A neutron logging method, system and electronic device for measuring formation porosity

Abstract

The present invention relates to the technical field of neutron logging, and particularly to a neutron logging method, system and electronic device for measuring formation porosity. The method includes: establishing a formation porosity model for characterizing the relationship between formation porosity, formation density and thermal neutron count ratio; substituting the thermal neutron count ratio of the target formation of the well to be measured and the formation density of the target formation of the well to be measured into the formation porosity model to obtain the formation porosity of the target formation of the well to be measured. By introducing the formation density, the sensitivity of measuring the formation porosity in the target formation such as a high-porosity rock formation is improved. And the instruments used in this method are all common instrument devices in this field, which are convenient for operation, implementation and testing.

Description

Background Art

[0002] Formation porosity measurement is a very important part of open-hole logging. In traditional porosity measurement, an Am-Be isotope chemical source is used as the radiation source. However, this method has disadvantages: on the one hand, before / after logging, manual addition / removal of the radiation source is required, which poses a radiation hazard to operators; on the other hand, there is a risk of the source getting stuck downhole during chemical source logging. Once the fishing fails, it will cause radiation hazards to the environment.

[0003] With the development of controllable neutron source technology and environmental protection requirements, more and more oil companies and related researchers have started to study the use of controllable neutron sources for formation porosity measurement. However, the deceleration length of high-energy neutrons emitted by controllable neutron sources in the formation is much longer than that using chemical sources, reducing the sensitivity of the thermal neutron ratio of near and far detectors to porosity, resulting in large measurement errors at high porosities and affecting its application in oil and gas exploration and development. Therefore, it is necessary to consider improving the sensitivity of porosity measurement.

[0004] In addition, since the formula of the chemical source porosity logging tool is simple, the number of calibration coefficients is small, and there are a large number of measured data at home and abroad, the existing porosity standard calibration wells can ensure the calibration requirements of the chemical source porosity logging tool. However, the formula of the controllable source porosity neutron logging tool is complex and the number of calibration coefficients is large. Especially as a new logging tool, there are currently no large amounts of measured data in China. Therefore, relying solely on the existing porosity standard calibration wells cannot meet the calibration requirements of the tool. To ensure the accuracy of instrument measurement, more standard calibration wells are needed to meet the calibration of the tool. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a neutron logging method, system and electronic device for measuring formation porosity in view of the deficiencies of the prior art.

[0006] The technical solution of a neutron logging method for measuring formation porosity of the present invention is as follows:

[0007] Establish a formation porosity model for characterizing the relationship between formation porosity, formation density and thermal neutron count ratio;

[0008] Substitute the thermal neutron count ratio of the target formation of the well to be measured and the formation density of the target formation of the well to be measured into the formation porosity model to obtain the formation porosity of the target formation of the well to be measured.

[0009] The beneficial effects of a neutron logging method for measuring formation porosity of the present invention are as follows:

[0010] Compared with the prior art, the formula of the present invention is concise and the measurement accuracy is high. By introducing formation density, the sensitivity of formation porosity measurement in target formations such as high-porosity rock formations is improved. Moreover, the instruments used in this method are all common instruments and equipment in this field, which are convenient for operation, implementation and testing.

[0011] On the basis of the above solution, a neutron logging method for measuring formation porosity of the present invention can be further improved as follows.

[0012] Further, the formation porosity model is: Wherein, represents formation porosity, R t is the thermal neutron count ratio, ρ is the formation density, f(R t ) = E(R t ) 2 + FR t + G, and A, B, C, D, E, F, G are all calibration coefficients.

[0013] Further, the process of obtaining the specific values of A, B, C, D, E, F, G includes:

[0014] S10. Place the formation porosity neutron logging tool into the porosity standard calibration well, measure the near-thermal neutron detector count and the far-thermal neutron detector count in the porosity standard calibration wells with different porosities, and obtain the experimental measurement values of the ratio of the near-thermal neutron count to the far-thermal neutron count of the formation porosity neutron logging tool in the porosity standard calibration wells with different porosities

[0015] S11. Construct Monte Carlo transport models for the porosity standard calibration wells with different porosities and the formation porosity neutron logging tool. Through the Monte Carlo transport models, simulate and obtain the ratio between the first simulated value of the near-thermal neutron count and the first simulated value of the far-thermal neutron count of the formation porosity neutron logging tool

[0016] S12. Establish a simulation relationship, and the simulation relationship is:

