High shale oil reservoir porosity measurement method and system

Abstract

The present application relates to the technical field of oil and gas exploration, and provides a high argillaceous shale oil reservoir porosity measurement method and system, the method comprising: obtaining two standard plunger samples and crushed samples; measuring the standard plunger sample saturated oil one-dimensional nuclear magnetic resonance T2 spectrum and the standard plunger sample saturated water one-dimensional nuclear magnetic resonance T2 spectrum; normalizing to obtain parallel sample cross-saturation T2 spectrum; establishing a linear relationship between the standard sample signal intensity and porosity; substituting the parallel sample cross-saturation T2 spectrum and the crushed sample 350 DEG C heated nuclear magnetic resonance T2 spectrum into the linear relationship to obtain the parallel sample cross-saturation porosity and the crushed sample 350 DEG C heated porosity; and obtaining the total porosity based on the parallel sample cross-saturation porosity and the crushed sample 350 DEG C heated porosity. The present application can fully obtain the pore space occupied by the dispersed components by performing oil saturation and water saturation nuclear magnetic resonance on the parallel plunger samples and performing normalization processing and analysis.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil and gas exploration, and particularly relates to a high-mud shale oil reservoir porosity measurement method and system. BACKGROUND

[0002] Unconventional oil and gas resources with huge potential have gradually become a research hotspot in recent years. Shale oil and gas reservoirs, as a kind of unconventional oil and gas reservoirs, have attracted more and more attention in recent years. Shale is both a source rock and a reservoir, with typical self-generation and self-storage characteristics, and complex reservoir space, including primary pores, secondary pores and microfractures. Since shale oil and gas reservoirs are obviously different from conventional oil and gas reservoirs, the evaluation method of conventional oil and gas reservoirs cannot meet the comprehensive evaluation of shale oil and gas reservoirs. As an important parameter for the evaluation of unconventional reservoirs, accurate determination of shale oil reservoir porosity is helpful for rapid and effective evaluation of shale reservoirs, production capacity prediction and reserve calculation. When the core analysis porosity is studied under the ground experimental condition, the core used inevitably loses oil, gas and water, and the conventional method cannot completely detect the porosity of the lost components, resulting in inconsistency between the laboratory measured shale oil and gas reservoir porosity and the real porosity underground.

[0003] Shale rock porosity measurement usually uses pressurized saturation method, but high-mud shale reservoirs are affected by reservoir wettability, development of small pores and high-mud content, and the conventional pressurized saturation method has disadvantages. Only pressurized saturation of oil will lead to inaccurate measurement of clay bound space, and only pressurized saturation of water cannot completely measure oil-wet pore space. SUMMARY

[0004] The present application aims to solve at least one of the technical problems in the background art, and provides a high-mud shale oil reservoir porosity measurement method and system.

[0005] To achieve the above-mentioned purpose, the present application provides a high-mud shale oil reservoir porosity measurement method, comprising:

[0006] The shale sample is obtained, the shale sample is cut and processed to form two standard plunger samples with similar lengths, the remaining shale sample is crushed to 60 mesh by a core crusher, and the crushed sample with the same mass as the average mass of the two standard plunger samples is taken out for use;

[0007] One of the standard plunger samples is vacuumized, then saturated with aviation kerosene and pressurized, and after being taken out, the one-dimensional nuclear magnetic resonance T2 spectrum of the standard plunger sample saturated with oil is measured; the other standard plunger sample is vacuumized, then saturated with distilled water and pressurized, and after being taken out, the one-dimensional nuclear magnetic resonance T2 spectrum of the standard plunger sample saturated with water is measured; the one-dimensional nuclear magnetic resonance T2 spectrum of the standard plunger sample saturated with oil and the one-dimensional nuclear magnetic resonance T2 spectrum of the standard plunger sample saturated with water are normalized by quality, then put into the same coordinate system, and the maximum value of the signal intensity component at each point of the two is taken to obtain a new T2 spectrum, which is denoted as a cross-saturation T2 spectrum of the parallel sample;

[0008] The crushed sample is heated at 350 DEG C for 10 hours to remove hydrocarbon substances in the crushed sample, and the remaining part is a rock skeleton and kerogen; the measured nuclear magnetic signal is taken as a core background signal; and the measured nuclear magnetic signal is inverted to obtain a crushed sample 350 DEG C heating nuclear magnetic resonance T2 spectrum;

