stream suitable for CAN bus transmission is formed, and is transmitted to the transmission module 102 through the CAN bus 104.

[0117] As shown in Fig. 3, the transmission module 102 includes a well depth associated feature acquisition unit 304. The well depth associated feature acquisition unit 304 is used to acquire associated features including casing well liquid temperature, casing collar magnetic positioning, and casing outer formation gamma value at the current well depth position, and integrates and encapsulates each associated feature to form an associated parameter data stream. In addition, the transmission module 102 further includes a CAN mode encapsulation unit 305. The CAN mode encapsulation unit 305 is used to integrate and encapsulate the shallow detection complete encapsulation, and / or the deep detection complete encapsulation, and the associated parameter data stream to form a CAN mode complete data stream.

[0118] In addition, the transmission module 102 further comprises a mode conversion unit 306 and an AMI mode encapsulation unit 307. The mode conversion unit 306 is connected with the CAN mode encapsulation unit 305, and is configured to convert the CAN mode complete data stream output from the CAN mode encapsulation unit 305 into an AMI mode data stream. The AMI mode encapsulation unit 307 is connected with the mode conversion unit 306. The AMI mode encapsulation unit 307 is configured to encapsulate the AMI mode data stream output from the mode conversion unit 306 to form an AMI mode encapsulation data stream (i.e. casing and formation measurement information), and transmit the encapsulated AMI mode encapsulation data (casing and formation measurement information) stream to the surface module 103 through the AMI bus 105.

[0119] Specifically, the transmission module 102 comprises a well depth correlation feature acquisition unit 304 configured to determine temperature, magnetic positioning and gamma value. The well depth correlation feature acquisition unit 304 is capable of generating three measurement parameters about temperature, magnetic positioning and gamma value to provide parameters such as fluid temperature and casing collar position near different well depth measurement points of the measurement instrument 101, and establish a corresponding relationship between each correlation feature and measurement depth by measuring the gamma value outside the casing. The three measurement parameters at each measurement depth are encapsulated in the well depth correlation feature acquisition unit 304 to generate encapsulation data (shallow detection complete encapsulation and / or deep detection complete encapsulation) in a mode unified with the CAN mode data stream encapsulation mode generated by the measurement instrument encapsulation unit 303 of the downhole instrument 101, and are sent to the CAN mode encapsulation unit 305 together, to generate a complete CAN mode encapsulation data stream 506. The CAN mode encapsulation data stream 506 is sent to the CAN / AMI conversion unit 306 for mode conversion from CAN mode to AMI mode, and the converted data is further generated into an AMI mode encapsulation data stream suitable for transmission through the AMI bus 105 in the AMI mode encapsulation unit 307.

[0120] Subsequently, the AMI mode encapsulation data stream is transmitted to the surface module 103, and the data is decapsulated in the data decapsulation unit 308 in the surface panel module of the surface module 103. Meanwhile, the decapsulated data is combined with the logging depth (i.e. depth tracking data) or logging time (time tracking data) obtained by the surface measurement unit 309 to generate standard transient electromagnetic resistivity measurement point data (recorded standard logging data) in the standard data unit 310 in the surface panel module, and the data is displayed and interpreted by the data processing module 207.

[0121] The purpose of the encapsulation shown in Fig. 3 is to generate 8 transient electromagnetic resistivity logging curves for completing various detection functions when the measuring instrument 101 contains at least the shallow detection downhole instrument 201 and the deep detection downhole instrument 202, and each group of CAN mode encapsulation data streams (shallow detection complete encapsulation and deep detection complete encapsulation) has a corresponding group of temperature, magnetic positioning and gamma three-way correlation measurement characteristic parameters.

[0122] If the logging needs only one shallow detection downhole instrument 201 or deep detection downhole instrument 202, the data encapsulation of the data transmission system of the measuring instrument 101 is shown in Fig. 4.

[0123] Fig. 4 is a schematic diagram of data encapsulation between a single resistivity detection instrument and a transmission module in a transient electromagnetic resistivity logging system according to an embodiment of the present application. As shown in Fig. 4, the 4 transient electromagnetic resistivity logging curves with shallow detection depth generated by the shallow detection downhole instrument 201 are completely encapsulated in the shallow detection data complete encapsulation unit 401 of the data encapsulation unit 303, thereby forming a shallow detection complete encapsulation, and transmitted to the CAN mode encapsulation unit 305 of the transmission module 102 through the CAN bus 104 to generate a complete CAN mode encapsulation data stream; or the 4 transient electromagnetic resistivity logging curves with deep detection depth generated by the deep detection downhole instrument 202 are completely encapsulated in the deep detection data complete encapsulation unit 402 of the data encapsulation unit 303, thereby forming a deep detection complete encapsulation, and transmitted to the CAN mode encapsulation unit 305 of the transmission module 102 through the CAN bus 104 to generate a complete CAN mode encapsulation data stream.

[0124] Fig. 5 is a schematic diagram of generating a CAN mode complete data stream in a transient electromagnetic resistivity logging system according to an embodiment of the present application. As shown in Fig. 5, the CAN mode data stream 501 generated by the data encapsulation unit 303 of the measuring instrument 101, including the shallow detection complete encapsulation and the deep detection complete encapsulation, is directly transmitted to the CAN mode encapsulation unit 305 of the transmission module 102 through the CAN bus 104. The temperature measurement unit 502, the magnetic positioning measurement unit 503 and the gamma measurement unit 504 in the well depth correlation characteristic acquisition unit 304 of the transmission module 102 can generate temperature, magnetic positioning and gamma three-way measurement data, and the three-way measurement data is encapsulated in the data encapsulation unit 304 to generate a correlation parameter data stream 505, which is consistent with the encapsulation mode of the CAN mode data stream 501 generated by the data encapsulation unit 303 of the measuring instrument 101.

