Method and device for determining mobility of reservoir multi-scale shale oil

Abstract

The embodiment of the invention provides a method and device for determining the mobility of reservoir multi-scale shale oil and a storage medium, and belongs to the technical field of unconventional oil and gas development. The method for determining the mobility of the multi-scale shale oil of the reservoir comprises the following steps: acquiring the component contents of a plurality of to-be-detected mineral components in a plurality of shale samples in the to-be-detected shale reservoir and the recovery rates of the plurality of shale samples under a plurality of pore scales; determining a component content-recovery ratio correlation degree value of the component content of each to-be-detected mineral component and the recovery ratio of the shale sample under each pore scale according to the component content of each to-be-detected mineral component in the plurality of shale samples and the recovery ratio of the plurality of shale samples under each pore scale; and determining the shale oil mobility of the shale reservoir to be detected under each pore scale according to the component contents of the plurality of mineral components to be detected and the corresponding component content-recovery ratio correlation degree values. According to the method, the mobility of the shale oil of the reservoir can be quantitatively represented.

Description

Technical Field

[0001] The present invention relates to the technical field of unconventional oil and gas development, and in particular to a method and device for determining the multi-scale shale oil mobility of a reservoir. Background Art

[0002] With the increasing depletion of conventional oil and gas resources and the continued increase in energy demand, the development of unconventional oil and gas resources is becoming increasingly important. Shale oil, a key unconventional oil and gas resource, has a global resource volume exceeding 900 billion tons, with approximately 40 billion tons technically recoverable, including nearly 9 billion tons of continental shale oil, offering enormous development potential.

[0003] Currently, shale oil mobility evaluation methods generally use observations of seepage experimental phenomena and displacement experimental phenomena to qualitatively analyze the shale oil mobility of the reservoir. However, none of the above existing methods can quantitatively evaluate the shale oil mobility of the reservoir.

[0004] Therefore, how to quantitatively characterize the shale oil mobility in the reservoir has become a technical problem that needs to be solved urgently. Summary of the Invention

[0005] The purpose of the embodiments of the present application is to provide a method, device and storage medium for determining the multi-scale shale oil mobility of a reservoir, so as to solve the problem of how to quantitatively characterize the shale oil mobility of a reservoir in the prior art.

[0006] To achieve the above objectives, a first aspect of an embodiment of the present application provides a method for determining the multi-scale shale oil mobility of a reservoir, the method comprising: Obtaining component contents of multiple mineral components to be tested in multiple shale samples in a shale reservoir to be tested and recovery factors of the multiple shale samples at multiple pore scales; Determining a component content-recovery factor correlation value between the component content of each mineral component to be tested and the recovery factor of the shale samples at each pore scale based on the component content of each mineral component to be tested in the multiple shale samples and the recovery factor of the multiple shale samples at each pore scale; The shale oil mobility of the shale reservoir to be tested at various pore scales is determined based on the component contents of multiple mineral components to be tested and the corresponding component content-recovery factor correlation values.

[0007] In an embodiment of the present application, determining the shale oil mobility of the shale reservoir to be tested at each pore scale based on the component contents of multiple mineral components to be tested and the corresponding component content-recovery rate correlation degree values ​​includes: determining the first product value of the component content of each mineral component to be tested in each shale sample and the corresponding component content-recovery rate correlation degree value, and adding each first product value to determine the shale oil mobility of each shale sample at each pore scale; determining the average value of the shale oil mobility of multiple shale samples at each pore scale to obtain the shale oil mobility of the shale reservoir to be tested at each pore scale.

[0008] In an embodiment of the present application, the shale oil mobility of the shale reservoir to be tested at each pore scale is determined based on the component contents of multiple mineral components to be tested and the corresponding component content-recovery rate correlation values, including: taking the average value of the component content of each mineral component to be tested in multiple shale samples to obtain the average value of the component content of each mineral component to be tested; determining a second product value of the average value of the component content of each mineral component to be tested and the corresponding component content-recovery rate correlation value, and adding each second product value to obtain the shale oil mobility of the shale reservoir to be tested at each pore scale.

[0009] In an embodiment of the present application, obtaining the recovery rates of multiple shale samples at multiple pore scales includes: obtaining the recovery rates of multiple shale samples at multiple pore scales and multiple preset rotational speeds, wherein the multiple preset rotational speeds are arranged in order from large to small or from small to large; determining the component content-recovery rate correlation degree value between the component content of each mineral component to be tested and the recovery rate of the shale samples at each pore scale according to the component content of each mineral component to be tested in the multiple shale samples and the recovery rate of the multiple shale samples at each pore scale; and determining the component content-recovery rate correlation degree value between the component content of each mineral component to be tested and the recovery rate of the shale samples at each pore scale and multiple preset rotational speeds according to the component content of each mineral component to be tested in the multiple shale samples and the recovery rate of the multiple shale samples at multiple pore scales and multiple preset rotational speeds. value; screening multiple mineral components to be tested according to the component content-recovery factor correlation value corresponding to each pore scale of each mineral component to be tested at each preset rotational speed to obtain a target mineral component; determining the target component content-recovery factor correlation value corresponding to the target mineral component according to the component content-recovery factor correlation value corresponding to each pore scale of the target mineral component at each preset rotational speed; determining the shale oil mobility of the shale reservoir to be tested at each pore scale according to the component content of the multiple mineral components to be tested and the corresponding component content-recovery factor correlation value, including: determining the shale oil mobility of the shale reservoir to be tested at each pore scale according to the component content of the target mineral component in multiple shale samples and the target component content-recovery factor correlation value corresponding to the target mineral component.

