Shale fluid porosity conversion method, apparatus, device, and medium at different frequencies

Abstract

The application discloses a shale fluid porosity conversion method, device, equipment and medium of different frequencies, relates to the oil and gas exploration and development technical field, and includes constructing a shale multi-component original digital core; constructing shale multi-component digital cores with different pyrite contents, different clay mineral contents and different clay mineral types based on the shale multi-component original digital core; inverting echo data of a multi-frequency nuclear magnetic resonance experiment, constraining transverse surface relaxation intensity when numerically simulating the shale multi-component original digital core; simulating nuclear magnetic resonance response characteristics to generate target echo data; inverting and accumulating the target echo data to obtain porosities of inorganic pore water and organic pore oil, complete porosity conversion of different nuclear magnetic resonance instrument frequencies and different pore types for shale oil samples, simplify operations, reduce time consumption, reflect influences of single factors on nuclear magnetic resonance responses, and accurately evaluate nuclear magnetic resonance porosities of shale oil samples.

Description

Technical Field

[0001] This invention relates to the field of oil and gas exploration and development technology, and in particular to a method, apparatus, equipment and medium for transforming the porosity of shale fluids at different frequencies. Background Technology

[0002] Shale oil reservoirs are characterized by low porosity, low permeability, complex mineral composition, and strong heterogeneity in organic matter distribution. Nuclear magnetic resonance (NMR) technology holds great potential for evaluating the rock physical properties of porous rocks. However, the complexity of the mineral composition of shale oil reservoirs, the heterogeneity of organic matter distribution, the differences in frequency between NMR logging instruments and laboratory measuring instruments, and the variations in acquisition parameters make it difficult for NMR technology to accurately determine the rock physical parameters of shale oil. Porosity, as an important rock physical parameter, represents the ability of shale oil to store fluids. Currently, there are few reports on fundamental theoretical studies regarding the influence of different mineral contents and types in shale oil reservoirs on NMR response and their impact on NMR porosity. Studies on the effects of echo interval and NMR instrument frequency on NMR response and porosity are based on NMR experiments using actual shale cores. These experimental methods are complex, time-consuming, and cannot reflect the influence of a single factor. Furthermore, these methods lack guidance from theories relating to the frequency dependence of pore fluids. This makes it impossible to accurately evaluate the NMR porosity of shale oil samples with different echo intervals, mineral contents and types, and NMR instrument frequencies.

[0003] As can be seen from the above, how to simplify the operation, reduce the time consumption, and reflect the influence of a single factor on the nuclear magnetic resonance response, and achieve accurate conversion of porosity for different echo intervals, different mineral contents, types, different nuclear magnetic resonance instrument frequencies, and different pore types, so as to accurately evaluate the nuclear magnetic resonance porosity of shale oil samples, is a problem to be solved in this field. Summary of the Invention

[0004] In view of this, the purpose of this invention is to provide a method, apparatus, equipment, and medium for converting the porosity of shale fluids at different frequencies. This method simplifies operation, reduces time consumption, and reflects the influence of a single factor on the nuclear magnetic resonance (NMR) response. It achieves accurate conversion of porosity for different echo intervals, mineral contents, types, NMR instrument frequencies, and pore types, thereby enabling accurate evaluation of the NMR porosity of shale oil samples. The specific scheme is as follows:

[0005] In a first aspect, this application discloses a method for transforming the porosity of shale fluids at different frequencies, including:

[0006] Focused ion beam scanning electron microscope (FIS) images and multi-frequency nuclear magnetic resonance (NMR) experimental echo data of shale oil samples were acquired, and multi-component original digital cores of shale were constructed based on the FIS images.

[0007] Based on the original digital cores of the multi-component shale, and using the preset three-dimensional morphological method, multi-component digital cores of shale with different pyrite contents, different clay mineral contents, and different clay mineral types were constructed respectively.

[0008] The echo data from the multi-frequency nuclear magnetic resonance experiment were inverted to obtain the T2 distribution of the multi-frequency nuclear magnetic resonance experiment. The T2 distribution of the multi-frequency nuclear magnetic resonance experiment was used to constrain the lateral surface relaxation intensity when numerically simulating the original digital core of the multi-component shale.

[0009] The nuclear magnetic resonance response characteristics of the multi-component digital core of the shale were simulated by using numerical simulation methods and based on the transverse surface relaxation intensity of the original digital core of the shale, so as to generate target echo data for characterizing different nuclear magnetic resonance instrument frequencies, different echo intervals, different pyrite contents, different clay mineral contents, and different clay mineral types.

[0010] The target echo data is inverted to obtain the target T2 distribution. The target T2 distribution is then summed to obtain the porosity of inorganic pore water and organic pore oil, thereby completing the porosity conversion for different nuclear magnetic resonance instrument frequencies and different pore types of the shale oil sample.

[0011] Optionally, the step of constructing shale multi-component digital cores with different pyrite contents, different clay mineral contents, and different clay mineral types based on the original multi-component digital cores of the shale and using a preset three-dimensional morphological method includes:

[0012] Organic pores, inorganic pores, framework, and organic matter are used as the first mixed component. The shale multi-component digital core and the first mixed component are processed using a preset three-dimensional morphological method and Boolean operation. The content and spatial location of the fixed components including the organic pores, inorganic pores, and organic matter are made consistent with the original shale multi-component digital core to construct shale multi-component digital cores with different pyrite contents.

[0013] The organic pores, the framework, the organic matter, and pyrite are used as the second mixed component. The shale multi-component digital core and the second mixed component are processed using a preset three-dimensional morphological method and Boolean operations. The content and spatial location of the fixed components, including the organic pores, the inorganic pores, the organic matter, and the pyrite, are made consistent with the original shale multi-component digital core to construct shale multi-component digital cores with different clay mineral contents.

[0014] Select any shale multi-component digital core with any clay mineral content from shale multi-component digital cores to serve as shale multi-component digital cores for different clay mineral types.

[0015] Optionally, the process of processing the shale multi-component digital core and the first mixed component using a preset three-dimensional morphological method and Boolean operations includes:

[0016] The shale multi-component digital core and the first mixed component are processed using a preset three-dimensional morphological method to obtain shale multi-component digital cores with different pyrite contents in the intermediate state. Boolean operations are then used to process the original shale multi-component digital core and the shale multi-component digital cores with different pyrite contents in the intermediate state.

[0017] Accordingly, the process of processing the shale multi-component digital core and the second mixed component using a preset three-dimensional morphological method and Boolean operations includes:

[0018] The shale multi-component digital core and the second mixed component are processed using a preset three-dimensional morphological method to obtain shale multi-component digital cores with different clay mineral contents in an intermediate state. Boolean operations are then used to process the original shale multi-component digital core and the shale multi-component digital cores with different clay mineral contents in the intermediate state.

[0019] Optionally, the lateral surface relaxation intensity during numerical simulation using the T2 distribution constraint of the multi-component original digital core of the shale obtained from the multi-frequency nuclear magnetic resonance experiment includes:

[0020] The transverse surface relaxation intensity at different nuclear magnetic resonance instrument frequencies was determined using the Korb model;

[0021] The transverse surface relaxation intensity of the original digital core of multi-component shale was used to conduct numerical simulation by constraining the transverse surface relaxation intensity of the different nuclear magnetic resonance instrument frequencies and the T2 distribution of the multi-frequency nuclear magnetic resonance experiment.