[0009] The 1%, 3%, 5%, 10% and 15% porosity standard samples provided with the nuclear magnetic resonance instrument are respectively placed into a holder to measure the nuclear magnetic resonance signals of the standard samples, and a linear relationship between the signal intensity and the porosity is established; the cross-saturation T2 spectrum of the parallel sample and the crushed sample 350 DEG C heating nuclear magnetic resonance T2 spectrum are substituted into the linear relationship to obtain a T2 spectrum with the porosity as the ordinate and the transverse relaxation time as the abscissa, so that the cross-saturation T2 spectrum of the parallel sample and the crushed sample 350 DEG C heating nuclear magnetic resonance T2 spectrum are calibrated to the porosity, and the cross-saturation porosity of the parallel sample and the crushed sample 350 DEG C heating porosity of the standard plunger sample are respectively obtained;

[0010] The total porosity is obtained based on the cross-saturation porosity of the parallel sample and the crushed sample 350 DEG C heating porosity.

[0011] According to one aspect of the present application, the nuclear magnetic resonance signal of the standard plunger sample in the original state is measured by using the nuclear magnetic resonance instrument, and then the measured signal is inverted to obtain a nuclear magnetic resonance T2 spectrum, which is as follows:

[0012] The nuclear magnetic resonance signal of the standard plunger sample in the original state is measured by using the MesoMR23-060H-I type nuclear magnetic resonance instrument, including the nuclear magnetic signals of the kerogen, structural water, asphalt and all hydrogen-containing components with high fluidity than asphalt, and then the measured signal is inverted to obtain a nuclear magnetic resonance T2 spectrum, and the parameters include: TE=0.06 ms, TW=2000 ms, and NECH=32.

[0013] According to one aspect of the present application, one of the standard plunger samples is vacuumed for 4 hours, then saturated with aviation kerosene for 72 hours, pressurized to 35 MPa, and after being taken out, the one-dimensional nuclear magnetic resonance T2 spectrum of the standard plunger sample saturated with oil is measured; the other standard plunger sample is vacuumed for 4 hours, then saturated with distilled water for 72 hours, pressurized to 35 MPa, and after being taken out, the one-dimensional nuclear magnetic resonance T2 spectrum of the standard plunger sample saturated with water is measured.

[0014] According to one aspect of the present application, the total porosity is obtained based on the cross-saturation porosity of the parallel samples and the 350℃ heating porosity of the crushed samples as follows:

[0015] φ 总 = φ CPMG(交叉饱和) - φ CPMG(350℃) ;

[0016] In the formula, φ 总 is the calculated total porosity, φ CPMG(交叉饱和) is the cross-saturation porosity of the parallel samples, and φ CPMG(350℃) is the 350℃ heating porosity of the crushed samples.

[0017] To achieve the above object, the present application further provides a porosity measurement system for a high-mud shale oil reservoir, comprising:

[0018] a sample obtaining module, which obtains a shale sample, cuts and processes the shale sample to form two standard plunger samples with similar lengths, and crushes the remaining shale sample to 60 mesh using a core crusher to obtain a crushed sample with the same mass as the average mass of the two standard plunger samples for standby use;

[0019] a nuclear magnetic resonance T2 spectrum obtaining module, which measures the nuclear magnetic resonance signal of the standard plunger sample in the original state using a nuclear magnetic resonance instrument, and then obtains the nuclear magnetic resonance T2 spectrum by inverting the measured signal;

[0020] a cross-saturation T2 spectrum obtaining module, which vacuums one of the standard plunger samples, then saturates the standard plunger sample with aviation kerosene and pressurizes, and after being taken out, measures the one-dimensional nuclear magnetic resonance T2 spectrum of the standard plunger sample saturated with oil; vacuums the other standard plunger sample, then saturates the standard plunger sample with distilled water and pressurizes, and after being taken out, measures the one-dimensional nuclear magnetic resonance T2 spectrum of the standard plunger sample saturated with water; normalizes the one-dimensional nuclear magnetic resonance T2 spectrum of the standard plunger sample saturated with oil and the one-dimensional nuclear magnetic resonance T2 spectrum of the standard plunger sample saturated with water by mass, then puts them into the same coordinate system, and obtains a new T2 spectrum by taking the maximum value of the signal intensity components at each point as the cross-saturation T2 spectrum of the parallel samples;

[0021] The pulverized sample is heated at 350 DEG C for 10 hours to remove hydrocarbon substances in the pulverized sample, and the remaining part is rock skeleton and kerogen, and the measured nuclear magnetic signal is taken as the core background signal, and the pulverized sample 350 DEG C heating nuclear magnetic resonance T2 spectrum is obtained after inversion of the measured nuclear magnetic signal;

[0022] The standard plunger sample porosity acquisition module measures the nuclear magnetic resonance signals of 1%, 3%, 5%, 10% and 15% porosity standard samples provided by the nuclear magnetic resonance instrument and establishes a linear relationship between the standard sample signal intensity and the porosity; the parallel sample cross saturation T2 spectrum and the pulverized sample 350 DEG C heating nuclear magnetic resonance T2 spectrum are substituted into the linear relationship to obtain a T2 spectrum with porosity as the ordinate and transverse relaxation time as the abscissa, so that the parallel sample cross saturation T2 spectrum and the pulverized sample 350 DEG C heating nuclear magnetic resonance T2 spectrum are calibrated to the porosity, and the parallel sample cross saturation porosity of the standard plunger sample and the pulverized sample 350 DEG C heating porosity are obtained respectively.