[0010] In an embodiment of the present application, a plurality of mineral components to be tested are screened according to the component content-recovery rate correlation degree values ​​corresponding to each pore scale of each mineral component to be tested at each preset rotational speed to obtain a target mineral component, including: determining whether the component content-recovery rate correlation degree values ​​corresponding to each pore scale of each mineral component to be tested at each preset rotational speed meet a preset condition, wherein the preset condition is that the signs of the component content-recovery rate correlation degree values ​​corresponding to the last three adjacent target preset rotational speeds are the same; if the preset condition is met, determining that the mineral component to be tested is the target mineral component.

[0011] In an embodiment of the present application, a target component content-recovery rate correlation value corresponding to a target mineral component is determined based on the component content-recovery rate correlation value corresponding to each pore scale of the target mineral component at each preset rotational speed, including: determining a component content-recovery rate correlation value set based on the component content-recovery rate correlation value corresponding to each pore scale of the target mineral component at each preset rotational speed, wherein the component content-recovery rate correlation value set includes a component content-recovery rate correlation value corresponding to the target preset rotational speed, and a component content-recovery rate correlation value corresponding to a preset rotational speed having the same sign as the component content-recovery rate correlation value corresponding to the target preset rotational speed and adjacent to the target preset rotational speed; determining the average of multiple component content-recovery rate correlation value values ​​within the component content-recovery rate correlation value set to obtain the target component content-recovery rate correlation value corresponding to the target mineral component.

[0012] In an embodiment of the present application, obtaining the recovery rates of multiple shale samples at multiple pore scales includes: obtaining initial T2 spectra of multiple shale samples before centrifugation and centrifuged T2 spectra of multiple shale samples after centrifugation; obtaining the initial oil phase content of multiple shale samples at each pore scale based on the multiple initial T2 spectra; obtaining the centrifuged oil phase content of multiple shale samples at each pore scale based on the multiple centrifuged T2 spectra; obtaining the recovery rates of multiple shale samples at multiple pore scales based on the initial oil phase content and the centrifuged oil phase content, wherein the recovery rate is the ratio of the deviation between the initial oil phase content and the centrifuged oil phase content to the initial oil phase content.

[0013] In an embodiment of the present application, the method also includes: obtaining a pore scale weight corresponding to each pore scale based on the initial oil phase content of each pore scale; determining a third product value of the shale oil mobility at each pore scale and the corresponding pore scale weight, and adding multiple third product values ​​to obtain the comprehensive shale oil mobility of the shale reservoir to be tested.

[0014] A second aspect of an embodiment of the present application provides a device for determining the multi-scale shale oil mobility of a reservoir, comprising: a memory configured to store instructions; and a processor configured to call instructions from the memory and to implement the above-mentioned method for determining the multi-scale shale oil mobility of a reservoir when executing the instructions.

[0015] A third aspect of an embodiment of the present application provides a machine-readable storage medium having stored thereon instructions for enabling a machine to execute the above-mentioned method for determining the multi-scale shale oil mobility of a reservoir.

[0016] The above technical solution obtains the component contents of multiple mineral components to be tested in multiple shale samples in the shale reservoir to be tested and the recovery rates of multiple shale samples at multiple pore scales to obtain the component content-recovery rate correlation degree values ​​of the component content of each mineral component to be tested and the recovery rate of the shale samples at each pore scale, thereby quantitatively characterizing the shale oil mobility of the shale reservoir to be tested at each pore scale based on the component contents of the multiple mineral components to be tested and the corresponding component content-recovery rate correlation degree values.

[0017] Other features and advantages of the embodiments of the present invention will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to provide a further understanding of the embodiments of the present invention and constitute a part of the specification. Together with the following detailed description, they are used to explain the embodiments of the present invention, but do not constitute a limitation of the embodiments of the present invention. In the accompanying drawings: Figure 1 A schematic diagram of a process for determining multi-scale shale oil mobility in a reservoir according to an embodiment of the present application is shown; Figure 2 A schematic diagram schematically illustrates a correlation curve between the recovery rate of multiple shale samples at a rotation speed of 2000 rpm and a small pore scale and the quartz percentage of the multiple shale samples according to an embodiment of the present application. DETAILED DESCRIPTION

[0019] To make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the specific implementation methods described herein are only used to illustrate and explain the embodiments of the present application and are not used to limit the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0020] It should be noted that the acquisition, transmission, storage, use, and processing of data in the technical solution of this application are in compliance with the relevant provisions of national laws and regulations. In the embodiments of this application, certain software, components, models, and other existing solutions in the industry may be mentioned. These should be considered as exemplary. Their purpose is only to illustrate the feasibility of implementing the technical solution of this application, but it does not mean that the applicant has or will necessarily use such solutions.

