Method and apparatus for determining reservoir multiscale shale oil mobility

Abstract

The embodiment of the present application provides a kind of for determining reservoir multiscale shale oil mobility method, device and storage medium, belong to unconventional oil and gas development technical field.The method for determining reservoir multiscale shale oil mobility includes: obtaining the component content of multiple mineral components to be measured in multiple shale samples in the shale reservoir to be measured and the recovery rate of multiple shale samples under multiple pore scales;According to the component content of each mineral component to be measured in multiple shale samples and the recovery rate of multiple shale samples under each pore scale, determine the component content-mineral component content-recovery rate correlation degree value of the component content of each mineral component to be measured and the recovery rate of shale sample under each pore scale;According to the component content of multiple mineral components to be measured and the corresponding component content-mineral component content-recovery rate correlation degree value, determine the shale oil mobility of the shale reservoir to be measured under each pore scale.The present application can realize the quantitative characterization of the shale oil mobility of reservoir.

Description

TECHNICAL FIELD

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

[0002] With the increasing depletion of conventional oil and gas resources and the continuous increase of energy demand, the development of unconventional oil and gas resources becomes increasingly important. As an important unconventional oil and gas resource, the global resource of shale oil is more than 900 billion tons, and the technically recoverable amount is about 40 billion tons, of which the continental shale oil is nearly 9 billion tons, with great development potential.

[0003] At present, the shale oil mobility evaluation method usually uses percolation experiment phenomenon observation and displacement experiment phenomenon observation to qualitatively analyze the shale oil mobility of the reservoir. However, the above existing methods cannot quantitatively evaluate the shale oil mobility of the reservoir.

[0004] Therefore, how to quantitatively characterize the shale oil mobility of the reservoir has become a technical problem to be solved. SUMMARY

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

[0006] In order to achieve the above purpose, the first aspect of the embodiments of the present application provides a method for determining reservoir multi-scale shale oil mobility, the method comprising:

[0007] obtaining the component content of a plurality of mineral components to be measured in a plurality of shale samples in a shale reservoir to be measured and the recovery rate of the plurality of shale samples at a plurality of pore scales;

[0008] determining the component content-recovery rate correlation degree value of the component content of each mineral component to be measured and the recovery rate of the shale sample at each pore scale according to the component content of each mineral component to be measured in the plurality of shale samples and the recovery rate of the plurality of shale samples at each pore scale;

[0009] determining the shale oil mobility of the shale reservoir to be measured at each pore scale according to the component content of the plurality of mineral components to be measured and the corresponding component content-recovery rate correlation degree value.

[0010] In the embodiment of the present application, the shale oil mobility of the shale reservoir to be measured at each pore scale is determined according to the component content of each mineral component to be measured and the corresponding component content-recovery rate correlation degree value, which includes: determining a first product value of the component content of each mineral component to be measured 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; and determining an average value of the shale oil mobility of the plurality of shale samples at each pore scale to obtain the shale oil mobility of the shale reservoir to be measured at each pore scale.

[0011] In the embodiment of the present application, the shale oil mobility of the shale reservoir to be measured at each pore scale is determined according to the component content of each mineral component to be measured and the corresponding component content-recovery rate correlation degree value, which includes: determining a first product value of the component content of each mineral component to be measured 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; and determining an average value of the shale oil mobility of the plurality of shale samples at each pore scale to obtain the shale oil mobility of the shale reservoir to be measured at each pore scale.

[0012] In the embodiment of the present application, the recovery rate of the plurality of shale samples at the plurality of pore scales is obtained, which includes: obtaining the recovery rate of the plurality of shale samples at the plurality of pore scales and a plurality of preset rotational speeds, wherein the plurality of preset rotational speeds are arranged in descending order or ascending order; and determining the component content-recovery rate correlation degree value of the component content of each mineral component to be measured in the plurality of shale samples and the recovery rate of the shale sample at each pore scale according to the component content of each mineral component to be measured in the plurality of shale samples and the recovery rate of the plurality of shale samples at each pore scale, which includes: determining the component content-recovery rate correlation degree value corresponding to each pore scale of each mineral component to be measured at each preset rotational speed according to the component content of each mineral component to be measured in the plurality of shale samples and the recovery rate of the plurality of shale samples at the plurality of pore scales and the plurality of preset rotational speeds; screening the plurality of mineral components to be measured according to the component content-recovery rate correlation degree value corresponding to each pore scale of each mineral component to be measured at each preset rotational speed to obtain a target mineral component; determining a target component content-recovery rate correlation degree value corresponding to the target mineral component according to the component content-recovery rate correlation degree value corresponding to each pore scale of the target mineral component at each preset rotational speed; and determining the shale oil mobility of the shale reservoir to be measured at each pore scale according to the component content of the plurality of mineral components to be measured and the corresponding component content-recovery rate correlation degree value, which includes: determining the shale oil mobility of the shale reservoir to be measured at each pore scale according to the component content of the target mineral component in the plurality of shale samples and the target component content-recovery rate correlation degree value corresponding to the target mineral component.

