Method, device and equipment for acquiring rock physical parameters and storage medium

Abstract

The embodiment of the invention provides a method and device for obtaining rock physical parameters, equipment and a storage medium, and is used for improving the accuracy of the rock physical parameters. The method comprises the steps that a preset conversion relation is obtained; the preset conversion relation is used for converting rock physical parameters obtained based on transverse relaxation time into rock physical parameters obtained based on effective spin-spin relaxation time; measuring the target shale oil reservoir to obtain target echo data; performing inversion on the target echo data to obtain target nuclear magnetic resonance transverse relaxation time distribution; performing parameter conversion on the target nuclear magnetic resonance transverse relaxation time distribution to obtain to-be-converted rock physical parameters; and converting the to-be-converted rock physical parameters based on the preset conversion relation to obtain target rock physical parameters.

Description

Technical Field

[0001] The present application relates to the technical field of oil and gas exploration and development, and in particular to a method, device, equipment and storage medium for obtaining rock physical parameters. Background Art

[0002] In the process of oil and gas exploration and development, it is necessary to obtain rock physical parameters in order to accurately determine the underground oil and gas storage. However, the accuracy of rock physical parameters obtained based on existing technologies is low. Therefore, how to improve the accuracy of obtained rock physical parameters has become a technical problem that needs to be solved at present. Summary of the invention

[0003] In view of the above problems, the purpose of the present invention is to provide a method, device, equipment and storage medium for obtaining rock physical parameters to improve the accuracy of the obtained rock physical parameters. The specific scheme is as follows:

[0004] In a first aspect, an embodiment of the present application provides a method for obtaining rock physical parameters, the method comprising:

[0005] Obtaining a preset conversion relationship; the preset conversion relationship is used to convert the rock physical parameters obtained based on the transverse relaxation time into the rock physical parameters obtained based on the effective spin-spin relaxation time;

[0006] Measure the target shale oil reservoir to obtain target echo data;

[0007] Invert the target echo data to obtain the target NMR transverse relaxation time distribution;

[0008] Performing parameter transformation on the target nuclear magnetic resonance transverse relaxation time distribution to obtain rock physical parameters to be transformed;

[0009] The rock physical parameters to be converted are converted based on the preset conversion relationship to obtain target rock physical parameters.

[0010] Optionally, obtaining a preset conversion relationship includes:

[0011] Establishing a first formation model and a second formation model; the first formation model is used to simulate a known shale oil reservoir, and the second formation model is used to simulate an unknown shale oil reservoir;

[0012] Performing numerical simulation based on the second formation model, the numerical simulation parameters, the effective spin-spin relaxation time, and the transverse relaxation time to obtain first echo data and second echo data; the first echo data is echo data based on the transverse relaxation time; the second echo data is echo data based on the effective spin-spin relaxation time;

[0013] Determine a first rock physical parameter and a second rock physical parameter based on the first echo data and the second echo data; the first rock physical parameter is a rock physical parameter determined based on the first echo data; the second rock physical parameter is a rock physical parameter determined based on the second echo data;

[0014] The preset conversion relationship is constructed based on the first rock physical parameter and the second rock physical parameter.

[0015] Optionally, determining numerical simulation parameters based on the first formation model includes:

[0016] Obtain the effective spin-spin relaxation rate;

[0017] Based on the effective spin-spin relaxation rate and the first formation model, simulating surface relaxation and dephasing behavior of fluid protons;

[0018] The surface relaxation intensity of the fluid in the first formation model and the instrument correction coefficient of the fluid and organic matter are calibrated based on the first formation model.

[0019] Optionally, the calibrating the surface relaxation intensity of the fluid in the first formation model and the instrument correction coefficient of the fluid and organic matter based on the first formation model includes:

[0020] Perform forward modeling based on the first formation model to obtain echo data;

[0021] Inverting the echo data based on the first formation model to obtain a nuclear magnetic resonance experimental effective spin-spin relaxation time distribution, a nuclear magnetic resonance transverse relaxation time distribution, and a nuclear magnetic resonance numerical simulation effective spin-spin relaxation time distribution;

[0022] Based on the first formation model, the nuclear magnetic resonance experimental effective spin-spin relaxation time distribution, the nuclear magnetic resonance transverse relaxation time distribution, and the nuclear magnetic resonance numerical simulation effective spin-spin relaxation time distribution, the surface relaxation intensity of the fluid in the first formation model and the instrument correction coefficients of the fluid and organic matter are calibrated.

[0023] Optionally, obtaining the effective spin-spin relaxation rate includes:

[0024] Obtain the relaxation rate characterized by magnetic field inhomogeneities, the net observed relaxation rate of shale oil fluids, and the relaxation rate of the internal magnetic field;

[0025] The effective spin-spin relaxation rate is generated based on the relaxation rate characterized by the magnetic field inhomogeneity, the net observed relaxation rate of the shale oil fluid, and the relaxation rate of the internal magnetic field.