[0022] Optionally, the lateral surface relaxation intensity when using the different nuclear magnetic resonance instrument frequencies and the T2 distribution of the multi-frequency nuclear magnetic resonance experiment to constrain the original digital core of the shale multi-component rock for numerical simulation includes:

[0023] The peak positions of the T2 distribution of inorganic pore water and organic pore oil in the multi-frequency nuclear magnetic resonance experiment were determined, and the peak positions of different frequency results of numerical simulation based on the original digital core of the multi-component shale were also determined.

[0024] The minimum error between the peak position of the T2 distribution and the peak position of the results at different frequencies is calculated to obtain the initial transverse surface relaxation intensity when numerically simulating the multi-component digital core of the shale under different frequency nuclear magnetic resonance instruments.

[0025] The initial transverse surface relaxation intensity is used as the calibration of the transverse surface relaxation intensity at different instrument frequencies to obtain the transverse surface relaxation intensity values ​​at different nuclear magnetic resonance instrument frequencies.

[0026] Optionally, the step of simulating the nuclear magnetic resonance response characteristics of the multi-component digital core of the shale using a numerical simulation method based on the transverse surface relaxation intensity during numerical simulation, to generate target echo data for characterizing different nuclear magnetic resonance instrument frequencies, different echo intervals, different pyrite contents, different clay mineral contents, and different clay mineral types, includes:

[0027] Calculation of the internal magnetic field gradient at different nuclear magnetic resonance instrument frequencies based on magnetic dipole theory;

[0028] Numerical simulation methods were used to simulate the one-dimensional nuclear magnetic resonance (NMR) acquisition process of shale oil based on the transverse surface relaxation intensity values ​​and the internal magnetic field gradient at different NMR instrument frequencies. In combination with a platform model, target echo data were simulated to characterize different NMR instrument frequencies, different echo intervals, different pyrite contents, different clay mineral contents, and different clay mineral types.

[0029] Optionally, the inversion of the target echo data to obtain the target T2 distribution, and the summation of the target T2 distributions to obtain the porosity of inorganic pore water and organic pore oil, to complete the porosity conversion for different NMR instrument frequencies and different pore types of the shale oil sample, includes:

[0030] The echo data of the inorganic pore water and the echo data of the organic pore oil in the target echo data are inverted to obtain the corresponding target T2 distribution;

[0031] The target T2 distributions are accumulated to obtain the porosity of inorganic pore water and organic pore oil. Based on the correspondence between the porosity and the different NMR instrument frequencies, different echo intervals, different pyrite contents, different clay mineral contents, and different clay mineral types, the porosity conversion for different NMR instrument frequencies and different pore types of shale oil samples is completed.

[0032] Secondly, this application discloses a device for converting the porosity of shale fluids at different frequencies, comprising:

[0033] The image data acquisition module is used to acquire focused ion beam scanning electron microscope images and multi-frequency nuclear magnetic resonance experimental echo data of shale oil samples, and to construct multi-component original digital cores of shale based on the focused ion beam scanning electron microscope images;

[0034] The core construction module is used to construct shale multi-component digital cores with different pyrite contents, different clay mineral contents, and different clay mineral types based on the original multi-component digital cores of the shale and using a preset three-dimensional morphological method.

[0035] The inversion module is used to invert the echo data of the multi-frequency nuclear magnetic resonance experiment to obtain the T2 distribution of the multi-frequency nuclear magnetic resonance experiment, and to use the T2 distribution of the multi-frequency nuclear magnetic resonance experiment to constrain the lateral surface relaxation intensity when performing numerical simulation of the original digital core of the multi-component shale.

[0036] The data generation module is used to simulate the nuclear magnetic resonance response characteristics of the multi-component digital core of the shale by means of a numerical simulation method and based on the transverse surface relaxation intensity of the original digital core of the shale, so as to generate target echo data for characterizing different nuclear magnetic resonance instrument frequencies, different echo intervals, different pyrite contents, different clay mineral contents, and different clay mineral types.

[0037] The porosity conversion module is used to invert the target echo data to obtain the target T2 distribution, and to accumulate the target T2 distribution to obtain the porosity of inorganic pore water and organic pore oil, so as to complete the porosity conversion for different nuclear magnetic resonance instrument frequencies and different pore types of the shale oil sample.

[0038] Thirdly, this application discloses an electronic device, including:

[0039] Memory, used to store computer programs;

[0040] A processor is used to execute the computer program to implement the aforementioned method for converting the porosity of shale fluids at different frequencies.

[0041] Fourthly, this application discloses a computer storage medium for storing a computer program; wherein, when the computer program is executed by a processor, it implements the steps of the aforementioned shale fluid porosity conversion method at different frequencies.

[0042] As can be seen, this application provides a method for converting the porosity of shale fluids at different frequencies, including acquiring focused ion beam scanning electron microscope (FSE) images and multi-frequency nuclear magnetic resonance (NMR) experimental echo data of shale oil samples; constructing a multi-component original digital core of shale based on the FSE images; constructing multi-component digital cores of shale with different pyrite contents, different clay mineral contents, and different clay mineral types based on the multi-component original digital cores of shale using a preset three-dimensional morphological method; inverting the multi-frequency NMR experimental echo data to obtain the multi-frequency NMR experimental T2 distribution; and using the multi-frequency NMR experimental T2 distribution to constrain the multi-component original digital cores of shale for further processing. The transverse surface relaxation intensity during numerical simulation is used to simulate the nuclear magnetic resonance response characteristics of the multi-component digital core of the shale using numerical simulation methods based on the original digital core of the shale multi-component core. This generates target echo data to characterize different nuclear magnetic resonance instrument frequencies, different echo intervals, different pyrite contents, different clay mineral contents, and different clay mineral types. The target echo data is inverted to obtain the target T2 distribution. The target T2 distribution is accumulated to obtain the porosity of inorganic pore water and organic pore oil, thus completing the porosity conversion for different nuclear magnetic resonance instrument frequencies and different pore types of the shale oil sample. This application constructs multi-component digital cores of shale with varying pyrite, clay mineral content, and clay mineral types using original multi-component digital cores. This simplifies operation, reduces time consumption, and reflects the influence of a single factor on the NMR response. The T2 distribution of multi-frequency NMR experimental echo data is obtained through inversion. This T2 distribution is then used to constrain the transverse surface relaxation intensity during numerical simulation of the original multi-component digital cores of shale. The NMR response characteristics of the multi-component digital cores are simulated using numerical simulation methods to generate target echo data. This data is then inverted and accumulated to obtain the porosity of inorganic pore water and organic pore oil. This allows for accurate conversion of porosity based on different echo intervals, mineral contents, types, NMR instrument frequencies, and pore types, thus enabling accurate evaluation of the NMR porosity of shale oil samples. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0044] Figure 1This is a flowchart of a shale fluid porosity conversion method with different nuclear magnetic resonance frequencies disclosed in this application;

[0045] Figure 2 This is a graph showing the variation of transverse surface relaxation intensity at different nuclear magnetic resonance frequencies with correlation time, as disclosed in this application.

