Method and device for testing shale wicking capacity

Abstract

The embodiment of the present application discloses a shale infiltration capacity testing method and device. The method comprises the following steps: determining the initial core matrix peak area and the initial micro-fracture peak area of a core sample collected from a target shale reservoir section; determining a test temperature and a test confining pressure, and determining the total amount of infiltration, the target core matrix peak area and the target micro-fracture peak area of the core sample at a target time under the condition that the core sample is at the test temperature and the test confining pressure; and determining the matrix dynamic infiltration amount and the micro-fracture dynamic infiltration amount of the core sample according to the initial core matrix peak area, the initial micro-fracture peak area, the total amount of infiltration, the target core matrix peak area and the target micro-fracture peak area. The technical scheme of the embodiment of the present application realizes the testing of the infiltration capacity of the matrix and the micro-fracture of shale.

Description

Technical Field

[0001] This invention relates to the field of oil and gas technology, and in particular to a method and apparatus for testing the permeability of shale. Background Technology

[0002] Compared to conventional sandstone reservoirs, shale typically develops multi-scale micro- and nano-pores. Its matrix and microfracture pores are the main storage spaces for shale, and the fluid permeation capacity in the shale matrix and microfracture pores can reflect the fluid flow capacity, which has important guiding significance for finding "sweet spots" in oil exploration and development.

[0003] Currently, the use of tens of thousands of cubic meters of water-based fracturing fluid to enter the formation and achieve multi-stage, multi-cluster volumetric fracturing stimulation in horizontal wells is a key technology for large-scale shale gas development. The large-scale use of water-based fracturing fluid and the complex fracture network system make the interaction between shale and fracturing fluid more prominent and profound. Unlike conventional sandstone reservoirs, shale exhibits significant differences in reservoir characteristics, fracturing technology, and fracture area. Shale gas wells show distinctly different post-fracturing flowback characteristics. Numerous field statistics show an unusual phenomenon of "low flowback rate and high production capacity" in shale gas wells. To explain this unique flowback phenomenon, it is necessary to first study the shale water phase adsorption mechanism. The shale water phase adsorption capacity directly affects the flowback rate of shale gas wells, and can be indirectly used to predict and evaluate shale gas well production capacity. The shale water phase adsorption capacity is jointly determined by the shale matrix and microfractures.

[0004] However, due to the presence of multi-component minerals in shale, the physical and chemical interactions between shale and the aqueous phase, and the dynamic changes in the shale matrix and microfracture pores, testing the water absorption capacity of shale is extremely difficult. Currently, there is no method for testing the water absorption capacity of shale matrix and microfractures, which needs to be addressed. Summary of the Invention

[0005] This invention provides a method and apparatus for testing the permeability of shale, enabling the testing of the permeability of the shale matrix and microfractures.

[0006] According to one aspect of the present invention, a method for testing the permeability of shale is provided, which may include:

[0007] For core samples collected from the target shale reservoir section, the initial core matrix peak area and the initial microfracture peak area of ​​the core samples were determined.

[0008] Determine the test temperature and test confining pressure, and under the test temperature and test confining pressure conditions, determine the total amount of permeation of the core sample at the target time, the target core matrix peak area, and the target microfracture peak area.

[0009] Based on the initial core matrix peak area, initial microfracture peak area, total permeation, target core matrix peak area, and target microfracture peak area, determine the dynamic permeation of the core sample matrix and the dynamic permeation of the microfracture.

[0010] According to another aspect of the present invention, a shale permeability testing device is provided, which may include:

[0011] The initial microfracture peak area determination module is used to determine the initial core matrix peak area and initial microfracture peak area of ​​core samples obtained from the target shale reservoir section.

[0012] The target microfracture peak area determination module is used to determine the test temperature and test confining pressure, and under the test temperature and test confining pressure, determine the total permeation of the core sample at the target time, the target core matrix peak area, and the target microfracture peak area.