[0023] The shale porosity calculation module obtains the total porosity based on the parallel sample cross saturation porosity and the pulverized sample 350 DEG C heating porosity.

[0024] To achieve the above object, the application further provides an electronic device, which comprises a processor, a memory and a computer program stored on the memory and executable on the processor, and the computer program is executed by the processor to realize the high shale oil reservoir porosity measurement method.

[0025] To achieve the above object, the application further provides a computer readable storage medium, which stores a computer program, and the computer program is executed by a processor to realize the high shale oil reservoir porosity measurement method.

[0026] According to the scheme of the application, the application proposes a parallel sample cross saturation method to fully consider the influence of wettability on saturation by performing oil saturation and water saturation nuclear magnetic on the parallel plunger sample, and then performing normalization processing and analysis, so that the pore space occupied by the dispersed components can be obtained more fully, and the problems existing in single saturation can be avoided. BRIEF DESCRIPTION OF DRAWINGS

[0027] Figure 1 T2 signal intensity T2 spectrum of the plunger sample saturated with oil;

[0028] Figure 2 T2 signal intensity T2 spectrum of the plunger sample saturated with water;

[0029] Figure 3 T2 signal intensity T2 spectrum of the plunger sample parallel sample cross saturation;

[0030] Figure 4 T2 spectrum for crushed sample 350℃ heated T2 signal intensity

[0031] Figure 5 Fitting plot for porosity standard calibration

[0032] Figure 6 Porosity T2 spectrum for plunger sample as is

[0033] Figure 7 Porosity T2 spectrum for plunger sample saturated with oil

[0034] Figure 8 Porosity T2 spectrum for plunger sample saturated with water

[0035] Figure 9 Porosity T2 spectrum for plunger sample parallel sample cross-saturation

[0036] Figure 10 Porosity T2 spectrum for crushed sample 350℃ heated DETAILED DESCRIPTION

[0037] The present application will now be discussed with reference to exemplary embodiments. It should be appreciated that the embodiments discussed are only for purposes of better illustrating and thus enabling those of ordinary skill in the art to make and use the present application, and are not intended to limit the scope of the present application in any way.

[0038] As used herein, the term "including" and its variants are to be construed as open-ended terms that mean "including, but not limited to." The term "based on" is to be construed as "based at least in part on." The terms "one embodiment" and "an embodiment" are to be construed as "at least one embodiment."

[0039] According to an embodiment of the present application, a method for measuring porosity of a high shale oil reservoir with high mud content, comprising:

[0040] Obtaining a shale sample, cutting and processing the shale sample to form two standard plunger samples of similar length, crushing the remaining shale sample to 60 mesh using a core crusher, and taking out a crushed sample of the same mass as the average mass of the two standard plunger samples for use;

[0041] Performing vacuum extraction on one of the standard plunger samples, then saturating with aviation kerosene and pressurizing, taking out the standard plunger sample, and measuring the one-dimensional nuclear magnetic resonance T2 spectrum of the standard plunger sample saturated with oil, as shown in Figure 1 Performing vacuum extraction on the other standard plunger sample, then saturating with distilled water and pressurizing, taking out the standard plunger sample, and measuring the one-dimensional nuclear magnetic resonance T2 spectrum of the standard plunger sample saturated with water, as shown in Figure 2as shown; the standard plunger sample saturated oil one-dimensional nuclear magnetic resonance T2 spectrum and the standard plunger sample saturated water one-dimensional nuclear magnetic resonance T2 spectrum are normalized by quality, then put into the same coordinate system, and the maximum value of the signal intensity component at each point of the two is taken to obtain a new T2 spectrum, which is denoted as the parallel sample cross-saturation T2 spectrum, as shown in Figure 3

[0042] The crushed sample is heated at 350℃ for 10 hours to remove the hydrocarbon substances in the crushed sample, and the remaining part is the rock skeleton and kerogen. The nuclear magnetic signal is measured as the core background signal. The background signal value is removed during the T2 spectrum analysis and calculation. The nuclear magnetic signal after inversion is the crushed sample 350℃ heating nuclear magnetic resonance T2 spectrum, as shown in Figure 4