[0046] Figure 3 This is a transverse surface relaxation strength calibration map required for numerical simulation of multi-component digital core of shale as disclosed in this application;

[0047] Figure 4 This is a diagram showing the internal magnetic field gradient distribution for different pyrite contents as disclosed in this application.

[0048] Figure 5 This is a flowchart of another method for transforming the porosity of shale fluids at different nuclear magnetic resonance frequencies disclosed in this application;

[0049] Figure 6 This application discloses the results of nuclear magnetic resonance numerical simulation of shale oil with different pyrite contents.

[0050] Figure 7 This application discloses the conversion results of porosity of a shale oil sample on nuclear magnetic resonance instruments at different frequencies.

[0051] Figure 8 This is a schematic diagram of a shale fluid porosity conversion device with different nuclear magnetic resonance frequencies disclosed in this application;

[0052] Figure 9 This application provides a structural diagram of an electronic device. Detailed Implementation

[0053] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0054] Shale oil reservoirs are characterized by low porosity, low permeability, complex mineral composition, and strong heterogeneity in organic matter distribution. Nuclear magnetic resonance (NMR) technology holds great potential for evaluating the rock physical properties of porous rocks. However, the complexity of the mineral composition of shale oil reservoirs, the heterogeneity of organic matter distribution, the differences in frequency between NMR logging instruments and laboratory measuring instruments, and the variations in acquisition parameters make it difficult for NMR technology to accurately determine the rock physical parameters of shale oil. Porosity, as an important rock physical parameter, represents the ability of shale oil to store fluids. Currently, there are few reports on fundamental theoretical studies regarding the influence of different mineral contents and types in shale oil reservoirs on NMR response and their impact on NMR porosity. Studies on the effects of echo interval and NMR instrument frequency on NMR response and porosity are based on NMR experiments using actual shale cores. These experimental methods are complex, time-consuming, and cannot reflect the influence of single factors. Furthermore, these methods lack guidance from theories related to the frequency dependence of pore fluids. This makes it impossible to accurately evaluate the NMR porosity of shale oil samples from different echo intervals, mineral contents and types, and NMR instrument frequencies. Therefore, simplifying the operation, reducing time consumption, and reflecting the influence of single factors on NMR response, while achieving accurate conversion of porosity across different echo intervals, mineral contents and types, NMR instrument frequencies, and pore types, is a problem that needs to be solved in this field for accurate evaluation of the NMR porosity of shale oil samples.

[0055] See Figure 1 As shown in the figure, this invention discloses a method for transforming the porosity of shale fluids at different frequencies, which may specifically include:

[0056] Step S11: Obtain focused ion beam scanning electron microscope (FSE) images and multi-frequency nuclear magnetic resonance (NMR) experimental echo data of shale oil samples, and construct multi-component original digital cores of shale oil based on the FSE images.

[0057] It is understandable that FIB-SEM (Focused Ion Beam-Scanning Electron Microscope) images are three-dimensional images of shale oil samples generated by superimposing several FIB-SEM sub-images, and multi-frequency NMR experimental echo data (i.e., multi-frequency nuclear magnetic resonance experimental echo data) are the measurement results of shale oil samples at different instrument frequencies.

[0058] Step S12: Based on the original digital core of the shale multi-component, and using a preset three-dimensional morphological method, construct shale multi-component digital cores with different pyrite contents, different clay mineral contents, and different clay mineral types.

[0059] Step S13: Invert the echo data of the multi-frequency nuclear magnetic resonance experiment to obtain the T2 distribution of the multi-frequency nuclear magnetic resonance experiment, and use the T2 distribution of the multi-frequency nuclear magnetic resonance experiment to constrain the lateral surface relaxation intensity when performing numerical simulation of the original digital core of the multi-component shale.

[0060] In this embodiment, the echo data of the multi-frequency nuclear magnetic resonance experiment is inverted to obtain the T2 distribution of the multi-frequency nuclear magnetic resonance experiment. The transverse surface relaxation intensity of different nuclear magnetic resonance instrument frequencies is determined by the Korb model. The transverse surface relaxation intensity of the multi-component original digital core of shale is constrained by the transverse surface relaxation intensity of the different nuclear magnetic resonance instrument frequencies and the T2 distribution of the multi-frequency nuclear magnetic resonance experiment when performing numerical simulation.

[0061] Specifically, the peak positions of the T2 distribution of inorganic pore water and organic pore oil in the multi-frequency nuclear magnetic resonance experiment are determined, and the peak positions of the numerical simulation results at different frequencies based on the original digital core of the shale multi-component rock are also determined. The minimum error is calculated between the peak positions of the T2 distribution and the peak positions of the different frequency results to obtain the initial transverse surface relaxation intensity when numerically simulating the shale multi-component digital core under different frequency nuclear magnetic resonance instruments. This initial transverse surface relaxation intensity is used as the calibration of the transverse surface relaxation intensity at different instrument frequencies to obtain the transverse surface relaxation intensity values ​​at different nuclear magnetic resonance instrument frequencies.

[0062] It is understandable that the Korb model is used to determine the transverse surface relaxation intensity at different NMR instrument frequencies; the transverse surface relaxation intensity obtained when the peak position of the T2 distribution of inorganic pore water and organic pore oil in the multi-frequency NMR experiment has the minimum error with the peak position of the simulation results of different frequencies (taking 2MHz and 21.36MHz as examples) based on the original digital core of the shale at the original frequency of 2MHz and 21.36MHz is used as the transverse surface relaxation intensity required for the numerical simulation of the digital core of the shale at the NMR instrument at the frequency of 2MHz and 21.36MHz; the transverse surface relaxation intensity required for the numerical simulation of the digital core of the shale at the frequency of 2MHz and 21.36MHz is used as the calibration of the transverse surface relaxation intensity at the different instrument frequencies, and the transverse surface relaxation intensity values ​​at different NMR instrument frequencies can be obtained; specifically, according to the Korb model, the surface relaxation rate of inorganic pore water and organic pore oil can be expressed as:

[0063]

[0064] Where, d W and R OThis refers to the 2D and 1D diffusion models in the Korb model, where B and C are related to the paramagnetic ion concentrations on inorganic and organic pores, the densities of inorganic pore water and organic pore oil, the specific surface areas of inorganic and organic pores, the translational correlation times of inorganic pore water and organic pore oil, the surface residence times of inorganic pore water and organic pore oil, and the magnetic moment of the pore surface. 1 H is related to the magnetic moment of paramagnetic ions and their angular frequencies. Generally, B and C are related to the pore structure and pore fluid properties of shale oil reservoirs.