[0026] Optionally, the performing numerical simulation based on the second formation model, the numerical simulation parameters, the effective spin-spin relaxation time, and the transverse relaxation time to obtain the first echo data and the second echo data includes:

[0027] Based on the numerical simulation parameters and the effective spin-spin relaxation rate, simulate first echo data of the second formation model based on the effective spin-spin relaxation time;

[0028] Based on the numerical simulation parameters and the effective spin-spin relaxation rate, second echo data of the second formation model based on the transverse relaxation time is simulated.

[0029] Optionally, determining a first rock physical parameter and a second rock physical parameter based on the first echo data and the second echo data includes:

[0030] Inverting the first echo data to obtain a target effective spin-spin relaxation time distribution;

[0031] Inverting the second echo data to obtain a target transverse relaxation time distribution;

[0032] converting the target effective spin-spin relaxation time distribution into the first petrophysical parameter;

[0033] The target lateral relaxation time distribution is converted into the second petrophysical parameter.

[0034] In a second aspect, an embodiment of the present application provides a device for obtaining rock physical parameters, the device comprising:

[0035] An acquisition module, used to acquire a preset conversion relationship; the preset conversion relationship is used to convert the rock physical parameters obtained based on the transverse relaxation time into the rock physical parameters obtained based on the effective spin-spin relaxation time;

[0036] A measurement module is used to measure the target shale oil reservoir and obtain target echo data;

[0037] An inversion module is used to invert the target echo data to obtain the target NMR transverse relaxation time distribution;

[0038] A first conversion module is used to perform parameter conversion on the target nuclear magnetic resonance transverse relaxation time distribution to obtain the rock physical parameters to be converted;

[0039] The second conversion module is used to convert the rock physical parameters to be converted based on the preset conversion relationship to obtain target rock physical parameters.

[0040] In a third aspect, an embodiment of the present application provides an electronic device, including:

[0041] Memory, used to store computer programs;

[0042] A processor is used to execute the computer program to implement any one of the above methods for obtaining rock physical parameters.

[0043] In a fourth aspect, an embodiment of the present application provides a computer-readable storage medium for storing a computer program; wherein, when the computer program is executed by a processor, any one of the above-mentioned methods for obtaining rock physical parameters is implemented.

[0044] Compared with the prior art, this application has the following beneficial effects:

[0045] By obtaining the preset conversion relationship, the target shale oil reservoir is measured to obtain the target echo data. The target echo data is inverted to obtain the target NMR transverse relaxation time distribution. The target NMR transverse relaxation time distribution is parameterized to obtain the rock physical parameters to be converted. The rock physical parameters to be converted are converted based on the preset conversion relationship to obtain the target rock physical parameters. * The accuracy of the obtained rock physical parameters is high, and the preset conversion relationship is used to convert the rock physical parameters obtained based on the transverse relaxation time into the rock physical parameters obtained based on the effective spin-spin relaxation time, thereby converting the rock physical parameters obtained based on T2 into the rock physical parameters obtained based on T2 through the preset conversion relationship. * The obtained rock physical parameters realize T2 * The accurate conversion of rock physical parameters based on T2 is obtained. * The obtained rock physical parameters can improve the accuracy of the final obtained rock physical parameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] In order to more clearly illustrate the embodiments of the present application 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 some embodiments recorded in the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0047] Figure 1 A schematic diagram of a method for obtaining rock physical parameters provided in this application;

[0048] Figure 2 A schematic diagram of the process of obtaining a preset conversion relationship provided for this application;

[0049] Figure 3A schematic diagram of a complex mineral shale digital core provided for this application;

[0050] Figure 4 The NMR experiment T2 provided for this application * Schematic diagram of the distribution;

[0051] Figure 5 A schematic diagram of the process of simulating echo data provided for this application;

[0052] Figure 6 A shale oil T2 provided in this application * Schematic diagram of numerical simulation results;

[0053] Figure 7 A schematic diagram of a preset conversion relationship curve provided for this application;

[0054] Figure 8 A schematic diagram of the structure of a device for obtaining rock physical parameters disclosed in the present application;

[0055] Fig. 9 A structural diagram of an electronic device provided for this application. DETAILED DESCRIPTION

[0056] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0057] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments described herein can be implemented in an order other than that illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0058] An analysis of the existing technologies shows that the existing nuclear magnetic resonance (NMR) logging technology based on the transverse relaxation time T2 can directly obtain the rock physical properties of underground reservoirs, but it is difficult to accurately characterize the rock physical properties of organic matter. In addition, the differences in frequency and acquisition parameters between the nuclear magnetic resonance logging instrument and the laboratory measurement instrument lead to differences in the rock physical parameters from the same shale oil reservoir, making it difficult to obtain accurate rock physical properties. Although based on the effective spin-spin relaxation time T2 * The NMR experimental technology can accurately characterize the rock physical properties of shale oil organic matter, but this method cannot be used for NMR logging. In order to solve the above technical problems, the technical solution adopted in this application is as follows.

