Shale nuclear magnetic resonance aperture calibration method, device, equipment and medium

Abstract

The invention discloses a shale nuclear magnetic resonance aperture calibration method, device, equipment and medium, and relates to the technical field of shale reservoir pore characterization, and the method comprises the following steps: preparing a shale core sample into a nuclear magnetic column sample, drying the nuclear magnetic column sample under a preset high temperature condition, measuring the original nuclear magnetic resonance # imgabs0 # map of the treated column sample, and calculating the original nuclear magnetic resonance # imgabs0 # map according to the original nuclear magnetic resonance # imgabs0 # map. Carrying out water saturation treatment on the treated column sample under a preset high-pressure condition, and measuring a target nuclear magnetic resonance # imgabs1 # map of the column sample subjected to water saturation treatment; obtaining a shale pore nuclear magnetic resonance # imgabs2 # curve, drying the column sample subjected to water saturation treatment under a preset high-temperature condition, performing a nitrogen adsorption experiment on the obtained powder sample, and calculating a nitrogen adsorption pore size distribution curve of the powder sample; acquiring a nuclear magnetic resonance porosity component curve and a nitrogen adsorption porosity component curve; performing nonlinear fitting on the curve, determining a corresponding relation between the nuclear magnetic resonance relaxation time and the nitrogen pore diameter, and calibrating the nuclear magnetic resonance pore diameter of the shale according to the corresponding relation. And aperture calibration is realized.

Description

Technical Field

[0001] The present invention relates to the technical field of shale reservoir pore characterization, and in particular to a shale nuclear magnetic resonance pore size calibration method, device, equipment and medium. Background Art

[0002] Shale reservoir evaluation is very important for shale gas exploration and development. Since the pore size distribution range of shale reservoirs spans a wide range, with pores ranging from nanometers to micrometers, it is very difficult to achieve full pore size characterization of shale reservoirs. The detailed characterization of shale pore structure has become the key to shale gas exploration and development.

[0003] The commonly used techniques for characterizing the pores of shale reservoirs include field emission scanning electron microscopy, gas adsorption, high-pressure mercury injection, nuclear magnetic resonance, etc. Currently, these experimental techniques all have problems. The pores characterized are mostly concentrated in a certain scale, and it is difficult to achieve full-aperture shale pore characterization. Nuclear magnetic resonance is an emerging non-destructive experimental technology in recent years. It mainly uses the behavior of water molecules in a magnetic field to infer the pore structure of shale. When liquid molecules are in the pores, their magnetic resonance signals will be affected by the pore morphology, size and surface properties. Compared with other experimental techniques, its advantages are mainly reflected in the wide range of pores characterized and the experiment is non-destructive to the samples. However, nuclear magnetic resonance experiments are conducted through The relationship between relaxation time and pore size can be used to characterize the distribution characteristics of shale pores. The relaxation time is calibrated to the pore size, thus achieving quantitative characterization of the multi-scale pore structure of shale reservoirs.

[0004] At present, NMR is usually combined with other technologies (such as shale column saturation-centrifugation experiment technology) to achieve NMR of shale reservoirs. The calibration of relaxation time and pore size is mainly calculated by physical principle formula or nuclear magnetic resonance The curve shape is matched with other curves to achieve this. Among them, the method of calculating the physical principle formula is mainly through nuclear magnetic resonance The empirical formula of spectrum and aperture is calculated together with the formula of pressure and aperture. Due to the error of the empirical formula, this method usually has large errors and inaccurate calibration results. However, due to the difference in the measurement range of each method, the peak values ​​of the curve morphology matching method also have large differences. Direct curve morphology matching leads to highly subjective calibration results and is not applicable to a large range. Summary of the invention

[0005] In view of this, the purpose of the present invention is to provide a shale nuclear magnetic resonance pore size calibration method, device, equipment and medium, which can solve the problem of directly calibrating nuclear magnetic resonance based on nitrogen adsorption curve. The problem of large aperture error of spectrum curve is solved by improving calibration accuracy. The specific scheme is as follows:

[0006] In a first aspect, the present application discloses a shale nuclear magnetic resonance aperture calibration method, comprising:

[0007] The shale core sample is prepared into a nuclear magnetic column sample, the nuclear magnetic column sample is dried under a preset high temperature condition, and the original nuclear magnetic resonance of the corresponding column sample after treatment is measured. Spectrum, saturating the treated column sample with water under a preset high pressure condition, and measuring the target nuclear magnetic resonance of the corresponding saturated column sample Atlas;

[0008] Based on the original NMR Spectra and NMR of the target Shale pore NMR curve, drying the saturated column sample under a preset high temperature condition to obtain a powder sample, and performing a nitrogen adsorption experiment on the powder sample to calculate the nitrogen adsorption pore size distribution curve of the powder sample;

[0009] Based on the shale pore nuclear magnetic resonance The curve and the nitrogen adsorption pore size distribution curve respectively obtain the corresponding nuclear magnetic resonance porosity component curve and nitrogen adsorption porosity component curve; the nuclear magnetic resonance porosity component curve is a curve determined based on the nuclear magnetic resonance relaxation time and the nuclear magnetic resonance porosity component; the nitrogen adsorption porosity component curve is a curve determined based on the nitrogen pore size and the nitrogen adsorption porosity component;

[0010] The nitrogen adsorption porosity component curve and the nuclear magnetic resonance porosity component curve are nonlinearly fitted to determine the corresponding relationship between the nuclear magnetic resonance relaxation time and the nitrogen pore size, and the nuclear magnetic resonance pore size of the shale is calibrated according to the corresponding relationship.