[0013] The module for determining the dynamic permeation of microfractures is used to determine the dynamic permeation of the matrix and the dynamic permeation of microfractures in a core sample based on the initial core matrix peak area, the initial microfracture peak area, the total permeation, the target core matrix peak area, and the target microfracture peak area.

[0014] The technical solution of this invention, for core samples collected from a target shale reservoir section, determines the initial core matrix peak area and the initial microfracture peak area of ​​the core sample; determines the test temperature and test confining pressure, and under the test temperature and test confining pressure, determines the total permeation of the core sample at a target time, the target core matrix peak area, and the target microfracture peak area; based on the initial core matrix peak area, the initial microfracture peak area, the total permeation, the target core matrix peak area, and the target microfracture peak area, determines the dynamic permeation of the core sample's matrix and the dynamic permeation of its microfractures. This technical solution, by using the initial core matrix peak area, the initial microfracture peak area, the total permeation, the target core matrix peak area, and the target microfracture peak area as determining factors for the dynamic permeation of the core sample's matrix and the dynamic permeation of its microfractures, achieves the testing of the permeation capacity of the shale matrix and its microfractures.

[0015] It should be understood that the description in this section is not intended to identify key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a flowchart of a shale permeability testing method according to an embodiment of the present invention;

[0018] Figure 2 This is a schematic diagram of real-time testing of shale permeability in a shale permeability testing method provided by an embodiment of the present invention;

[0019] Figure 3 This is a schematic diagram of a target T2 spectrum curve in a shale permeability testing method provided by an embodiment of the present invention;

[0020] Figure 4 This is a schematic diagram of another target T2 spectrum curve in a shale permeability testing method provided according to an embodiment of the present invention;

[0021] Figure 5 This is a schematic diagram of an initial T2 spectrum curve in a shale permeability testing method provided by an embodiment of the present invention;

[0022] Figure 6 This is a flowchart of another shale permeability testing method provided by an embodiment of the present invention;

[0023] Figure 7 This is a flowchart of another shale permeability testing method provided by an embodiment of the present invention;

[0024] Figure 8 This is a structural diagram of an optional example of a shale permeability testing method provided by an embodiment of the present invention;

[0025] Figure 9 This is a structural block diagram of a shale permeability testing device according to an embodiment of the present invention. Detailed Implementation

[0026] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0027] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. The same applies to "target," "original," etc., and will not be repeated here. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0028] Figure 1 This is a flowchart of a shale permeability testing method provided in an embodiment of the present invention. This embodiment is applicable to shale permeability testing. The method can be executed by the shale permeability testing device provided in this embodiment of the invention. This device can be implemented by software and / or hardware, and can be integrated into an electronic device, which can be various user terminals or servers.

[0029] See Figure 1 The method of this invention specifically includes the following steps:

[0030] S110. For core samples collected from the target shale reservoir section, determine the initial core matrix peak area and the initial microfracture peak area of ​​the core samples.

[0031] The target shale reservoir section is the shale reservoir section for which the permeability and absorption capacity needs to be tested. The initial core matrix peak area can be represented as the total hydrogen atom signal value of the matrix portion in the untested core sample. The initial microfracture peak area can be represented as the total hydrogen atom signal value of the microfracture portion in the untested core sample.

[0032] In this embodiment of the invention, shale can be collected from the target shale formation and prepared into core samples for testing the permeability of the target shale reservoir. For example, a target collection well capable of collecting shale from the target shale reservoir can be used to collect downhole core samples from the target shale reservoir, which can then be prepared into core samples of a predetermined size. It should be noted that after collecting the core samples, they can be dried to constant weight to improve the accuracy of the shale permeability test.

[0033] For example, well numbered QC-1 can be used as the target well. The actual downhole core of the middle part of the target shale reservoir section at 2000-2060m of the target well can be collected. The downhole core can be made into a standard core with a diameter of 2.5cm and a length of 5cm. The standard core can be placed in a 100℃ oven and dried to constant weight. The standard core dried to constant weight can be used as a core sample.