[0043] The 1%, 3%, 5%, 10%, and 15% porosity standards provided by the nuclear magnetic resonance instrument are respectively placed into the clamp to measure the nuclear magnetic resonance signal of the standard sample, and a linear relationship between the signal intensity and the porosity is established. The parallel sample cross-saturation T2 spectrum and the crushed sample 350℃ heating nuclear magnetic resonance T2 spectrum are substituted into the above linear relationship to obtain a T2 spectrum with porosity as the ordinate and transverse relaxation time as the abscissa, so that the parallel sample cross-saturation T2 spectrum and the crushed sample 350℃ heating nuclear magnetic resonance T2 spectrum are calibrated to porosity, and the parallel sample cross-saturation porosity of the standard plunger sample and the crushed sample 350℃ heating porosity are obtained respectively.

[0044] In the embodiment, the porosity standard calibration fitting graph is as shown in Figure 5 Figure 5 The linear relationship between the signal intensity and the nuclear magnetic T2 spectrum measured by the 1%, 3%, 5%, 10%, and 15% porosity standards provided by the nuclear magnetic experiment is shown. In the figure, x is the T2 time, y is the measured signal intensity, and R is the formula fitting correlation coefficient. The standard plunger sample original porosity T2 spectrum is as shown in Figure 6 The standard plunger sample saturated oil porosity T2 spectrum is as shown in Figure 7 The standard plunger sample saturated water porosity T2 spectrum is as shown in Figure 8 The standard plunger sample parallel sample cross-saturation porosity T2 spectrum is as shown in Figure 9 The crushed sample 350℃ heating porosity T2 spectrum is as shown in Figure 10

[0045] The total porosity is obtained based on the parallel sample cross-saturation porosity and the crushed sample 350℃ heating porosity.

[0046] Further, according to an embodiment of the present application, the nuclear magnetic resonance signal of the standard plunger sample in the original state is measured by the nuclear magnetic resonance instrument, and the nuclear magnetic resonance T2 spectrum after inversion of the measured signal is as follows:

[0047] ​​​​The standard plunger sample is measured by a MesoMR23-060H-I type nuclear magnetic resonance instrument in a standard state, including the nuclear magnetic signals of the kerogen, structural water, asphalt and all hydrogen-containing components with high fluidity than asphalt, and then the measured signals are inversed to obtain a nuclear magnetic resonance T2 spectrum, and the parameters include: TE=0.06 ms, TW=2000 ms, and NECH=32.

[0048] Further, according to one embodiment of the present application, one of the standard plunger samples is vacuumized for 4 hours, then saturated with aviation kerosene for 72 hours, pressurized to 35 MPa, and after being taken out, the one-dimensional nuclear magnetic resonance T2 spectrum of the standard plunger sample saturated with oil is measured; and the other standard plunger sample is vacuumized for 4 hours, then saturated with distilled water for 72 hours, pressurized to 35 MPa, and after being taken out, the one-dimensional nuclear magnetic resonance T2 spectrum of the standard plunger sample saturated with water is measured.

[0049] Further, according to one embodiment of the present application, the total porosity is obtained based on the cross-saturation porosity of the parallel sample and the 350℃ heating porosity of the crushed sample as follows:

[0050] φ 总 = φ CPMG(交叉饱和) - φ CPMG(350℃) ;

[0051] In the formula, is the calculated total porosity, is the cross-saturation porosity of the parallel sample, is the 350℃ heating porosity of the crushed sample.

[0052] According to the above scheme of the present application, the problem of the influence of wettability which cannot be solved by the conventional saturation method is solved by using the cross-saturation method of the parallel sample, the oil-saturated and water-saturated nuclear magnetic resonance of the parallel plunger sample is performed, the influence of wettability on saturation is fully considered, then normalized processing analysis is performed, the pore space occupied by the lost components can be more fully obtained, and the problems existing in the single saturation can be avoided.