[0059] like Figure 1 As shown, the embodiment of the present application provides a method for obtaining rock physical parameters, the method comprising:

[0060] S101: Obtaining a preset conversion relationship; the preset conversion relationship is used to convert the rock physical parameters obtained based on the transverse relaxation time into the rock physical parameters obtained based on the effective spin-spin relaxation time.

[0061] Pre-build the rock physical parameters obtained based on T2 * The correspondence between the obtained rock physical parameters.

[0062] Specifically, Figure 2 The step of obtaining the preset conversion relationship includes the following steps S201 to S205.

[0063] S201: Establish a first formation model and a second formation model; the first formation model is used to simulate known shale oil reservoirs, and the second formation model is used to simulate unknown shale oil reservoirs.

[0064] Specifically, a numerical simulation method is used to simulate and establish a first formation model and a second formation model. The first formation model is a shale oil formation model including fluid components such as organic interstitial oil, inorganic pore water and organic matter. The second formation model simulates the digital core of the target shale oil reservoir. Figure 3 As shown, the second stratigraphic model has different mineral composition, mineral content, mineral distribution, and organic matter distribution characteristics from those of the first stratigraphic model.

[0065] S202: Determine numerical simulation parameters based on the first formation model.

[0066] The numerical simulation parameters include the surface relaxation of fluid protons, dephasing behavior, surface relaxation intensity of the fluid, and instrument correction factors of the fluid and organic matter.

[0067] In an optional embodiment, determining numerical simulation parameters based on the first formation model includes:

[0068] Obtain the effective spin-spin relaxation rate;

[0069] Based on the effective spin-spin relaxation rate and the first formation model, the surface relaxation and dephasing behavior of fluid protons are simulated;

[0070] The surface relaxation intensity of the fluid in the first formation model and the instrument correction coefficients of the fluid and organic matter are calibrated based on the first formation model.

[0071] Specifically, based on the first formation model and the effective spin-spin relaxation rate, the surface relaxation and dephasing behavior of fluid protons are simulated using a random walk method based on the free induction decay sequence (FID). The surface relaxation of fluid protons characterizes the change in amplitude after the inelastic collision between pore fluid protons and the skeleton or organic matter. The dephasing behavior of fluid protons characterizes the change in the amplitude of fluid protons by simulating the change in phase during the motion of pore fluid protons, which is used to describe the difference in magnetic sensitivity of the internal magnetic field.

[0072] It should be noted that in addition to using the random walk method of FID to simulate the surface relaxation and dephasing behavior of fluid protons, the embodiment of the present application can also use a spin echo pulse sequence (Carr Purcell Meiboom Gill, CPMG) for random walk to simulate the surface relaxation and dephasing behavior of fluid protons.

[0073] In an optional embodiment, obtaining the effective spin-spin relaxation rate includes:

[0074] Obtain the relaxation rate characterized by magnetic field inhomogeneities, the net observed relaxation rate of shale oil fluids, and the relaxation rate of the internal magnetic field;

[0075] The effective spin-spin relaxation rate is generated based on the relaxation rate characterized by magnetic field inhomogeneities, the net observed relaxation rate of shale oil fluid, and the relaxation rate of the internal magnetic field.

[0076] Specifically, assuming that the pore structure and fluid properties of the first formation model do not change with the NMR pulse sequence, the transverse surface relaxation intensity of pore fluid protons based on the FID pulse sequence is:

[0077]

[0078] is the transverse surface relaxation intensity of the pore fluid protons when the pore fluid protons are water. is the transverse surface relaxation intensity of the pore fluid protons when the pore fluid protons are oil. B is a parameter used to characterize the pore structure, C is a parameter used to characterize the fluid properties, and J represents the spectral density function characterizing the heteronuclear dipole-dipole interaction between paramagnetic substances and pore fluid protons. ω I is the angular frequency of the fluid protons, ω s is the angular frequency of the paramagnetic ions, and τ is the rotational correlation time of the fluid protons.

[0079] Based on NMR T2 * The relaxation signal is:

[0080] M(t)=M0[M B (t)·M S (t)·M D (t)]

[0081] M B (t) is the volume relaxation signal of the pore fluid, M S (t) is the surface relaxation signal of the pore fluid, M D (t) is the diffusion relaxation signal of the pore fluid, and M0 is the initial signal intensity of the pore fluid.

[0082] Since the effective spin-spin relaxation rate includes the effective spin-spin relaxation rate of fluid protons and the effective spin-spin relaxation rate of organic protons, it can be expressed as:

[0083]

[0084] is the net observed relaxation rate, is the relaxation rate of the internal magnetic field, is the relaxation rate characterized by magnetic field inhomogeneity. Since the external magnetic field B0 is uniformly distributed, the relaxation rate characterized by magnetic field inhomogeneity is is zero.