[0034] In this embodiment of the invention, after collecting the core sample, the permeation area of ​​the core sample can be calculated based on the end face dimensions of the core sample. For example, the permeation area of ​​a core sample with a diameter of 2.5 cm and a length of 5 cm may be 4.9 cm². 2 The test measurement length can also be determined based on the length of the core sample. For example, the test measurement length of a core sample with a diameter of 2.5 cm and a length of 5 cm may be 5 cm.

[0035] For example, for core samples collected from a target shale reservoir section, the T2 spectrum curve of the untested core sample can be obtained by scanning it with a nuclear magnetic resonance (NMR) device. Based on the T2 spectrum curve, the initial core matrix peak area and the initial microfracture peak area of ​​the core sample can be determined. For example, the initial core matrix peak area can be determined to be 5860, and the initial microfracture peak area to be 242. In this embodiment of the invention, the method for determining the initial core matrix peak area and the initial microfracture peak area of ​​the core sample is not specifically limited.

[0036] S120. Determine the test temperature and test confining pressure, and under the conditions of the test temperature and test confining pressure, determine the total amount of permeation of the core sample at the target time, the target core matrix peak area, and the target microfracture peak area.

[0037] The test temperature is the temperature required to heat the core sample during testing. The test confining pressure is the confining pressure required to apply to the core sample during testing. The total permeate is the total amount of self-absorbed fluids such as fracturing fluid absorbed by the core sample. The target core matrix peak area can be represented as the total hydrogen atom signal value of the matrix portion of the core sample at the target time. The target microfracture peak area can be represented as the total hydrogen atom signal value of the microfracture portion of the core sample at the target time.

[0038] In this embodiment of the invention, the test temperature can be determined based on a preset temperature, and the test confining pressure can be determined based on a preset confining pressure; alternatively, the test temperature and test confining pressure can be determined based on the acquisition well parameters of the target acquisition well. In this embodiment of the invention, no specific limitation is made on the method of determining the test temperature and test confining pressure. The acquisition well parameters are parameters related to the target acquisition well and / or the area where the target acquisition well is located.

[0039] In this embodiment of the invention, the test temperature and test confining pressure can be determined, and the core sample can be tested experimentally based on the test temperature and test confining pressure; under the test temperature and test confining pressure, the total amount of permeation of the core sample at the target time, the target core matrix peak area, and the target microfracture peak area can be determined.

[0040] It is important to note that the target time can be the time when the core sample is under the test temperature and confining pressure; the target time can be a target moment, such as a preset moment or a moment after a preset time interval. For example, if the preset time interval is 0.5 hours, the target moment could be 0.5 hours after the preset time; the target time can also be a target period, such as a preset period or a period corresponding to a preset duration after the preset time. For example, if the preset duration is 0.5 hours, the target period could be 0.5 hours after the preset time; the number of target times can be one or multiple, for example, the target time could be the moment at each preset time interval after the preset time. The preset time can be the time at the start of the test, or it can be understood as the time when the core sample begins to absorb fracturing fluid.

[0041] In this embodiment of the invention, no specific limitation is made on the method of determining the total amount of permeation of the core sample at the target time, the peak area of ​​the target core matrix, and the peak area of ​​the target microfracture.

[0042] S130. Based on the initial core matrix peak area, initial microfracture peak area, total permeation, target core matrix peak area, and target microfracture peak area, determine the dynamic permeation of the core sample matrix and the dynamic permeation of the microfracture.

[0043] Among them, the dynamic permeation of the matrix is ​​the amount of self-absorbed liquids such as fracturing fluid absorbed by the matrix portion of the core sample at the target time. The dynamic permeation of the microfracture is the amount of self-absorbed liquids such as fracturing fluid absorbed by the microfracture portion of the core sample at the target time.

[0044] In this embodiment of the invention, no specific limitation is made on the method of determining the dynamic permeation of the matrix and the dynamic permeation of the microfracture of the core sample based on the initial core matrix peak area, the initial microfracture peak area, the total permeation, the target core matrix peak area, and the target microfracture peak area.

