Method for testing performance of polar plate of water-based micro-resistivity imaging logger

Abstract

The invention discloses a water-based micro-resistivity imaging logging instrument pole plate performance testing method, and belongs to the technical field of petroleum logging. Comprising the following steps: determining parameters of a dynamic signal source and a simulation load network according to a required test environment; the dynamic signal source emits a plurality of excitation voltage signals with the same frequency and amplitude program-controlled dynamic change; after receiving the excitation voltage signal, the simulation load network converts the excitation voltage signal into an intensity current signal for simulating a logging specific well surrounding environment response current signal; and a plurality of electrodes on the polar plate receive the corresponding intensity current signals, a dynamic logging well surrounding environment is simulated, and the performance of the polar plate of the water-based micro-resistivity imaging logging instrument is tested in the environment. Current signals received by each electrode of the polar plate can be dynamically converted in real time, multi-point static characteristic detection similar to a polar plate scale box can be achieved, and whether the response of the measuring effect of the instrument polar plate to the dynamic well surrounding environment is correct and accurate can be detected.

Description

Technical Field

[0001] The invention belongs to the technical field of petroleum logging and relates to a method for testing the performance of a water-based microresistivity imaging logging instrument plate. Background Art

[0002] The water-based microresistivity imaging logging instrument adopts the principle of lateral focusing logging. Through numerical simulation theory, there is a monotonic correlation between the electrode current signal measured by the instrument plate and the formation resistivity; however, in the actual logging process, for low-resistance formations, the measurement signal and the sensitivity of the formation resistivity are reduced due to the influence of mud diversion, and it is necessary to ensure that the plate can "detect accurately"; and for high-resistance formations, the measurement signal and the sensitivity of the formation resistivity are also reduced due to the limitation of small signal detection capability, and it is necessary to ensure that the plate can "detect". Therefore, not only before the logging instrument is lowered into the well, it is necessary to conduct a pre-test on the plate to ensure that the plate works properly and the performance consistency between different plates and between different electrodes in the plate. At the same time, it is also necessary to simulate a variety of specific logging well environments to detect whether the plate's response to the formation resistivity meets the logging requirements. Therefore, the plate performance test is a very important part to ensure the success of the instrument logging. At present, the test of the plate performance of the water-based microresistivity imaging logging instrument is mainly centered on whether the plate works properly and the consistency between plates and buttons. The detection method is through an external plate simulation box, which uses resistors of different resistance values ​​to connect the plate electrodes, and then provides an AC voltage of fixed frequency and fixed amplitude through the instrument to generate an AC current for the plate electrodes to receive. Usually, the resistance value is divided into two gears, high and low, corresponding to two groups of different resistance values. At present, this method realizes multi-point static response measurement of the plate by switching the resistance value, and cannot realize continuous dynamic response measurement, nor can it simulate the logging well environment to test whether the instrument plate performance meets the specific logging index requirements. Summary of the invention

[0003] The purpose of the present invention is to solve the technical problem that the prior art cannot realize continuous dynamic response measurement and cannot simulate the well logging environment to check whether the instrument plate performance meets the specific logging index requirements, and provide a water-based micro-resistivity imaging logging instrument plate performance test method. The plate performance test method in the present invention is upgraded from static response detection to dynamic response detection, and the environmental simulation method is upgraded from resistance simulation to well logging well environment impedance network simulation. The simulation of the real logging state is achieved, and the dynamic logging test of the detection plate response of a variety of specific well logging well environments can be simulated.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions:

[0005] In a first aspect, the present invention provides a method for testing the performance of a plate of a water-based microresistivity imaging logging tool, comprising the following steps:

[0006] Determine the parameters of the dynamic signal source and simulated load network according to the required test environment;

[0007] The dynamic signal source sends out several excitation voltage signals with the same frequency and amplitude that are dynamically changed by program control;

[0008] After receiving the excitation voltage signal, the simulated load network converts it into an intensity current signal of a response current signal of a specific wellbore environment for simulating well logging;

[0009] Several electrodes on the plate receive corresponding strength current signals, simulating the dynamic well logging environment around the well, and the performance of the water-based microresistivity imaging logging tool plate is tested in this environment.