[0085] Furthermore, the effective spin-spin relaxation rate of fluid protons includes the surface relaxation, volume relaxation and dephasing behavior of fluid protons. The effective spin-spin relaxation rate of organic protons includes the volume relaxation rate of organic protons and the relaxation rate caused by the internal magnetic field. Shale oil T2 * The net observed relaxation rate can be expressed as:

[0086]

[0087] The net observed relaxation rate includes the net observed relaxation rate of fluid and the net observed relaxation rate of organic matter. is the net observed relaxation rate of the fluid, is the net observed relaxation rate of organic matter, is the surface relaxation rate of the pore fluid protons, is the volume relaxation rate of pore fluid protons, is the volume relaxation rate of organic matter. L is the proton of pore fluid, which can be water or oil. For example, when the proton of pore fluid is water, L is W, and when the proton of pore fluid is oil, L is O. Then is the surface relaxation rate of the pore fluid protons when the pore fluid protons are water, is the surface relaxation rate of the pore fluid protons when the pore fluid protons are oil. is the volume relaxation rate of pore fluid protons when the pore fluid protons are water, is the volume relaxation rate of the pore fluid protons when the pore fluid protons are oil.

[0088] The relaxation rate of the internal magnetic field is:

[0089]

[0090] Δχ1 represents the difference in magnetic sensitivity between protons in pore fluid and the skeleton; Δχ2 represents the difference in magnetic sensitivity between organic matter and the skeleton, and γ is the gyromagnetic ratio of protons.

[0091] The relaxation rate of the internal magnetic field and the shale oil T2 * Substituting the relaxation into the expression of the effective spin-spin relaxation rate, we get the effective spin-spin relaxation rate:

[0092]

[0093] γ·Δχ1·B0 represents the dephasing behavior of pore fluid protons, and γ·Δχ2·B0 represents the dephasing behavior of organic matter protons. The effective spin-spin relaxation rate includes the effective spin-spin relaxation rate of the fluid and the effective spin-spin relaxation rate of the organic matter. is the effective spin-spin relaxation rate of the fluid, is the effective spin-spin relaxation rate of organic matter.

[0094] Specifically, calibrating the surface relaxation intensity of the fluid in the first formation model and the instrument correction coefficient of the fluid and organic matter based on the first formation model includes:

[0095] Perform forward modeling based on the first formation model to obtain echo data;

[0096] Based on the first formation model, the echo data is inverted to obtain the effective spin-spin relaxation time distribution of the NMR experiment, the transverse relaxation time distribution of the NMR logging, and the effective spin-spin relaxation time distribution of the NMR numerical simulation;

[0097] Based on the first formation model, the effective spin-spin relaxation time distribution of NMR experiments, the transverse relaxation time distribution of NMR logging, and the effective spin-spin relaxation time distribution of NMR numerical simulation, the surface relaxation intensity of the fluid in the first formation model and the instrument correction coefficients of fluid and organic matter are calibrated.

[0098] Based on the first formation model, the forward modeling was performed to obtain the NMR T2 * Experiment, NMR logging T2 and NMR-based T2 * The numerical simulation echo data is then inverted to obtain the nuclear magnetic resonance experimental T2 * distribution, NMR logging T2 distribution and NMR numerical simulation T2 * The NMR logging T2 distribution is compared with the lateral surface relaxation intensity of pore fluid protons based on the FID pulse sequence to calibrate the surface relaxation intensity of the fluid in the first formation model. * Distribution and numerical simulation of T2 in NMR * The distribution is compared to calibrate the instrument correction factors of fluid and organic matter.

[0099] For example, the NMR experiment T2 * Distribution Figure 4 As shown, a plurality of different first instrument correction coefficients are set, and numerical simulation is performed based on the plurality of different first instrument correction coefficients to obtain a plurality of nuclear magnetic resonance numerical simulation T2 * Distribution, multiple NMR numerical simulation T2 * Distribution and NMR Experiment T2 * The distribution was compared and the T2 * Numerical simulation of nuclear magnetic resonance with minimal distribution error T2 * The first instrument correction factor corresponding to the distribution is used as the instrument correction factor for fluid and organic matter.

[0100] Specifically, the spin-spin relaxation rate of pore fluid protons can be simulated using a random walk method based on a FID pulse sequence. When pore fluid protons collide with the pore surface, the amplitude of the fluid protons will decay. The expression for the amplitude of the proton change is:

[0101]

[0102] γ is the gyromagnetic ratio of the proton, ρ 2S，L is the surface relaxation strength, and D is the diffusion coefficient of the fluid.