[0013] In the embodiment of the present application, the plurality of mineral components to be measured are screened according to the component content-recovery rate correlation degree values corresponding to the plurality of pore scales at the plurality of preset rotation speeds of each mineral component to be measured, to obtain the target mineral component, including: judging whether the component content-recovery rate correlation degree values corresponding to the plurality of pore scales at the plurality of preset rotation speeds of each mineral component to be measured satisfy a preset condition, wherein the preset condition is that the signs of the component content-recovery rate correlation degree values corresponding to the target preset rotation speed are the same; in the case of satisfying the preset condition, the mineral component to be measured is determined as the target mineral component.

[0014] In the embodiment of the present application, the target component content-recovery rate correlation degree value corresponding to the target mineral component is determined according to the component content-recovery rate correlation degree values corresponding to the plurality of pore scales at the plurality of preset rotation speeds of the target mineral component, including: determining a component content-recovery rate correlation degree value set according to the component content-recovery rate correlation degree values corresponding to the plurality of pore scales at the plurality of preset rotation speeds of the target mineral component, wherein the component content-recovery rate correlation degree value set includes the component content-recovery rate correlation degree value corresponding to the target preset rotation speed, and the component content-recovery rate correlation degree values corresponding to the preset rotation speeds adjacent to the target preset rotation speed and having the same sign as the component content-recovery rate correlation degree value corresponding to the target preset rotation speed; determining the mean of the plurality of component content-recovery rate correlation degree values in the component content-recovery rate correlation degree value set, to obtain the target component content-recovery rate correlation degree value corresponding to the target mineral component.

[0015] In the embodiment of the present application, the recovery rates of the plurality of shale samples at the plurality of pore scales are obtained, including: obtaining initial T2 spectra of the plurality of shale samples without centrifugal treatment and centrifugal T2 spectra of the plurality of shale samples after centrifugal treatment; obtaining initial oil phase contents of the plurality of shale samples at the plurality of pore scales according to the plurality of initial T2 spectra; obtaining centrifugal oil phase contents of the plurality of shale samples at the plurality of pore scales according to the plurality of centrifugal T2 spectra; obtaining the recovery rates of the plurality of shale samples at the plurality of pore scales according to the initial oil phase contents and the centrifugal oil phase contents, 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.

[0016] In the embodiment of the present application, the method further includes: obtaining a pore scale weight corresponding to each pore scale according to 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 the plurality of third product values to obtain the comprehensive shale oil mobility of the shale reservoir to be measured.

[0017] The second aspect of the embodiment of the present application provides a device for determining multi-scale shale oil mobility of a reservoir, comprising: a memory configured to store instructions; and a processor configured to call the instructions from the memory and capable of implementing the method for determining multi-scale shale oil mobility of a reservoir according to the above when executing the instructions.

[0018] The third aspect of the embodiment of the present application provides a machine readable storage medium, which stores instructions for causing a machine to execute the method for determining multi-scale shale oil mobility of a reservoir according to the above.

[0019] The above technical solution obtains the component content of each mineral component to be measured in a plurality of shale samples to be measured and the recovery rate of the plurality of shale samples at a plurality of pore scales, to obtain a component content-recovery rate correlation degree value of the component content of each mineral component to be measured and the recovery rate of the shale sample at each pore scale, so as to quantitatively characterize the shale oil mobility of the shale reservoir to be measured at each pore scale according to the component content of the plurality of mineral components to be measured and the corresponding component content-recovery rate correlation degree value.

[0020] Other features and advantages of the embodiments of the present application will be described in detail in the following specific implementation part. BRIEF DESCRIPTION OF DRAWINGS

[0021] The accompanying drawings are included to provide a further understanding of the embodiments of the present application, and constitute a part of the specification, and are used together with the following specific implementation to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. In the drawings:

[0022] Figure 1 The accompanying drawings are included to provide a further understanding of the embodiments of the present application, and constitute a part of the specification, and are used together with the following specific implementation to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. In the drawings:

[0023] Figure 2 The accompanying drawings are included to provide a further understanding of the embodiments of the present application, and constitute a part of the specification, and are used together with the following specific implementation to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. In the drawings: DETAILED DESCRIPTION

[0024] In order to make the purposes, technical solutions and advantages of the embodiments of the present application more clear, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. It should be understood that the specific implementation described herein is only used to illustrate and explain the embodiments of the present application, and is not used to limit the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0025] It should be noted that the acquisition, transmission, storage, use, processing, etc. of data in the technical solutions of the present application comply with relevant provisions of national laws and regulations. In the embodiments of the present application, some existing industry solutions such as software, components, models, etc. may be mentioned, which should be considered as exemplary, and the purpose is only to illustrate the feasibility of the implementation of the technical solutions of the present application, but it does not mean that the applicant has or will necessarily use the solution.

[0026] It should be noted that if the directionality indication (such as up, down, left, right, front, back, etc.) is involved in the embodiments of the present application, the directionality indication is only used to explain the relative position relationship, motion condition, etc. between components in a certain posture (as shown in the drawings), and if the certain posture changes, the directionality indication also changes accordingly.