[0021] It should be noted that if the embodiments of the present application involve directional indications (such as up, down, left, right, front, back, etc.), such directional indications are only used to explain the relative position relationship, movement status, etc. between the various components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0022] In addition, if there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of such features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the fact that they can be implemented by ordinary technicians in this field. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0023] It should be noted that the acquisition, transmission, storage, use, and processing of data in the technical solution of this application are in compliance with the relevant provisions of laws and regulations. In the embodiments of this application, certain software, components, models, and other existing solutions in the industry may be mentioned. These should be considered as exemplary. Their purpose is only to illustrate the feasibility of implementing the technical solution of this application, but it does not mean that the applicant has or will necessarily use such solutions.

[0024] Figure 1 The following schematically shows a flow chart for determining the interaction state of reservoir fluids in one embodiment of the present application. Figure 1 As shown, the embodiment of the present application provides a method for determining the multi-scale shale oil mobility of a reservoir. Taking the application of this method to a processor as an example, the method may include the following steps: Step S101: obtaining the component contents of multiple mineral components to be tested in multiple shale samples in a shale reservoir to be tested and the recovery rates of the multiple shale samples at multiple pore scales.

[0025] Step S102: Determine the component content-recovery factor correlation value between the component content of each mineral component to be tested and the recovery factor of the shale samples at each pore scale based on the component content of each mineral component to be tested in the multiple shale samples and the recovery factor of the multiple shale samples at each pore scale.

[0026] Step S103 : determining the shale oil mobility of the shale reservoir to be tested at various pore sizes based on the component contents of the multiple mineral components to be tested and the corresponding component content-recovery factor correlation values.

[0027] It is understood that the shale reservoir to be tested is the shale reservoir to be predicted. The shale sample is a sample selected from the shale reservoir. The mineral components to be tested are the mineral components contained in the shale sample in the shale reservoir to be predicted. Specifically, the mineral components to be tested can also be the total content of certain mineral components contained in the shale sample, such as the total content of illite, montmorillonite, illite, and chlorite in clay minerals. Each pore scale can include both macropores and micropores. The recovery rate refers to the ratio of the cumulative oil and gas produced at a certain stage of development of an oil or gas reservoir to the original geological reserves of the oil or gas reservoir. It can be the ratio of the deviation between the initial oil phase content and the centrifugal oil phase content to the initial oil phase content, where the initial oil phase content and the centrifugal oil phase content are calculated using T2 spectroscopy. The component content-recovery rate correlation value is the correlation between the component content and the recovery rate, obtained based on the component content of each mineral component to be tested in multiple shale samples and the recovery rates of the multiple shale samples at various pore scales. Shale oil mobility refers to the ease with which crude oil in shale reservoirs flows from pores, fractures and other storage spaces to the wellbore.

[0028] Specifically, the processor obtains the component contents of multiple mineral components to be tested in multiple shale samples in the shale reservoir to be tested and the recovery rates of the multiple shale samples at multiple pore scales, takes the recovery rates of the multiple shale samples at multiple pore scales as dependent variables, and takes the component contents of multiple mineral components to be tested in the multiple shale samples in the shale reservoir to be tested as independent variables to perform linear regression analysis, and obtains the component content-recovery rate correlation degree value between the component content of each mineral component to be tested and the recovery rate of each shale sample at each pore scale, for example, Figure 2As shown, the quartz component content (i.e., quartz percentage) in multiple shale samples from the shale reservoir to be tested is used as the independent variable, and the recovery rate of the multiple shale samples at a small pore scale is used as the dependent variable. Based on multiple sets of independent and dependent variables, a linear regression analysis is performed to obtain a component content-recovery rate correlation curve between the quartz component content and the recovery rate of each shale sample at a small pore scale. The slope of this component content-recovery rate correlation curve is the component content-recovery rate correlation value. Furthermore, the processor can determine the shale oil mobility of the shale reservoir to be tested at various pore scales based on the component content of the multiple mineral components to be tested and the corresponding component content-recovery rate correlation values.

[0029] The above technical solution obtains the component contents of multiple mineral components to be tested in multiple shale samples in the shale reservoir to be tested and the recovery rates of multiple shale samples at multiple pore scales to obtain the component content-recovery rate correlation degree values ​​of the component content of each mineral component to be tested and the recovery rate of the shale samples at each pore scale, thereby quantitatively characterizing the shale oil mobility of the shale reservoir to be tested at each pore scale based on the component contents of the multiple mineral components to be tested and the corresponding component content-recovery rate correlation degree values.

[0030] In one embodiment, determining the shale oil mobility of the shale reservoir to be tested at each pore scale based on the component contents of multiple mineral components to be tested and the corresponding component content-recovery rate correlation degree values ​​includes: determining a first product value of the component content of each mineral component to be tested in each shale sample and the corresponding component content-recovery rate correlation degree value, and adding each first product value to determine the shale oil mobility of each shale sample at each pore scale; determining an average value of the shale oil mobility of multiple shale samples at each pore scale to obtain the shale oil mobility of the shale reservoir to be tested at each pore scale.

[0031] It can be understood that the first product value is the product value of the component content of each mineral component to be tested in each shale sample and the corresponding component content-recovery factor correlation value.