[0011] Optionally, the original nuclear magnetic resonance Spectra and NMR of the target Shale pore NMR Curves, including:

[0012] The original NMR Spectrum and the target NMR The difference between the spectra is determined as the shale pore NMR curve.

[0013] Optionally, the performing a nitrogen adsorption experiment on the powder sample to calculate a nitrogen adsorption pore size distribution curve of the powder sample includes:

[0014] A nitrogen adsorption experiment is performed on the powder sample, and a nitrogen adsorption pore size distribution curve of the powder sample is obtained by BET specific surface area detection method and BJH method.

[0015] Optionally, the shale pore nuclear magnetic resonance The curve and the nitrogen adsorption pore size distribution curve respectively obtain the corresponding nuclear magnetic resonance porosity component curve and nitrogen adsorption porosity component curve, including:

[0016] Nuclear magnetic resonance imaging of shale pores The values ​​corresponding to the curve are accumulated to obtain a first overall accumulated value;

[0017] Determine the shale pore size by NMR a first accumulated value of each data point corresponding to the curve, and dividing the first accumulated value by the first overall accumulated value to obtain a nuclear magnetic resonance porosity component of each data point;

[0018] Determining the NMR porosity component curve according to each of the NMR porosity components and the NMR relaxation time;

[0019] Accumulating the values ​​corresponding to the nitrogen adsorption pore size distribution curve to obtain a second overall accumulated value;

[0020] Determine a second cumulative value of each data point corresponding to the nitrogen adsorption pore size distribution curve, and divide the second cumulative value by the second overall cumulative value to obtain a nitrogen adsorption porosity component of each data point;

[0021] The nitrogen adsorption porosity component curve is determined according to each of the nitrogen adsorption porosity components and the nitrogen pore diameter.

[0022] Optionally, before performing nonlinear fitting on the nitrogen adsorption porosity component curve and the nuclear magnetic resonance porosity component curve, the method further includes:

[0023] The data points of nitrogen adsorption are internally interpolated according to the number of NMR data points so that the shale pore NMR The data points of the curve correspond one-to-one to the data points of the nitrogen adsorption pore size distribution curve.

[0024] Optionally, before performing nonlinear fitting on the nitrogen adsorption porosity component curve and the nuclear magnetic resonance porosity component curve, the method further includes:

[0025] The conversion coefficient of the nonlinear fitting is determined based on a plurality of the nuclear magnetic resonance porosity components and a plurality of the nitrogen adsorption porosity components by using a preset conversion coefficient determination formula; the preset conversion coefficient determination formula is:

[0026] ;

[0027] in, is the NMR porosity component; is the nitrogen adsorption porosity component; a and b are the conversion coefficients.

[0028] Optionally, performing nonlinear fitting on the nitrogen adsorption porosity component curve and the nuclear magnetic resonance porosity component curve comprises:

[0029] The nitrogen adsorption porosity component curve and the nuclear magnetic resonance porosity component curve are nonlinearly fitted based on the conversion coefficient.

[0030] In a second aspect, the present application discloses a shale nuclear magnetic resonance aperture calibration device, comprising:

[0031] The spectrum measurement module is used to prepare the shale core sample into a nuclear magnetic column sample, dry the nuclear magnetic column sample under a preset high temperature condition, and measure the original nuclear magnetic resonance of the corresponding column sample after treatment. Spectrum, saturating the treated column sample with water under a preset high pressure condition, and measuring the target nuclear magnetic resonance of the corresponding saturated column sample Atlas;

[0032] Curve calculation module for calculating the original NMR Spectra and NMR of the target Shale pore NMR curve, drying the saturated column sample under a preset high temperature condition to obtain a powder sample, and performing a nitrogen adsorption experiment on the powder sample to calculate the nitrogen adsorption pore size distribution curve of the powder sample;

[0033] Curve acquisition module, used for shale pore nuclear magnetic resonance The curve and the nitrogen adsorption pore size distribution curve respectively obtain the corresponding nuclear magnetic resonance porosity component curve and nitrogen adsorption porosity component curve; the nuclear magnetic resonance porosity component curve is a curve determined based on the nuclear magnetic resonance relaxation time and the nuclear magnetic resonance porosity component; the nitrogen adsorption porosity component curve is a curve determined based on the nitrogen pore size and the nitrogen adsorption porosity component;

[0034] The pore size calibration module is used to perform nonlinear fitting on the nitrogen adsorption porosity component curve and the nuclear magnetic resonance porosity component curve to determine the corresponding relationship between the nuclear magnetic resonance relaxation time and the nitrogen pore size, and calibrate the nuclear magnetic resonance pore size of shale according to the corresponding relationship.

[0035] In a third aspect, the present application discloses an electronic device, comprising:

[0036] Memory, used to store computer programs;

[0037] A processor is used to execute the computer program to implement the shale nuclear magnetic resonance aperture calibration method as described above.