[0010] A further improvement of the present invention is:

[0011] The simulated load network consists of a plate load, a mud load and an electrode load; the mud load includes a first mud load and a second mud load; the electrode load is arranged between a single electrode and a loop pole; the plate load and the second mud load are arranged between a plate body and a loop pole; the first mud load is arranged between a single electrode and a plate body.

[0012] The simulated plate load, simulated mud load and simulated electrode load are all composed of resistors and capacitors connected in parallel.

[0013] Each electrode is connected to a simulated load network; the resistance value of each electrode load is adjusted individually.

[0014] The number of electrodes on the electrode plate is 24; the number of the excitation voltage signals is 24 corresponding to the electrodes.

[0015] The dynamic signal source is composed of a fixed-frequency sine wave generator and an arbitrary waveform generator.

[0016] The fixed-frequency sine wave generator sends out a standard sine wave voltage signal; the arbitrary waveform generator sends out a low-frequency voltage signal, and the low-frequency voltage signal is proportional to the logging dynamic current value.

[0017] The excitation voltage signal is modulated by a standard sinusoidal voltage signal and a low-frequency voltage signal.

[0018] The parameters of the dynamic signal source and the simulated load network determined according to the required test environment are obtained through numerical simulation theory simulation.

[0019] The numerical simulation theory simulation calculates the logging dynamic current value flowing through a plurality of electrodes on the electrode plate in a specific wellbore environment, and adjusts the parameters of the dynamic signal source and the simulation load network according to the calculation results.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The invention discloses a method for testing the performance of a plate of a water-based micro-resistivity imaging logging instrument. First, the parameters of a dynamic signal source and a simulated load network are determined according to a required test environment, and the parameters are used to simulate the real logging dynamic process to detect the overall performance of the instrument plate. The dynamic signal source generates a plurality of excitation voltage signals with the same frequency and amplitude program-controlled dynamic changes, and the simulated dynamic logging well environment is introduced into the plate performance test; the excitation voltage signal becomes an intensity current signal of a simulated logging specific well environment response current signal after passing through the simulated load network, and then each electrode on the plate receives a corresponding intensity current signal, simulating the dynamic logging well environment, and testing the performance of the plate of the water-based micro-resistivity imaging logging instrument under this environment, and the current signal received by each electrode of the plate can be dynamically transformed in real time, thereby simulating the real dynamic logging process under a variety of specific environments, so that the response of the plate of the water-based micro-resistivity imaging logging instrument to a variety of specific environments can be detected more comprehensively and accurately, and the plate performance can be tested in all aspects. Not only can the multi-point static characteristic detection similar to the plate calibration box be realized, but also whether the response of the instrument plate measurement effect to the well environment is correct and accurate can be detected. The present invention is beneficial to the daily maintenance and inspection of the microresistivity imaging logging instrument, and can provide corresponding test data for further improvement and upgrading of the instrument. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0023] Figure 1 It is a flow chart of the method for testing the performance of the electrode plate of the water-based microresistivity imaging logging tool in the present invention;

[0024] Figure 2 A schematic diagram of array electrodes and resistivity imaging of a microresistivity imaging logging tool in the present invention;

[0025] Figure 3 It is a functional block diagram of the dynamic signal source in the present invention;

[0026] Figure 4 This is a block diagram of a simulated load network in the present invention;

[0027] Figure 5 This is a flow chart of plate detection in the present invention. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0029] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0031] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0032] See also Figure 1 The embodiment of the present invention discloses a method for testing the performance of a plate of a water-based microresistivity imaging logging tool, comprising the following steps:

[0033] S1, determine the parameters of the dynamic signal source and the simulated load network according to the required test environment;

[0034] S2, the dynamic signal source sends out several excitation voltage signals with the same frequency and amplitude that are dynamically changed by program control;

[0035] S3, after receiving the excitation voltage signal, the simulated load network converts it into an intensity current signal of a response current signal of a specific wellbore environment for simulating well logging;

[0036] S4, several electrodes on the plate receive corresponding strength current signals, simulating the dynamic logging well environment, and testing the performance of the water-based microresistivity imaging logging tool plate in this environment.

[0037] The plate performance test method in this method is upgraded from static response detection to dynamic response detection, and the environmental simulation method is upgraded from resistance simulation to well logging well environment impedance network simulation. It realizes the simulation of real well logging state and can simulate well logging dynamic test of detection plate response of various specific well logging well environment.