[0032] Specifically, each shale sample in the processor has multiple component contents of multiple mineral components to be tested. After obtaining the component content-recovery factor correlation value corresponding to each mineral component, the component content of each mineral component to be tested in each shale sample is multiplied by the component content-recovery factor correlation value corresponding to each mineral component to be tested. The multiplication results are then added together to obtain the shale oil mobility of each shale sample. Finally, the shale oil mobility of multiple shale samples is averaged to represent the mobility of the shale reservoir to be tested.

[0033] In one embodiment, the shale oil mobility of the shale reservoir to be tested at each pore scale is determined based on the component contents of multiple mineral components to be tested and the corresponding component content-recovery factor correlation values, including: taking the average value of the component content of each mineral component to be tested in multiple shale samples to obtain the average value of the component content of each mineral component to be tested; determining a second product value of the average value of the component content of each mineral component to be tested and the corresponding component content-recovery factor correlation value, and adding each second product value to obtain the shale oil mobility of the shale reservoir to be tested at each pore scale.

[0034] It can be understood that the second product value is the product value of the average value of the component content of each mineral component to be measured and the corresponding component content-recovery factor correlation degree value.

[0035] Specifically, the processor calculates the average value of the component content of the same mineral component to be tested in multiple shale samples, and then multiplies the average value of the component content of each mineral component to be tested by the component content-recovery rate correlation value corresponding to each mineral component to be tested at each pore scale, and then adds the multiplication results to respectively characterize the shale oil mobility of the shale reservoir to be tested at each pore scale.

[0036] In one embodiment, obtaining the recovery rates of multiple shale samples at multiple pore scales includes: obtaining the recovery rates of multiple shale samples at multiple pore scales and multiple preset rotational speeds, wherein the multiple preset rotational speeds are arranged in order from large to small or from small to large; determining the component content-recovery rate correlation degree value between the component content of each mineral component to be tested and the recovery rate of the shale samples at each pore scale based on the component content of each mineral component to be tested in the multiple shale samples and the recovery rate of the multiple shale samples at each pore scale; and determining the component content-recovery rate correlation degree value between the component content of each mineral component to be tested and the recovery rate of the shale samples at each pore scale and multiple preset rotational speeds. value; screening multiple mineral components to be tested according to the component content-recovery factor correlation value corresponding to each pore scale of each mineral component to be tested at each preset rotational speed to obtain a target mineral component; determining the target component content-recovery factor correlation value corresponding to the target mineral component according to the component content-recovery factor correlation value corresponding to each pore scale of the target mineral component at each preset rotational speed; determining the shale oil mobility of the shale reservoir to be tested at each pore scale according to the component content of the multiple mineral components to be tested and the corresponding component content-recovery factor correlation value, including: determining the shale oil mobility of the shale reservoir to be tested at each pore scale according to the component content of the target mineral component in multiple shale samples and the target component content-recovery factor correlation value corresponding to the target mineral component.

[0037] It is understood that the preset speed is a pre-set speed. The target mineral component is a mineral component that affects the mobility of shale oil. The target component content-recovery factor correlation value is a component content-recovery factor correlation value corresponding to the target mineral component.

[0038] Specifically, the processor can obtain the recovery rates of multiple shale samples at multiple pore scales and multiple preset rotational speeds arranged in order from large to small or from small to large, thereby determining the component content-recovery rate correlation degree value corresponding to each pore scale of each mineral component to be tested at each preset rotational speed based on the component content of each mineral component to be tested in the multiple shale samples and the recovery rates of the multiple shale samples at multiple pore scales and multiple preset rotational speeds, and then analyzing the component content-recovery rate correlation degree value corresponding to each pore scale at each preset rotational speed, and screening out the mineral components that affect the mobility of shale oil based on the component content-recovery rate correlation degree value corresponding to each pore scale at each preset rotational speed. After screening out the mineral components that affect the mobility of shale oil, the processor processes the component content-recovery rate correlation degree values ​​at multiple rotational speeds to obtain the target component content-recovery rate correlation degree values ​​corresponding to the mineral components that affect the mobility of shale oil. Finally, the shale oil mobility of the shale reservoir to be tested at each pore scale is quantitatively characterized according to each mineral component that affects the mobility of shale oil and the target component content-recovery rate correlation degree values ​​corresponding to the mineral components that affect the mobility of shale oil. The processor obtains the recovery rate packages of multiple shale samples at multiple pore scales and multiple preset rotational speeds arranged in order from large to small or from small to large. The method includes the following steps: obtaining initial T2 spectra of multiple shale samples before centrifugation, and obtaining second centrifugation T2 spectra of multiple shale samples after centrifugation at multiple preset rotation speeds that increase or decrease in sequence; obtaining the initial oil phase content of multiple shale samples at each pore scale based on the multiple initial T2 spectra; obtaining the second centrifugation oil phase content of multiple shale samples at each pore scale and each rotation speed based on the multiple second centrifugation T2 spectra; obtaining the recovery rate of multiple shale samples at each pore scale and each rotation speed based on the initial oil phase content and the second centrifugation oil phase content, and the recovery rate is the ratio of the deviation between the initial oil phase content and the second centrifugation oil phase content to the initial oil phase content. This application uses a gradient centrifugation experimental process from low speed to high speed, combined with nuclear magnetic resonance detection methods, to conduct an in-depth study of the influence of different mineral components to be tested on the mobility of shale oil from a statistical perspective.