[0125] In the CAN mode encapsulation unit 305 of the transmission module 102, the CAN mode data stream 501 generated by the data encapsulation unit 303 of the measuring instrument 101 is merged with the above-mentioned associated parameter data stream 505 to form a CAN mode complete data stream 506.

[0126] Fig. 7 is a schematic diagram of data encapsulation principle of a single probe instrument in the transient electromagnetic resistivity logging system according to the embodiment of the present application. Fig. 7 shows a schematic diagram of data encapsulation principle of a complete logging curve measurement formed by a downhole instrument 201 or 202 in one measurement period (T).

[0127] As shown in Fig. 7, the four transient electromagnetic resistivity logging curves generated by the shallow probe measurement unit 301 in one measurement period (T) are respectively: a time spectrum curve ζ s (701) mainly characterized by formation resistivity signal, and a time spectrum curve ε s (703) mainly characterized by casing signal, generated by the transmitting coil in forward transmission; and a time spectrum curve ζ s '(705), and a time spectrum curve ε s '(707), generated by the transmitting coil in reverse transmission.

[0128] The time spectrum curve ζ s of 701 is encapsulated in 702 encapsulation 1 according to the designated data encapsulation protocol, and similarly, the time spectrum curve ε s of 703 is encapsulated in 704 encapsulation 2 according to the designated data encapsulation protocol, the time spectrum curve ζ s 'of 705 is encapsulated in 706 encapsulation 3 according to the designated data encapsulation protocol, and the time spectrum curve ε s 'of 707 is encapsulated in 708 encapsulation 4 according to the designated data encapsulation protocol. In the embodiment of the present application, the four transient electromagnetic resistivity logging curves use the same kind of data encapsulation protocol.

[0129] After the four transient electromagnetic resistivity logging curves of the shallow probe downhole instrument 201 are encapsulated by 702, 704, 706 and 708 respectively, they are sent to the shallow probe complete encapsulation unit 401 for further data encapsulation to form a shallow probe complete encapsulation CAN mode data stream suitable for transmission of the CAN bus 104.

[0130] Similarly, the 4 TEM resistivity logging curves generated by the deep-probing measurement unit 302 of the deep-probing downhole instrument 202 of the downhole module 101 are encapsulated in the same way as the 4 TEM resistivity logging curves of the shallow-probing downhole instrument 201, that is, the 4 TEM resistivity logging curves generated by the deep-probing measurement unit 302 are encapsulated independently and then sent to the deep-probing complete encapsulation unit 402 for further data encapsulation to form the deep-probing complete encapsulation CAN mode data stream suitable for transmission of the CAN bus 104.

[0131] Fig. 8 is a schematic diagram of the data encapsulation principle of the measurement instrument in the TEM-based resistivity logging system according to the embodiment of the present application.

[0132] In Fig. 8, the shallow-probing measurement unit 301 generates the shallow-probing data as shown in 801 in one measurement period (T) and forms 4 shallow-probing TEM resistivity logging curves as shown in 802 curve 1 to 804 curve 4, which are encapsulated to form the corresponding single-curve-based encapsulation data, for example, the encapsulation 1 data of 803 is formed by encapsulating the 802 curve 1, and the encapsulation 4 data of 805 is formed by encapsulating the 804 curve 4. Meanwhile, the deep-probing measurement unit 302 also generates the deep-probing data as shown in 801 in the same measurement period (T) and forms 4 deep-probing TEM resistivity logging curves as shown in 806 curve 1 to 808 curve 4, which are encapsulated to form the encapsulation data, for example, the encapsulation 5 data of 807 is formed by encapsulating the 806 deep-probing curve 1, and the encapsulation 8 data of 809 is formed by encapsulating the 808 deep-probing curve 4.

[0133] The 8 encapsulation data are further encapsulated in the data encapsulation unit 303 to generate the CAN mode encapsulation data stream 501 suitable for transmission of the CAN bus 104. In the embodiment of the present application, the 8 TEM resistivity logging curves use the same data encapsulation protocol.

[0134] The 4 shallow-probing TEM resistivity logging curves of the shallow-probing downhole instrument 201 can be encapsulated by using the designated encapsulation protocol to generate the shallow-probing CAN mode data stream. Similarly, the 4 deep-probing TEM resistivity logging curves of the deep-probing downhole instrument 202 can also be encapsulated by using the designated encapsulation protocol to generate the deep-probing CAN mode data stream. Further, the shallow-probing CAN mode data stream and the deep-probing CAN mode data stream with different encapsulation protocols can be further combined and encapsulated to generate the CAN mode data stream of the two sets of downhole instruments.

[0135] The transmission module 102 has a well depth correlation feature acquisition unit, which can generate temperature, magnetic positioning and gamma three-way measurement parameters 810, provide fluid temperature near the measurement point of the downhole instrument and parameters such as the casing collar position in the well, and establish a corresponding relationship between the correlation parameters and the measurement depth by measuring the gamma values inside and outside the casing. The three-way measurement parameters 810 are encapsulated in the data encapsulation unit 304 (see FIG. 3) to generate encapsulated 0 data 811.

[0136] The encapsulated 0 data 811 and the encapsulated 1 data 803 to encapsulated 4 data 805, encapsulated 5 data 807 to encapsulated 8 data 809 are nine encapsulated data, which generate a complete CAN mode encapsulated data stream and are collectively sent to the CAN mode encapsulation unit 305 (see FIG. 3).

[0137] In addition, if only one set of downhole instruments 201 or 202 is working, that is, only four transient electromagnetic resistivity logging curves of shallow detection or deep detection are encapsulated into corresponding encapsulated 1 data 803 to encapsulated 4 data 805 or encapsulated 5 data 807 to encapsulated 8 data 809, then the encapsulated 0 data 811 and the encapsulated 1 data 803 to encapsulated 4 data 805 are five encapsulated data, which generate a complete shallow detection CAN mode encapsulated data stream and are collectively sent to the CAN mode encapsulation unit 305 (see FIG. 3); or, the encapsulated 0 data 811 and the encapsulated 5 data 807 to encapsulated 8 data 809 are five encapsulated data, which generate a complete deep detection CAN mode encapsulated data stream and are collectively sent to the CAN mode encapsulation unit 305 (see FIG. 3).