[0017] S13. Mix the formation materials of the porosity standard calibration well with pure water in different volume percentages, substitute them into the Monte Carlo transport model, obtain a calibrated simulation well with a new porosity, and numerically simulate and obtain the ratio between the second simulated value of the near-thermal neutron count and the second simulated value of the far-thermal neutron count of the formation porosity neutron logging tool

[0018] S14. According to the simulation relationship for Make corrections to obtain the corrected thermal neutron count ratio of the formation porosity neutron logging tool in the calibrated analog well. Indicates the new formation porosity;

[0019] S15. Take As the thermal neutron count ratio R in the formation porosity model t , take the formation density and porosity of the porosity standard calibration well as ρ and Substitute into the formation porosity model, and take As the thermal neutron count ratio R in the formation porosity model t , take the formation density and porosity of the porosity calibrated analog well as ρ and Substitute into the formation porosity model, and solve for the specific values of A, B, C, D, E, F, and G.

[0020] Furthermore, it also includes:

[0021] Measure the thermal neutron count ratio of the target formation of the well to be measured through a neutron logging tool.

[0022] The technical solution of a neutron logging system for measuring formation porosity of the present invention is as follows:

[0023] It includes a model establishment module and a substitution calculation module;

[0024] The model establishment module is used to: establish a formation porosity model for characterizing the relationship between formation porosity, formation density, and thermal neutron count ratio;

[0025] The substitution calculation module is used to: substitute the thermal neutron count ratio of the target formation of the well to be measured and the formation density of the target formation of the well to be measured into the formation porosity model to obtain the formation porosity of the target formation of the well to be measured.

[0026] The beneficial effects of a neutron logging system for measuring formation porosity of the present invention are as follows:

[0027] Compared with the prior art, the formula of the present invention is simple, the measurement accuracy is high, and by introducing the formation density, the sensitivity of measuring the formation porosity in the target formation such as high-porosity rock layers is improved. And the instruments used in this method are all common instrument devices in the field, which are convenient for operation, implementation, and testing.

[0028] On the basis of the above solution, a neutron logging system for measuring formation porosity of the present invention can also be improved as follows.

[0029] Furthermore, the formation porosity model is: Wherein, represents the formation porosity, R t is the thermal neutron count ratio, ρ is the formation density, f(R t ) = E(R t ) 2 + FR t + G, where A, B, C, D, E, F, and G are all calibration coefficients.

[0030] Furthermore, the model establishment module is also used for:

[0031] Put the formation porosity neutron logging tool into the porosity standard calibration well, measure the near-thermal neutron detector count and the far-thermal neutron detector count in the porosity standard calibration well with different porosities, and obtain the experimental measurement value of the ratio of the near-thermal neutron count to the far-thermal neutron count of the formation porosity neutron logging tool in the porosity standard calibration well with different porosities

[0032] Construct Monte Carlo transport models for the porosity standard calibration wells with different porosities and the formation porosity neutron logging tool. Through the Monte Carlo transport models, simulate and obtain the ratio between the first simulated value of the near-thermal neutron count and the first simulated value of the far-thermal neutron count of the formation porosity neutron logging tool

[0033] Establish a simulation relationship, and the simulation relationship is:

[0034] Mix the formation materials of the porosity standard calibration well with pure water according to different volume percentages, substitute them into the Monte Carlo transport model, obtain a calibrated simulation well with a new porosity, and through numerical simulation, obtain the ratio between the second simulated value of the near-thermal neutron count and the second simulated value of the far-thermal neutron count of the formation porosity neutron logging tool

[0035] According to the simulation relationship Perform correction to obtain the corrected thermal neutron count ratio of the formation porosity neutron logging tool in the calibrated simulation well represents the new formation porosity;

[0036] Take as the thermal neutron count ratio R in the formation porosity model t , take the formation density and porosity of the porosity standard calibration well as ρ and Substitute them into the formation porosity model, and take as the thermal neutron count ratio R in the formation porosity model t, taking the formation density and porosity that simulate the well porosity of the scale as ρ and Substitute into the formation porosity model to solve for the specific values of A, B, C, D, E, F, and G.

[0037] Furthermore, it further includes a measurement module, and the measurement module is used for:

[0038] Measure the thermal neutron count ratio of the target formation of the well to be measured through a neutron logging instrument.

[0039] A storage medium of the present invention stores instructions, and when a computer reads the instructions, it causes the computer to execute a neutron logging method for measuring formation porosity described in any one of the above.