[0039] In one embodiment, a plurality of mineral components to be tested are screened according to the component content-recovery rate correlation degree values ​​corresponding to each pore scale of each mineral component to be tested at each preset rotational speed to obtain a target mineral component, including: determining whether the component content-recovery rate correlation degree values ​​corresponding to each pore scale of each mineral component to be tested at each preset rotational speed meet a preset condition, wherein the preset condition is that the signs of the component content-recovery rate correlation degree values ​​corresponding to the last three adjacent target preset rotational speeds are the same; if the preset condition is met, determining that the mineral component to be tested is the target mineral component.

[0040] It can be understood that the target preset speeds are the last three adjacent preset speeds.

[0041] Specifically, a determination is made as to whether the component content-recovery factor correlation values ​​corresponding to each pore size for each mineral component to be measured at each preset rotational speed satisfy the condition that the signs of the component content-recovery factor correlation values ​​corresponding to the last three adjacent target preset rotational speeds are the same. If the signs of the component content-recovery factor correlation values ​​corresponding to the last three adjacent target preset rotational speeds are the same, the mineral component to be measured is determined to be the target mineral component.

[0042] In one embodiment, a target component content-recovery rate correlation value corresponding to a target mineral component is determined based on the component content-recovery rate correlation value corresponding to each pore scale of the target mineral component at each preset rotational speed, including: determining a component content-recovery rate correlation value set based on the component content-recovery rate correlation value corresponding to each pore scale of the target mineral component at each preset rotational speed, wherein the component content-recovery rate correlation value set includes the component content-recovery rate correlation value corresponding to the target preset rotational speed, and the component content-recovery rate correlation value corresponding to a preset rotational speed having the same sign as the component content-recovery rate correlation value corresponding to the target preset rotational speed and adjacent to the target preset rotational speed; determining the average of multiple component content-recovery rate correlation value values ​​within the component content-recovery rate correlation value set to obtain the target component content-recovery rate correlation value corresponding to the target mineral component.

[0043] It can be understood that the component content-recovery rate correlation degree value set includes the component content-recovery rate correlation degree values ​​corresponding to the last three adjacent preset speeds and the component content-recovery rate correlation degree values ​​corresponding to the last three adjacent preset speeds, which have the same sign as the component content-recovery rate correlation degree values ​​corresponding to the last three adjacent preset speeds and correspond to the preset speeds adjacent to the last three adjacent preset speeds.

[0044] Specifically, after determining the target mineral components in each shale sample, the processor determines a component content-recovery rate correlation degree value set based on the component content-recovery rate correlation degree value of the target mineral components, averages the multiple component content-recovery rate correlation degree values ​​in the component content-recovery rate correlation degree value set, and determines the target component content-recovery rate correlation degree value of each target mineral component in each shale sample, thereby quantitatively characterizing the shale oil mobility of the shale reservoir to be tested at each pore scale based on the component content of each target mineral component in each shale sample and the target component content-recovery rate correlation degree value of each target mineral component.

[0045] In one embodiment, obtaining the recovery rates of multiple shale samples at multiple pore scales includes: obtaining initial T2 spectra of multiple shale samples before centrifugation and centrifuged T2 spectra of multiple shale samples after centrifugation; obtaining the initial oil phase content of multiple shale samples at each pore scale based on the multiple initial T2 spectra; obtaining the centrifuged oil phase content of multiple shale samples at each pore scale based on the multiple centrifuged T2 spectra; obtaining the recovery rates of multiple shale samples at multiple pore scales based on the initial oil phase content and the centrifuged oil phase content, wherein the recovery rate is the ratio of the deviation between the initial oil phase content and the centrifuged oil phase content to the initial oil phase content.

[0046] It can be understood that the initial T2 spectra are the T2 spectra of multiple shale samples before centrifugation. The centrifuged T2 spectra are the T2 spectra of multiple shale samples after centrifugation. The initial oil content is the oil content obtained based on the multiple initial T2 spectra. The centrifuged oil content is the oil content obtained based on the multiple centrifuged T2 spectra. The recovery factor is the ratio of the deviation between the initial oil content and the centrifuged oil content to the initial oil content.

[0047] Specifically, the processor obtains initial T2 spectra of multiple shale samples before centrifugation and centrifuged T2 spectra of multiple shale samples after centrifugation at a preset speed, and determines the demarcation points of each pore scale based on the valley points in the initial T2 spectra. The initial T2 spectra are then integrated at each pore scale using the demarcation points as boundaries to obtain the initial oil phase content of each pore scale. The processor determines the demarcation points of each pore scale based on the valley points in the centrifuged T2 spectra, and the centrifuged T2 spectra are integrated at each pore scale using the demarcation points as boundaries to obtain the centrifuged oil phase content of each pore scale. Finally, the processor obtains the recovery factors of the multiple shale samples at multiple pore scales based on the initial oil phase content and the centrifuged oil phase content.

[0048] In one embodiment, the method further includes: obtaining a pore scale weight corresponding to each pore scale based on the initial oil phase content of each pore scale; determining a third product value of the shale oil mobility at each pore scale and the corresponding pore scale weight, and adding multiple third product values ​​to obtain the comprehensive shale oil mobility of the shale reservoir to be tested.