[0065] Assuming the pores are cylindrical, under the condition of the shortest echo interval, the transverse relaxation rate is approximately equal to the transverse surface relaxation rate, expressed as:

[0066]

[0067] Based on the Korb model, the parameters in the formula are varied within the same order of magnitude to simulate the variation of transverse surface relaxation intensity with correlation time at different NMR instrument frequencies, such as... Figure 2 The figures (a), (b), (c), (d), (e), and (f) in the figure show the peak positions (T2) of the T2 distributions of inorganic pore water and organic pore oil in the multi-frequency NMR experiment. 2，exp，peak The peak positions (T) of the simulation results based on the original digital core of the multi-component shale at 2MHz and 21.36MHz are compared with those of the simulation results. 2，Korb,peak The error, as the objective function, can be expressed as:

[0068] min{||T 2，exp，peak -T 2，Korb，peak ||2};

[0069] The transverse surface relaxation intensity obtained at the minimum value of the above formula is used as the transverse surface relaxation intensity of inorganic pore water and organic pore oil required for numerical simulation of the multi-component digital core of the shale under NMR instruments at frequencies of 2MHz and 21.36MHz. Figure 3 As shown in (a) and (b) in the figure.

[0070] Step S14: Simulate the nuclear magnetic resonance response characteristics of the multi-component digital core of the shale by using a numerical simulation method and based on the transverse surface relaxation intensity of the original digital core of the shale, so as to generate target echo data for characterizing different nuclear magnetic resonance instrument frequencies, different echo intervals, different pyrite contents, different clay mineral contents, and different clay mineral types.

[0071] In this embodiment, the internal magnetic field gradient at different NMR instrument frequencies is calculated based on magnetic dipole theory. A numerical simulation method is used to simulate the one-dimensional NMR acquisition process of shale oil based on the transverse surface relaxation intensity value and the internal magnetic field gradient at different NMR instrument frequencies. The platform model is combined to simulate target echo data for characterizing different NMR instrument frequencies, different echo intervals, different pyrite contents, different clay mineral contents, and different clay mineral types.

[0072] Specifically, the internal magnetic field gradient at different instrument frequencies can be calculated using the dipole summation method based on magnetic dipole theory, as shown in the following formula:

[0073]

[0074]

[0075]

[0076] Where, φ r δ and r are the angle and distance between the magnetic dipole and a certain position, respectively. L B represents the difference in magnetic susceptibility between inorganic porous water or organic porous oil and the surrounding minerals, where B0 is the magnetic field strength and R is the equivalent spherical radius of each voxel. z (r i -r r ) is the contribution of the i-th magnetic dipole to the magnetic field strength at the r-th position in the pore space.

[0077] Taking different pyrite contents as examples, the calculated results of their internal magnetic field gradients are as follows: Figure 4 As shown. The transverse volume relaxation rate of organic matter at different NMR instrument frequencies, simulated using a platform model, is driven by intramolecular dipole-dipole interactions and can be expressed as:

[0078]

[0079]

[0080]

[0081] Among them, J P (ω,τ R，K ,τ l,K τ is the spectral density function of the P-model. R,K It is the rotational correlation time driven by dipole-dipole interactions between organic molecules. R R，K It is the radius of rotation driven by the dipole-dipole interactions between organic molecules, η. K s K , and τl，K These are the viscosity, generalized order parameter, and internal rotation time of organic molecules.

[0082] Step S15: Invert the target echo data to obtain the target T2 distribution, and sum the target T2 distributions to obtain the porosity of inorganic pore water and organic pore oil, so as to complete the porosity conversion for different nuclear magnetic resonance instrument frequencies and different pore types of the shale oil sample.

[0083] In this embodiment, the echo data of inorganic pore water and organic pore oil in the target echo data are inverted to obtain the corresponding target T2 distribution; the target T2 distributions are accumulated to obtain the porosity of inorganic pore water and organic pore oil; based on the correspondence between the porosity and the different NMR instrument frequencies, the different echo intervals, the different pyrite contents, the different clay mineral contents, and the different clay mineral types, the porosity conversion for different NMR instrument frequencies and different pore types of shale oil samples is completed.

[0084] In this embodiment, the one-dimensional NMR acquisition process of shale oil is simulated using a numerical simulation method to obtain echo data of inorganic pore water and organic pore oil in shale oil. The volume relaxation times of inorganic pore water and organic pore oil are set to 2.6s and 1.1s, respectively. Based on the transverse surface relaxation intensity values ​​at different NMR instrument frequencies, the internal magnetic field gradient G, and the transverse volume relaxation time T of organic matter, the data is analyzed. 2B，K Substitute them into the following formula to achieve numerical simulation:

[0085]

[0086] Among them, T 2B，W T 2B,O T 2B，K T 2S，W T 2S,O T 2D，W T 2D，O These are the volume relaxation time of inorganic pore water, the volume relaxation time of organic pore oil, the volume relaxation time of organic matter, the surface relaxation time of inorganic pore water, the surface relaxation time of organic pore oil, the diffusion relaxation time of inorganic pore water, and the diffusion relaxation time of organic pore oil.

[0087] In this embodiment, focused ion beam scanning electron microscope (FBS) images and multi-frequency nuclear magnetic resonance (NMR) echo data of shale oil samples are acquired. Based on the FBS images, a multi-component original digital core of the shale is constructed. Based on this original digital core, and using a preset three-dimensional morphological method, multi-component digital cores of shale with different pyrite contents, clay mineral contents, and clay mineral types are constructed. The multi-frequency NMR echo data is inverted to obtain the multi-frequency NMR experimental T2 distribution. The T2 distribution is then used to constrain the lateral surface relaxation of the original multi-component digital core during numerical simulation. The lateral surface relaxation intensity of the shale multi-component digital core is simulated using numerical simulation methods to simulate the nuclear magnetic resonance response characteristics of the shale multi-component digital core. This generates target echo data to characterize different nuclear magnetic resonance instrument frequencies, different echo intervals, different pyrite contents, different clay mineral contents, and different clay mineral types. The target echo data is inverted to obtain the target T2 distribution. The target T2 distribution is then summed to obtain the porosity of inorganic pore water and organic pore oil, thus completing the porosity conversion for different nuclear magnetic resonance instrument frequencies and different pore types of the shale oil sample. This application constructs multi-component digital cores of shale with varying pyrite, clay mineral content, and clay mineral types using original multi-component digital cores. This simplifies operation, reduces time consumption, and reflects the influence of a single factor on the NMR response. The T2 distribution of multi-frequency NMR experimental echo data is obtained through inversion. This T2 distribution is then used to constrain the transverse surface relaxation intensity during numerical simulation of the original multi-component digital cores of shale. The NMR response characteristics of the multi-component digital cores are simulated using numerical simulation methods to generate target echo data. This data is then inverted and accumulated to obtain the porosity of inorganic pore water and organic pore oil. This allows for accurate conversion of porosity based on different echo intervals, mineral contents, types, NMR instrument frequencies, and pore types, thus enabling accurate evaluation of the NMR porosity of shale oil samples.

[0088] See Figure 5 As shown in the figure, this invention discloses a method for transforming the porosity of shale fluids at different frequencies, which may specifically include:

[0089] Step S21: Obtain focused ion beam scanning electron microscope (FIS) images and multi-frequency nuclear magnetic resonance (NMR) experimental echo data of shale oil samples, and construct multi-component original digital cores of shale oil based on the FIS images.