[0040] An electronic device of the present invention includes a processor and the above storage medium, and the processor executes the instructions in the storage medium. Description of the Drawings

[0041] Figure 1 It is a schematic flow chart of a neutron logging method for measuring formation porosity according to an embodiment of the present invention;

[0042] Figure 2 It is a schematic flow chart of the calibration of a neutron logging instrument for measuring formation porosity according to an embodiment of the present invention;

[0043] Figure 3 It is a relationship diagram between the formation porosity obtained by the present invention and the true formation porosity.

[0044] Figure 4 It is a schematic flow chart of a neutron logging system for measuring formation porosity according to an embodiment of the present invention. Detailed Embodiments

[0045] As Figure 1 shown, a neutron logging method for measuring formation porosity according to an embodiment of the present invention includes the following steps:

[0046] S1. Establish a formation porosity model for characterizing the relationship between formation porosity, formation density, and thermal neutron count ratio;

[0047] Among them, the formation porosity model is: Among them, represents the formation porosity, R t is the thermal neutron count ratio, ρ is the formation density, f(R t ) = E(R t ) 2 + FR t + G, and A, B, C, D, E, F, and G are all calibration coefficients.

[0048] S2. Substitute the thermal neutron count ratio of the target formation of the well to be measured and the formation density of the target formation of the well to be measured into the formation porosity model to obtain the formation porosity of the target formation of the well to be measured. Wherein, the target formation is the formation at the preset depth of the well to be measured.

[0049] Wherein, the thermal neutron count ratio of the target formation of the well to be measured is measured by a neutron logging tool.

[0050] Compared with the prior art, the formula of the present invention is simple and the measurement accuracy is high. By introducing the formation density, the sensitivity of the formation porosity measurement in the target formation such as high-porosity rock formations is improved. And the thermal neutron counter used in this method, such as the He3 counter tube, is a common device in well logging tools in this field, which is convenient for operation, implementation and testing.

[0051] Wherein, the reason for improving the sensitivity of the formation porosity measurement in the target formation such as high-porosity rock formations by introducing the formation density is as follows:

[0052] In traditional formation porosity measurement methods, generally the formula "aln(R t ) + b" is used to calculate the formation porosity of the target formation. However, when the target formation is a high-porosity rock formation and the neutron source energy of the neutron logging tool is relatively high, the change of R t with the formation porosity is not obvious, resulting in a decrease in the measurement sensitivity of the formation porosity. In the present invention, by introducing the formation density, when the formation porosity changes, the change of the formation density is obvious, thereby improving the sensitivity of the formation porosity measurement in the target formation such as high-porosity rock formations.

[0053] Optionally, in the above technical solution, it further includes: measuring the thermal neutron count ratio of the target formation of the well to be measured by a neutron logging tool. Specifically:

[0054] Determine the ratio between the thermal neutron count of the target formation in the well to be measured detected by the near neutron detector of the neutron logging tool and the thermal neutron count of the target formation in the well to be measured detected by the far neutron detector of the neutron logging tool as the thermal neutron count ratio of the target formation of the well to be measured.

[0055] Optionally, in the above technical solution, the process of obtaining the specific values of A, B, C, D, E, F, and G includes:

[0056] It further includes: the process of obtaining the specific values of A, B, C, D, E, F, and G includes:

[0057] S10. Place the formation porosity neutron logging instrument into a porosity standard calibration well, measure the near-thermal neutron detector counts and far-thermal neutron detector counts in the porosity standard calibration wells of different porosities, and obtain experimental measurement values ​​of the ratio of the near-thermal neutron counts to the far-thermal neutron counts of the formation porosity neutron logging instrument in the porosity standard calibration wells of different porosities.

[0058] S11, constructing a Monte Carlo transport model of porosity standard calibration wells with different porosities and a formation porosity neutron logging instrument, and simulating the ratio between the first simulated value of the near thermal neutron count and the first simulated value of the far thermal neutron count of the formation porosity neutron logging instrument through the Monte Carlo transport model

[0059] S12, establish a simulation relationship, the simulation relationship is:

[0060] S13, the formation material of the porosity standard calibration well is mixed with pure water according to different volume percentages, and substituted into the Monte Carlo transport model to obtain a calibration simulation well with a new porosity, and the ratio between the second simulation value of the near thermal neutron count and the second simulation value of the far thermal neutron count of the formation porosity neutron logging instrument is obtained by numerical simulation.