[0045] For example, when the target time is the time at 0.5-hour intervals after a preset time, i.e., when there are multiple target times, the dynamic permeation of the matrix and the dynamic permeation of the microfracture in the core sample corresponding to each target time can be determined based on the initial core matrix peak area, initial microfracture peak area, total permeation, target core matrix peak area, and target microfracture peak area. This allows us to obtain the dynamic changes of the matrix dynamic permeation and the microfracture dynamic permeation over time, which can facilitate the improvement of the accuracy of shale production capacity prediction based on the dynamic matrix dynamic permeation and the dynamic microfracture dynamic permeation of the core sample.

[0046] In an embodiment of the present invention, see Figure 2 The target time can also be the real-time time after the core sample reaches the test temperature and test confining pressure. That is, under the test temperature and test confining pressure, the total permeation of the core sample, the target core matrix peak area, and the target microfracture peak area can be determined in real time. Based on the initial core matrix peak area, the initial microfracture peak area, the total permeation, the target core matrix peak area, and the target microfracture peak area, the dynamic permeation of the core sample matrix and the dynamic permeation of the microfractures can be determined in real time. This enables real-time online testing of the permeation capacity of the shale matrix and microfractures, allowing field engineers to predict production capacity and evaluate sweet spots based on the shale permeation capacity obtained from the above tests.

[0047] In this embodiment of the invention, the dynamic permeation of the matrix and the dynamic permeation of the microfractures in the core sample can be determined, thereby enabling quantitative characterization of shale permeability and clarifying the contribution of different pore types to shale permeability. This solves the problem that conventional spontaneous permeation test methods cannot simultaneously test the dynamic permeation of the matrix and the dynamic permeation of the microfractures, providing a new experimental research method for studying shale permeability testing.

[0048] The technical solution of this invention, for core samples collected from a target shale reservoir section, determines the initial core matrix peak area and the initial microfracture peak area of ​​the core sample; determines the test temperature and test confining pressure, and under the test temperature and test confining pressure, determines the total permeation of the core sample at a target time, the target core matrix peak area, and the target microfracture peak area; based on the initial core matrix peak area, the initial microfracture peak area, the total permeation, the target core matrix peak area, and the target microfracture peak area, determines the dynamic permeation of the core sample's matrix and the dynamic permeation of its microfractures. This technical solution, by using the initial core matrix peak area, the initial microfracture peak area, the total permeation, the target core matrix peak area, and the target microfracture peak area as determining factors for the dynamic permeation of the core sample's matrix and the dynamic permeation of its microfractures, achieves the testing of the permeation capacity of the shale matrix and its microfractures.

[0049] An optional technical solution involves determining the target core matrix peak area and the target microfracture peak area of ​​the core sample at a target time under test temperature and test confining pressure conditions. This includes: determining the target T2 spectrum curve of the core sample at a target time under test temperature and test confining pressure conditions; and determining the target core matrix peak area and the target microfracture peak area of ​​the core sample at a target time based on the target T2 spectrum curve.

[0050] The target T2 spectrum curve is the T2 spectrum curve of the core sample obtained by scanning the core sample with a nuclear magnetic resonance device at the target time.

[0051] In this embodiment of the invention, the core sample can be scanned using a nuclear magnetic resonance (NMR) device at a target time under test temperature and test confining pressure to obtain the target T2 spectrum curve of the core sample at the target time; the peak area corresponding to each peak in the target T2 spectrum curve is determined; the leftmost first peak in the target T2 spectrum curve is taken as the peak corresponding to the matrix part of the core sample, and the other peaks in the target T2 spectrum curve other than the leftmost first peak are taken as the peaks corresponding to the microfracture part of the core sample; the peak area of ​​the peak corresponding to the matrix part is taken as the target core matrix peak area of ​​the core sample, and the peak area of ​​the peak corresponding to the microfracture part is taken as the target microfracture peak area of ​​the core sample.