[0049] It can be understood that the pore scale weight is the proportion of the impact of shale oil mobility at each pore scale on the comprehensive mobility of shale oil. The third product value is the product of the shale oil mobility at each pore scale and the corresponding pore scale weight.

[0050] Specifically, the processor determines the pore scale weight corresponding to each pore scale based on the ratio of the initial oil phase content of each pore scale, and adds the product values ​​of the shale oil mobility at each pore scale and the corresponding pore scale weight to obtain the comprehensive shale oil mobility of the shale reservoir to be tested.

[0051] The specific steps can be as follows: Step 1: Shale sample pretreatment 1. Sample drying: Place the core sample in a 60°C oven and dry it for 3 days to ensure that the sample is completely dry; 2. Basic physical property test: measure the diameter, length, and mass of the core and calculate the sample volume, as shown in Table 1; 3. Porosity and permeability test: Use the PDP-200 instrument to conduct pulse decay experiments to measure the porosity and permeability of the core; 4. Mineral composition analysis: X-ray diffraction analysis (XRD) was used to determine the mineral composition of the core, including the contents of quartz, potassium feldspar, plagioclase, calcite, pyrite, ankerite and clay minerals, as well as the relative contents of illite-montmorillonite mixed layers, illite and chlorite in clay minerals, as shown in Table 2.

[0052] Table 1 Basic physical properties and pore structure of samples in Example 1

[0053] Table 2 Mineral composition of samples from Example 1

[0054] Step 2: Oil phase saturation Dried core samples were saturated with oil using a high-pressure saturation device. The saturation conditions were as follows: 24 hours after vacuuming, the pressure was increased to 30 MPa and maintained for 72 hours to ensure that the crude oil fully filled the pores. The saturated core samples were removed, the surface of the residual oil wiped, and the saturation was calculated by weighing. The crude oil volume was calculated by dividing the crude oil mass by the crude oil density, and the oil phase saturation was calculated by dividing the crude oil volume by the shale sample volume.

[0055] Step 3: Initial NMR T2 spectroscopy and pore structure analysis 1. Use a nuclear magnetic resonance analyzer to measure the T2 spectrum of the core sample after oil saturation; Test parameters: resonance frequency 12.798 MHz, magnet temperature 35.00±0.02℃, probe coil diameter 25 mm, magnetic field strength 0.28 T, echo time 0.07 ms, number of echoes 6000, and scans 32; 2. Record the initial T2 spectrum as a benchmark for subsequent analysis; 3. Determine the demarcation point of multiple pore scales, such as large pores and small pores, through T2 spectrum analysis and calculate the volume ratio of each pore system.

[0056] Step 4: Step Centrifugation-NMR Testing 1. Centrifuge at 400, 800, 1200, 2000, 2400, and 4000 rpm in sequence. After 30 minutes at each stage, remove the sample and perform nuclear magnetic resonance T2 spectrum measurement. 2. Record T2 spectrum data at each speed level to analyze the changes in oil content in large and small pores. Through experiments at 6 different speeds, a total of 24 data points were obtained from 4 samples, greatly increasing the reliability of statistical analysis.

[0057] Step 5: Multi-scale pore division and recovery calculation 1. Determine the boundary between multi-pore scales, such as macropores and micropores, based on the bimodal distribution characteristics of the T2 spectrum; 1. Calculate the changes in oil volume at various pore scales, such as large and small pores, at various centrifugal speeds, as shown in Table 3. Large pore recovery factor = (large pore initial oil volume - large pore final remaining oil volume) / large pore initial oil volume × 100%. Small pore recovery factor = (small pore initial oil volume - small pore final remaining oil volume) / small pore initial oil volume × 100%.

[0058] Table 3 Recovery rate experimental results of Example 1

[0059] Step 6: Description of the correlation analysis method Linear regression analysis was performed on the mobility and mineral content at each centrifugal speed to obtain the slope m of the correlation line y = mx + b. The average slope at all speeds was calculated as the influence coefficient of the mineral component.

[0060] Step 7: Analysis of the relationship between mineral composition and mobility Based on experimental data from four samples at six different rotational speeds (a total of 24 data points), the correlation between mineral composition and recovery at each rotational speed was analyzed to calculate the influence coefficient a of each mineral component. For the G shale in this example, the established quantitative relationship is as follows: Factors affecting macropore mobility: Macropore mobility (LPM) = 0.9605 × X 石英总含量 -0.4740 ×X 粘土总量 Factors affecting pinhole mobility: Pinhole mobility (SPM) = 0.7904 × X 石英总含量 + 0.2084 ×X 伊利石总含量 - 0.5040 × X 伊蒙混层总含量 - 0.2825 × X 绿泥石总含量 .

[0061] The coefficients are the average values ​​of the correlation slopes at different rotational speeds. It should be emphasized that these coefficients are derived for the specific samples of this embodiment, and the corresponding coefficients need to be re-determined for shale reservoirs of different regions and types based on actual conditions.

[0062] Example 2: S shale reservoir evaluation Step 1: Experimental material preparation. Basic physical properties and pore structure are shown in Table 4. Sample mineral composition is shown in Table 5. The mineral composition characteristics of the S shale samples are different from those in Example 1. Some samples have a higher calcite content, demonstrating the applicability of this method to shales with different mineral compositions. There are 6 S shale core samples, numbered S1, S2, S3, S4, S5 and S6. Step 2: Crude oil injection into target reservoir The same experimental process and analysis method as in Example 1 were used to conduct system experiments at six different rotation speeds (400, 800, 1200, 2000, 2400, and 4000 rpm). The recovery factor results are shown in Table 6.