[0053] NMR measurement technology has the advantages of non-destructive, fast, multi-parameter measurement, and more importantly, it can realize online measurement under high temperature and high pressure in the process of oil production flow experiment, and obtain various seepage parameters of formation conditions such as porosity, pore size distribution, permeability, oil saturation and the like, which opens up a new way for experimental research of shale oil and gas. The micro pores and cracks of shale reservoirs are obviously distributed on the NMR T2 spectrum. The shale residual component signal is measured by using the NMR experimental method, and then the porosity is converted. Since the research object is high argillaceous shale, the oil washing operation is not required in the experimental process. NMR can not only measure the pore space occupied by the residual part of shale, i.e. the participating components including clay bound water, adsorbed hydrocarbon, residual oil, residual water and the like, but also the components of non-pore space but having NMR signal such as structural water, kerogen, asphaltene and the like. When the temperature is heated to 350 DEG C, the light hydrocarbon and medium hydrocarbon remaining in shale are all dissipated, and the asphaltene, kerogen and high molecular hydrocarbon are still retained. Therefore, the 350 DEG C pyrolysis NMR is added to distinguish the pore space and non-pore space in the NMR signal, so that the pore space occupied by the residual component is obtained. Therefore, based on the laboratory 23MHz NMR, the parallel sample cross saturation NMR experimental method is used for the porosity experimental method research of high argillaceous shale, the influence of wettability on the saturation method porosity measurement is avoided, the shale oil reservoir porosity is accurately obtained, and the problem that the experimental porosity of shale reservoir is lower than the underground porosity is effectively solved.

[0054] Further, in order to achieve the above object, the application further provides a high argillaceous shale oil reservoir porosity measurement system, comprising:

[0055] A sample acquisition module acquires a shale sample, cuts and processes the shale sample to form two standard plunger samples with similar lengths, and uses a core crusher to crush the remaining shale sample to 60 mesh, and takes out a crushed sample with the same mass as the average mass of the two standard plunger samples for use.

[0056] A parallel sample cross saturation T2 spectrum acquisition module evacuates one of the standard plunger samples, then saturates aviation kerosene and pressurizes, takes out the standard plunger sample, and measures the one-dimensional NMR T2 spectrum of the standard plunger sample saturated with oil, as shown in Figure 1 A parallel sample cross saturation T2 spectrum acquisition module evacuates one of the standard plunger samples, then saturates aviation kerosene and pressurizes, takes out the standard plunger sample, and measures the one-dimensional NMR T2 spectrum of the standard plunger sample saturated with oil, as shown in Figure 2 A parallel sample cross saturation T2 spectrum acquisition module evacuates one of the standard plunger samples, then saturates aviation kerosene and pressurizes, takes out the standard plunger sample, and measures the one-dimensional NMR T2 spectrum of the standard plunger sample saturated with oil, as shown in Figure 3 A parallel sample cross saturation T2 spectrum acquisition module evacuates one of the standard plunger samples, then saturates aviation kerosene and pressurizes, takes out the standard plunger sample, and measures the one-dimensional NMR T2 spectrum of the standard plunger sample saturated with oil, as shown in

[0057] The pulverized sample is heated at 350 DEG C for 10 hours to remove hydrocarbon substances in the pulverized sample, and the remaining part is rock skeleton and kerogen, and the NMR signal is measured as a core background signal, and the background signal value is removed in T2 spectrum analysis and calculation, and the NMR signal after inversion is obtained as the NMR T2 spectrum of the pulverized sample heated at 350 DEG C, as shown in Figure 4

[0058] The standard plunger sample porosity acquisition module measures the NMR signals of 1%, 3%, 5%, 10% and 15% porosity standard samples provided by the NMR instrument and placed in the holder, and establishes a linear relationship between the signal intensity and the porosity; the parallel sample cross-saturation T2 spectrum and the NMR T2 spectrum of the pulverized sample heated at 350 DEG C are substituted into the linear relationship to obtain a T2 spectrum with porosity as the ordinate and transverse relaxation time as the abscissa, so that the parallel sample cross-saturation T2 spectrum and the NMR T2 spectrum of the pulverized sample heated at 350 DEG C are calibrated to porosity, and the parallel sample cross-saturation porosity and the 350 DEG C heated porosity of the standard plunger sample are obtained respectively.

[0059] In the embodiment, the porosity standard sample calibration fitting graph is as shown in Figure 5 Figure 5 The linear relationship between the signal intensity and the NMR T2 spectrum measured by the 1%, 3%, 5%, 10% and 15% porosity standard samples provided by the NMR instrument is shown; wherein, x is T2 time, y is the measured signal intensity respectively, and R is the formula fitting correlation coefficient. The standard plunger sample original porosity T2 spectrum is as shown in Figure 6 The standard plunger sample saturated oil porosity T2 spectrum is as shown in Figure 7 The standard plunger sample saturated water porosity T2 spectrum is as shown in Figure 8 The standard plunger sample parallel sample cross-saturation porosity T2 spectrum is as shown in Figure 9 The pulverized sample 350 DEG C heated porosity T2 spectrum is as shown in Figure 10 .

[0060] The shale porosity calculation module obtains the total porosity based on the parallel sample cross-saturation porosity and the 350 DEG C heated porosity of the pulverized sample.