[0027] In addition, if the description of "first", "second", etc. is involved in the embodiments of the present application, the description of "first", "second", etc. is only for the purpose of description, and cannot be understood as indicating or implying the relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include at least one of the features. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that a person skilled in the art can realize it, and when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor is it within the scope of protection claimed by the present application.

[0028] It should be noted that the acquisition, transmission, storage, use, processing, etc. of data in the technical solutions of the present application comply with relevant provisions of national laws and regulations. In the embodiments of the present application, some existing industry solutions such as software, components, models, etc. may be mentioned, which should be considered as exemplary, and the purpose is only to illustrate the feasibility of the implementation of the technical solutions of the present application, but it does not mean that the applicant has or will necessarily use the solution.

[0029] Figure 1 A flowchart for determining the interaction state of the oil reservoir fluid in an embodiment of the present application is schematically shown. As shown in Figure 1 The present application provides a method for determining the multi-scale shale oil mobility of a reservoir. The method is applied to a processor, which can include the following steps:

[0030] In step S101, the component content of a plurality of mineral components to be measured in a plurality of shale samples in a shale reservoir to be measured and the recovery rate of a plurality of shale samples at a plurality of pore scales are obtained.

[0031] In step S102, the component content-recovery correlation degree value of each mineral component is determined according to the component content of each mineral component in the plurality of shale samples and the recovery of the plurality of shale samples at each pore scale.

[0032] In step S103, the shale oil mobility of the shale reservoir to be measured at each pore scale is determined according to the component content of the plurality of mineral components and the corresponding component content-recovery correlation degree value.

[0033] It can be understood that the shale reservoir to be measured is a shale reservoir to be predicted. The shale sample is a sample selected from the shale reservoir. The mineral component to be measured is a mineral component contained in the shale sample in the shale reservoir to be predicted. In particular, the mineral component to be measured can also be the total amount of the component content of certain mineral components contained in the shale sample, such as the total amount of the component content of illite-smectite mixed layer, illite and chlorite in clay minerals. Each pore scale can include large pores and small pores. The recovery is the cumulative production of oil and gas reservoirs developed to a certain stage, and the ratio of the cumulative production of oil and gas to the original geological reserves of the oil and gas reservoir. It can be the ratio of the deviation of the initial oil phase content and the centrifugal oil phase content to the initial oil phase content, wherein the initial oil phase content and the centrifugal oil phase content are calculated by T2 spectrum. The component content-recovery correlation degree value is the correlation degree value between the component content and the recovery obtained according to the component content of each mineral component in the plurality of shale samples and the recovery of the plurality of shale samples at each pore scale. The shale oil mobility is the degree of difficulty of the flow of crude oil from the pore, fracture and other reservoir spaces to the wellbore in the shale reservoir.

[0034] Specifically, the processor obtains the component content of the plurality of mineral components in the plurality of shale samples in the shale reservoir to be measured and the recovery of the plurality of shale samples at the plurality of pore scales, performs linear regression analysis by taking the recovery of the plurality of shale samples at the plurality of pore scales as the dependent variable and the component content of the plurality of mineral components in the plurality of shale samples in the shale reservoir to be measured as the independent variable, and obtains the component content-recovery correlation degree value of each mineral component and the recovery of each shale sample at each pore scale, for example, as shown in formula (1). Figure 2As shown, the component content (i.e., the percentage of quartz) of quartz in a plurality of shale samples in the shale reservoir to be measured is taken as the independent variable, and the recovery at the small pore scale of the plurality of shale samples is taken as the dependent variable. According to a plurality of independent variables and dependent variables, linear regression analysis is performed to obtain a component content-recovery correlation degree curve of the component content of quartz and the recovery at the small pore scale of each shale sample. The slope of the component content-recovery correlation degree curve is the component content-recovery correlation degree value. Further, the processor can determine the shale oil mobility at each pore scale of the shale reservoir to be measured according to the component content of a plurality of mineral components to be measured and the corresponding component content-recovery correlation degree value.

[0035] The above technical solution obtains the component content of a plurality of mineral components to be measured in a plurality of shale samples in the shale reservoir to be measured and the recovery at a plurality of pore scales of the plurality of shale samples to obtain the component content-recovery correlation degree value of each mineral component to be measured and the recovery at each pore scale of the shale sample. Thus, the shale oil mobility at each pore scale of the shale reservoir to be measured is quantitatively characterized according to the component content of a plurality of mineral components to be measured and the corresponding component content-recovery correlation degree value.

[0036] In one embodiment, determining the shale oil mobility at each pore scale of the shale reservoir to be measured according to the component content of a plurality of mineral components to be measured and the corresponding component content-recovery correlation degree value includes: determining a first product value of the component content of each mineral component to be measured in each shale sample and the corresponding component content-recovery correlation degree value, and adding each first product value to determine the shale oil mobility at each pore scale of each shale sample; and determining an average value of the shale oil mobility at each pore scale of the plurality of shale samples to obtain the shale oil mobility at each pore scale of the shale reservoir to be measured.

[0037] It can be understood that the first product value is the product value of the component content of each mineral component to be measured in each shale sample and the corresponding component content-recovery correlation degree value.