[0063] Table 4 Basic physical properties and pore structure of samples from Example 2

[0064] Table 5 Mineral composition of samples from Example 2

[0065] Table 6 Recovery rate experimental results of Example 2

[0066] Step 3: Analysis of the advantages of multi-speed experiments By testing six samples at six different rotational speeds, a total of 36 data points were obtained, a sixfold increase in data volume compared to traditional single-speed experiments. By increasing the rotational speed gradient within limited sample conditions, more experimental data points were obtained, observing the gradual trend of the influence of mineral composition and identifying mineral compositions that only showed correlation within a specific rotational speed range.

[0067] Step 4: Comprehensive mobility evaluation and dessert selection 1. Based on the ratio of macropore volume to micropore volume, the 10 samples are divided into different pore structure types: Macropore-dominated type (macropore ratio > 60%): Sample 3, S3, S4. Micropore-dominated type (micropore ratio > 60%): Sample 2, Sample 4, S2, S5. Mixed type (similar macropore and micropore ratios): Sample 1, S1, S6 2. Comprehensive mobility weighted calculation: Comprehensive Mobility Index (CMI) = Macropore ratio × LPM + Micropore ratio × SPM Based on the comprehensive analysis of 10 samples, the following evaluation criteria are established: High-quality reservoir (sweet spot): Comprehensive Mobility Index CMI > 22%. Medium-quality reservoir: 18% < CMI ≤ 22%. Medium-quality reservoirs include Sample 3 (23.77%), S1 (22.87%), S3 (29.68%), S4 (24.95%), S6 (22.31%), Sample 1 (20.06%). Poor-quality reservoir (non-sweet spot): CMI ≤ 18%. Poor-quality reservoirs include: Sample 2 (15.17%), Sample 4 (16.24%), S2 (15.72%), S5 (15.22%) Step 5: Model reliability analysis Correlation trend analysis Through the correlation analysis of 10 samples at different rotation speeds, it is found that: The quartz content shows a stable positive correlation trend with the mobility of macropores and micropores at all rotation speeds; The total amount of clay minerals shows a stable negative correlation trend with the macropore mobility after the rotation speed > 800 rpm; Illite shows a stable positive correlation trend in micropores after the rotation speed > 1200 rpm; Illite-smectite mixed layer and chlorite show a stable negative correlation trend in micropores after the rotation speed > 1200 rpm.

[0068] Since the hydrophilicity and smooth surface of quartz are beneficial to the flow of oil phase, it shows a positive contribution in both macropores and micropores; clay minerals mainly show a physical blocking effect in macropores, and the surface chemical properties of different types of clay play a dominant role in micropores; illite is relatively oil-loving and helps the mobility in micropores; the strong hydrophilicity of illite-smectite mixed layer and chlorite is instead unfavorable to the flow of oil phase in micropores. Therefore, the model is reliable.

[0069] In one embodiment, the embodiment of the present application provides a device for determining the multi-scale shale oil mobility of a reservoir, including: a memory configured to store instructions; and a processor configured to call instructions from the memory and be able to implement the method for determining the multi-scale shale oil mobility of a reservoir according to the above.

[0070] In one embodiment, the present application provides a machine-readable storage medium having stored thereon instructions for causing a machine to execute the above-mentioned method for determining the multi-scale shale oil mobility of a reservoir.

[0071] It should also be noted that the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, commodity, or apparatus that includes a series of elements includes not only those elements but also other elements not explicitly listed, or includes elements inherent to such process, method, commodity, or apparatus. In the absence of further limitations, an element defined by the phrase "comprises a ..." does not exclude the presence of other identical elements in the process, method, commodity, or apparatus that includes the element.

[0072] The above are merely embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present application should all be included within the scope of the claims of the present application.

Claims

1. A method for determining the multi-scale shale oil mobility of a reservoir, characterized in that: The method comprises: Obtaining component contents of multiple mineral components to be tested in multiple shale samples in a shale reservoir to be tested and recovery factors of the multiple shale samples at multiple pore scales; Determining, based on the component content of each of the mineral components to be tested in the multiple shale samples and the recovery factors of the multiple shale samples at each of the pore scales, a component content-recovery factor correlation value between the component content of each of the mineral components to be tested and the recovery factors of the shale samples at each of the pore scales; The shale oil mobility of the shale reservoir to be tested at each pore scale is determined based on the component contents of the multiple mineral components to be tested and the corresponding component content-recovery factor correlation values.

2. The method according to claim 1, characterized in that Determining the shale oil mobility of the shale reservoir to be tested at each pore scale according to the component contents of the multiple mineral components to be tested and the corresponding component content-recovery factor correlation values ​​includes: Determining a first product value of the component content of each of the mineral components to be tested in each of the shale samples and the corresponding component content-recovery factor correlation value, and adding the first product values ​​to determine the shale oil mobility of each of the shale samples at each of the pore scales; The average value of the shale oil mobility of the plurality of shale samples at each pore scale is determined to obtain the shale oil mobility of the shale reservoir to be tested at each pore scale.