[0103] During the FID simulation, the phase angle of the unabsorbed hydrogen nuclei changes. At the initial moment of the FID simulation process, a 90-degree pulse flips the spin torque of all hydrogen nuclei to the transverse plane, and the magnetization intensity is simulated by the FID pulse sequence. At this time, affected by the difference in core and pore scales, the spin torque of the fluid protons can be added with a correction term, so the dephasing behavior can also be expressed by the following formula:

[0104]

[0105] K is the number of protons, k represents the kth proton, N is the number of voxels in the pore, n represents the nth voxel in the pore, C' is the instrument correction factor for fluid and organic matter, is the phase of the proton and i is the imaginary unit.

[0106] The phase of each proton is:

[0107] γ is the gyromagnetic ratio of protons, B(z n k (τ)) is the z of the kth proton at the nth pore voxel n k The magnetic field intensity at the position and the number of pores can be expressed as:

[0108] B(z n k (t))=B0+G·z n k (t)

[0109] B0 represents the magnetic field strength, and G represents the internal magnetic field gradient. Since each pore has at most one hydrogen nucleus, the proton spins of all pores relative to the pore center are the same. Therefore, the number of pores is It can be divided into three components:

[0110] B(z n k (t))=B0+G·z n0 +G·z k (t)

[0111] z k is the kth proton relative to the pore center z n0 Move the position and Substitute M D (t), the out-of-phase behavior of the FID pulse train can be expressed as:

[0112]

[0113] because represents the contribution of the external magnetic field to the phase, and the cumulative phase does not occur in the embodiment of the present application, so the contribution of the external magnetic field to the phase can be changed from M D (t) is eliminated from the expression:

[0114]

[0115] Followed by and Simulation can complete the numerical simulation of shale oil FID pulse sequence.

[0116] S203: Perform numerical simulation based on the second formation model, numerical simulation parameters, effective spin-spin relaxation time, and transverse relaxation time to obtain first echo data and second echo data; the first echo data is echo data based on the transverse relaxation time; the second echo data is echo data based on the effective spin-spin relaxation time.

[0117] In an optional embodiment, numerical simulation is performed based on the second formation model, numerical simulation parameters, effective spin-spin relaxation time, and transverse relaxation time to obtain first echo data and second echo data, including:

[0118] Simulating first echo data of a second formation model based on the effective spin-spin relaxation time based on the numerical simulation parameters and the effective spin-spin relaxation rate;

[0119] Based on the numerical simulation parameters and the spin-spin relaxation rate, second echo data of a second formation model based on the transverse relaxation time is simulated.

[0120] Specifically, numerical simulation methods are used to simulate the T2 * The invention also provides first echo data of the second formation model based on T2, and second echo data of the second formation model based on T2.

[0121] For ease of understanding, the following example illustrates the use of numerical simulation methods to simulate echo data:

[0122] like Figure 5 As shown, Q1 protons are randomly placed in the pore, and the initial amplitude of each proton is set to 1.0. At any time, if the Q2 proton diffuses to a new position, it is determined whether the proton collides with any of the skeleton, fluid surface, and organic matter. If no collision occurs, the proton is returned to the original position, and the initial amplitude of the proton is set to 1.0. If a collision occurs, it is further determined whether the proton collides with the pore wall. If so, the amplitude of the proton decays to If not, the proton is returned to its original position and the initial amplitude of the proton is set to 1.0. After resetting the initial amplitude or amplitude attenuation, determine whether Q2 is equal to Q1. If not, continue to determine whether the proton collides with any of the skeleton, fluid surface, and organic matter. If so, record the amplitude value of each proton at each residence time during the numerical simulation process, and combine the dephasing behavior and the volume relaxation of the pore fluid to calculate the echo data of the pore fluid proton

[0123] Porosity is porosity, S w，j is the saturation of the pore fluid, such as water saturation, oil saturation, and HI is the hydrogen index. Obtain the phase loss behavior of pore fluid protons, instrument correction coefficients of fluids and organic matter, and volume relaxation of organic matter, and obtain echo data based on the second formation model

[0124] S204: Determine a first rock physical parameter and a second rock physical parameter based on the first echo data and the second echo data; the first rock physical parameter is a rock physical parameter determined based on the first echo data; the second rock physical parameter is a rock physical parameter determined based on the second echo data.

[0125] In an optional embodiment, determining the first rock physical parameter and the second rock physical parameter based on the first echo data and the second echo data includes:

[0126] Invert the first echo data to obtain the target effective spin-spin relaxation time distribution;

[0127] Invert the second echo data to obtain the target transverse relaxation time distribution;

[0128] converting the target effective spin-spin relaxation time distribution into a first petrophysical parameter;

[0129] The target lateral relaxation time distribution is converted into a second petrophysical parameter.

[0130] Specifically, target T2 * The target T2 distribution is converted into the first rock physical parameter, and the target T2 distribution is converted into the second rock physical parameter. The conversion method can be set based on actual needs. For example, when the first rock physical parameter includes porosity, the target T2 * The magnitudes of the distributions are summed to give the porosity.