[0038] In a fourth aspect, the present application discloses a computer-readable storage medium for storing a computer program; wherein, when the computer program is executed by a processor, the aforementioned shale nuclear magnetic resonance aperture calibration method is implemented.

[0039] The present invention first prepares a shale core sample into a nuclear magnetic column sample, and then performs a drying treatment on the nuclear magnetic column sample under a preset high temperature condition, and measures the original nuclear magnetic resonance of the corresponding column sample after treatment. Spectrum, saturating the treated column sample with water under a preset high pressure condition, and measuring the target nuclear magnetic resonance of the corresponding saturated column sample Spectrum; based on the original NMR Spectra and NMR of the target Shale pore NMR curve, drying the saturated column sample under a preset high temperature condition to obtain a powder sample, performing a nitrogen adsorption experiment on the powder sample to calculate the nitrogen adsorption pore size distribution curve of the powder sample; and then based on the shale pore nuclear magnetic resonance The curve and the nitrogen adsorption pore size distribution curve respectively obtain the corresponding nuclear magnetic resonance porosity component curve and nitrogen adsorption porosity component curve; the nuclear magnetic resonance porosity component curve is a curve determined based on the nuclear magnetic resonance relaxation time and the nuclear magnetic resonance porosity component; the nitrogen adsorption porosity component curve is a curve determined based on the nitrogen pore size and the nitrogen adsorption porosity component; finally, the nitrogen adsorption porosity component curve and the nuclear magnetic resonance porosity component curve are nonlinearly fitted to determine the corresponding relationship between the nuclear magnetic resonance relaxation time and the nitrogen pore size, and the nuclear magnetic resonance pore size of the shale is calibrated according to the corresponding relationship. It can be seen that the present application obtains the nuclear magnetic resonance porosity component curve and the nitrogen adsorption porosity component curve through multiple experiments, and determines the corresponding relationship between the nuclear magnetic resonance relaxation time and the nitrogen pore size by fitting the two curves, thereby realizing the precise calibration of the nuclear magnetic resonance pore size by nitrogen adsorption, and improving the accuracy of pore size calibration. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0041] Figure 1 This is a flow chart of a shale nuclear magnetic resonance aperture calibration method disclosed in this application;

[0042] Figure 2 A sample nuclear magnetic resonance disclosed in this application Schematic diagram of the curve;

[0043] Figure 3 A schematic diagram of nitrogen adsorption pore size distribution of a sample disclosed in this application;

[0044] Figure 4 This is a schematic diagram of nitrogen adsorption porosity component distribution disclosed in this application;

[0045] Figure 5 This is a schematic diagram of a nuclear magnetic porosity component distribution disclosed in this application;

[0046] Figure 6 A schematic diagram of a nuclear magnetic resonance and nitrogen adsorption porosity component fitting disclosed in the present application;

[0047] Figure 7 A schematic diagram of a nuclear magnetic resonance pore size distribution disclosed in this application;

[0048] Figure 8 This is a schematic diagram of the structure of a shale nuclear magnetic resonance aperture calibration device disclosed in this application;

[0049] Fig. 9 This is a structural diagram of an electronic device disclosed in this application. DETAILED DESCRIPTION

[0050] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. 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.

[0051] At present, NMR is usually combined with other technologies (such as shale column saturation-centrifugation experiment technology) to achieve NMR of shale reservoirs. The calibration of relaxation time and pore size is mainly calculated by physical principle formula or nuclear magnetic resonance The curve shape is matched with other curves to achieve this. Among them, the method of calculating the physical principle formula is mainly through nuclear magnetic resonance The empirical formula of spectrum and pore size is calculated together with the formula of pressure and pore size. Due to the error problem of the empirical formula, this method usually has a large error and the calibration result is inaccurate. However, the peak value of the curve morphology matching method has a large difference due to the difference in the measurement range of each method. The calibration result of the curve morphology matching is highly subjective and not applicable to a large range. In order to solve the above technical problems, the present application discloses a shale nuclear magnetic resonance pore size calibration method, device, equipment and medium, which can solve the problem of directly calibrating the nuclear magnetic resonance based on the nitrogen adsorption curve. The problem of large aperture error of the spectrum curve is solved to improve the calibration accuracy.

[0052] See also Figure 1 As shown, the embodiment of the present invention discloses a shale nuclear magnetic resonance aperture calibration method, comprising:

[0053] Step S11: Prepare the shale core sample into a nuclear magnetic column sample, dry the nuclear magnetic column sample under a preset high temperature condition, and measure the original nuclear magnetic resonance of the corresponding column sample after treatment. Spectrum, saturating the treated column sample with water under a preset high pressure condition, and measuring the target nuclear magnetic resonance of the corresponding saturated column sample Atlas.

[0054] In this embodiment, the present application first prepares fresh shale core samples, prepares them into standard NMR columns (cylinders with a length of 5 cm and a diameter of 2.5 cm), and then dries the columns at high temperature (60°) for 24 hours to measure their original NMR. The column sample is then taken out for high-pressure saturation, that is, the treated column sample is saturated with water under preset high-pressure conditions, saturated with formation water at 20 MPa pressure for 48 hours, and its nuclear magnetic resonance after saturation is measured. Spectra, and then obtain the original NMR Spectra and targeted NMR of water-saturated column samples Atlas.