[0038] See also Figure 3The dynamic signal source is a programmable voltage source, which is used to generate an excitation voltage signal with a fixed frequency and a programmable amplitude that can be dynamically changed in real time. The dynamic signal source consists of a fixed frequency sine wave generator and an arbitrary waveform generator. The fixed frequency sine wave generator emits a standard sine wave voltage signal; the arbitrary waveform generator emits a low-frequency voltage signal, and the low-frequency voltage signal is proportional to the dynamic current value of the logging. The excitation voltage signal is modulated by a standard sine wave voltage signal and a low-frequency voltage signal. The frequency and amplitude of the standard sine wave voltage signal are fixed. The amplitude of the low-frequency voltage signal is proportional to the amplitude of the current value flowing through the 24 electrodes of the plate in a specific logging well environment calculated by numerical simulation theory. Since a plate contains 24 array electrodes, the dynamic signal source can provide 24 voltage signal outputs, each output is independent and does not affect each other, and each voltage signal output includes a positive terminal and a negative terminal.

[0039] The main function of the dynamic signal source is to transmit 24 excitation voltage signals with fixed frequency and real-time dynamic amplitude changes. According to the previous simulation calculation results, the arbitrary waveform generator is programmed to simulate the dynamic change process of the electrode receiving current signal amplitude in a specific well environment. The fixed signal frequency generator generates a sine wave with fixed amplitude and frequency, and the sine wave increases the load capacity through the driving function block. After the above two signal carriers are modulated, 24 groups of excitation voltage signals are generated and applied to the simulated load network.

[0040] See also Figure 4 , the simulated load network contains 24 groups, corresponding to the 24 electrodes of the plate. According to the numerical simulation theory, under the action of the current signal at the level of 10 kHz to 100 kHz, the impedance characteristics of the wellbore environment are composed of impedance and capacitive reactance, so the load network is composed of resistance and capacitance in parallel. According to the loop characteristics of the current signal characteristics flowing through the instrument during well logging, the loop load includes the plate-formation load, the plate-mud load and the electrode-formation load. Set 24 electrodes to simulate the electrode load, a total of 24.

[0041] A single simulated load network is composed of multiple resistors and capacitors, including an electrode load, a plate load, a first mud load, and a second mud load. The electrode load is composed of a resistor and a capacitor in parallel. This load simulates the emission of current signals from the electrode to the surrounding formations and finally to the loop pole during logging. The plate load is composed of a resistor and a capacitor in parallel. This load simulates the emission of current signals from the plate to the surrounding formations and finally to the loop pole during logging. The first mud load is composed of a resistor and a capacitor in parallel. This load simulates the emission of current signals from the electrode to the mud and finally to the plate body during logging. The second mud load is composed of a resistor and a capacitor in parallel. This load simulates the emission of current signals from the plate to the mud and finally to the loop pole during logging.

[0042] When the positive and negative ends of the excitation voltage signal of the dynamic signal source act on the electrode load and loop pole of the simulated load network, a current signal will be generated. By programming the dynamic signal source amplitude and adjusting the resistance and capacitance values ​​of the simulated load network, different types of plate performance tests can be simulated. For example, when the output voltage amplitude of the dynamic signal source remains unchanged and the resistance values ​​of the 24 channels of the simulated load network are all the same, the consistency performance of the 24 electrodes of the plate can be tested. When the output voltage amplitude of the dynamic signal source remains unchanged and the resistance values ​​of the 24 channels of the simulated load network increase in an arithmetic progression, the consistency performance between the instrument plates can be tested. The dynamic signal source output voltage is programmed, and when the resistance and capacitance values ​​of the 24 channels of the simulated load network are set differently, specific wellbore formation environmental characteristics can be simulated to test the image quality of the plate resistivity imaging.

[0043] See also Figure 5 First, the parameters of the dynamic signal source and the simulated load network are selected according to the content to be tested. The parameters include the real-time amplitude of the dynamic signal source output voltage signal and the 24 resistance and capacitance parameters of the simulated load network. Secondly, the dynamic signal source is started to transmit the voltage signal through the simulated load network to generate a current signal for the 24 electrodes to receive. Finally, after the electrode receives the current signal, the performance of the electrode plate is tested.