[0038] Specifically, the processor has a plurality of component contents of a plurality of mineral components to be measured in each shale sample. After obtaining the corresponding component content-recovery correlation degree value of each mineral component, the component content of each mineral component to be measured in each shale sample is multiplied by the corresponding component content-recovery correlation degree value of each mineral component to be measured, and the multiplication results are added to obtain the shale oil mobility of each shale sample. Finally, the shale oil mobility of the plurality of shale samples is averaged to characterize the mobility of the shale reservoir to be measured.

[0039] In one embodiment, the shale oil mobility of the shale reservoir under each pore scale is determined according to the component content of each of the plurality of mineral components to be measured and the corresponding component content-recovery correlation degree value, including: obtaining the average value of the component content of each of the plurality of mineral components to be measured in the plurality of shale samples to obtain the average value of the component content of each of the plurality of mineral components to be measured; determining the second product value of the average value of the component content of each of the plurality of mineral components to be measured and the corresponding component content-recovery correlation degree value, and adding each of the second product values to obtain the shale oil mobility of the shale reservoir under each pore scale.

[0040] It can be understood that the second product value is the product value of the average value of the component content of each of the plurality of mineral components to be measured and the corresponding component content-recovery correlation degree value.

[0041] Specifically, the processor obtains the average value of the component content of the same mineral component to be measured in the plurality of shale samples, multiplies the average value of the component content of each of the plurality of mineral components to be measured and the corresponding component content-recovery correlation degree value of each of the plurality of mineral components under each pore scale, and adds the multiplication results to respectively represent the shale oil mobility of the shale reservoir under each pore scale.

[0042] In one embodiment, the recovery of the plurality of shale samples under the plurality of pore scales is obtained, including: obtaining the recovery of the plurality of shale samples under the plurality of pore scales and a plurality of preset rotation speeds, wherein the plurality of preset rotation speeds are arranged in descending order or ascending order; determining the component content-recovery correlation degree value of the component content of each of the plurality of mineral components to be measured and the recovery of the shale sample under each pore scale according to the component content of each of the plurality of mineral components to be measured in the plurality of shale samples and the recovery of the plurality of shale samples under each pore scale, including: determining the component content-recovery correlation degree value of each pore scale corresponding to each of the plurality of mineral components to be measured under each preset rotation speed according to the component content of each of the plurality of mineral components to be measured in the plurality of shale samples and the recovery of the plurality of shale samples under the plurality of pore scales and the plurality of preset rotation speeds; screening the plurality of mineral components to be measured according to the component content-recovery correlation degree value of each pore scale corresponding to each of the plurality of mineral components to be measured under each preset rotation speed to obtain a target mineral component; determining the target component content-recovery correlation degree value corresponding to the target mineral component according to the component content-recovery correlation degree value of each pore scale corresponding to the target mineral component under each preset rotation speed; and determining the shale oil mobility of the shale reservoir under each pore scale according to the component content of the plurality of mineral components to be measured and the corresponding component content-recovery correlation degree value, including: determining the shale oil mobility of the shale reservoir under each pore scale according to the component content of the target mineral component in the plurality of shale samples and the target component content-recovery correlation degree value corresponding to the target mineral component.

[0043] It can be understood that the preset rotation speed is a pre-set rotation speed. The target mineral component is a mineral component that has an impact on shale oil mobility. The target component content-recovery correlation degree value is a component content-recovery correlation degree value corresponding to the target mineral component.

[0044] Specifically, the processor can obtain the recoveries of the plurality of shale samples at the plurality of pore scales and the plurality of preset rotation speeds arranged in descending order or ascending order, so as to determine the component content-recovery correlation degree values corresponding to each pore scale at each preset rotation speed of each to-be-tested mineral component in the plurality of shale samples according to the component content of each to-be-tested mineral component and the recoveries of the plurality of shale samples at the plurality of pore scales and the plurality of preset rotation speeds, and then analyze the component content-recovery correlation degree values corresponding to each pore scale at each preset rotation speed, and screen out the mineral components that have an impact on shale oil mobility according to the component content-recovery correlation degree values corresponding to each pore scale at each preset rotation speed. After the processor screens out the mineral components that have an impact on shale oil mobility, the processor obtains the target component content-recovery correlation degree values corresponding to the mineral components that have an impact on shale oil mobility by processing the component content-recovery correlation degree values at the plurality of rotation speeds, and finally quantitatively characterizes the shale oil mobility of the to-be-tested shale reservoir at each pore scale according to each mineral component that has an impact on shale oil mobility and the target component content-recovery correlation degree values corresponding to the mineral components that have an impact on shale oil mobility. The processor obtains the recoveries of the plurality of shale samples at the plurality of pore scales and the plurality of preset rotation speeds arranged in descending order or ascending order, including the following steps: obtaining initial T2 spectra of the plurality of shale samples without centrifugal treatment, and second centrifugal T2 spectra of the plurality of shale samples after being subjected to centrifugal treatment at the plurality of preset rotation speeds arranged in descending order or ascending order; obtaining initial oil phase contents of the plurality of shale samples at each pore scale according to the plurality of initial T2 spectra; obtaining second centrifugal oil phase contents of the plurality of shale samples at each pore scale and each rotation speed according to the plurality of second centrifugal T2 spectra; and obtaining the recoveries of the plurality of shale samples at each pore scale and each rotation speed corresponding to the initial oil phase contents and the second centrifugal oil phase contents, the recovery being a ratio of a deviation between the initial oil phase content and the second centrifugal oil phase content to the initial oil phase content. Through the gradient centrifugal experiment process from low speed to high speed and the nuclear magnetic resonance detection means, the influence of different to-be-tested mineral components on shale oil mobility can be deeply studied from a statistical point of view.