[0131] It should be noted that clay mineral content and frequency will affect T2 * In the scenario with a frequency of 21 Hz, the T2 of inorganic pore water * Distribution Figure 6 As shown, T d For the dwell time.

[0132] S205: Constructing a preset conversion relationship based on the first rock physical parameter and the second rock physical parameter.

[0133] Specifically, the preset conversion relationship can be in the form of a curve, a formula, etc. that can express the corresponding relationship between the first rock physical parameter and the second rock physical parameter. For example, the preset conversion relationship is a curve. Figure 7 As shown, the first rock physical parameter is set as the vertical axis, the second rock physical parameter is set as the longitudinal axis, and the frequency is set as the horizontal axis to draw a relationship curve between the first rock physical parameter and the second rock physical parameter to obtain a preset conversion relationship.

[0134] S102: Measure the target shale oil reservoir to obtain target echo data.

[0135] The target shale oil reservoir is a shale oil reservoir for which rock physical parameters need to be obtained. The target shale oil reservoir is measured by a pulse sequence such as CPMG to obtain target echo data of nuclear magnetic resonance T2 distribution for the target shale oil reservoir.

[0136] S103: Invert the target echo data to obtain the target nuclear magnetic resonance transverse relaxation time distribution.

[0137] The target echo data is inverted to obtain the target T2 distribution, that is, the NMR T2 distribution of the target shale oil reservoir.

[0138] S104: Perform parameter transformation on the target nuclear magnetic resonance transverse relaxation time distribution to obtain the rock physical parameters to be transformed.

[0139] The T2 distribution is converted into the form of rock physical parameters to obtain the rock physical parameters to be converted.

[0140] S105: Transform the rock physical parameters to be transformed based on a preset transformation relationship to obtain target rock physical parameters.

[0141] In the curve corresponding to the preset conversion relationship, find the parameter on the vertical axis that has a corresponding relationship with the rock physical parameter to be converted, and obtain the target rock physical parameter corresponding to the rock physical parameter to be converted. * Determine the rock physical parameters and improve the accuracy of rock physical parameters.

[0142] By obtaining the preset conversion relationship, the target shale oil reservoir is measured to obtain the target echo data. The target echo data is inverted to obtain the target NMR transverse relaxation time distribution. The target NMR transverse relaxation time distribution is parameterized to obtain the rock physical parameters to be converted. The rock physical parameters to be converted are converted based on the preset conversion relationship to obtain the target rock physical parameters. * The accuracy of the obtained rock physical parameters is high, and the preset conversion relationship is used to convert the rock physical parameters obtained based on the transverse relaxation time into the rock physical parameters obtained based on the effective spin-spin relaxation time, thereby converting the rock physical parameters obtained based on T2 into the rock physical parameters obtained based on T2 through the preset conversion relationship. * The obtained rock physical parameters realize T2 * The accurate conversion of rock physical parameters based on T2 is obtained. * The obtained rock physical parameters can improve the accuracy of the final obtained rock physical parameters.

[0143] like Figure 8 As shown, the embodiment of the present application provides a device for obtaining rock physical parameters, the device comprising:

[0144] The acquisition module 801 is used to acquire a preset conversion relationship; the preset conversion relationship is used to convert the rock physical parameters obtained based on the transverse relaxation time into the rock physical parameters obtained based on the effective spin-spin relaxation time;

[0145] The measurement module 802 is used to measure the target shale oil reservoir and obtain target echo data;

[0146] An inversion module 803 is used to invert the target echo data to obtain a target NMR transverse relaxation time distribution;

[0147] The first conversion module 804 is used to perform parameter conversion on the target nuclear magnetic resonance transverse relaxation time distribution to obtain the rock physical parameters to be converted;

[0148] The second conversion module 805 is used to convert the rock physical parameters to be converted based on a preset conversion relationship to obtain target rock physical parameters.

[0149] In an optional embodiment, the acquisition module 801 is specifically used for:

[0150] Establishing a first formation model and a second formation model; the first formation model is used to simulate a known shale oil reservoir, and the second formation model is used to simulate a target shale oil reservoir;

[0151] determining numerical simulation parameters based on the first formation model;

[0152] Performing numerical simulation based on the second formation model, numerical simulation parameters, effective spin-spin relaxation time, and transverse relaxation time to obtain first echo data and second echo data;

[0153] Based on the first echo data and the second echo data, petrophysical parameters of the target shale oil reservoir are determined.

[0154] In an optional embodiment, the acquisition module 801 is specifically used for:

[0155] Invert the first echo data to obtain the target effective spin-spin relaxation time distribution;

[0156] Invert the second echo data to obtain the target transverse relaxation time distribution;

[0157] converting the target effective spin-spin relaxation time distribution into a first petrophysical parameter;

[0158] The target lateral relaxation time distribution is converted into a second petrophysical parameter.