[0138] Further, the measurement instrument encapsulation unit 303 is also used to transmit the complete shallow detection encapsulation and / or the complete deep detection encapsulation to the transmission module 102 by frame packet transmission in a timing mode. Each logging curve is at least 75 frame packets. Among them, the communication cycle range of the first bus (for example: CAN bus) standard frame is 120μs-200μs. After transmitting a standard frame packet, the first bus is in an idle state until the next frame standard frame packet is transmitted.

[0139] FIG. 12 is a schematic diagram of the frame packet transmission mode timing and standard frame format of the CAN bus in the transient electromagnetic resistivity logging system according to the embodiment of the application. Taking the example that two sets of downhole instruments 201 and 202 work simultaneously, according to the above content, if the time channel number in the T / 4 range is preferably 200, and the data is transmitted by non-compressed encapsulated data, then the capacity of one CAN mode data stream 501 is at least 4800 bytes.

[0140] In order to transmit a large capacity data stream of at least 4800 bytes, the measuring instrument packaging unit 303 adopts a package transmission mode (labeled as 1201) to set the number of packages as m, and define each package data as a frame, so that the capacity of a CAN mode data stream 501 = the amount of data transmitted per frame x the number of packages m. The preferred transmission frame package of the present application is a standard frame, and the data segment is 64 bits, which can transmit 8 bytes of data, so that 4800 bytes need at least 600 frame packages. Therefore, for each logging curve, at least 75 frame packages are needed. Similarly, if only one set of downhole instrument 201 or 202 works, only 2400 bytes need to be transmitted, and the number of packages m = 300.

[0141] Figure 12 (a) shows the data frame package timing transmission flow and timing, and the steps are as follows:

[0142] First, determine the time T required for each frame package data to pass through the CAN bus C′ ;

[0143] Set the timing time T C , wherein the timing time T C is greater than the frame package transmission time T C′ ;

[0144] From the first frame, the first frame package data is transmitted through the CAN bus 104 within the first timing time T C1 , and the time T C1′ is consumed, and after the transmission is completed, the bus is idle;

[0145] Within the second timing time T C2 , the second frame package data is transmitted through the CAN bus 104, and the time T C2′ is consumed, and after the transmission is completed, the bus is idle;

[0146] In succession, within the mth timing time T Cm , the mth frame package data is transmitted through the CAN bus 104, and the time T Cm′ is consumed, and after the transmission is completed, the bus is idle;

[0147] At this point, the transmission of a CAN mode data stream is completed.

[0148] The present application adopts a timing mode in the frame package transmission process of the CAN bus, which helps to release the occupation of the measuring instrument processor. The measuring instrument processor is only occupied at each frame package transmission, and during the idle period of the frame package transmission, the CAN bus is in an idle state, and the processor is released to process other tasks.

[0149] The communication of the CAN bus 104 adopts a standard frame format, one standard frame format is shown in Fig. 12(b). In Fig. 12(b), 1202 is a frame standard frame. The structure of the standard frame is: frame start 1 bit, arbitration 11 bits, control section 7 bits, data section 0-64 bits, CRC section 16 bits (CRC sequence 15 bits + 1 bit delimiter), ACK section 2 bits, frame end 7 bits. Only the data section of the standard frame is used to transmit the encapsulated logging data, which adopts a 64-bit full-fill mode, and the CAN bus 104 transmits a maximum of 8 bytes of logging data in one CAN communication.

[0150] The T C1′ is the effective transmission time of the first standard frame, i.e. the time required for the first frame of data to pass through the CAN bus, 1203, and the time required for each frame of data to pass through the CAN bus thereafter is also equal to T C1′ .

[0151] Further, if the two sets of downhole instruments 201 and 202 work simultaneously, the time channel number in the range of T / 4 is preferably 200, and the data adopts non-compressed encapsulated data transmission, then the capacity of one CAN mode complete data stream 506 is at least 4800 bytes; if only one set of downhole instruments 201 or 202 works, the time channel number is still preferably 200, and the data adopts non-compressed encapsulated data transmission, then the capacity of one CAN mode complete data stream 506 is at least 2400 bytes.

[0152] The data stream 506 is sent to the CAN / AMI conversion unit 306 for mode conversion from CAN mode to AMI mode, and in the second bus (AMI bus) mode encapsulation unit 307, the converted data is further generated into an AMI mode encapsulated data stream suitable for transmission on the AMI bus 105.

[0153] Further, the second bus mode encapsulation unit 307 described above is used to transmit the second mode encapsulated data stream containing logging data in a data frame format. Each second bus data frame contains a data header, data bits, check bits and end bits, wherein the data bits can encapsulate 4 bytes of logging data. In the embodiment of the present application, the second bus (AMI bus) is not idle during the continuous transmission of data frames.

[0154] Fig. 13 is a timing diagram of the frame packet transmission mode of the AMI bus in the transient electromagnetic resistivity logging system according to the embodiment of the present application.

[0155] The CAN / AMI mode conversion is only to convert the transmission mode of data from the CAN mode of two states of "0" and "1" to the AMI mode of three states of "-1", "0" and "1", and does not change the transmission amount of data, therefore, after the CAN / AMI mode conversion, in the AMI mode encapsulation unit 307, the capacity of an AMI mode encapsulation data stream generated and the encapsulation protocol are unchanged, that is, two sets of downhole instruments work simultaneously, the capacity of an AMI mode encapsulation data stream is at least 5000 bytes, and 0-9 data encapsulations (see FIG. 7 and FIG. 8); if one set of downhole instruments works, the capacity of an AMI mode encapsulation data stream is at least 2500 bytes, and 0-5 data encapsulations (see FIG. 7 and FIG. 8).