[0045] In one embodiment, the target mineral component is determined according to the degree of correlation between the component content and the recovery rate of each pore size of each preset rotating speed of each to-be-tested mineral component, and the target mineral component is obtained by screening the to-be-tested mineral components, including: determining whether the degree of correlation between the component content and the recovery rate of each pore size of each preset rotating speed of each to-be-tested mineral component meets a preset condition, wherein the preset condition is that the degrees of correlation between the component content and the recovery rate of each preset rotating speed are of the same sign; and in the case of meeting the preset condition, the to-be-tested mineral component is determined as the target mineral component.

[0046] It can be understood that the target preset rotating speed is the last three adjacent preset rotating speeds.

[0047] Specifically, it is determined whether the degree of correlation between the component content and the recovery rate of each pore size of each preset rotating speed of each to-be-tested mineral component meets the condition that the degrees of correlation between the component content and the recovery rate of each preset rotating speed are of the same sign. If the degrees of correlation between the component content and the recovery rate of the last three adjacent target preset rotating speeds are of the same sign, the to-be-tested mineral component is determined as the target mineral component.

[0048] In one embodiment, the target component content-recovery rate correlation degree value corresponding to the target mineral component is determined according to the degree of correlation between the component content and the recovery rate of each pore size of each preset rotating speed of the target mineral component, including: determining a set of component content-recovery rate correlation degree values according to the degree of correlation between the component content and the recovery rate of each pore size of each preset rotating speed of the target mineral component, wherein the set of component content-recovery rate correlation degree values includes the component content-recovery rate correlation degree value corresponding to the target preset rotating speed, and the component content-recovery rate correlation degree values corresponding to the preset rotating speeds adjacent to the target preset rotating speed and having the same sign as the component content-recovery rate correlation degree value corresponding to the target preset rotating speed; and determining the mean value of the plurality of component content-recovery rate correlation degree values in the set of component content-recovery rate correlation degree values to obtain the target component content-recovery rate correlation degree value corresponding to the target mineral component.

[0049] It can be understood that the set of component content-recovery rate correlation degree values includes the component content-recovery rate correlation degree values corresponding to the last three adjacent preset rotating speeds and the component content-recovery rate correlation degree values corresponding to the preset rotating speeds adjacent to the last three adjacent preset rotating speeds and having the same sign as the component content-recovery rate correlation degree values corresponding to the last three adjacent preset rotating speeds.

[0050] Specifically, the processor determines the component content-recovery correlation degree value set according to the component content-recovery correlation degree values of the target mineral components after determining the target mineral components in each shale sample, determines the target component content-recovery correlation degree value of each target mineral component in each shale sample by averaging a plurality of component content-recovery correlation degree values in the component content-recovery correlation degree value set, and quantitatively characterizes the shale oil mobility of the shale reservoir under each pore scale according to the component content of each target mineral component in each shale sample and the target component content-recovery correlation degree value of each target mineral component.

[0051] In one embodiment, obtaining the recovery of the plurality of shale samples under the plurality of pore scales comprises: obtaining initial T2 spectra of the plurality of shale samples without centrifugal treatment and centrifugal T2 spectra of the plurality of shale samples after centrifugal treatment; obtaining initial oil phase contents of the plurality of shale samples under each pore scale according to the plurality of initial T2 spectra; obtaining centrifugal oil phase contents of the plurality of shale samples under each pore scale according to the plurality of centrifugal T2 spectra; and obtaining the recovery of the plurality of shale samples under the plurality of pore scales according to the initial oil phase contents and the centrifugal oil phase contents, wherein the recovery is a ratio of a deviation between the initial oil phase contents and the centrifugal oil phase contents to the initial oil phase contents.

[0052] It can be understood that the initial T2 spectra are T2 spectra of the plurality of shale samples without centrifugal treatment. The centrifugal T2 spectra are T2 spectra of the plurality of shale samples after centrifugal treatment. The initial oil phase contents are oil phase contents obtained according to the plurality of initial T2 spectra. The centrifugal oil phase contents are oil phase contents obtained according to the plurality of centrifugal T2 spectra. The recovery is a ratio of a deviation between the initial oil phase contents and the centrifugal oil phase contents to the initial oil phase contents.