3. The method according to claim 1, characterized in that Determining the shale oil mobility of the shale reservoir to be tested at each pore scale based on the component contents of the multiple mineral components to be tested and the corresponding component content-recovery factor correlation values ​​includes: Calculating an average value of the component content of each of the mineral components to be tested in the plurality of shale samples to obtain an average value of the component content of each of the mineral components to be tested; Determine a second product value of the average component content of each of the mineral components to be tested and the corresponding component content-recovery factor correlation value, and add each of the second product values ​​to obtain the shale oil mobility of the shale reservoir to be tested at each of the pore scales.

4. The method according to claim 1, wherein Obtaining the recovery factors of the plurality of shale samples at a plurality of pore scales includes: Obtaining recovery factors of multiple shale samples at multiple pore sizes and multiple preset rotational speeds, wherein the multiple preset rotational speeds are arranged in order from large to small or from small to large; Determining the component content-recovery factor correlation value between the component content of each of the mineral components to be tested and the recovery factor of the shale samples at each pore scale based on the component content of each of the mineral components to be tested in the multiple shale samples and the recovery factors of the multiple shale samples at each pore scale includes: Determining a component content-recovery factor correlation value corresponding to each pore size of each mineral component to be tested at each preset rotational speed based on the component content of each mineral component to be tested in the multiple shale samples and the recovery factors of the multiple shale samples at multiple pore sizes and multiple preset rotational speeds; Screening the plurality of mineral components to be tested according to the component content-recovery factor correlation value corresponding to each pore size of each mineral component to be tested at each preset rotation speed to obtain a target mineral component; Determining a target component content-recovery factor correlation value corresponding to the target mineral component according to the component content-recovery factor correlation value corresponding to each pore scale of the target mineral component at each preset rotation speed; Determining the shale oil mobility of the shale reservoir to be tested at each pore scale according to the component contents of the multiple mineral components to be tested and the corresponding component content-recovery factor correlation values ​​includes: The shale oil mobility of the shale reservoir to be tested at each pore scale is determined based on the component content of the target mineral component in the plurality of shale samples and the target component content-recovery factor correlation value corresponding to the target mineral component.

5. The method according to claim 4, characterized in that The screening of the plurality of mineral components to be tested according to the component content-recovery factor correlation value corresponding to each pore size of each mineral component to be tested at each preset rotation speed to obtain the target mineral component includes: Determine whether the component content-recovery factor correlation value corresponding to each pore scale of each of the mineral components to be measured at each preset rotational speed meets a preset condition, wherein the preset condition is that the component content-recovery factor correlation value corresponding to the last three adjacent target preset rotational speeds have the same sign; When the preset conditions are met, the mineral component to be tested is determined to be the target mineral component.

6. The method according to claim 4, characterized in that Determining the target component content-recovery factor correlation value corresponding to the target mineral component based on the component content-recovery factor correlation value corresponding to each pore size at each preset rotation speed includes: Determining a component content-recovery factor correlation value set based on the component content-recovery factor correlation value corresponding to each pore scale of the target mineral component at each preset rotational speed, wherein the component content-recovery factor correlation value set includes the component content-recovery factor correlation value corresponding to the target preset rotational speed, and the component content-recovery factor correlation value corresponding to a preset rotational speed having the same sign as the component content-recovery factor correlation value corresponding to the target preset rotational speed and being adjacent to the target preset rotational speed; The average of the plurality of component content-recovery factor correlation values ​​within the component content-recovery factor correlation value set is determined to obtain a target component content-recovery factor correlation value corresponding to the target mineral component.

7. The method according to claim 1, characterized in that Obtaining the recovery factors of the plurality of shale samples at a plurality of pore scales includes: Obtaining initial T2 spectra of the plurality of shale samples before centrifugation and centrifuged T2 spectra of the plurality of shale samples after centrifugation; Obtaining the initial oil phase content of the plurality of shale samples at each pore scale according to the plurality of initial T2 spectra; Obtaining the centrifugal oil phase content of the plurality of shale samples at each pore scale according to the plurality of centrifugal T2 spectra; The recovery rates of the multiple shale samples at multiple pore scales are obtained based on the initial oil phase content and the centrifugal oil phase content, wherein the recovery rate is the ratio of the deviation between the initial oil phase content and the centrifugal oil phase content to the initial oil phase content.

8. The method according to claim 4, characterized in that The method further comprises: Obtaining a pore scale weight corresponding to each pore scale according to the initial oil phase content of each pore scale; Determine a third product value of the shale oil mobility at each pore scale and the corresponding pore scale weight, and add multiple third product values ​​to obtain the comprehensive shale oil mobility of the shale reservoir to be tested.

9. A device for determining the multi-scale shale oil mobility of a reservoir, characterized in that: include: a memory configured to store instructions; as well as A processor is configured to call the instructions from the memory and to implement the method for determining multi-scale shale oil mobility of a reservoir according to any one of claims 1 to 8 when executing the instructions.

10. A machine-readable storage medium, characterized in that The machine-readable storage medium stores instructions for causing a machine to execute the method for determining multi-scale shale oil mobility in a reservoir according to any one of claims 1 to 8.

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