[0156] An AMI mode encapsulation data stream with a large capacity is transmitted through the AMI bus 105, which is also completed in the form of packaging, one frame package of AMI has a 32-bit data segment, and can transmit 4 bytes of data, therefore, if 5000 bytes are transmitted, 1250 packages are needed; if 2500 bytes are transmitted, 625 packages are needed.

[0157] Different from the CAN frame package, in the continuous transmission of the AMI frame package, the AMI bus 105 is not set with a timing in the embodiment of the application. Therefore, during the transmission of all frame packages of an AMI mode encapsulation data stream, the AMI bus 105 is always in a busy state of transmission. That is, when an AMI mode encapsulation data stream starts to be transmitted through the AMI bus 105, the AMI frame package is transmitted frame by frame from the first frame package, without any pause, until the transmission of an AMI mode encapsulation data stream is completed, the AMI bus 105 sends idle data until the arrival of the next AMI mode encapsulation data stream. That is, the AMI bus 105 is always in a busy state during the entire data transmission.

[0158] In FIG. 13, 1301 is the first frame package of an AMI mode encapsulation data stream, 1302 is the second frame package, and 1303 is the last frame package of the AMI mode encapsulation data stream. As can be seen from FIG. 13, one AMI mode frame package such as 1301 includes a data header 1304, a data segment 1305, a check bit 1306 and an end bit 1307.

[0159] FIG. 14 is a data transmission timing diagram of the transient electromagnetic resistivity logging system based on the embodiment of the application. In the embodiment of the application, the measurement periods of the two sets of downhole instruments 201 and 202 of the measuring instrument 101 are the same, and are T, in FIG. 14, 1T is the first measurement period, and 2T is the second measurement period.

[0160] In the embodiment of the present application, the measurement period T is preferably 240 ms to 800 ms. Further, the measurement period T is 600 ms. One measurement period T is equally divided into four time periods, and the transmitting period of the transmitting coil of the downhole instrument 201 and 202 is T / 4, and the receiving period of the receiving coil is also T / 4.

[0161] As shown in FIG. 14, the label 1601 is the transmitting time sequence of the transmitting coil of the downhole instrument 201 when the shallow detection downhole instrument 201 of the measuring instrument 101 is working, and the detailed description is referred to FIG. 9, and the transmitting period is 150 ms. The label 1602 is the collection time sequence of the receiving coil of the downhole instrument 201 when the shallow detection downhole instrument 201 of the measuring instrument 101 is working, and the detailed description is referred to FIG. 9, and the receiving period is 150 ms. The label 1603 is the transmitting time sequence of the transmitting coil of the deep detection downhole instrument 202 when the deep detection downhole instrument 202 of the measuring instrument 101 is working, and the transmitting time sequence is the same as that of FIG. 9, and the transmitting period is 150 ms. The label 1604 is the collection time sequence of the receiving coil of the deep detection downhole instrument 202 when the deep detection downhole instrument 202 of the measuring instrument 101 is working, and the collection process is the same as that of FIG. 9, and the receiving period is 150 ms. The label 1605 is the time sequence of the CAN mode data stream 501 (see FIG. 5) generated when the downhole instruments 201 and 202 of the measuring instrument 101 are working simultaneously and transmitted through the CAN bus 104. The label 1606 is the time sequence of the AMI mode encapsulation data stream (see FIG. 13) generated when the downhole instruments 201 and 202 of the measuring instrument 101 are working simultaneously and transmitted through the AMI bus 105.

[0162] In the label 1602 and the label 1604, the rectangular block with diagonal line represents the data amount of the curve generated in the receiving period (or time period), and "curve 1-2" represents two time spectrum curves ζ s , ζ d and ε s , ε d generated by the simultaneous excitation, in which ζ s ' and ζ d ' are the time spectrum curves mainly characterized by the formation resistivity signal, and ε s ' and ε d ' are the time spectrum curves mainly characterized by the casing signal.

[0163] In the annotation 1605, the downhole instruments 201 and 202 of the measuring instrument 101 are set to work simultaneously, and the data amounts of 4 curves CAN1 (shallow detection complete package) and CAN2 (deep detection complete package) are generated, the total transmission time of CAN1 and CAN2 through the CAN bus 104 is about 60 ms, and the CAN bus 104 is set to transmit CAN1 and then transmit CAN2; if the downhole instruments 201 and 202 work simultaneously to generate the data amounts of 8 curves, the transmission time through the CAN bus 104 is about 120 ms. In addition, the rectangular blocks with oblique lines CAN1 and CAN2 also indicate that the CAN bus 104 is only occupied in this time period, and the CAN bus 104 is idle in the rest of the time.

[0164] Similarly, in the annotation 1606, the downhole instruments 201 and 202 of the measuring instrument 101 are set to work simultaneously, and the data amounts of 4 curves AMI1 and AMI2 are generated, the total transmission time of AMI1 and AMI2 through the AMI bus 105 is about 200 ms, and the AMI bus 105 is set to transmit AMI1 and then transmit AMI2; if the downhole instruments 201 and 202 work simultaneously to generate the data amounts of 8 curves, the transmission time through the AMI bus 105 is about 400 ms. In addition, the rectangular blocks with oblique lines AMI1 and AMI2 also indicate that the AMI bus 105 is only occupied in this time period, and the transmitted data is valid data; the rectangular blocks with vertical lines also indicate that the AMI bus 105 is only occupied in this time period, and the transmitted data is idle data. The AMI bus 105 is always busy.

[0165] Further, in FIG. 14, the first measurement period 1T is a time period of 0-600 ms, and the second measurement period 2T is a time period of 600-1200 ms. In the time period of 0-600 ms, the downhole instruments 201 and 202 of the measuring instrument 101 work simultaneously to generate the data amounts of 8 curves of the first measurement period 1T, and form the complete CAN data stream 506 of the first measurement period 1T. In the time period of 600-1200 ms, the data amounts of 8 curves of the second measurement period 2T are generated, and the complete CAN data stream 506 of the second measurement period 2T is formed; at the same time, the complete CAN data stream 1607 generated in the first period 1T is transmitted; at the same time, an AMI data stream 1608 is formed and completed. Thus, the shallow detection downhole instrument or the deep detection downhole instrument of the measuring instrument 101 always generates complete measurement data in a measurement period, and transmits the measurement data to the surface module 103 in the next measurement period.