[0090] Step S22: Using organic pores, inorganic pores, framework, and organic matter as the first mixed component, the shale multi-component digital core and the first mixed component are processed using a preset three-dimensional morphological method and Boolean operation. The content and spatial location of the fixed components including the organic pores, inorganic pores, and organic matter are made consistent with the original shale multi-component digital core to construct shale multi-component digital cores with different pyrite contents.

[0091] In this embodiment, organic pores, inorganic pores, the framework, and organic matter are used as the first mixed component. The shale multi-component digital core and the first mixed component are processed using a preset three-dimensional morphology method to obtain shale multi-component digital cores with different pyrite contents in an intermediate state. Boolean operations are then used to process the original shale multi-component digital core and the intermediate shale multi-component digital cores with different pyrite contents, ensuring that the content and spatial location of the fixed components, including the organic pores, inorganic pores, and organic matter, are consistent with the original shale multi-component digital core, thereby constructing shale multi-component digital cores with different pyrite contents.

[0092] Step S23: Using the organic pores, the framework, the organic matter, and pyrite as the second mixed component, the shale multi-component digital core and the second mixed component are processed using a preset three-dimensional morphological method and Boolean operations. The content and spatial location of the fixed components, including the organic pores, the inorganic pores, the organic matter, and the pyrite, are made consistent with the original shale multi-component digital core to construct shale multi-component digital cores with different clay mineral contents.

[0093] In this embodiment, the organic pores, the framework, the organic matter, and pyrite are used as the second mixed component. A preset three-dimensional morphological method is used to process the shale multi-component digital core and the second mixed component to obtain shale multi-component digital cores with different clay mineral contents in an intermediate state. Boolean operations are then used to process the original shale multi-component digital core and the intermediate shale multi-component digital cores with different clay mineral contents, ensuring that the content and spatial location of the fixed components, including the organic pores, the inorganic pores, the organic matter, and the pyrite, are consistent with those of the original shale multi-component digital core, thereby constructing shale multi-component digital cores with different clay mineral contents.

[0094] Step S24: Select any shale multi-component digital core with any clay mineral content from shale multi-component digital cores with different clay mineral contents as shale multi-component digital cores of different clay mineral types.

[0095] In this embodiment, a multi-component original digital core of shale is constructed based on FIB-SEM images. A three-dimensional morphological method is used to construct multi-component digital cores of shale with different pyrite contents, clay mineral contents, and clay mineral types. This includes: treating organic pores, inorganic pores, the framework, and organic matter as a mixed component, represented by the number 1, and pyrite by the number 0; selecting 2×2×2 structural elements; and processing the mixed components of the multi-component digital core of shale based on a three-dimensional morphological corrosion algorithm to obtain three-dimensional morphological corrosion. The intermediate state of shale multi-component digital cores with different pyrite contents was obtained. Based on Boolean operations, the positions represented by fixed components such as organic pores, inorganic pores, and organic matter in the original shale multi-component digital cores were assigned to the intermediate state of shale multi-component digital cores with different pyrite contents. This ensures that the content and spatial position of fixed components such as organic pores, inorganic pores, and organic matter are consistent with the original shale multi-component digital cores. In this way, pyrite occupies part of the framework position in the digital cores, thus obtaining the three-dimensional morphological corrosion results of different pyrite contents. A large quantity of multi-component digital cores of shale were obtained. Organic pores, inorganic pores, framework, and organic matter were considered as a mixed component. Structural elements of size 2×2×2 were selected, and a three-dimensional morphological corrosion algorithm was used to process the mixed components of the shale multi-component digital cores to obtain intermediate states of shale multi-component digital cores with different pyrite contents after three-dimensional morphological corrosion. Based on Boolean operations, the positions represented by the fixed components such as organic pores, inorganic pores, and organic matter in the original shale multi-component digital cores were assigned to the different pyrite contents in the intermediate states. A large number of shale multi-component digital cores were obtained to ensure that the content and spatial location of fixed components such as organic pores, inorganic pores, and organic matter were consistent with the original shale multi-component digital cores. In this way, pyrite occupied part of the framework in the digital cores, thus obtaining shale multi-component digital cores with different pyrite contents after three-dimensional morphological corrosion. A shale multi-component digital core with a certain clay mineral content was selected from the shale multi-component digital cores with different clay mineral contents as the shale multi-component digital core for simulating the influence of different clay mineral types on the nuclear magnetic resonance response.

[0096] Step S25: Invert the echo data of the multi-frequency nuclear magnetic resonance experiment to obtain the T2 distribution of the multi-frequency nuclear magnetic resonance experiment, and use the T2 distribution of the multi-frequency nuclear magnetic resonance experiment to constrain the lateral surface relaxation intensity when performing numerical simulation of the original digital core of the multi-component shale.

[0097] In this embodiment, the T2 distribution of the multi-frequency nuclear magnetic resonance (NMR) experiment is obtained by inverting the multi-frequency NMR real echo data. Taking different pyrite contents as examples, the T2 distribution is as follows: Figure 6The results are shown in (a), (b), (c), (d), (e), (f), (g), (h), and (i). The porosity of inorganic pore water and organic pore oil under the given conditions is obtained by summing the T2 distributions, thus completing the porosity conversion for the target shale oil sample under different NMR instrument frequencies and pore types under the given conditions. Taking pyrite as an example, its porosity conversion results are shown in... Figure 7 As shown.

[0098] Step S26: Simulate the nuclear magnetic resonance response characteristics of the multi-component digital core of the shale by using a numerical simulation method and based on the transverse surface relaxation intensity of the original digital core of the shale, so as to generate target echo data for characterizing different nuclear magnetic resonance instrument frequencies, different echo intervals, different pyrite contents, different clay mineral contents, and different clay mineral types.

[0099] Step S27: Invert the target echo data to obtain the target T2 distribution, and sum the target T2 distributions to obtain the porosity of inorganic pore water and organic pore oil, so as to complete the porosity conversion for different nuclear magnetic resonance instrument frequencies and different pore types of the shale oil sample.

[0100] In this embodiment, focused ion beam scanning electron microscope (FBS) images and multi-frequency nuclear magnetic resonance (NMR) echo data of shale oil samples are acquired. Based on the FBS images, a multi-component original digital core of the shale is constructed. Based on this original digital core, and using a preset three-dimensional morphological method, multi-component digital cores of shale with different pyrite contents, clay mineral contents, and clay mineral types are constructed. The multi-frequency NMR echo data is inverted to obtain the multi-frequency NMR experimental T2 distribution. The T2 distribution is then used to constrain the lateral surface relaxation of the original multi-component digital core during numerical simulation. The lateral surface relaxation intensity of the shale multi-component digital core is simulated using numerical simulation methods to simulate the nuclear magnetic resonance response characteristics of the shale multi-component digital core. This generates target echo data to characterize different nuclear magnetic resonance instrument frequencies, different echo intervals, different pyrite contents, different clay mineral contents, and different clay mineral types. The target echo data is inverted to obtain the target T2 distribution. The target T2 distribution is then summed to obtain the porosity of inorganic pore water and organic pore oil, thus completing the porosity conversion for different nuclear magnetic resonance instrument frequencies and different pore types of the shale oil sample. This application constructs multi-component digital cores of shale with varying pyrite, clay mineral content, and clay mineral types using original multi-component digital cores. This simplifies operation, reduces time consumption, and reflects the influence of a single factor on the NMR response. The T2 distribution of multi-frequency NMR experimental echo data is obtained through inversion. This T2 distribution is then used to constrain the transverse surface relaxation intensity during numerical simulation of the original multi-component digital cores of shale. The NMR response characteristics of the multi-component digital cores are simulated using numerical simulation methods to generate target echo data. This data is then inverted and accumulated to obtain the porosity of inorganic pore water and organic pore oil. This allows for accurate conversion of porosity based on different echo intervals, mineral contents, types, NMR instrument frequencies, and pore types, thus enabling accurate evaluation of the NMR porosity of shale oil samples.