[0061] Further, according to an embodiment of the present application, the NMR signal of the standard plunger sample in the original state is measured by the NMR instrument, and the NMR T2 spectrum after inversion is obtained as:

[0062] ​​The standard plunger sample is measured by a MesoMR23-060H-I type nuclear magnetic resonance instrument in a standard state, including the nuclear magnetic signals of the kerogen, structural water, asphalt and all hydrogen-containing components with high fluidity than asphalt, and then the measured signals are inversed to obtain a nuclear magnetic resonance T2 spectrum, and the parameters include: TE=0.06 ms, TW=2000 ms, and NECH=32.

[0063] Further, according to one embodiment of the present application, one of the standard plunger samples is vacuumized for 4 hours, then saturated with aviation kerosene for 72 hours, pressurized to 35 MPa, and after being taken out, the one-dimensional nuclear magnetic resonance T2 spectrum of the standard plunger sample saturated with oil is measured; and the other standard plunger sample is vacuumized for 4 hours, then saturated with distilled water for 72 hours, pressurized to 35 MPa, and after being taken out, the one-dimensional nuclear magnetic resonance T2 spectrum of the standard plunger sample saturated with water is measured.

[0064] Further, according to one embodiment of the present application, the total porosity is obtained based on the cross-saturation porosity of the parallel sample and the 350℃ heating porosity of the crushed sample as follows:

[0065] φ 总 = φ CPMG(交叉饱和) - φ CPMG(350℃) ;

[0066] In the formula, is the calculated total porosity, is the cross-saturation porosity of the parallel sample, is the 350℃ heating porosity of the crushed sample.

[0067] According to the above scheme of the present application, in view of the problem that the conventional saturation method cannot solve the influence of wettability, the cross-saturation method of the parallel sample is adopted, the parallel plunger sample is saturated with oil and water respectively, the influence of wettability on saturation is fully considered, then normalized processing analysis is performed, the pore space occupied by the lost components can be obtained more fully, and the problems existing in the separate saturation can be avoided.

[0068] NMR measurement technology has the advantages of non-destructive, fast, multi-parameter measurement and the like, and more importantly, can realize online measurement under high temperature and high pressure in the process of oil production flow experiment, and obtain various seepage parameters of formation conditions such as porosity, pore size distribution, permeability, oil saturation and the like, thereby opening up a new way for experimental research on shale oil and gas. The micro pores and cracks of the shale reservoir are obviously distinguished in the NMR T2 spectrum. The NMR experiment method is used to measure the shale residual component signal, and then the porosity is converted. Since the research object is high argillaceous shale, the oil washing operation is not required in the experimental process. The NMR can measure the pore space occupied by the shale residual part, i.e. the participating components including clay bound water, adsorbed hydrocarbon, residual oil, residual water and the like, and the components of non-pore space but having NMR signal such as structural water, kerogen, asphaltene and the like. When the temperature is heated to 350 DEG C, the light hydrocarbon and medium hydrocarbon remaining in the shale are all dissipated, and the asphaltene, kerogen and high molecular hydrocarbon are still retained. Therefore, the pyrolysis NMR of 350 DEG C is added to distinguish the pore space and non-pore space in the NMR signal, so that the pore space occupied by the residual component is obtained. Therefore, the parallel sample cross saturation NMR experiment method is used for the high argillaceous shale porosity experiment method research based on the laboratory 23MHz NMR, the influence of wettability on the saturation method porosity measurement is avoided, the shale oil reservoir porosity is accurately obtained, and the problem that the experimental porosity of the shale reservoir is lower than the underground porosity is effectively solved.

[0069] Further, to achieve the above object, the application further provides an electronic device, comprising a processor, a memory, and a computer program stored on the memory and executable on the processor, and the computer program is executed by the processor to implement the high argillaceous shale oil reservoir porosity measurement method.

[0070] Further, to achieve the above object, the application further provides a computer readable storage medium, and the computer readable storage medium stores a computer program, and the computer program is executed by the processor to implement the high argillaceous shale oil reservoir porosity measurement method.

[0071] Those skilled in the art can understand that the modules and algorithm steps described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are realized in hardware or software mode depends on the specific application and design constraints of the technical solution. The skilled person can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the application.

[0072] Those skilled in the art can clearly understand that, for the convenience and brevity of the description, the specific working process of the above-described device and equipment can refer to the corresponding process in the foregoing method embodiments, which will not be described here.

[0073] In the embodiments provided by the present application, it should be understood that the disclosed apparatus and method can be implemented in other manners. For example, the described apparatus embodiment is merely schematic. For example, the division of the modules is only a logical function division. For another example, a plurality of modules or components can be combined or integrated into another system, or some features can be ignored or not implemented. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections between different modules can be indirect couplings or communication connections through some interfaces, and electrical, mechanical or other forms.