[0166] Further, the transmission module 102 is built-in with an FPGA and an ARM processor, the FPGA processor includes an AMI mode packaging unit 307. The FPGA processor realizes the strict timing output of the AMI data stream based on the strict control of the AMI communication timing. The FPGA processor and the ARM processor intercommunicate information by means of a bus. The ARM processor includes a well depth correlation feature acquisition unit 304, a CAN mode packaging unit 305 and a mode conversion unit 306. The ARM processor acquires sensor parameters such as temperature, magnetic positioning and gamma, temporarily caches in a memory, and transmits to the FPGA processor together with the complete packaging data of the shallow detection and / or the deep detection. The ARM processor is configured with a CAN communication network, and different instrument ports of the measuring instrument are respectively hung.

[0167] Fig. 15 is a module structure diagram of the ground module in the transient electromagnetic resistivity logging system according to the embodiment of the application. As shown in Fig. 15, the ground panel module 205 in the ground module 103 includes a ground unpacking unit 308. The ground unpacking unit 308 receives and unpacks a complete AMI mode packaging data stream transmitted by the AMI bus 105 according to a preset data packaging protocol, and forms multi-channel decoding data 1701. That is, if the downhole instruments 201 and 202 of the measuring instrument 101 work simultaneously, a complete AMI mode packaging data stream can be resolved into one original value of three parameters including temperature, magnetic positioning and gamma, and four shallow detection resistivity downhole instrument measurement curves and four deep detection resistivity downhole instrument measurement curves corresponding to the three parameters; if only one set of downhole instrument 201 (or 202) of the downhole module 101 works, a complete AMI mode packaging data stream can be resolved into one original value of three parameters including temperature, magnetic positioning and gamma, and four shallow detection resistivity downhole instrument measurement curve data (or four deep detection resistivity downhole instrument measurement curve data) corresponding to the three parameters.

[0168] The multi-channel decoding data 1701 is subjected to data processing such as filtering, noise elimination, abnormal point elimination, interpolation and other technical solutions in a data processing unit, so as to become standard logging data 1702 which is easy to display and read. Taking the example that the downhole instruments 201 and 202 of the downhole module 101 work simultaneously, the standard logging data 1702 includes: a shallow detection same direction excitation time spectrum curve ζ s mainly characterized by a formation resistivity signal and a shallow detection reverse direction excitation time spectrum curve ζ s mainly characterized by a formation resistivity signal; a deep detection same direction excitation time spectrum curve ζ s mainly characterized by a formation resistivity signal and a deep detection reverse direction excitation time spectrum curve ζ s mainly characterized by a casing signal. dand the time spectrum curve ε mainly characterized by the casing signal d ; the time spectrum curve ζ mainly characterized by the formation resistivity signal excited by the deep investigation reverse d and the time spectrum curve ε mainly characterized by the casing signal d , totally 8 curve data.

[0169] Further, the ground panel module comprises a depth tracking unit for realizing depth tracking of the downhole measuring instrument during instrument measurement. Depth tracking refers to determining the depth value of the well logging by counting the depth coding pulses. When the downhole instrument moves in the well, the linear motion of the cable makes the disc of the depth encoder move in a circle, generating corresponding depth pulses, which are sent to the depth processing circuit of the ground panel module 205, and after depth correction, are counted by the depth counter to generate depth tracking data 1703.

[0170] Further, the ground panel module further comprises a time tracking unit for realizing time tracking of the downhole measuring instrument during cable logging instrument measurement. Time tracking refers to setting a clock circuit on the ground panel module 205, and generating a time tracking data 1704 by time counting.

[0171] In the ground panel module, on the one hand, the standard logging data 1702 and the depth tracking data 1703 are combined to generate a kind of recording standard logging data 1705; on the other hand, the standard logging data 1702 and the time tracking data 1704 are also combined to generate another way of recording standard logging data 1705. Each recording standard logging data 1705 has a depth tracking data 1703 (or a time tracking data 1704) and corresponding associated characteristic parameters corresponding thereto.

[0172] Further, each recording standard logging data 1705 generated by the ground panel module 205 is transmitted to the database 1706 of the data processing module 207 for storage through the high-speed USB bus 206. The data communication between the ground panel module and the data processing module adopts high-speed USB mode, and the appropriate range of transmission rate is 5M-10M Bps.

[0173] Further, the data processing module 207 is configured with algorithms capable of completing curve fitting, calibration chart and influence factor correction and other data interpretation, so as to complete accurate data display, formation interpretation and oil well analysis and evaluation. The data processing module 207 can also display the logging engineering value and instrument state in real time, and draw the logging value curve with depth, and display the logging information to the field logging personnel in real time.

[0174] Further, the database 1706 stores the standard logging data 1705, in which the shallow-probe forward-excitation time-spectrum curve ζ mainly characterized by the formation resistivity signal s , the shallow-probe reverse-excitation time-spectrum curve ζ mainly characterized by the formation resistivity signal s , the deep-probe forward-excitation time-spectrum curve ζ mainly characterized by the formation resistivity signal d , and the deep-probe reverse-excitation time-spectrum curve ζ mainly characterized by the formation resistivity signal d , totally 4 curve data used for completing the formation resistivity display 1707; the database 1706 stores the standard data record 1705, in which the shallow-probe forward-excitation time-spectrum curve ε mainly characterized by the casing signal s , the shallow-probe reverse-excitation time-spectrum curve ε mainly characterized by the casing signal s , the deep-probe forward-excitation time-spectrum curve ε mainly characterized by the casing signal d , and the deep-probe reverse-excitation time-spectrum curve ε mainly characterized by the casing signal d , totally 4 curve data used for completing the casing quality display 1708.