[0159] In an optional embodiment, the acquisition module 801 is specifically used for:

[0160] Obtain the effective spin-spin relaxation rate;

[0161] Based on the effective spin-spin relaxation rate and the first formation model, the surface relaxation and dephasing behavior of fluid protons are simulated;

[0162] The surface relaxation intensity of the fluid in the first formation model and the instrument correction coefficients of the fluid and organic matter are calibrated based on the first formation model.

[0163] In an optional embodiment, the acquisition module 801 is specifically used for:

[0164] Perform forward modeling based on the first formation model to obtain echo data;

[0165] Based on the first formation model, the echo data is inverted to obtain the effective spin-spin relaxation time distribution of the NMR experiment, the transverse relaxation time distribution of the NMR logging, and the effective spin-spin relaxation time distribution of the NMR numerical simulation;

[0166] Based on the first formation model, the effective spin-spin relaxation time distribution of NMR experiments, the transverse relaxation time distribution of NMR logging, and the effective spin-spin relaxation time distribution of NMR numerical simulation, the surface relaxation intensity of the fluid in the first formation model and the instrument correction coefficients of fluid and organic matter are calibrated.

[0167] In an optional embodiment, the acquisition module 801 is specifically used for:

[0168] Obtain the relaxation rate characterized by magnetic field inhomogeneities, the net observed relaxation rate of shale oil fluids, and the relaxation rate of the internal magnetic field;

[0169] The effective spin-spin relaxation rate is generated based on the relaxation rate characterized by magnetic field inhomogeneities, the net observed relaxation rate of shale oil fluid, and the relaxation rate of the internal magnetic field.

[0170] In an optional embodiment, the acquisition module 801 is specifically used for:

[0171] Simulating first echo data of a second formation model based on the effective spin-spin relaxation time based on the numerical simulation parameters and the effective spin-spin relaxation rate;

[0172] Based on the numerical simulation parameters and the effective spin-spin relaxation rate, second echo data of a second formation model based on the transverse relaxation time is simulated.

[0173] By obtaining the preset conversion relationship, the target shale oil reservoir is measured to obtain the target echo data. The target echo data is inverted to obtain the target NMR transverse relaxation time distribution. The target NMR transverse relaxation time distribution is parameterized to obtain the rock physical parameters to be converted. The rock physical parameters to be converted are converted based on the preset conversion relationship to obtain the target rock physical parameters. * The accuracy of the obtained rock physical parameters is high, and the preset conversion relationship is used to convert the rock physical parameters obtained based on the transverse relaxation time into the rock physical parameters obtained based on the effective spin-spin relaxation time, thereby converting the rock physical parameters obtained based on T2 into the rock physical parameters obtained based on T2 through the preset conversion relationship. * The obtained rock physical parameters realize T2 * The accurate conversion of rock physical parameters based on T2 is obtained. * The obtained rock physical parameters can improve the accuracy of the final obtained rock physical parameters.

[0174] An embodiment of the present application provides an electronic device, including:

[0175] Memory, used to store computer programs;

[0176] A processor is used to execute a computer program to implement any of the above methods for obtaining rock physical parameters.

[0177] like Fig. 9As shown, 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 a method for obtaining rock physical parameters performed by an electronic device disclosed in any of the above embodiments.

[0178] 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.

[0179] An embodiment of the present application provides a computer-readable storage medium for storing a computer program; wherein, when the computer program is executed by a processor, any one of the above-mentioned methods for obtaining rock physical parameters is implemented.

[0180] Computer readable media include permanent and non-permanent, removable and non-removable media that can be implemented by any method or technology to store information. Information can be computer readable instructions, data structures, program modules or other data. Examples of computer storage media include, but are not limited to, phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disk read-only memory (CD-ROM), digital versatile disk (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices or any other non-transmission media that can be used to store information that can be accessed by a computing device. As defined herein, computer readable media does not include temporary computer readable media (transitory media), such as modulated data signals and carrier waves.

[0181] 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 the present invention.

[0182] The technical content provided by the present invention is introduced in detail above. Specific examples are used in this article to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only used to help understand the method of the present invention and its core idea. At the same time, for general technical personnel in the field, according to the idea of ​​the present invention, 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 invention.

Claims

1. A method for obtaining rock physical parameters, characterized in that: The method comprises: Obtaining a preset conversion relationship; the preset conversion relationship is used to convert the rock physical parameters obtained based on the transverse relaxation time into the rock physical parameters obtained based on the effective spin-spin relaxation time; Measure the target shale oil reservoir to obtain target echo data; Inverting the target echo data to obtain a target nuclear magnetic resonance transverse relaxation time distribution; Performing parameter transformation on the target nuclear magnetic resonance transverse relaxation time distribution to obtain rock physical parameters to be transformed; The rock physical parameters to be converted are converted based on the preset conversion relationship to obtain target rock physical parameters.