[0055] Step S12: Based on the original nuclear magnetic resonance Spectra and NMR of the target Shale pore NMR curve, drying the saturated column sample under preset high temperature conditions to obtain a powder sample, and performing a nitrogen adsorption experiment on the powder sample to calculate the nitrogen adsorption pore size distribution curve of the powder sample.

[0056] In this embodiment, the original NMR is obtained. Spectra and targeted NMR of water-saturated column samples After the spectrum, the water-saturated NMR Spectra minus the original NMR Spectrum acquisition of shallow shale pore nuclear magnetic resonance Curve. The original NMR Atlas Targeted NMR Atlas The difference between the two values ​​is determined as the shale pore NMR curve .

[0057] ;

[0058] Then, the column sample after saturated NMR was dried at high temperature (60°) for 48 hours to be processed into a powder sample of 50 mesh to 10 mesh. The powder sample was subjected to nitrogen adsorption experiment to calculate the nitrogen adsorption pore size distribution curve of the powder sample. Specifically, the nitrogen adsorption pore size distribution curve was obtained by BET method (Formula 1) and BJH method (Formula 2):

[0059] ; (Formula 1)

[0060] Where V is the nitrogen adsorption capacity (cm 3 / g); is the relative pressure, dimensionless; C is the BET constant, dimensionless; is the monolayer molecular adsorption capacity (cm 3 / g).

[0061] ; (Formula 2)

[0062] in, is the small change in adsorption amount related to pore size (cm 3 / g); is the maximum adsorption capacity (cm 3 / g); is the density of nitrogen (cm 3 / g); is the experimental pressure (MPa); is the experimental pressure (MPa).

[0063] Step S13: Based on the shale pore nuclear magnetic resonance The curve and the nitrogen adsorption pore size distribution curve respectively obtain the corresponding nuclear magnetic resonance porosity component curve and nitrogen adsorption porosity component curve; the nuclear magnetic resonance porosity component curve is a curve determined based on the nuclear magnetic resonance relaxation time and the nuclear magnetic resonance porosity component; the nitrogen adsorption porosity component curve is a curve determined based on the nitrogen pore size and the nitrogen adsorption porosity component.

[0064] In this embodiment, shale pore nuclear magnetic resonance is obtained. The pore size distribution curve of nitrogen adsorption was analyzed based on shale pore nuclear magnetic resonance. The corresponding NMR porosity component curve and nitrogen adsorption porosity component curve are obtained by using the NMR porosity distribution curve and the nitrogen adsorption porosity distribution curve. The curve and the nitrogen adsorption pore size distribution curve are processed, and the two sets of curve values ​​are accumulated respectively to obtain the final overall accumulated value, and the accumulated value of each data point is divided by the final overall accumulated value to obtain its individual data porosity components. Among them, for the accumulated value of each data point, for example, if there are 10 data points, the accumulated value of the 3rd data point is the value corresponding to the third data point plus the values ​​corresponding to the first two data points; the accumulated value of the 4th data point is the value corresponding to the 4th data point plus the values ​​corresponding to the first 3 data points. The overall accumulated value is the accumulated value of 10 data points. It should be noted that the nuclear magnetic resonance porosity component curve here is a curve determined based on the nuclear magnetic resonance relaxation time (horizontal axis) and the nuclear magnetic resonance porosity component (vertical axis); the nitrogen adsorption porosity component curve is a curve determined based on the nitrogen pore size (horizontal axis) and the nitrogen adsorption porosity component (vertical axis). Specifically:

[0065] ;

[0066] in, is the NMR porosity component; For NMR Spectral signal strength.

[0067] ;

[0068] in, is the nitrogen adsorption porosity component; is the nitrogen adsorption pore volume.

[0069] Step S14, performing nonlinear fitting on the nitrogen adsorption porosity component curve and the nuclear magnetic resonance porosity component curve to determine the corresponding relationship between the nuclear magnetic resonance relaxation time and the nitrogen pore size, and calibrating the nuclear magnetic resonance pore size of the shale according to the corresponding relationship.

[0070] In this embodiment, due to nuclear magnetic resonance The data acquisition frequency of the curve is high, and its data points are more, while the data points of nitrogen adsorption are fewer. Therefore, the exponential fitting in the origin software is first used to internally interpolate the data points of nitrogen adsorption between 2 and 50 nm (point data of the mesopore part). The number of curve data points is adjusted to match the nitrogen data points. Then the NMR full pore size data is fitted with the mesopore part point data (N>30) to calibrate the corrected NMR pore size distribution data. The conversion coefficient of the nonlinear fitting is determined based on several NMR porosity components and several nitrogen adsorption porosity components through the preset conversion coefficient determination formula; the preset conversion coefficient determination formula is:

[0071] ;

[0072] in, is the NMR porosity component; is the nitrogen adsorption porosity component; a and b are conversion coefficients. Based on the conversion coefficient, the nitrogen adsorption porosity component curve and the nuclear magnetic resonance porosity component curve are nonlinearly fitted. Where:

[0073] ;

[0074] ;

[0075] is the NMR transverse relaxation time, d is the aperture; is the pore shape factor; is the surface area of ​​pores containing fluid; wei surface relaxation rate; The fluid pore volume is used to clarify the correspondence between the NMR relaxation time and the nitrogen pore size. The NMR pore size of the shale is then calibrated based on the correspondence to achieve the correspondence and conversion between the NMR relaxation time and the pore size.