[0074] The module illustrated or discussed as a separate part can or can not be physically separate, and the parts shown as modules can or can not be physical modules, i.e., can be located in one place or can be distributed on a plurality of network modules. In actual implementation, some or all of the modules can be selected according to the actual needs to achieve the purposes of the embodiments of the present application.

[0075] In addition, each functional module in the embodiments of the present application can be integrated in a processing module, or each module can exist physically independently, or two or more modules can be integrated in one module.

[0076] If the functions are implemented in the form of software function modules and sold or used as independent products, they can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application essentially or the parts that make contributions to the prior art or parts of the technical solutions can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the energy-saving signal transmission / reception method of the embodiments of the present application. The aforementioned storage medium includes: U disk, mobile hard disk, ROM, RAM, magnetic disk or optical disk, and various other media that can store program codes.

[0077] The above description is merely a preferred embodiment of the present application and a description of the principles of the applied technology. It should be understood by those skilled in the art that the scope of the application disclosed in the present application is not limited to the technical solutions formed by the specific combinations of the above technical features, and should also cover other technical solutions formed by any combinations of the above technical features or equivalent features without departing from the inventive concept. For example, the above features can be replaced with technical features disclosed in the present application (but not limited to) having similar functions to form technical solutions.

[0078] It should be understood that the size of the serial number of each step in the summary and embodiments of the present application does not absolutely mean the order of execution, and the execution order of each process should be determined according to its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

Claims

1. A method for measuring porosity in a high shale oil reservoir with clay, characterized by, The method comprises the following steps: Obtaining a shale sample, cutting and processing the shale sample to form two standard plunger samples with similar lengths, crushing the remaining shale sample to 60 mesh using a core crusher, and taking a crushed sample with the same mass as the average mass of the two standard plunger samples for use; Vacuumizing one of the standard plunger samples, then saturating the standard plunger sample with aviation kerosene and pressurizing, taking out the standard plunger sample, and measuring the one-dimensional nuclear magnetic resonance T2 spectrum of the standard plunger sample saturated with oil; vacuumizing the other standard plunger sample, then saturating the standard plunger sample with distilled water and pressurizing, taking out the standard plunger sample, and measuring the one-dimensional nuclear magnetic resonance T2 spectrum of the standard plunger sample saturated with water; normalizing the one-dimensional nuclear magnetic resonance T2 spectrum of the standard plunger sample saturated with oil and the one-dimensional nuclear magnetic resonance T2 spectrum of the standard plunger sample saturated with water by mass, then placing them in the same coordinate system, and taking the maximum value of the signal intensity component at each point to obtain a new T2 spectrum, which is referred to as a parallel sample cross-saturation T2 spectrum; Heating the crushed sample to 350 DEG C for 10 hours to remove hydrocarbon substances in the crushed sample, and taking the remaining part as a rock skeleton and kerogen, and measuring the nuclear magnetic signal as a core background signal, and obtaining the nuclear magnetic resonance T2 spectrum of the crushed sample heated at 350 DEG C by inversion of the measured nuclear magnetic signal; Placing 1%, 3%, 5%, 10% and 15% porosity standard samples provided with the nuclear magnetic resonance instrument into a holder to measure the nuclear magnetic resonance signals of the standard samples, and establishing a linear relationship between the signal intensity and the porosity; and substituting the parallel sample cross-saturation T2 spectrum and the nuclear magnetic resonance T2 spectrum of the crushed sample heated at 350 DEG C into the linear relationship to obtain a T2 spectrum with porosity as the ordinate and transverse relaxation time as the abscissa, so as to calibrate the parallel sample cross-saturation T2 spectrum and the nuclear magnetic resonance T2 spectrum of the crushed sample heated at 350 DEG C to porosity, and obtain the parallel sample cross-saturation porosity and the crushed sample 350 DEG C heating porosity of the standard plunger sample, respectively. The total porosity is obtained based on the parallel sample cross-saturation porosity and the crushed sample 350 DEG C heating porosity.

2. The method of claim 1, wherein, The method further comprises the following steps: Measuring the nuclear magnetic resonance signal of the standard plunger sample in the original state using the nuclear magnetic resonance instrument, and then obtaining the nuclear magnetic resonance T2 spectrum by inversion of the measured signal, which is: Measuring the nuclear magnetic resonance signal of the standard plunger sample in the original state using the MesoMR23-060H-I nuclear magnetic resonance instrument, including the nuclear magnetic signals of the kerogen, structural water, bitumen and all hydrogen-containing components with higher fluidity than bitumen, and then obtaining the nuclear magnetic resonance T2 spectrum by inversion of the measured signal, and the parameters include: TE=0.06 ms, TW=2000 ms, and NECH=32.