2. The method according to claim 1, characterized in that The obtaining of the preset conversion relationship includes: Establishing a first formation model and a second formation model; the first formation model is used to simulate a known shale oil reservoir, and the second formation model is used to simulate an unknown shale oil reservoir; Determining numerical simulation parameters based on the first formation model; Performing numerical simulation based on the second formation model, the numerical simulation parameters, the effective spin-spin relaxation time, and the transverse relaxation time to obtain first echo data and second echo data; the first echo data is echo data based on the transverse relaxation time; the second echo data is echo data based on the effective spin-spin relaxation time; Determine a first rock physical parameter and a second rock physical parameter based on the first echo data and the second echo data; the first rock physical parameter is a rock physical parameter determined based on the first echo data; the second rock physical parameter is a rock physical parameter determined based on the second echo data; The preset conversion relationship is constructed based on the first rock physical parameter and the second rock physical parameter.

3. The method according to claim 2, characterized in that The determining of numerical simulation parameters based on the first formation model includes: Obtain the effective spin-spin relaxation rate; Based on the effective spin-spin relaxation rate and the first formation model, simulating surface relaxation and dephasing behavior of fluid protons; The surface relaxation intensity of the fluid in the first formation model and the instrument correction coefficient of the fluid and organic matter are calibrated based on the first formation model.

4. The method according to claim 3, characterized in that The step of calibrating the surface relaxation intensity of the fluid in the first formation model and the instrument correction coefficient of the fluid and organic matter based on the first formation model includes: Perform forward modeling based on the first formation model to obtain echo data; Inverting the echo data based on the first formation model to obtain a nuclear magnetic resonance experimental effective spin-spin relaxation time distribution, a nuclear magnetic resonance transverse relaxation time distribution, and a nuclear magnetic resonance numerical simulation effective spin-spin relaxation time distribution; Based on the first formation model, the nuclear magnetic resonance experimental effective spin-spin relaxation time distribution, the nuclear magnetic resonance transverse relaxation time distribution, and the nuclear magnetic resonance numerical simulation effective spin-spin relaxation time distribution, the surface relaxation intensity of the fluid in the first formation model and the instrument correction coefficients of the fluid and organic matter are calibrated.

5. The method according to claim 3, characterized in that: The obtaining of the effective spin-spin relaxation rate comprises: Obtain the relaxation rate characterized by magnetic field inhomogeneities, the net observed relaxation rate of shale oil fluids, and the relaxation rate of the internal magnetic field; The effective spin-spin relaxation rate is generated based on the relaxation rate characterized by the magnetic field inhomogeneity, the net observed relaxation rate of the shale oil fluid, and the relaxation rate of the internal magnetic field.

6. The method according to claim 3, characterized in that The performing of numerical simulation based on the second formation model, the numerical simulation parameters, the effective spin-spin relaxation time, and the transverse relaxation time to obtain first echo data and second echo data includes: Based on the numerical simulation parameters and the effective spin-spin relaxation rate, simulate first echo data of the second formation model based on the effective spin-spin relaxation time; Based on the numerical simulation parameters and the effective spin-spin relaxation rate, second echo data of the second formation model based on the transverse relaxation time is simulated.

7. The method according to claim 2, characterized in that Determining a first rock physical parameter and a second rock physical parameter based on the first echo data and the second echo data includes: Inverting the first echo data to obtain a target effective spin-spin relaxation time distribution; Inverting the second echo data to obtain a target transverse relaxation time distribution; converting the target effective spin-spin relaxation time distribution into the first petrophysical parameter; The target lateral relaxation time distribution is converted into the second petrophysical parameter.

8. A device for obtaining rock physical parameters, characterized in that: The device comprises: An acquisition module, used to acquire a preset conversion relationship; the preset conversion relationship is used to convert the rock physical parameters obtained based on the transverse relaxation time into the rock physical parameters obtained based on the effective spin-spin relaxation time; A measurement module is used to measure the target shale oil reservoir and obtain target echo data; An inversion module is used to invert the target echo data to obtain the target NMR transverse relaxation time distribution; A first conversion module is used to perform parameter conversion on the target nuclear magnetic resonance transverse relaxation time distribution to obtain the rock physical parameters to be converted; The second conversion module is used to convert the rock physical parameters to be converted based on the preset conversion relationship to obtain target rock physical parameters.

9. An electronic device, characterized in that: include: Memory, used to store computer programs; A processor, used to execute the computer program to implement a method for obtaining rock physical parameters as described in any one of claims 1 to 7.

10. A computer-readable storage medium, characterized in that: Used to store computer programs; wherein, when the computer program is executed by a processor, a method for obtaining rock physical parameters as described in any one of claims 1 to 7 is implemented.

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