[0076] In summary, the present invention first prepares the shale core sample into a nuclear magnetic column sample, and then dries the nuclear magnetic column sample under a preset high temperature condition, and measures the original nuclear magnetic resonance of the corresponding column sample after treatment. Spectrum, saturating the treated column sample with water under a preset high pressure condition, and measuring the target nuclear magnetic resonance of the corresponding saturated column sample Spectrum; based on the original NMR Spectra and NMR of the target Shale pore NMR curve, drying the saturated column sample under a preset high temperature condition to obtain a powder sample, performing a nitrogen adsorption experiment on the powder sample to calculate the nitrogen adsorption pore size distribution curve of the powder sample; and then based on the shale pore nuclear magnetic resonance The curve and the nitrogen adsorption pore size distribution curve respectively obtain the corresponding nuclear magnetic resonance porosity component curve and nitrogen adsorption porosity component curve; the nuclear magnetic resonance porosity component curve is a curve determined based on the nuclear magnetic resonance relaxation time and the nuclear magnetic resonance porosity component; the nitrogen adsorption porosity component curve is a curve determined based on the nitrogen pore size and the nitrogen adsorption porosity component; finally, the nitrogen adsorption porosity component curve and the nuclear magnetic resonance porosity component curve are nonlinearly fitted to determine the corresponding relationship between the nuclear magnetic resonance relaxation time and the nitrogen pore size, and the nuclear magnetic resonance pore size of the shale is calibrated according to the corresponding relationship. It can be seen that the present application obtains the nuclear magnetic resonance porosity component curve and the nitrogen adsorption porosity component curve through multiple experiments, and determines the corresponding relationship between the nuclear magnetic resonance relaxation time and the nitrogen pore size by fitting the two curves, thereby realizing the precise calibration of the nuclear magnetic resonance pore size by nitrogen adsorption, and improving the accuracy of pore size calibration.

[0077] Next, the specific process of the shale nuclear magnetic resonance aperture calibration method will be described in detail in conjunction with a specific embodiment.

[0078] In a specific embodiment, for the calibration of the pore size of shallow shale (current burial depth less than 2000m), firstly, 5 fresh shale core samples were selected, and the same sample was prepared into a standard nuclear magnetic column sample with a length of 5cm and a diameter of 2.5cm. Then, the column sample was dried at high temperature (60°) for 24 hours, and its original nuclear magnetic resonance was measured. The column sample was then taken out for high-pressure saturation. The formation water was saturated at 20 MPa for 48 hours, and the nuclear magnetic resonance after saturation was measured. Spectrum, and then obtain Figure 2 NMR images of the five samples shown Spectrum. Using NMR after saturation with water Spectra minus the original NMR Spectrum acquisition of shallow shale pore nuclear magnetic resonance curve.

[0079] Afterwards, the column sample after saturated NMR was dried at high temperature (60°) for 48 hours and processed into a powder sample of 50-10 mesh. The nitrogen adsorption experiment was carried out and the BET method and BJH method were used to calculate the following: Figure 3 Its nitrogen adsorption pore size distribution curve is shown.

[0080] The obtained NMR and nitrogen adsorption data were processed according to the following formula: The curve and nitrogen adsorption pore size distribution data were processed as follows Figure 4 and Figure 5 Porosity component data shown.

[0081] ;

[0082] in, is the NMR porosity component; For NMR Spectral signal strength.

[0083] ;

[0084] in, is the nitrogen adsorption porosity component; is the nitrogen adsorption pore volume.

[0085] However, since the nitrogen adsorption data is mainly for the pores in the mesopore part, the pore size distribution range it controls is mainly in the range of 2~50nm, and since the pore size distribution range of the NMR curve is relatively large, linear fitting is not applicable, so nonlinear fitting is used. The data in the nitrogen pore size range of 2~50nm are intercepted respectively, and the porosity component corresponding to the NMR porosity component is selected according to the porosity component data of nitrogen adsorption. According to the number of NMR data points, the data points of nitrogen adsorption are interpolated internally to make them correspond, and then the porosity components of the two methods are used as the basis to clarify the correspondence between NMR relaxation time and nitrogen pore size, such as Figure 6 As shown. The conversion coefficient a is determined to be 50.537 and b is 0.9106. Finally, the following is obtained: Figure 7 The calibrated NMR pore size distribution diagram is shown.

[0086] It can be seen that the present application obtains the NMR porosity component curve and the nitrogen adsorption porosity component curve through multiple experiments, and determines the correspondence between the NMR relaxation time and the nitrogen pore size by fitting the two curves, thereby realizing the precise calibration of the NMR pore size by nitrogen adsorption, thereby improving the accuracy of the pore size calibration.