[0053] Specifically, the processor obtains initial T2 spectra of the plurality of shale samples without centrifugal treatment and centrifugal T2 spectra of the plurality of shale samples after centrifugal treatment at a preset rotating speed, determines the demarcation points of each pore scale according to the troughs in the initial T2 spectra, and obtains the initial oil phase contents of each pore scale by integrating the areas of each pore scale in the initial T2 spectra with the demarcation points as boundaries. The processor determines the demarcation points of each pore scale according to the troughs in the centrifugal T2 spectra, and obtains the centrifugal oil phase contents of each pore scale by integrating the areas of each pore scale in the centrifugal T2 spectra with the demarcation points as boundaries. Finally, the processor obtains the recovery of the plurality of shale samples under the plurality of pore scales according to the initial oil phase contents and the centrifugal oil phase contents.

[0054] In one embodiment, 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; determining a third product value of the shale oil mobility under each pore scale and the corresponding pore scale weight, and adding the plurality of third product values to obtain the shale oil comprehensive mobility of the shale reservoir to be measured.

[0055] It can be understood that the pore scale weight is the proportion of the influence of the shale oil mobility of each pore scale on the shale oil comprehensive mobility. The third product value is the product value of the shale oil mobility under each pore scale and the corresponding pore scale weight.

[0056] Specifically, the processor determines the pore scale weight corresponding to each pore scale according to the ratio of the initial oil phase content of each pore scale, and adds the product value of the shale oil mobility under each pore scale and the corresponding pore scale weight to obtain the shale oil comprehensive mobility of the shale reservoir to be measured.

[0057] The specific steps can be as follows:

[0058] Step 1: Pretreatment of shale sample

[0059] 1. Sample drying: Place the core sample in a 60°C oven for drying for 3 days to ensure complete drying of the sample.

[0060] 2. Basic physical property test: Measure the diameter, length and mass of the core, and calculate the sample volume, as shown in Table 1.

[0061] 3. Porosity and permeability test: Perform pulse attenuation experiment using PDP-200 instrument to measure the porosity and permeability of the core.

[0062] 4. Mineral component analysis: Determine the mineral composition of the core by X-ray diffraction analysis (XRD), including the content of quartz, potassium feldspar, plagioclase, calcite, pyrite, ankerite and clay minerals, and the relative content of illite-smectite mixed layer, illite and chlorite in the clay minerals, as shown in Table 2.

[0063] Table 1: Basic physical properties and pore structure of the sample in the example

[0064]

[0065] Table 2: Mineral composition of the sample in the example

[0066]

[0067] Step 2: Oil phase saturation

[0068] The dried core sample was saturated with oil using a high-pressure saturation device. The saturation conditions were as follows: after vacuumizing for 24 hours, the pressure was increased to 30 MPa and maintained for 72 hours to ensure that the oil was fully filled into the pores; the saturated core sample was taken out, the surface residual oil was wiped off, and the weight was measured to calculate the saturation degree. The oil volume was obtained by dividing the mass of the oil by the density of the oil, and the oil phase saturation degree was obtained by dividing the oil volume by the volume of the shale sample.

[0069] Step 3: Initial NMR T2 spectrum measurement and pore structure analysis

[0070] 1. The core sample saturated with oil was measured for T2 spectrum using a nuclear magnetic resonance analyzer;

[0071] 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, echo number 6000, scan number 32; 2. Record the initial T2 spectrum as the basis for subsequent analysis; 3. Determine the dividing point of the pore scales such as large pores and small pores by T2 spectrum analysis, and calculate the volume proportion of each pore system.

[0072] Step 4: Stepwise centrifugation-NMR test

[0073] 1. Centrifugation was carried out at 400, 800, 1200, 2000, 2400 and 4000 rpm in turn, and the sample was taken out after each level of centrifugation for 30 minutes for NMR T2 spectrum measurement;

[0074] 2. Record the T2 spectrum data at each speed, and analyze the change of oil phase content in large pores and small pores; 24 data points are obtained from 4 samples at 6 different speeds, greatly increasing the reliability of statistical analysis.

[0075] Step 5: Multi-scale pore division and recovery calculation

[0076] 1. According to the bimodal distribution characteristics of the T2 spectrum, the dividing point of the pore scales such as large pores and small pores is determined;

[0077] 1. The change of oil phase volume in the pore scales such as large pores and small pores at each level of centrifugation speed was calculated, as shown in Table 3; Large pore recovery rate = (initial oil amount in large pores - final remaining oil amount in large pores) / initial oil amount in large pores x 100%. Small pore recovery rate = (initial oil amount in small pores - final remaining oil amount in small pores) / initial oil amount in small pores x 100%.

[0078] Table 3: Recovery experiment results of Example 1

[0079]

[0080] Step 6: Correlation analysis method explanation

[0081] Linear regression analysis was performed on the mobility and mineral component content at each centrifugal speed to obtain the slope m value of the correlation line y = mx + b. The average value of the slope at all speeds was calculated as the influence coefficient of the mineral component.

[0082] Step 7: Analysis of the relationship between mineral components and mobility

[0083] Based on the experimental data of 4 samples at 6 different speeds (a total of 24 data points), the influence coefficient a value of each mineral component was calculated by analyzing the correlation between the mineral component and the recovery rate at each speed. For the G shale in this example, the established quantitative relationship is as follows:

[0084] Large pore mobility influencing factor: Large pore mobility (LPM) = 0.9605 × X 石英总含量 - 0.4740 ×X 粘土总量 Small pore mobility influencing factor: Small pore 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 .