[0061] S14, according to the simulation relationship Correction is performed to obtain the corrected thermal neutron count ratio of the formation porosity neutron logging instrument in the calibration simulation well. Indicates the new formation porosity;

[0062] S15. As the thermal neutron count ratio R in the formation porosity model t , the formation density and porosity of the porosity standard well are used as ρ and Substitute into the formation porosity model and As the thermal neutron count ratio R in the formation porosity model t , the formation density and porosity of the porosity scale simulation well are used as ρ and Substitute the formation porosity model and solve to obtain specific values ​​of A, B, C, D, E, F, and G.

[0063] A neutron logging method for measuring formation porosity of the present invention is described below by means of an embodiment, which specifically includes:

[0064] S100, establish formation porosity model: Among them, A, B, C, D, E, F, and G are scale factors;

[0065] S101. Measure the near thermal neutron detector count and far thermal neutron detector count in porosity standard calibration wells with different porosities, and obtain the experimental measurement values of the ratio of the near thermal neutron count to the far thermal neutron count of the formation porosity neutron logging instrument in the porosity standard calibration wells with different porosities.

[0066] S102. Construct Monte Carlo transport models for porosity standard calibration wells with different porosities and the formation porosity neutron logging instrument. Through the Monte Carlo transport model, simulate and obtain the first simulation value of the ratio of the near thermal neutron count to the far thermal neutron count of the formation porosity neutron logging instrument.

[0067] S103. Utilize the results of steps S101 and S102 to establish a simulation relationship between the experimental measurement value and the simulation value of the thermal neutron count ratio. The simulation relationship is:

[0068] S104. Mix the formation materials of the porosity standard calibration well with pure water according to different volume percentages, substitute them into the Monte Carlo transport model, obtain a new porosity calibration simulation well, and obtain the ratio between the second simulation value of the near thermal neutron count and the second simulation value of the far thermal neutron count of the formation porosity neutron logging instrument through numerical simulation.

[0069] S105. Correct the second ratio of the thermal neutron count ratio according to the simulation relationship in step S103 to obtain the corrected thermal neutron count ratio of the formation porosity neutron logging instrument in the calibration simulation well. represents the new formation porosity;

[0070] S106. Take and as the thermal neutron count ratio R in the formation porosity model t ;

[0071] S107. Substitute the thermal neutron count ratio R in step S106 t together with the corresponding formation density and porosity into the formula of the formation porosity and substitute them into the formation porosity model Solve to obtain the specific values of the calibration coefficients A, B, C, D, E, F, G;

[0072] S108. Obtain the formation density of the target formation of the well to be measured through a compensated density logging tool;

[0073] S109. Obtain the thermal neutron count ratio of the target formation of the well to be measured through a formation porosity neutron logging tool;

[0074] S110. Substitute the formation density in S107 and the thermal neutron count ratio in S108 into the formation porosity model to obtain the formation porosity of the target formation of the well to be measured.

[0075] Through Figure 3 Illustrate the accuracy of the formation porosity of the target formation obtained by the present invention. Specifically:

[0076] As Figure 3 shown, when the true formation porosity of the target formation is 32.5 p.u., the ordinate of the corresponding black rectangle is: the formation porosity calculated by the present invention, which is 32.57 p.u., and the accuracy reaches more than 99.7%.

[0077] In the above embodiments, although the steps are numbered S1, S2, etc., they are only specific embodiments given in the present application. Those skilled in the art can adjust the execution order of S1, S2, etc. according to the actual situation, which is also within the protection scope of the present invention. It can be understood that in some embodiments, it may include some or all of the above embodiments.

[0078] As Figure 4 shown, a neutron logging system 200 for measuring formation porosity according to the present invention includes a model establishment module 210 and a substitution calculation module 220;

[0079] The model establishment module 210 is used for: establishing a formation porosity model for characterizing the relationship between formation porosity, formation density, and thermal neutron count ratio;

[0080] The substitution calculation module 220 is used for: substituting the thermal neutron count ratio of the target formation of the well to be measured and the formation density of the target formation of the well to be measured into the formation porosity model to obtain the formation porosity of the target formation of the well to be measured.

[0081] Compared with the prior art, the formula of the present invention is simple and the measurement accuracy is high. By introducing the formation density, the sensitivity of measuring the formation porosity in the target formation such as high-porosity rock formations is improved. And the instruments used in this method are all common instrument devices in the art, which are convenient for operation, implementation, and testing.

[0082] Optionally, in the above technical solution, the formation porosity model is: Among them, represents the formation porosity, R t is the thermal neutron count ratio, ρ is the formation density, f(R t ) = E(R t ) 2 + FR t + G, where A, B, C, D, E, F, and G are all calibration coefficients.