[0087] See also Figure 8 As shown, the embodiment of the present invention discloses a shale nuclear magnetic resonance aperture calibration device, comprising:

[0088] The spectrum measurement module 11 is used to prepare the shale core sample into a nuclear magnetic column sample, dry the nuclear magnetic column sample under a preset high temperature condition, and measure the original nuclear magnetic resonance of the corresponding column sample after treatment. Spectrum, saturating the treated column sample with water under a preset high pressure condition, and measuring the target nuclear magnetic resonance of the corresponding saturated column sample Atlas;

[0089] The curve calculation module 12 is used to calculate the original nuclear magnetic resonance Spectra and NMR of the target Shale pore NMR curve, drying the saturated column sample under a preset high temperature condition to obtain a powder sample, and performing a nitrogen adsorption experiment on the powder sample to calculate the nitrogen adsorption pore size distribution curve of the powder sample;

[0090] The curve acquisition module 13 is used to obtain the shale pore nuclear magnetic resonance The curve and the nitrogen adsorption pore size distribution curve respectively obtain the corresponding nuclear magnetic resonance porosity component curve and nitrogen adsorption porosity component curve; the nuclear magnetic resonance porosity component curve is a curve determined based on the nuclear magnetic resonance relaxation time and the nuclear magnetic resonance porosity component; the nitrogen adsorption porosity component curve is a curve determined based on the nitrogen pore size and the nitrogen adsorption porosity component;

[0091] The pore size calibration module 14 is used to perform nonlinear fitting on the nitrogen adsorption porosity component curve and the nuclear magnetic resonance porosity component curve to determine the corresponding relationship between the nuclear magnetic resonance relaxation time and the nitrogen pore size, and calibrate the nuclear magnetic resonance pore size of shale according to the corresponding relationship.

[0092] In summary, the present invention first prepares the shale core sample into a nuclear magnetic column sample, and then dries the nuclear magnetic column sample under a preset high temperature condition, and measures the original nuclear magnetic resonance of the corresponding column sample after treatment. Spectrum, saturating the treated column sample with water under a preset high pressure condition, and measuring the target nuclear magnetic resonance of the corresponding saturated column sample Spectrum; based on the original NMR Spectra and NMR of the target Shale pore NMR curve, drying the saturated column sample under a preset high temperature condition to obtain a powder sample, performing a nitrogen adsorption experiment on the powder sample to calculate the nitrogen adsorption pore size distribution curve of the powder sample; and then based on the shale pore nuclear magnetic resonance The curve and the nitrogen adsorption pore size distribution curve respectively obtain the corresponding nuclear magnetic resonance porosity component curve and nitrogen adsorption porosity component curve; the nuclear magnetic resonance porosity component curve is a curve determined based on the nuclear magnetic resonance relaxation time and the nuclear magnetic resonance porosity component; the nitrogen adsorption porosity component curve is a curve determined based on the nitrogen pore size and the nitrogen adsorption porosity component; finally, the nitrogen adsorption porosity component curve and the nuclear magnetic resonance porosity component curve are nonlinearly fitted to determine the corresponding relationship between the nuclear magnetic resonance relaxation time and the nitrogen pore size, and the nuclear magnetic resonance pore size of the shale is calibrated according to the corresponding relationship. It can be seen that the present application obtains the nuclear magnetic resonance porosity component curve and the nitrogen adsorption porosity component curve through multiple experiments, and determines the corresponding relationship between the nuclear magnetic resonance relaxation time and the nitrogen pore size by fitting the two curves, thereby realizing the precise calibration of the nuclear magnetic resonance pore size by nitrogen adsorption, and improving the accuracy of pore size calibration.

[0093] In some specific embodiments, the curve calculation module 12 may specifically include:

[0094] A curve determination unit is used to convert the original nuclear magnetic resonance Spectrum and the target NMR The difference between the spectra is determined as the shale pore NMR curve.

[0095] In some specific embodiments, the curve calculation module 12 may specifically include:

[0096] The curve calculation unit is used to perform a nitrogen adsorption experiment on the powder sample, and obtain the nitrogen adsorption pore size distribution curve of the powder sample by BET specific surface area detection method and BJH method.

[0097] In some specific embodiments, the curve acquisition module 13 may specifically include:

[0098] The first accumulating unit is used for nuclear magnetic resonance of the shale pores. The values ​​corresponding to the curve are accumulated to obtain a first overall accumulated value;

[0099] The NMR porosity component acquisition unit is used to determine the shale pore NMR a first accumulated value of each data point corresponding to the curve, and dividing the first accumulated value by the first overall accumulated value to obtain a nuclear magnetic resonance porosity component of each data point;

[0100] A first curve determining unit, configured to determine the NMR porosity component curve according to each of the NMR porosity components and the NMR relaxation time;

[0101] A second accumulation unit, used for accumulating the values ​​corresponding to the nitrogen adsorption pore size distribution curve to obtain a second overall accumulated value;

[0102] a nitrogen adsorption porosity component acquisition unit, configured to determine a second cumulative value of each data point corresponding to the nitrogen adsorption pore size distribution curve, and divide the second cumulative value by the second overall cumulative value to acquire a nitrogen adsorption porosity component of each data point;

[0103] The second curve determining unit is used to determine the nitrogen adsorption porosity component curve according to each of the nitrogen adsorption porosity components and the nitrogen pore diameter.

[0104] In some specific embodiments, the device may further include:

[0105] The difference module is used to internally interpolate the data points of nitrogen adsorption according to the number of NMR data points so that the shale pore NMR The data points of the curve correspond one-to-one to the data points of the nitrogen adsorption pore size distribution curve.