3. The high shale oil reservoir porosity measurement method of claim 1, wherein, Vacuumizing one of the standard plunger samples for 4 hours, then saturating the standard plunger sample with aviation kerosene for 72 hours, pressurizing to 35 MPa, taking out the standard plunger sample, and measuring the one-dimensional nuclear magnetic resonance T2 spectrum of the standard plunger sample saturated with oil; vacuumizing the other standard plunger sample for 4 hours, then saturating the standard plunger sample with distilled water for 72 hours, pressurizing to 35 MPa, taking out the standard plunger sample, and measuring the one-dimensional nuclear magnetic resonance T2 spectrum of the standard plunger sample saturated with water.

4. The high shale oil reservoir porosity measurement method of any one of claims 1-3, wherein, The total porosity obtained based on the parallel sample cross-saturation porosity and the crushed sample 350 DEG C heating porosity is: ； wherein is the calculated total porosity, is the cross-saturation porosity of the parallel sample, is the 350°C-heated porosity of the pulverized sample.

5. A high shale oil reservoir porosity measurement system characterized by, The method comprises the following steps: A sample acquisition module acquires a shale sample, cuts the shale sample to form two standard plunger samples of similar length, and grinds the remaining shale sample to 60 mesh using a core grinder to obtain a ground sample of the same mass as the two standard plunger samples; A nuclear magnetic resonance T2 spectrum acquisition module measures a nuclear magnetic resonance signal of the standard plunger samples in a raw state using a nuclear magnetic resonance instrument, and then obtains a nuclear magnetic resonance T2 spectrum by inverting the measured signal; A parallel sample cross-saturation T2 spectrum acquisition module evacuates one of the standard plunger samples, then saturates the standard plunger sample with aviation kerosene and pressurizes the standard plunger sample, and then measures a one-dimensional nuclear magnetic resonance T2 spectrum of the standard plunger sample saturated with the aviation kerosene; evacuates the other standard plunger sample, then saturates the standard plunger sample with distilled water and pressurizes the standard plunger sample, and then measures a one-dimensional nuclear magnetic resonance T2 spectrum of the standard plunger sample saturated with the distilled water; normalizes the one-dimensional nuclear magnetic resonance T2 spectrum of the standard plunger sample saturated with the aviation kerosene and the one-dimensional nuclear magnetic resonance T2 spectrum of the standard plunger sample saturated with the distilled water by mass, and then places the two T2 spectra in the same coordinate system, and obtains a new T2 spectrum by taking the maximum value of the signal intensity components at each point of the two T2 spectra, and the new T2 spectrum is referred to as a parallel sample cross-saturation T2 spectrum; A ground sample nuclear magnetic resonance signal measurement module heats the ground sample at 350°C for 10 hours to remove hydrocarbon substances in the ground sample, and the remaining part is a rock skeleton and kerogen, and a nuclear magnetic resonance signal of the ground sample is measured as a core background signal, and a 350°C heated nuclear magnetic resonance T2 spectrum of the ground sample is obtained by inverting the measured nuclear magnetic resonance signal; A standard plunger sample porosity acquisition module places 1%, 3%, 5%, 10%, and 15% porosity standard samples provided with a nuclear magnetic resonance instrument into a holder to measure nuclear magnetic resonance signals of the standard samples, and establishes a linear relationship between signal intensity and porosity; and the parallel sample cross-saturation T2 spectrum and the 350°C heated nuclear magnetic resonance T2 spectrum of the ground sample are substituted into the linear relationship to obtain a T2 spectrum with porosity as the ordinate and transverse relaxation time as the abscissa, so that the parallel sample cross-saturation T2 spectrum and the 350°C heated nuclear magnetic resonance T2 spectrum of the ground sample are calibrated to porosity, and a parallel sample cross-saturation porosity and a 350°C heated porosity of the standard plunger sample are obtained, respectively; A shale porosity calculation module obtains a total porosity based on the parallel sample cross-saturation porosity and the 350°C heated porosity of the ground sample.

6. An electronic device, characterized by A computer readable storage medium stores a computer program, and the computer program is executed by a processor to implement the high shale oil reservoir porosity measurement method according to any one of claims 1-4.

7. A computer readable storage medium, characterized in that, A computer readable storage medium stores a computer program, and the computer program is executed by a processor to implement the high shale oil reservoir porosity measurement method according to any one of claims 1-4.

Images