[0101] See Figure 8 As shown, this embodiment of the invention discloses a shale fluid porosity conversion device with different frequencies, which may specifically include:

[0102] Image data acquisition module 11 is used to acquire focused ion beam scanning electron microscope images and multi-frequency nuclear magnetic resonance experimental echo data of shale oil samples, and to construct multi-component original digital cores of shale based on the focused ion beam scanning electron microscope images;

[0103] The core construction module 12 is used to construct shale multi-component digital cores with different pyrite contents, different clay mineral contents, and different clay mineral types based on the original multi-component digital cores of the shale and using a preset three-dimensional morphological method.

[0104] Inversion module 13 is used to invert the echo data of the multi-frequency nuclear magnetic resonance experiment to obtain the T2 distribution of the multi-frequency nuclear magnetic resonance experiment, and to use the T2 distribution of the multi-frequency nuclear magnetic resonance experiment to constrain the lateral surface relaxation intensity when performing numerical simulation of the original digital core of the multi-component shale.

[0105] Data generation module 14 is used to simulate the nuclear magnetic resonance response characteristics of the multi-component digital core of the shale by means of a numerical simulation method and based on the transverse surface relaxation intensity of the original digital core of the shale, so as to generate target echo data for characterizing different nuclear magnetic resonance instrument frequencies, different echo intervals, different pyrite contents, different clay mineral contents, and different clay mineral types.

[0106] The porosity conversion module 15 is used to invert the target echo data to obtain the target T2 distribution, and to accumulate the target T2 distribution to obtain the porosity of inorganic pore water and organic pore oil, so as to complete the porosity conversion for different nuclear magnetic resonance instrument frequencies and different pore types of the shale oil sample.

[0107] Focused ion beam scanning electron microscope (FIS) images and multi-frequency nuclear magnetic resonance (NMR) echo data of shale oil samples were acquired. Based on the FIS images, multi-component digital cores of shale were constructed. Using these multi-component digital cores, multi-component digital cores with different pyrite contents, clay mineral contents, and clay mineral types were constructed using a pre-defined three-dimensional morphological method. The multi-frequency NMR echo data were inverted to obtain the multi-frequency NMR T2 distribution. The transverse surface relaxation intensity of the multi-component digital cores was then constrained during numerical simulation using the multi-component digital cores. The nuclear magnetic resonance (NMR) response characteristics of the multi-component digital core of the shale were simulated using a numerical simulation method based on the transverse surface relaxation intensity of the original digital core. This generated target echo data to characterize different NMR instrument frequencies, echo intervals, pyrite contents, clay mineral contents, and clay mineral types. The target echo data was inverted to obtain the target T2 distribution. The target T2 distributions were then summed to obtain the porosity of inorganic pore water and organic pore oil, thus completing the porosity conversion for different NMR instrument frequencies and pore types of the shale oil sample. This application constructs multi-component digital cores of shale with varying pyrite, clay mineral content, and clay mineral types using original multi-component digital cores. This simplifies operation, reduces time consumption, and reflects the influence of a single factor on the NMR response. The T2 distribution of multi-frequency NMR experimental echo data is obtained through inversion. This T2 distribution is then used to constrain the transverse surface relaxation intensity during numerical simulation of the original multi-component digital cores of shale. The NMR response characteristics of the multi-component digital cores are simulated using numerical simulation methods to generate target echo data. This data is then inverted and accumulated to obtain the porosity of inorganic pore water and organic pore oil. This allows for accurate conversion of porosity based on different echo intervals, mineral contents, types, NMR instrument frequencies, and pore types, thus enabling accurate evaluation of the NMR porosity of shale oil samples.

[0108] In some specific embodiments, the core construction module 12 may specifically include:

[0109] The first core construction module is used to process the shale multi-component digital core and the first mixed component using a preset three-dimensional morphological method and Boolean operations, and to ensure that the content and spatial location of the fixed components including the organic pores, the inorganic pores, and the organic matter are consistent with the original shale multi-component digital core, so as to construct shale multi-component digital cores with different pyrite contents.

[0110] The second core construction module is used to process the shale multi-component digital core and the second mixed component using the organic pores, the framework, the organic matter, and pyrite as the second mixed component. The module also ensures that the content and spatial location of the fixed components, including the organic pores, the inorganic pores, the organic matter, and the pyrite, are consistent with the original shale multi-component digital core, so as to construct shale multi-component digital cores with different clay mineral contents.

[0111] The third core construction module is used to select any shale multi-component digital core with any clay mineral content from shale multi-component digital cores with different clay mineral contents, as shale multi-component digital cores of different clay mineral types.

[0112] In some specific embodiments, the core construction module 12 may specifically include:

[0113] The first processing module is used to process the shale multi-component digital core and the first mixed component using a preset three-dimensional morphological method to obtain shale multi-component digital cores with different pyrite contents in the intermediate state, and to process the original shale multi-component digital core and the shale multi-component digital core with different pyrite contents in the intermediate state using Boolean operations.

[0114] In some specific embodiments, the core construction module 12 may specifically include:

[0115] The second processing module is used to process the shale multi-component digital core and the second mixed component using a preset three-dimensional morphological method to obtain shale multi-component digital cores with different clay mineral contents in the intermediate state, and to process the original shale multi-component digital core and the shale multi-component digital core with different clay mineral contents in the intermediate state using Boolean operations.

[0116] In some specific embodiments, the inversion module 13 may specifically include:

[0117] The module for determining the transverse surface relaxation intensity at different frequencies of nuclear magnetic resonance instruments is used to determine the transverse surface relaxation intensity at different frequencies of nuclear magnetic resonance instruments using the Korb model.

[0118] The constraint module is used to constrain the lateral surface relaxation intensity of the multi-component original digital core of shale during numerical simulation by using the lateral surface relaxation intensity of the different nuclear magnetic resonance instrument frequencies and the T2 distribution of the multi-frequency nuclear magnetic resonance experiment.

[0119] In some specific embodiments, the inversion module 13 may specifically include:

[0120] The peak position determination module is used to determine the peak positions of the T2 distribution of inorganic pore water and organic pore oil in the T2 distribution of the multi-frequency nuclear magnetic resonance experiment, and to determine the peak positions of different frequency results of numerical simulation based on the original digital core of the multi-component shale.