[0106] In some specific embodiments, the device may further include:

[0107] The conversion coefficient determination module is used to determine the conversion coefficient of the nonlinear fitting based on the plurality of the nuclear magnetic resonance porosity components and the plurality of the nitrogen adsorption porosity components by using a preset conversion coefficient determination formula; the preset conversion coefficient determination formula is:

[0108] ;

[0109] in, is the NMR porosity component; is the nitrogen adsorption porosity component; a and b are the conversion coefficients.

[0110] In some specific embodiments, the aperture calibration module 14 may specifically include:

[0111] A nonlinear fitting unit is used to perform nonlinear fitting on the nitrogen adsorption porosity component curve and the nuclear magnetic resonance porosity component curve based on the conversion coefficient.

[0112] Furthermore, the present application also discloses an electronic device. Fig. 9 This is a structural diagram of an electronic device 20 according to an exemplary embodiment. The content in the diagram cannot be regarded as any limitation on the scope of use of the present application.

[0113] Fig. 9A schematic diagram of the structure of an electronic device 20 provided in an embodiment of the present application. The electronic device 20 may specifically include: at least one processor 21, at least one memory 22, a power supply 23, a communication interface 24, an input / output interface 25, and a communication bus 26. The memory 22 is used to store a computer program, which is loaded and executed by the processor 21 to implement the relevant steps in the shale nuclear magnetic resonance aperture calibration method disclosed in any of the aforementioned embodiments. In addition, the electronic device 20 in this embodiment may specifically be an electronic computer.

[0114] In this embodiment, the power supply 23 is used to provide working voltage for each hardware device on the electronic device 20; the communication interface 24 can create a data transmission channel between the electronic device 20 and the external device, and the communication protocol it follows is any communication protocol that can be applied to the technical solution of the present application, and is not specifically limited here; the input and output interface 25 is used to obtain external input data or output data to the outside world, and its specific interface type can be selected according to specific application needs and is not specifically limited here.

[0115] In addition, the memory 22 as a carrier for resource storage may be a read-only memory, a random access memory, a disk or an optical disk, etc. The resources stored thereon may include an operating system 221, a computer program 222, etc., and the storage method may be temporary storage or permanent storage.

[0116] The operating system 221 is used to manage and control the hardware devices and computer program 222 on the electronic device 20, and can be Windows Server, Netware, Unix, Linux, etc. In addition to the computer program that can be used to complete the shale nuclear magnetic resonance aperture calibration method performed by the electronic device 20 disclosed in any of the aforementioned embodiments, the computer program 222 can further include computer programs that can be used to complete other specific tasks.

[0117] Furthermore, the present application also discloses a computer-readable storage medium for storing a computer program; wherein, when the computer program is executed by a processor, the aforementioned shale nuclear magnetic resonance aperture calibration method is implemented. The specific steps of the method can be referred to the corresponding contents disclosed in the aforementioned embodiments, and will not be repeated here.

[0118] In this specification, each embodiment is described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part.

[0119] Professionals may further appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of the two. In order to clearly illustrate the interchangeability of hardware and software, the composition and steps of each example have been generally described in the above description according to function. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professionals and technicians may use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0120] The steps of the method or algorithm described in conjunction with the embodiments disclosed herein may be implemented directly using hardware, a software module executed by a processor, or a combination of the two. The software module may be placed in a random access memory (RAM), a memory, a read-only memory (ROM), an electrically programmable ROM, an electrically erasable programmable ROM, a register, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art.

[0121] Finally, it should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the presence of other identical elements in the process, method, article or device including the elements.

[0122] The technical solution provided by the present application is introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present application. The description of the above embodiments is only used to help understand the method of the present application and its core idea. At the same time, for general technicians in this field, according to the idea of ​​the present application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as a limitation on the present application.

Claims

1. A shale nuclear magnetic resonance aperture calibration method, characterized in that: include: The shale core sample is prepared into a nuclear magnetic column sample, the nuclear magnetic column sample is dried under a preset high temperature condition, and the original nuclear magnetic resonance of the corresponding column sample after treatment is measured. Spectrum, saturating the treated column sample with water under a preset high pressure condition, and measuring the target nuclear magnetic resonance of the corresponding saturated column sample Atlas; Based on the original NMR Spectra and NMR of the target Shale pore NMR curve, drying the saturated column sample under a preset high temperature condition to obtain a powder sample, and performing a nitrogen adsorption experiment on the powder sample to calculate the nitrogen adsorption pore size distribution curve of the powder sample; Based on the shale pore nuclear magnetic resonance The curve and the nitrogen adsorption pore size distribution curve respectively obtain the corresponding nuclear magnetic resonance porosity component curve and nitrogen adsorption porosity component curve; the nuclear magnetic resonance porosity component curve is a curve determined based on the nuclear magnetic resonance relaxation time and the nuclear magnetic resonance porosity component; the nitrogen adsorption porosity component curve is a curve determined based on the nitrogen pore size and the nitrogen adsorption porosity component; The nitrogen adsorption porosity component curve and the nuclear magnetic resonance porosity component curve are nonlinearly fitted to determine the corresponding relationship between the nuclear magnetic resonance relaxation time and the nitrogen pore size, and the nuclear magnetic resonance pore size of the shale is calibrated according to the corresponding relationship.