[0175] Further, the database 1706 stores the standard logging data 1705, in which the shallow-probe forward-excitation time-spectrum curve ζ mainly characterized by the formation resistivity signal s and the time-spectrum curve ε mainly characterized by the casing signal s ; the shallow-probe reverse-excitation time-spectrum curve ζ mainly characterized by the formation resistivity signal s and the time-spectrum curve ε mainly characterized by the casing signal s ; the deep-probe forward-excitation time-spectrum curve ζ mainly characterized by the formation resistivity signal d and the time-spectrum curve ε mainly characterized by the casing signal d ; the deep-probe reverse-excitation time-spectrum curve ζ mainly characterized by the formation resistivity signal d and the time-spectrum curve ε mainly characterized by the casing signal d , totally 8 curve data used for completing the post-data processing 1709 to realize the post-reservoir or logging comprehensive evaluation.

[0176] It should be noted that the depth tracking unit and the encoding and decoding module inside the ground panel module respectively realize data exchange with the data processing module in the double-USB2.0 communication mode, the communication time is extremely short, and the scheduling overhead of the ground software on the communication task is reduced.

[0177] In the embodiment of the present application, the second bus (AMI bus) 105 is a seven-core cable. The AMI bus is at least 5000 m, the middle core is used as a signal transmission line, and the surrounding six cores are used as power supply lines. When the signal cable core is in the middle, the distributed capacitance is the smallest, which can effectively reduce the power supply noise interference.

[0178] Specifically, the six power supply lines include two groups of first power supply groups with a first direct current voltage and one group of second power supply groups with a second direct current voltage, and one group of power supply groups includes two power supply lines. The first power supply group is used to provide power supply for the measuring instrument, and the second power supply group is used to provide power supply for the transmission module. The first direct current voltage is 170 V, and the second direct current voltage is 140 V.

[0179] Further, in each group of power supply groups, the cable core of the power supply line is used as the positive pole of the corresponding power supply group, and the steel outer skin of the power supply line is used as the negative pole of the corresponding power supply group.

[0180] The ground module 103 and the transmission module 102 are connected through the logging cable 204 (AMI bus), the cable reel is on the logging winch, and the general length is about 7000 meters. The logging cable 204 is a logging special armored steel cable (labeled 1903), which contains 1-7 metal wires.

[0181] Fig. 16 is a schematic diagram of the armored cable structure of the AMI bus in the transient electromagnetic resistivity logging system according to the embodiment of the present application. As shown in Fig. 16, the upper end 1902 of the cable is connected to the data unpacking unit 308 of the ground panel module 205 of the ground module 103, the middle seventh core of the upper end 1902 of the cable transmits the AMI mode packaged data stream to the data unpacking unit 308 to complete data unpacking, and generates unpacked data 1701. The middle seventh core of the lower end 1904 of the cable receives the AMI mode packaged data stream, the AMI mode packaging unit 307 in the data processing board 203 of the transmission module 102 packages the logging data converted through CAN / AMI mode to generate an AMI mode packaged data stream, and transmits the AMI mode packaged data stream to the ground through the cable. The communication time consumption is basically not considered, as long as the data transmission time consumption of the whole system is ensured to arrive at the ground within the same double-polarity rectangular wave transmission time sequence.

[0182] The application discloses a transient electromagnetic resistivity logging system.

[0183] In addition, the logging data information generated by the transient electromagnetic resistivity logging instrument has a large amount of information, and the capacity is particularly huge, and the capacity of each depth measurement point reaches nearly 5000 bytes, which is far more than the data transmission capacity of conventional casing logging, and the transient electromagnetic resistivity logging data transmission system of the application forms a data stream suitable for different data transmission modes by reasonably setting three modules of the ground, transmission and downhole, constructs a CAN bus and an AMI bus, and through the design of different data transmission periods, synchronous data communication between modules and the setting of cable power supply mode and other measures, a large-capacity data channel with stable performance can be provided, and powerful guarantee for real-time and accurate uploading of "massive" data is provided.

[0184] In addition, in order to not lose valuable logging data, it is necessary to temporarily store in a large-capacity downhole memory, and after measurement, the instrument is taken to the ground to play back the data, but increasing the downhole memory also means that more circuit space and circuit design difficulty need to be increased, which causes greater drilling risk in the harsh high temperature and high pressure downhole operation environment, the transient electromagnetic resistivity logging data transmission system of the application utilizes the large-capacity cache of the downhole instrument itself, and simultaneously utilizes a stable and reliable data transmission channel and ground interpretation software, so that the downhole measurement data can be extracted and displayed in real time according to the set mode, the storage space of the downhole information is significantly released, and the hardware cost and the drilling risk caused thereby are reduced.

[0185] The above describes only the preferred specific embodiments of the application, but the protection scope of the application is not limited thereto, any person skilled in the art can easily think of changes or replacements within the technical range disclosed by the application, which should be covered within the protection scope of the application. Therefore, the protection scope of the application should be subject to the protection scope of the claims.

[0186] In the description of the present application, unless otherwise specified, the meaning of "a plurality of" is two or more than two; the terms "upper", "lower", "left", "right", "inner", "outer", "front end", "rear end", "head", "tail" and the like indicate the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present application and

[0187] The downhole measuring instrument of transient electromagnetic resistivity requires large power signal transmission, and the ground panel module 205 of the ground module 103 generates 3 sets of DC power supply, two of which are large power supply 170V, which is independently supplied to the two sets of downhole instruments 201 and 202 of the measuring instrument 101 through the cable cores 1, 6 and 5, 4 of the upper end 1902 and the lower end 1904 of the cable, and the power supply units of the downhole instruments 201 and 202 are 1907 and 1908 respectively.