[0121] The minimum error calculation module is used to calculate the minimum error between the peak position of the T2 distribution and the peak position of the results at different frequencies, so as to obtain the initial transverse surface relaxation intensity when numerically simulating the multi-component digital core of the shale under different frequency nuclear magnetic resonance instruments.

[0122] The calibration module is used to calibrate the initial transverse surface relaxation intensity as the transverse surface relaxation intensity at different instrument frequencies, so as to obtain the transverse surface relaxation intensity values ​​at different nuclear magnetic resonance instrument frequencies.

[0123] In some specific embodiments, the data generation module 14 may specifically include:

[0124] The internal magnetic field gradient calculation module is used to calculate the internal magnetic field gradient at different nuclear magnetic resonance instrument frequencies based on the magnetic dipole theory.

[0125] The target echo data determination module is used to simulate the one-dimensional nuclear magnetic resonance acquisition process of shale oil using numerical simulation methods and based on the transverse surface relaxation intensity value and the internal magnetic field gradient of the different nuclear magnetic resonance instrument frequencies. It also combines the platform model to simulate target echo data that characterizes different nuclear magnetic resonance instrument frequencies, different echo intervals, different pyrite contents, different clay mineral contents, and different clay mineral types.

[0126] In some specific embodiments, the porosity conversion module 15 may specifically include:

[0127] The echo data inversion module is used to invert the echo data of the inorganic pore water and the echo data of the organic pore oil in the target echo data respectively, so as to obtain the corresponding target T2 distribution;

[0128] The porosity conversion module is used to accumulate the target T2 distribution to obtain the porosity of inorganic pore water and organic pore oil. Based on the correspondence between the porosity and the different NMR instrument frequencies, different echo intervals, different pyrite contents, different clay mineral contents, and different clay mineral types, the module completes the porosity conversion for different NMR instrument frequencies and different pore types of shale oil samples.

[0129] Figure 9This is a schematic diagram of an electronic device provided in an embodiment of this 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 stores a computer program, which is loaded and executed by the processor 21 to implement the relevant steps in the shale fluid porosity conversion method at different frequencies disclosed in any of the foregoing embodiments.

[0130] In this embodiment, the power supply 23 is used to provide operating 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 external devices, and the communication protocol it follows can be any communication protocol applicable to the technical solution of this application, and is not specifically limited here; the input / output interface 25 is used to acquire 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.

[0131] In addition, the memory 22, as a carrier for resource storage, can be a read-only memory, random access memory, disk or optical disk, etc. The resources stored on it include operating system 221, computer program 222 and data 223, etc., and the storage method can be temporary storage or permanent storage.

[0132] The operating system 221 manages and controls the various hardware devices on the electronic device 20 and the computer program 222 to enable the processor 21 to perform calculations and processing on the data 223 in the memory 22. The operating system 221 can be Windows, Unix, Linux, etc. The computer program 222, in addition to including computer programs capable of performing the shale fluid porosity conversion methods of different frequencies executed by the electronic device 20 as disclosed in any of the foregoing embodiments, may further include computer programs capable of performing other specific tasks. The data 223 may include data received by the shale fluid porosity conversion device at different frequencies from data transmitted from external devices, and may also include data collected by its own input / output interface 25.

[0133] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein can be implemented directly by hardware, a software module executed by a processor, or a combination of both. The software module can be located in random access memory (RAM), main memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art.

[0134] Furthermore, this application also discloses a computer-readable storage medium storing a computer program. When the computer program is loaded and executed by a processor, it implements the steps of the shale fluid porosity conversion method at different frequencies disclosed in any of the foregoing embodiments.

[0135] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0136] The present invention provides a detailed description of a method, apparatus, device, and storage medium for converting the porosity of shale fluids at different frequencies. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A method for transforming the porosity of shale fluids at different frequencies, characterized in that, include: Focused ion beam scanning electron microscope (FIS) images and multi-frequency nuclear magnetic resonance (NMR) experimental echo data of shale oil samples were acquired, and multi-component original digital cores of shale were constructed based on the FIS images. Based on the original digital cores of the multi-component shale, and using the preset three-dimensional morphological method, multi-component digital cores of shale with different pyrite contents, different clay mineral contents, and different clay mineral types were constructed respectively. The echo data from the multi-frequency nuclear magnetic resonance experiment were inverted to obtain the T2 distribution of the multi-frequency nuclear magnetic resonance experiment. The T2 distribution of the multi-frequency nuclear magnetic resonance experiment was used to constrain the lateral surface relaxation intensity when numerically simulating the original digital core of the multi-component shale. The nuclear magnetic resonance response characteristics of the multi-component digital core of the shale were simulated by using numerical simulation methods and based on the transverse surface relaxation intensity of the original digital core of the shale, so as to generate target echo data for characterizing different nuclear magnetic resonance instrument frequencies, different echo intervals, different pyrite contents, different clay mineral contents, and different clay mineral types. The target echo data is inverted to obtain the target T2 distribution. The target T2 distribution is accumulated to obtain the porosity of inorganic pore water and organic pore oil, so as to complete the porosity conversion for different nuclear magnetic resonance instrument frequencies and different pore types of the shale oil sample. Based on original multi-component digital cores of shale, and using pre-defined three-dimensional morphological methods, multi-component digital cores of shale with different pyrite contents, clay mineral contents, and clay mineral types were constructed. This included: using organic pores, inorganic pores, the framework, and organic matter as the first mixed component; processing the multi-component digital cores and the first mixed component using pre-defined three-dimensional morphological methods and Boolean operations; and ensuring that the content and spatial location of fixed components, including organic pores, inorganic pores, and organic matter, are consistent with the original multi-component digital cores of shale, thus constructing multi-component digital cores of shale with different pyrite contents. The process involves using organic pores, framework, organic matter, and pyrite as the second mixed component. Pre-defined three-dimensional morphological methods and Boolean operations are employed to process the shale multi-component digital core and the second mixed component. The content and spatial location of the fixed components, including organic pores, inorganic pores, organic matter, and pyrite, are made consistent with the original shale multi-component digital core to construct shale multi-component digital cores with different clay mineral contents. From these shale multi-component digital cores, any shale multi-component digital core with any clay mineral content is selected as a shale multi-component digital core for different clay mineral types. The target echo data is inverted to obtain the target T2 distribution. The target T2 distributions are then summed to obtain the porosity of inorganic pore water and organic pore oil. This process is used to convert the porosity of shale oil samples for different NMR instrument frequencies and pore types. The process includes: inverting the echo data of inorganic pore water and organic pore oil in the target echo data to obtain the corresponding target T2 distributions; summing the target T2 distributions to obtain the porosity of inorganic pore water and organic pore oil; and based on the correspondence between porosity and different NMR instrument frequencies, different echo intervals, different pyrite contents, different clay mineral contents, and different clay mineral types, the porosity conversion for shale oil samples for different NMR instrument frequencies and pore types is completed.