[0083] Optionally, in the above technical solution, the model establishment module 210 is further configured to:

[0084] Place the formation porosity neutron logging tool in the porosity standard calibration well, measure the near thermal neutron detector count and the far thermal neutron detector count in the porosity standard calibration well with different porosities, and obtain the experimental measurement value of the ratio of the near thermal neutron count to the far thermal neutron count of the formation porosity neutron logging tool in the porosity standard calibration well with different porosities

[0085] Construct Monte Carlo transport models for the porosity standard calibration wells with different porosities and the formation porosity neutron logging tool. Through the Monte Carlo transport model, simulate the ratio between the first simulated value of the near thermal neutron count and the first simulated value of the far thermal neutron count of the formation porosity neutron logging tool

[0086] Establish a simulation relationship, and the simulation relationship is:

[0087] Mix the formation materials of the porosity standard calibration well with pure water according to different volume percentages, substitute them into the Monte Carlo transport model to obtain a calibrated simulation well with a new porosity, and through numerical simulation, obtain the ratio between the second simulated value of the near thermal neutron count and the second simulated value of the far thermal neutron count of the formation porosity neutron logging tool

[0088] According to the simulation relationship Perform correction to obtain the corrected thermal neutron count ratio of the formation porosity neutron logging tool in the calibrated simulation well Represent the new formation porosity;

[0089] As the thermal neutron count ratio R in the formation porosity model t , take the formation density and porosity of the porosity standard calibration well as ρ and Substitute them into the formation porosity model, and As the thermal neutron count ratio R in the formation porosity model t , take the formation density and porosity of the porosity calibrated simulation well as ρ and Substitute them into the formation porosity model, and calculate the specific values of A, B, C, D, E, F, and G.

[0090] Optionally, in the above technical solution, it further includes a measurement module, and the measurement module is used for:

[0091] Measure the thermal neutron count ratio of the target formation of the well to be measured through the neutron logging tool.​

[0092] For the parameters and the steps for each unit module in the neutron logging system 200 for measuring formation porosity of the present invention to achieve corresponding functions, reference may be made to the parameters and steps in the embodiments of the neutron logging method for measuring formation porosity in the foregoing text, which will not be elaborated herein.

[0093] A storage medium of the present invention stores instructions, and when a computer reads the instructions, the computer is caused to execute the neutron logging method for measuring formation porosity described in any one of the foregoing items.

[0094] An electronic device of the present invention includes a processor and the foregoing storage medium, and the processor executes the instructions in the storage medium. Among them, the electronic device can be a computer, a mobile phone, etc.

[0095] Those skilled in the art know that the present invention can be implemented as a system, a method, or a computer program product.

[0096] Therefore, the present disclosure can be specifically implemented in the following forms, that is: it can be all hardware, can also be all software (including firmware, resident software, microcode, etc.), and can also be a form of combination of hardware and software, generally referred to as "circuit", "module" or "system" in this article. In addition, in some embodiments, the present invention can also be implemented in the form of a computer program product in one or more computer-readable media, and the computer-readable media contains computer-readable program code.

[0097] Any combination of one or more computer-readable media can be adopted. The computer-readable media can be computer-readable signal media or computer-readable storage media. The computer-readable storage media can be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination of the above. More specific examples (non-exhaustive list) of the computer-readable storage media include: an electrical connection having one or more wires, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this document, the computer-readable storage media can be any tangible medium that contains or stores a program, and the program can be used by or in combination with an instruction execution system, apparatus, or device.