[0188] The transmission module 102 of transient electromagnetic resistivity does not require large power supply, so another set of small power supply 140V is independently supplied to the data processing board 203 of the transmission module 102 through the cable cores 3, 2 of the upper end 1902 and the lower end 1904 of the cable, and its power supply unit is 1905.

[0189] In order to further reduce the power impedance of the cable 1903, the cable cores 1, 6 can be connected together as the positive electrode of the large power supply 170V, and the steel outer skin of the cable is used as the negative loop of 170V to supply power to the downhole instrument 202; correspondingly, the cable cores 5, 4 can be connected together as the positive electrode of the large power supply 170V, and the steel outer skin of the cable is used as the negative loop of 170V to supply power to the downhole instrument 201. Similarly, the cable cores 3, 2 can also be connected together as the positive electrode of the small power supply 140V, and the steel outer skin of the cable is used as the negative of 140V to independently supply power to the data processing board 203 of the transmission module 102. In this way, both the large power supply 170V and the small power supply 140V are supplied through the cable skin, which ensures the stability of the reference level of the whole set of logging data acquisition system.

[0190] Further, in the embodiment of the present application, the transmission module 102 is relatively close to the measuring instrument 101, and the two are combined together by threaded connection during logging operation.

[0191] In the logging process, the transmission module 102 can mount multiple downhole instruments. The measuring instrument 101 emits a bipolar rectangular wave, the wave frequency is the same, and contains a synchronization mechanism to ensure that the time of the emitted wave is also the same. The transmission pulse width (T / 4) is adjustable, and the logging process remains unchanged. The bipolar rectangular wave period is selected in the interval of 240ms-800ms, and is generally selected as 500ms-600ms. When a single downhole instrument is mounted, the AMI communication time is about 200ms, and when two are mounted, the AMI communication time is 400ms. Therefore, when the rectangular wave period is less than 400ms, only one instrument can be mounted during logging operation, otherwise the bus communication time is too long, which affects communication.

[0192] In the embodiment of the present application, the logging data is collected in the current measurement period, and the data of one depth point is transmitted to the telemetry by the CAN bus in the next period. The telemetry unit (i.e. the well depth correlation feature acquisition unit) temporarily stores the through casing data and / or the flaw detection data, and acquires the magnetic positioning, GR and temperature parameters. The through casing data and / or the flaw detection data are packaged and transmitted by AMI.

[0193] In addition, in the embodiment of the present application, the measuring instrument realizes data transmission to the surface panel module within the same transmission waveform timing. The USB2.0 transmission baud rate can be up to hundreds of megabits, compared with CAN and AMI communication. The USB simplifies the description in the whole system, and is not intended to indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present application. In addition, the terms "first", "second", "third" and the like are only for descriptive purposes, and cannot be understood as indicating or implying relative importance.

[0194] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or detachably connected, or integrally connected; it can be mechanically connected, or electrically connected; it can be directly connected, or indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0195] It should be understood that the embodiments disclosed in the present application are not limited to the specific structure, processing steps or materials disclosed herein, but should be extended to the equivalent alternatives of these features understood by those skilled in the related art. It should also be understood that the terms used herein are only for the purpose of describing the specific embodiments, and do not mean limitation.

[0196] Reference in the specification to "one embodiment" or "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the application. The appearances of the phrase "in one embodiment" or "an embodiment" in various places in the specification are not necessarily all referring to the same embodiment.

[0197] Although the present application has been described with reference to the above embodiments, the contents described are merely adopted embodiments for facilitating the understanding of the present application, and are not intended to limit the present application. Any modification and change in the form and details of the embodiments can be made by any person skilled in the art without departing from the spirit and scope of the present application, and the patent protection scope of the present application shall be subject to the scope defined by the appended claims.

Claims

1. A transient electromagnetic based resistivity logging system characterized by, The application relates to a method for measuring casing and formation, comprising the following steps: a measuring instrument is used to simultaneously measure a defect detection well logging curve and a casing and formation resistivity measurement well logging curve; a transmission module is used to transmit casing and formation measurement information to the ground; a ground module is used to receive and analyze the casing and formation measurement information.

2. The resistivity logging system of claim 1, wherein, The measuring instrument comprises: at least one detection instrument which is used to emit a bipolar rectangular wave and receive two-way receiving signals which are respectively detected at different pulse transmission intervals, and a defect detection well logging curve is obtained by subtracting the two-way receiving signals, and a resistivity measurement well logging curve is obtained by adding the two-way receiving signals.

3. The resistivity logging system of claim 2, wherein, The measuring instrument comprises: a shallow detection instrument which comprises a shallow transmitting coil and two groups of shallow receiving coils, is used to emit a bipolar rectangular wave by the shallow transmitting coil, and is used to respectively detect a first defect detection well logging curve and a first resistivity measurement well logging curve by a first shallow receiving coil and a second shallow receiving coil at a forward pulse transmission interval, and is used to respectively detect a second defect detection well logging curve and a second resistivity measurement well logging curve by the first shallow receiving coil and the second shallow receiving coil at a reverse pulse transmission interval; and / or a deep detection instrument which comprises a deep transmitting coil and two groups of deep receiving coils, is used to emit a bipolar rectangular wave by the deep transmitting coil, and is used to respectively detect a third defect detection well logging curve and a third resistivity measurement well logging curve by a first deep receiving coil and a second deep receiving coil at a forward pulse transmission interval, and is used to respectively detect a fourth defect detection well logging curve and a fourth resistivity measurement well logging curve by the first deep receiving coil and the second deep receiving coil at a reverse pulse transmission interval.