2. The method for transforming shale fluid porosity at different frequencies according to claim 1, characterized in that, The process of processing the multi-component digital core of the shale and the first mixed component using a preset three-dimensional morphological method and Boolean operations includes: The shale multi-component digital core and the first mixed component are processed using a preset three-dimensional morphological method to obtain shale multi-component digital cores with different pyrite contents in the intermediate state. Boolean operations are then used to process the original shale multi-component digital core and the shale multi-component digital cores with different pyrite contents in the intermediate state. Accordingly, the process of processing the shale multi-component digital core and the second mixed component using a preset three-dimensional morphological method and Boolean operations includes: The shale multi-component digital core and the second mixed component are processed using a preset three-dimensional morphological method to obtain shale multi-component digital cores with different clay mineral contents in an intermediate state. Boolean operations are then used to process the original shale multi-component digital core and the shale multi-component digital cores with different clay mineral contents in the intermediate state.

3. The method for transforming shale fluid porosity at different frequencies according to claim 1, characterized in that, The lateral surface relaxation intensity used in numerical simulations of multi-component original digital cores of shale, constrained by the T2 distribution of the multi-frequency nuclear magnetic resonance experiment, includes: The transverse surface relaxation intensity at different nuclear magnetic resonance instrument frequencies was determined using the Korb model; The transverse surface relaxation intensity of the original digital core of multi-component shale was used to conduct numerical simulation by constraining the transverse surface relaxation intensity of the different nuclear magnetic resonance instrument frequencies and the T2 distribution of the multi-frequency nuclear magnetic resonance experiment.

4. The method for transforming shale fluid porosity at different frequencies according to claim 3, characterized in that, The lateral surface relaxation intensity used in numerical simulations of multi-component shale original digital cores constrained by the different frequencies of the nuclear magnetic resonance instruments and the T2 distribution of the multi-frequency nuclear magnetic resonance experiment includes: The peak positions of the T2 distribution of inorganic pore water and organic pore oil in the multi-frequency nuclear magnetic resonance experiment were determined, and the peak positions of different frequency results of numerical simulation based on the original digital core of the multi-component shale were also determined. The minimum error between the peak position of the T2 distribution and the peak position of the results at different frequencies is calculated to obtain the initial transverse surface relaxation intensity when numerically simulating the multi-component digital core of the shale under different frequency nuclear magnetic resonance instruments. The initial transverse surface relaxation intensity is used as a calibration of the transverse surface relaxation intensity at different NMR instrument frequencies to obtain the transverse surface relaxation intensity values ​​at different NMR instrument frequencies.

5. The method for transforming shale fluid porosity at different frequencies according to claim 4, characterized in that, The method of simulating the nuclear magnetic resonance response characteristics of the multi-component digital core of shale using the lateral surface relaxation intensity during numerical simulation based on the original digital core of the shale multi-component shale, in order to generate target echo data for characterizing different nuclear magnetic resonance instrument frequencies, different echo intervals, different pyrite contents, different clay mineral contents, and different clay mineral types, includes: Calculation of the internal magnetic field gradient at different nuclear magnetic resonance instrument frequencies based on magnetic dipole theory; Numerical simulation methods were used to simulate the one-dimensional nuclear magnetic resonance (NMR) acquisition process of shale oil based on the transverse surface relaxation intensity values ​​and the internal magnetic field gradient at different NMR instrument frequencies. In combination with a platform model, target echo data were simulated to characterize different NMR instrument frequencies, different echo intervals, different pyrite contents, different clay mineral contents, and different clay mineral types.

6. A device for converting the porosity of shale fluids at different frequencies, characterized in that, include: The image data acquisition module is used to acquire focused ion beam scanning electron microscope images and multi-frequency nuclear magnetic resonance experimental echo data of shale oil samples, and to construct multi-component original digital cores of shale based on the focused ion beam scanning electron microscope images; The core construction module is used to construct shale multi-component digital cores with different pyrite contents, different clay mineral contents, and different clay mineral types based on the original multi-component digital cores of the shale and using a preset three-dimensional morphological method. The inversion module is used to invert the echo data of the multi-frequency nuclear magnetic resonance experiment to obtain the T2 distribution of the multi-frequency nuclear magnetic resonance experiment, and to use the T2 distribution of the multi-frequency nuclear magnetic resonance experiment to constrain the lateral surface relaxation intensity when performing numerical simulation of the original digital core of the multi-component shale. The data generation module is used to simulate the nuclear magnetic resonance response characteristics of the multi-component digital core of the shale by means of a numerical simulation method and based on the transverse surface relaxation intensity of the original digital core of the shale, so as to generate target echo data for characterizing different nuclear magnetic resonance instrument frequencies, different echo intervals, different pyrite contents, different clay mineral contents, and different clay mineral types. The porosity conversion module is used to invert the target echo data to obtain the target T2 distribution, and to accumulate the target T2 distribution to obtain the porosity of inorganic pore water and organic pore oil, so as to complete the porosity conversion for different nuclear magnetic resonance instrument frequencies and different pore types of the shale oil sample. Based on original multi-component digital cores of shale, and using pre-defined three-dimensional morphological methods, multi-component digital cores of shale with different pyrite contents, clay mineral contents, and clay mineral types were constructed. This included: using organic pores, inorganic pores, the framework, and organic matter as the first mixed component; processing the multi-component digital cores and the first mixed component using pre-defined three-dimensional morphological methods and Boolean operations; and ensuring that the content and spatial location of fixed components, including organic pores, inorganic pores, and organic matter, are consistent with the original multi-component digital cores of shale, thus constructing multi-component digital cores of shale with different pyrite contents. The process involves using organic pores, framework, organic matter, and pyrite as the second mixed component. Pre-defined three-dimensional morphological methods and Boolean operations are employed to process the shale multi-component digital core and the second mixed component. The content and spatial location of the fixed components, including organic pores, inorganic pores, organic matter, and pyrite, are made consistent with the original shale multi-component digital core to construct shale multi-component digital cores with different clay mineral contents. From these shale multi-component digital cores, any shale multi-component digital core with any clay mineral content is selected as a shale multi-component digital core for different clay mineral types. The target echo data is inverted to obtain the target T2 distribution. The target T2 distributions are then summed to obtain the porosity of inorganic pore water and organic pore oil. This process is used to convert the porosity of shale oil samples for different NMR instrument frequencies and pore types. The process includes: inverting the echo data of inorganic pore water and organic pore oil in the target echo data to obtain the corresponding target T2 distributions; summing the target T2 distributions to obtain the porosity of inorganic pore water and organic pore oil; and based on the correspondence between porosity and different NMR instrument frequencies, different echo intervals, different pyrite contents, different clay mineral contents, and different clay mineral types, the porosity conversion for shale oil samples for different NMR instrument frequencies and pore types is completed.

7. An electronic device, characterized in that, include: Memory, used to store computer programs; A processor for executing the computer program to implement the shale fluid porosity conversion method at different frequencies as described in any one of claims 1 to 5.

8. A computer-readable storage medium, characterized in that, Used to store a computer program; wherein, when the computer program is executed by a processor, it implements the shale fluid porosity conversion method at different frequencies as described in any one of claims 1 to 5.

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