2. The shale nuclear magnetic resonance aperture calibration method according to claim 1, characterized in that: Based on the original nuclear magnetic resonance Spectra and NMR of the target Shale pore NMR Curves, including: The original NMR Spectrum and the target NMR The difference between the spectra is determined as the shale pore NMR curve.

3. The shale nuclear magnetic resonance aperture calibration method according to claim 1, characterized in that: The performing of a nitrogen adsorption experiment on the powder sample to calculate a nitrogen adsorption pore size distribution curve of the powder sample comprises: A nitrogen adsorption experiment is performed on the powder sample, and a nitrogen adsorption pore size distribution curve of the powder sample is obtained by BET specific surface area detection method and BJH method.

4. The shale nuclear magnetic resonance aperture calibration method according to claim 1, characterized in that: The shale pore nuclear magnetic resonance The curve and the nitrogen adsorption pore size distribution curve respectively obtain the corresponding nuclear magnetic resonance porosity component curve and nitrogen adsorption porosity component curve, including: Nuclear magnetic resonance imaging of shale pores The values ​​corresponding to the curve are accumulated to obtain a first overall accumulated value; Determine the shale pore size by NMR a first accumulated value of each data point corresponding to the curve, and dividing the first accumulated value by the first overall accumulated value to obtain a nuclear magnetic resonance porosity component of each data point; Determining the NMR porosity component curve according to each of the NMR porosity components and the NMR relaxation time; Accumulating the values ​​corresponding to the nitrogen adsorption pore size distribution curve to obtain a second overall accumulated value; Determine a second cumulative value of each data point corresponding to the nitrogen adsorption pore size distribution curve, and divide the second cumulative value by the second overall cumulative value to obtain a nitrogen adsorption porosity component of each data point; The nitrogen adsorption porosity component curve is determined according to each of the nitrogen adsorption porosity components and the nitrogen pore diameter.

5. The shale nuclear magnetic resonance aperture calibration method according to claim 1, characterized in that: Before performing nonlinear fitting on the nitrogen adsorption porosity component curve and the nuclear magnetic resonance porosity component curve, the method further includes: The data points of nitrogen adsorption are internally interpolated according to the number of NMR data points so that the shale pore NMR The data points of the curve correspond one-to-one to the data points of the nitrogen adsorption pore size distribution curve.

6. The shale nuclear magnetic resonance aperture calibration method according to any one of claims 1 to 5, characterized in that: Before performing nonlinear fitting on the nitrogen adsorption porosity component curve and the nuclear magnetic resonance porosity component curve, the method further includes: The conversion coefficient of the nonlinear fitting is determined based on a plurality of the nuclear magnetic resonance porosity components and a plurality of the nitrogen adsorption porosity components by using a preset conversion coefficient determination formula; the preset conversion coefficient determination formula is: ； in, is the NMR porosity component; is the nitrogen adsorption porosity component; a and b are the conversion coefficients.

7. The shale nuclear magnetic resonance aperture calibration method according to claim 6, characterized in that: The nonlinear fitting of the nitrogen adsorption porosity component curve and the nuclear magnetic resonance porosity component curve comprises: The nitrogen adsorption porosity component curve and the nuclear magnetic resonance porosity component curve are nonlinearly fitted based on the conversion coefficient.

8. A shale nuclear magnetic resonance aperture calibration device, characterized in that: include: The spectrum measurement module is used to prepare the shale core sample into a nuclear magnetic column sample, dry the nuclear magnetic column sample under a preset high temperature condition, and measure the original nuclear magnetic resonance of the corresponding column sample after treatment. Spectrum, saturating the treated column sample with water under a preset high pressure condition, and measuring the target nuclear magnetic resonance of the corresponding saturated column sample Atlas; Curve calculation module for calculating the original NMR Spectra and NMR of the target Shale pore NMR curve, drying the saturated column sample under a preset high temperature condition to obtain a powder sample, and performing a nitrogen adsorption experiment on the powder sample to calculate the nitrogen adsorption pore size distribution curve of the powder sample; Curve acquisition module, used for shale pore nuclear magnetic resonance The curve and the nitrogen adsorption pore size distribution curve respectively obtain the corresponding nuclear magnetic resonance porosity component curve and nitrogen adsorption porosity component curve; the nuclear magnetic resonance porosity component curve is a curve determined based on the nuclear magnetic resonance relaxation time and the nuclear magnetic resonance porosity component; the nitrogen adsorption porosity component curve is a curve determined based on the nitrogen pore size and the nitrogen adsorption porosity component; The pore size calibration module is used to perform nonlinear fitting on the nitrogen adsorption porosity component curve and the nuclear magnetic resonance porosity component curve to determine the corresponding relationship between the nuclear magnetic resonance relaxation time and the nitrogen pore size, and calibrate the nuclear magnetic resonance pore size of shale according to the corresponding relationship.

9. An electronic device, characterized in that: include: Memory, used to store computer programs; A processor, configured to execute the computer program to implement the shale nuclear magnetic resonance aperture calibration method as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: Used to store a computer program; wherein, when the computer program is executed by a processor, the shale nuclear magnetic resonance aperture calibration method according to any one of claims 1 to 7 is implemented.

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