4. The resistivity logging system of claim 3, wherein, The first shallow receiving coil, the second shallow receiving coil, the first deep receiving coil and the second deep receiving coil are all coil groups which are wound in a comparative mode, wherein, the shallow detection instrument is used to respectively detect a first near receiving signal and a second near receiving signal by two sub-coils in the first shallow receiving coil at a forward / reverse pulse transmission interval, so that the first near receiving signal and the second near receiving signal are subtracted to obtain the first defect detection well logging curve / the second defect detection well logging curve, and is used to respectively detect a third near receiving signal and a fourth near receiving signal by two sub-coils in the second shallow receiving coil at a forward / reverse pulse transmission interval, so that the third near receiving signal and the fourth near receiving signal are added to obtain the first resistivity measurement well logging curve / the second resistivity measurement well logging curve; the deep detection instrument is used to respectively detect a first near receiving signal and a second near receiving signal by two sub-coils in the first deep receiving coil at a forward / reverse pulse transmission interval, so that the first near receiving signal and the second near receiving signal are subtracted to obtain the third defect detection well logging curve / the fourth defect detection well logging curve, and is used to respectively detect a third near receiving signal and a fourth near receiving signal by two sub-coils in the second deep receiving coil at a forward / reverse pulse transmission interval, so that the third near receiving signal and the fourth near receiving signal are added to obtain the third resistivity measurement well logging curve / the fourth resistivity measurement well logging curve. The deep detection instrument is configured to detect a first far-receiving signal and a second far-receiving signal by the two sub-coils in the first deep receiving coil respectively during the forward / reverse pulse transmission interval, to perform subtraction operation on the first far-receiving signal and the second far-receiving signal to obtain the third defect detection well curve / the fourth defect detection well curve, and to detect a third far-receiving signal and a fourth far-receiving signal by the two sub-coils in the second deep receiving coil respectively during the forward / reverse pulse transmission interval, to perform addition operation on the third far-receiving signal and the fourth far-receiving signal to obtain the third resistivity measurement well curve / the fourth resistivity measurement well curve.

5. The resistivity logging system of claim 4, wherein, The second shallow receiving coil, the first deep receiving coil and the second deep receiving coil are internally provided with magnetic cores; The duty cycle of the transmission pulse width and the transmission interval time is 1:1, wherein the forward pulse transmission width and the reverse pulse transmission width are T / 4, and T represents a measurement period; There are a plurality of time channel curve sampling points in the time period during the transmission interval of the measurement instrument.

6. The resistivity logging system of claim 4, wherein, The near detection instrument further comprises a near signal processing unit corresponding to the first shallow receiving coil and the second shallow receiving coil, and the far detection instrument further comprises a far signal processing unit corresponding to the first deep receiving coil and the second deep receiving coil, wherein, The near signal processing unit / the far signal processing unit is configured to, after obtaining the receiving signals of the sub-coils, sequentially perform sampling, addition or subtraction operation, signal amplification and digital-to-analog conversion processing on a corresponding pair of sub-coil receiving signals to obtain corresponding well curves.

7. The resistivity logging system of any one of claims 4-6, wherein, The transmission module is further configured to connect with the measurement instrument through the first type of bus, to integrate the defect detection well curve and the resistivity measurement well curve to obtain casing and formation measurement information, and to convert the casing and formation measurement information from the first type of bus communication mode to the second type of bus communication mode, so as to transmit the casing and formation measurement information to the ground through the second type of bus.

8. The resistivity logging system of claim 7, wherein, The transmission module comprises a well depth correlation feature acquisition unit configured to acquire correlation features including casing well fluid temperature, casing collar magnetic positioning and casing outer formation gamma value at a current well depth position; A first bus mode packaging unit is configured to package the shallow detection complete package and / or the deep detection complete package, and the correlation features into a first bus mode complete data stream; A mode conversion unit is configured to convert the first bus mode complete data stream into a second bus mode data stream; A second bus mode packaging unit is configured to package the second bus mode data stream, and transmit the packaged second bus mode packaged data stream to the ground through the second bus.

9. The resistivity logging system of claim 8, wherein, The measurement instrument further comprises: The measurement instrument packaging unit is configured to separately package the defect detection well curve and the resistivity measurement well curve according to the number of the curves, and to package the well curve of the shallow detection instrument into the shallow detection complete package and / or to package the well curve of the deep detection instrument into the deep detection complete package.

10. The resistivity logging system of claim 9, wherein, The measurement instrument packaging unit is further configured to transmit the shallow detection complete package and / or the deep detection complete package to the transmission module in a timing mode through a frame packet, wherein a first bus is idle after transmitting a standard frame packet until transmitting a next standard frame packet.

11. The resistivity logging system of any one of claims 8-10, wherein, The second bus mode packaging unit is configured to transmit the second bus mode packaging data stream containing well logging data in a data frame format, each second bus data frame containing a data header, a data bit, a check bit and an end bit, wherein the data bit is configured to package well logging data, and the second bus is not idle during continuous transmission of data frames.

12. The resistivity logging system of any one of claims 7-11, wherein, The first type of bus is a CAN bus, and the transmission speed of the CAN bus is not less than 800 Kbps; The second type of bus is an AMI bus, and the transmission speed of the AMI bus is not less than 100 Kbps.

13. The resistivity logging system of any one of claims 7-12, wherein, The surface module comprises: a surface panel module configured to decode the casing and formation measurement information to obtain standard well logging data, and to combine the standard well logging data with the corresponding correlation features at different logging depths or logging times to form record standard well logging data; a data processing module connected to the surface panel module through a third type of bus, and configured to realize display of current well logging information, formation interpretation and oil well analysis and evaluation based on the record standard data.

14. The resistivity logging system of any one of claims 7-13, wherein, The second bus is a seven-core cable, wherein a middle core is used as a signal transmission line, and six surrounding cores are used as power supply lines, the six power supply lines including two first power supply groups having a first direct current voltage and one second power supply group having a second direct current voltage, one power supply group including two power supply lines, the first power supply group being configured to provide power supply for the measurement instrument, the second power supply group being configured to provide power supply for the transmission module, and the first direct current voltage being higher than the second direct current voltage.

15. The resistivity logging system of claim 14, wherein, In each power supply group, a cable core of a power supply line is used as a positive pole of the corresponding power supply group, and a steel outer sheath of the power supply line is used as a negative pole of the corresponding power supply group.

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