[0044] The working principle of the present invention is as follows:

[0045] The present invention aims to improve the accuracy and comprehensiveness of the plate performance test of the water-based microresistivity imaging logging instrument, and to perform plate testing in a dynamic measurement method that simulates a real well environment. Figure 2 As shown in the figure, for the water-based microresistivity imaging logging instrument, the plate is in an open state during logging, and the 24 electrodes on the plate are close to the well wall. At the same time, the instrument emits an alternating current, which returns to the loop electrode on the top of the instrument through the mud column in the well and the surrounding formation. Since the array electrode in the middle of the plate is at the same potential as the plate body, the current emitted by the array electrode is forced to enter the formation perpendicular to the well wall under the effect of focusing. As a result, the current of the array electrode is proportional to the conductivity flowing through the formation. During the upward lifting logging process, the instrument measures the resistivity of a certain section of the well environment. At the same time, the well environment resistivity changes dynamically with depth, including various specific well environments.

[0046] In summary, the plate test method that simulates the real dynamic logging process under various specific environments first calculates the instrument plate response parameters corresponding to various specific wellbore environmental characteristics (such as cracks, thin layers, etc.) based on the numerical simulation calculation results of the physical model of the water-based microresistivity imaging logging instrument, combined with the logging data of the historical microresistivity imaging logging instrument in the region, that is, the current received by the 24 electrodes of the plate and the total emission current of the instrument. Secondly, 24 current signals identical to the above results are generated for the plate electrodes to receive. In this way, the overall performance of the instrument plate is tested by simulating the real logging dynamic process.

[0047] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for testing the performance of a water-based microresistivity imaging logging tool plate, characterized in that: The following steps are involved: Determine the parameters of the dynamic signal source and simulated load network according to the required test environment; The dynamic signal source sends out several excitation voltage signals with the same frequency and amplitude that are dynamically changed by program control; After receiving the excitation voltage signal, the simulated load network converts it into an intensity current signal of a response current signal of a specific wellbore environment for simulating well logging; Several electrodes on the plate receive corresponding strength current signals, simulating the dynamic well logging environment around the well, and the performance of the water-based microresistivity imaging logging tool plate is tested in this environment.

2. The method for testing the performance of a water-based microresistivity imaging logging tool plate according to claim 1, characterized in that: The simulated load network consists of a plate load, a mud load and an electrode load; the mud load includes a first mud load and a second mud load; the electrode load is arranged between a single electrode and a loop pole; the plate load and the second mud load are arranged between a plate body and a loop pole; the first mud load is arranged between a single electrode and a plate body.

3. The method for testing the plate performance of a water-based microresistivity imaging logging tool according to claim 2, characterized in that: The simulated plate load, simulated mud load and simulated electrode load are all composed of resistors and capacitors connected in parallel.

4. The method for testing the performance of a water-based microresistivity imaging logging tool plate according to claim 1, characterized in that: Each electrode is connected to a simulated load network; the resistance value of each electrode load is adjusted individually.

5. The method for testing the performance of a water-based microresistivity imaging logging tool plate according to claim 1, characterized in that: The number of electrodes on the electrode plate is 24; the number of the excitation voltage signals is 24 corresponding to the electrodes.

6. The method for testing the performance of a water-based microresistivity imaging logging tool plate according to claim 1, characterized in that: The dynamic signal source is composed of a fixed-frequency sine wave generator and an arbitrary waveform generator.

7. The method for testing the performance of a water-based microresistivity imaging logging tool plate according to claim 6, characterized in that: The fixed-frequency sine wave generator sends out a standard sine wave voltage signal; the arbitrary waveform generator sends out a low-frequency voltage signal, and the low-frequency voltage signal is proportional to the logging dynamic current value.

8. The method for testing the performance of a water-based microresistivity imaging logging tool plate according to claim 7, characterized in that: The excitation voltage signal is modulated by a standard sinusoidal voltage signal and a low-frequency voltage signal.

9. The method for testing the performance of a water-based microresistivity imaging logging tool plate according to claim 1, characterized in that: The parameters of the dynamic signal source and the simulated load network determined according to the required test environment are obtained through numerical simulation theory simulation.

10. The method for testing the performance of a water-based microresistivity imaging logging tool plate according to claim 9, characterized in that: The numerical simulation theory simulation calculates the logging dynamic current value flowing through a plurality of electrodes on the electrode plate in a specific wellbore environment, and adjusts the parameters of the dynamic signal source and the simulation load network according to the calculation results.

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