[0098] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A neutron logging method for measuring formation porosity, characterized in that, Comprising: Establishing a formation porosity model for characterizing the relationship between formation porosity, formation density, and thermal neutron count ratio; Substituting the thermal neutron count ratio of the target formation of the well to be measured and the formation density of the target formation of the well to be measured into the formation porosity model to obtain the formation porosity of the target formation of the well to be measured; The formation porosity model is as follows: Wherein, represents the formation porosity, R t is the thermal neutron count ratio, ρ is the formation density, f(R t ) = E(R t ) 2 + FR t + G, and A, B, C, D, E, F, and G are all calibration coefficients; Also comprising: the process of obtaining the specific values of A, B, C, D, E, F, G, including: S10. Place the formation porosity neutron logging tool in the porosity standard calibration well, measure the near thermal neutron detector count and the far thermal neutron detector count in the porosity standard calibration well with different porosities, and obtain the experimental measurement value of the ratio of the near thermal neutron count to the far thermal neutron count of the formation porosity neutron logging tool in the porosity standard calibration well with different porosities S11. Construct porosity standard calibration wells with different porosities and Monte Carlo transport models of formation porosity neutron logging tools. Through the Monte Carlo transport models, simulate the ratio between the first simulated value of near-thermal neutron counts and the first simulated value of far-thermal neutron counts of the formation porosity neutron logging tools S12. Establish a simulation relationship, and the simulation relationship is as follows: S13. Mix the formation materials of the porosity standard calibration well with pure water according to different volume percentages, substitute them into the Monte Carlo transport model to obtain a calibrated simulation well with a new porosity, and obtain the ratio between the second simulation value of the near-thermal neutron count and the second simulation value of the far-thermal neutron count of the formation porosity neutron logging instrument through numerical simulation S14. According to the simulation relation, perform correction to obtain the corrected thermal neutron count ratio of the formation porosity neutron logging tool in the calibration simulation well which represents the new formation porosity; S15. Substitute as the thermal neutron count ratio R in the formation porosity model t , and take the formation density and porosity of the standard calibration well as ρ and Substitute into the formation porosity model. Take as the thermal neutron count ratio R in the formation porosity model t , and take the formation density and porosity of the porosity calibration simulation well as ρ and Substitute into the formation porosity model, and solve for the specific values of A, B, C, D, E, F, and G.

2. A neutron logging method for measuring formation porosity according to claim 1, characterized in that, Also comprising: Measuring the thermal neutron count ratio of the target formation of the well to be measured by a neutron logging instrument.

3. A neutron logging system for measuring formation porosity, characterized in that, Comprising a model establishment module and a substitution calculation module; The model establishment module is configured to: establish a formation porosity model for characterizing the relationship between formation porosity, formation density, and thermal neutron count ratio; The substitution calculation module is configured to: substitute the thermal neutron count ratio of the target formation of the well to be measured and the formation density of the target formation of the well to be measured into the formation porosity model to obtain the formation porosity of the target formation of the well to be measured; The formation porosity model is as follows: Wherein, represents the formation porosity, R t is the thermal neutron count ratio, ρ is the formation density, f(R t ) = E(R t ) 2 + FR t + G, and A, B, C, D, E, F, and G are all calibration coefficients; The model establishment module is further configured to: Place the formation porosity neutron logging tool in the porosity standard calibration well, measure the near thermal neutron detector count and the far thermal neutron detector count in the porosity standard calibration well with different porosities, and obtain the experimental measurement values of the ratio of the near thermal neutron count to the far thermal neutron count of the formation porosity neutron logging tool in the porosity standard calibration well with different porosities Construct a porosity standard calibration well with different porosities and a Monte Carlo transport model of a formation porosity neutron logging tool. Through the Monte Carlo transport model, simulate the ratio between the first simulated value of the near-thermal neutron count and the first simulated value of the far-thermal neutron count of the formation porosity neutron logging tool Establish a simulation relationship, and the simulation relationship is as follows: Mix the formation materials of the porosity standard calibration well with pure water in different volume percentages, substitute them into the Monte Carlo transport model to obtain a calibrated simulation well with a new porosity, and obtain the ratio between the second simulation value of the near-thermal neutron count and the second simulation value of the far-thermal neutron count of the formation porosity neutron logging tool through numerical simulation According to the simulation relation, perform correction to obtain the corrected thermal neutron count ratio of the formation porosity neutron logging tool in the calibrated simulation well which represents the new formation porosity; Take as the thermal neutron count ratio R in the formation porosity model t , take the formation density and porosity of the porosity standard calibration well as ρ and substitute them into the formation porosity model, and take as the thermal neutron count ratio R in the formation porosity model t , take the formation density and porosity of the porosity calibration simulation well as ρ and substitute them into the formation porosity model, and solve for the specific values of A, B, C, D, E, F, and G.

4. A neutron logging system for measuring formation porosity according to claim 3, characterized in that, Also comprising a measurement module, the measurement module is configured to: Measure the thermal neutron count ratio of the target formation of the well to be measured by a neutron logging instrument.

5. A storage medium, characterized in that, The storage medium stores instructions, and when a computer reads the instructions, the computer is caused to execute a neutron logging method for measuring formation porosity according to any one of claims 1 to 2.

6. An electronic device, characterized in that, Comprising a processor and the storage medium according to claim 5, and the processor executes the instructions in the storage medium.

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