[0085] Wherein, each coefficient is the average value of the correlation slope at different speeds. It is emphasized that these coefficients are obtained for the specific samples in this example, and different regions, different types of shale reservoirs need to determine the corresponding coefficients according to the actual situation.

[0086] Example two: S shale reservoir evaluation

[0087] Step 1: Experimental material preparation, basic properties and pore structure as shown in Table 4, sample mineral components as shown in Table 5, the mineral composition characteristics of S shale sample are different from those of example one, the calcite content in some samples is higher, which shows the applicability of this method to shale with different mineral compositions. Six S shale core samples, numbered S1, S2, S3, S4, S5 and S6

[0088] Step 2: Target reservoir crude oil injection

[0089] The same experimental process and analysis method as in example one was used to conduct systematic experiments at 6 different speeds (400, 800, 1200, 2000, 2400, 4000 revolutions / minute), and the recovery rate results are shown in Table 6.

[0090] Table 4 Basic properties and pore structure of samples in example two

[0091]

[0092] Table 5 Mineral composition of samples in Example 2

[0093]

[0094] Table 6 Results of recovery experiments in Example 2

[0095]

[0096] Step 3: Advantage analysis of multi-rotation experiments

[0097] Through experiments of 6 samples at 6 different rotation speeds, 36 data points were obtained, which increased by 6 times compared with traditional single rotation experiments. Under the condition of limited samples, more experimental data points were obtained by increasing the rotation speed gradient; the gradual trend of the influence of mineral components was observed, and the mineral components that only showed correlation in a certain rotation speed range were identified.

[0098] Step 4: Comprehensive mobility evaluation and sweet spot optimization

[0099] 1. Based on the volume ratio of large pores to small pores, 10 samples were divided into different pore structure types: large pore dominant type (large pore ratio > 60%): sample 3, S3, S4. Small pore dominant type (small pore ratio > 60%): sample 2, sample 4, S2, S5. Mixed type (similar large pore and small pore ratio): sample 1, S1, S6

[0100] 2. Comprehensive mobility weighted calculation:

[0101] Comprehensive mobility (CMI) = Large pore ratio × LPM + Small pore ratio × SPM

[0102] Based on the comprehensive analysis of 10 samples, the following evaluation criteria were established: high-quality reservoir (sweet spot area): comprehensive mobility index CMI > 22%. Medium reservoir: 18% < CMI ≤ 22%. Medium reservoirs include sample 3 (23.77%), S1 (22.87%), S3 (29.68%), S4 (24.95%), S6 (22.31%), sample 1 (20.06%). Poor reservoir (non-sweet spot area): CMI ≤ 18%. Poor reservoirs include: sample 2 (15.17%), sample 4 (16.24%), S2 (15.72%), S5 (15.22%)

[0103]

[0104] Step 5: Model reliability analysis

[0105] Correlation trend analysis

[0106] ​Through the correlation analysis of 10 samples at different rotational speeds, it is found that:

[0107] The quartz content and the large pore and small pore mobility show a stable positive correlation trend at all rotational speeds;

[0108] The total amount of clay minerals and the large pore mobility show a stable negative correlation trend after the rotational speed is greater than 800 rpm; illite shows a stable positive correlation trend in small pores after the rotational speed is greater than 1200 rpm; illite-smectite mixed layer and chlorite show a stable negative correlation trend in small pores after the rotational speed is greater than 1200 rpm.

[0109] Due to the hydrophilicity and smooth surface of quartz, which is beneficial to the flow of oil phase, it shows a positive contribution in both large pores and small pores; the clay minerals mainly show a physical blocking effect in large pores, and the surface chemical properties of different types of clay play a leading role in small pores; illite is relatively oil-wet, which helps the mobility in small pores; the strong hydrophilicity of illite-smectite mixed layer and chlorite is not conducive to the flow of oil phase in small pores, therefore, the model is reliable.

[0110] In one embodiment, the embodiment of the present application provides a device for determining reservoir multi-scale shale oil mobility, comprising: a memory configured to store instructions; and a processor configured to call the instructions from the memory and capable of realizing the method for determining reservoir multi-scale shale oil mobility according to the above when executing the instructions.

[0111] In one embodiment, the embodiment of the present application provides a machine readable storage medium, which stores instructions for causing a machine to execute the method for determining reservoir multi-scale shale oil mobility according to the above.

[0112] It should also be noted that the terms "comprising", "containing", or any other variant thereof are intended to cover non-exclusive inclusion, so that processes, methods, articles or devices including a series of elements not only include those elements, but also include other elements not explicitly listed, or further include elements inherent to such processes, methods, articles or devices. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of additional identical elements in the process, method, article or device including the element.

[0113] The above is only an embodiment of the present application and is not intended to limit the present application. The present application can have various modifications and changes for those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the scope of claims of the present application.

Claims

1. A method for determining the mobility of shale oil in reservoirs at multiple scales, characterized in that, The method includes: The composition content of multiple mineral components to be tested in multiple shale samples from multiple shale reservoirs and the recovery rate of the multiple shale samples at multiple pore scales are obtained. Based on the component content of each of the tested mineral components in the plurality of shale samples and the recovery rate of the plurality of shale samples at each of the specified pore scales, the correlation value between the component content of each of the tested mineral components and the recovery rate of the shale samples at each of the specified pore scales is determined, including: Based on the component content of each of the tested mineral components in the plurality of shale samples and the recovery rate of the plurality of shale samples at multiple pore scales and multiple preset rotation speeds, determine the correlation value between the component content and recovery rate of each of the tested mineral components at each preset rotation speed and at each pore scale. Based on the correlation value between the component content and recovery rate of each of the tested mineral components at each preset rotation speed and each pore size, multiple tested mineral components are screened to obtain multiple target mineral components, including: Determine whether the correlation value of component content-recovery rate corresponding to each pore size of each of the mineral components to be tested at each preset rotation speed meets the preset conditions, wherein the preset conditions are that the signs of the correlation value of component content-recovery rate corresponding to the target preset rotation speed are the same, and the target preset rotation speed is the last three adjacent preset rotation speeds; Under the condition that the preset conditions are met, the mineral component to be tested is determined to be the target mineral component; Based on the correlation value between the component content and recovery rate of the target mineral component at each pore size under each preset rotation speed, the correlation value between the target component content and recovery rate is determined, including: Based on the correlation values ​​of component content and recovery rate corresponding to each pore size of the target mineral component at each preset rotation speed, a set of correlation values ​​of component content and recovery rate is determined. The set of correlation values ​​of component content and recovery rate includes the correlation values ​​of component content and recovery rate corresponding to the target preset rotation speed, and the correlation values ​​of component content and recovery rate corresponding to preset rotation speeds that have the same sign as the correlation values ​​of component content and recovery rate corresponding to the target preset rotation speed and are adjacent to the target preset rotation speed. Determine the mean of multiple component content-recovery rate correlation values ​​within the set of component content-recovery rate correlation values ​​to obtain the target component content-recovery rate correlation value corresponding to the target mineral component; Based on the component content of the multiple tested mineral components and the corresponding correlation values ​​between the component content and the recovery rate, the shale oil mobility of the tested shale reservoir at each of the specified pore scales is determined, including: Based on the component content of the target mineral components in multiple shale samples and the correlation value between the target component content and the recovery rate, the shale oil mobility of the shale reservoir under test at each pore scale is determined.

2. The method according to claim 1, characterized in that, The determination of shale oil mobility of the shale reservoir at each pore scale based on the component content of the multiple tested mineral components and the corresponding component content-recovery correlation value includes: The first product value of the component content of each target mineral component in each shale sample and the corresponding correlation value of the component content-recovery rate is determined, and the first product values ​​are added together to determine the shale oil mobility of each shale sample at each pore scale. The average value of shale oil mobility of multiple shale samples at each pore scale is determined to obtain the shale oil mobility of the shale reservoir under test at each pore scale.

3. The method according to claim 1, characterized in that, The determination of shale oil mobility of the shale reservoir at each pore scale based on the component content of the multiple tested mineral components and the corresponding component content-recovery correlation value includes: The average content of each target mineral component in multiple shale samples is calculated to obtain the average content of each of the tested mineral components. The average content of each of the tested mineral components is determined, and the second product value of the corresponding correlation between the component content and the recovery rate is determined. The second product values ​​are then added together to obtain the shale oil mobility of the tested shale reservoir at each of the pore scales.

4. The method according to claim 1, characterized in that, The process of obtaining the recovery rate of multiple shale samples at multiple pore scales includes: The recovery rates of multiple shale samples at multiple pore sizes and multiple preset rotation speeds are obtained, wherein the multiple preset rotation speeds are arranged in descending or ascending order.

5. The method according to claim 1, characterized in that, The process of obtaining the recovery rate of multiple shale samples at multiple pore scales includes: The initial T2 spectra of the plurality of shale samples before centrifugation and the centrifuged T2 spectra of the plurality of shale samples after centrifugation were obtained. Based on the initial T2 spectra, the initial oil phase content of the shale samples at each of the pore scales was obtained; Based on the centrifuged T2 spectra, the oil phase content of the shale samples at each of the pore scales was obtained. Based on the initial oil phase content and the centrifuged oil phase content, the recovery rate of the multiple shale samples at multiple pore scales is obtained, 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.

6. The method according to claim 4, characterized in that, The method further includes: Based on the initial oil phase content of each pore size, the pore size weight corresponding to each pore size is obtained; The third product value of the shale oil mobility at each pore scale and the corresponding pore scale weight is determined, and multiple third product values ​​are added together to obtain the comprehensive shale oil mobility of the shale reservoir to be tested.

7. An apparatus for determining the mobility of shale oil reservoirs at multiple scales, characterized in that, include: The memory is configured to store instructions; as well as The processor is configured to retrieve the instructions from the memory and, when executing the instructions, to implement the method for determining the mobility of shale oil in a reservoir according to any one of claims 1 to 6.

8. A machine-readable storage medium, characterized in that, The machine-readable storage medium stores instructions for causing the machine to perform the method for determining the mobility of shale oil in a reservoir according to any one of claims 1 to 6.

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