[0052] For example, see Figure 3 and Figure 4 The system can scan core samples using nuclear magnetic resonance (NMR) equipment at target times of 5 hours and 10 hours after preset times, and under test temperature and confining pressure conditions, to obtain target T2 spectrum curves for each target time. For each target T2 spectrum curve at each target time, the peak area of ​​each peak in the target T2 spectrum curve is determined. The leftmost peak in the target T2 spectrum curve is taken as the peak corresponding to the matrix portion of the core sample, and the other peaks in the target T2 spectrum curve are taken as the peaks corresponding to the microfracture portion of the core sample. The peak area of ​​the peak corresponding to the matrix portion is taken as the target core matrix peak area of ​​the core sample, and the peak area of ​​the peak corresponding to the microfracture portion is taken as the target microfracture peak area of ​​the core sample.

[0053] In this embodiment of the invention, by determining the target core matrix peak area and target microfracture peak area of ​​the core sample at the target time based on the target T2 spectrum curve of the core sample at the target time, the accuracy of the obtained target core matrix peak area and target microfracture peak area can be improved.

[0054] Another optional technical solution is to determine the initial core matrix peak area and the initial microfracture peak area of ​​the core sample, including: determining the initial T2 spectrum curve of the core sample, and determining the peak area corresponding to at least one peak in the initial T2 spectrum curve; and determining the initial core matrix peak area and the initial microfracture peak area of ​​the core sample based on the peak area corresponding to at least one peak.

[0055] The initial T2 spectrum curve is obtained by scanning the untested core sample with a nuclear magnetic resonance device.

[0056] In an embodiment of the present invention, see Figure 5 The initial T2 spectrum curves of untested core samples were obtained by scanning them with nuclear magnetic resonance (NMR) equipment. The peak areas corresponding to each peak in the initial T2 spectrum curves were determined. The leftmost peak in the initial T2 spectrum curve was taken as the peak corresponding to the matrix portion of the core sample, and the other peaks in the initial T2 spectrum curves, excluding the leftmost peak, were taken as the peaks corresponding to the microfracture portion of the core sample. The peak areas corresponding to the matrix portion were taken as the initial core matrix peak areas of the core sample, and the peak areas corresponding to the microfracture portion were taken as the initial microfracture peak areas of the core sample.

[0057] In this embodiment of the invention, the initial core matrix peak area and initial microfracture peak area of ​​the core sample are determined by using the initial T2 spectrum curve of the core sample, which can improve the accuracy of the obtained initial core matrix peak area and initial microfracture peak area.

[0058] Another optional technical solution involves determining the dynamic permeation of the matrix and the dynamic permeation of the microfractures in the core sample based on the initial matrix peak area, the initial microfracture peak area, the total permeation, the target matrix peak area, and the target microfracture peak area. This includes: determining the matrix permeation peak area ratio based on the initial matrix peak area, the initial microfracture peak area, the target matrix peak area, and the target microfracture peak area; determining the microfracture permeation peak area ratio based on the initial matrix peak area, the initial microfracture peak area, the target matrix peak area, and the target microfracture peak area; determining the dynamic permeation of the matrix in the core sample based on the total permeation and the matrix permeation peak area ratio; and determining the dynamic permeation of the microfractures in the core sample based on the total permeation and the microfracture permeation peak area ratio.

[0059] The matrix permeation peak area ratio characterizes the proportion of the matrix portion of the core sample corresponding to the area change of the matrix peak area before and after testing. The microfracture permeation peak area ratio characterizes the proportion of the microfracture portion of the core sample corresponding to the area change of the microfracture peak area before and after testing.

[0060] In this embodiment of the invention, the ratio of matrix permeation peak area can be determined based on the initial core matrix peak area, the initial microfracture peak area, the target core matrix peak area, and the target microfracture peak area. For example, it can be determined using a formula. Determine the proportion of matrix permeation peak areas. Among them, P m The proportion of matrix permeation peak area is dimensionless; S m S represents the area of ​​the dimensionless target core matrix peak; f S represents the dimensionless target microcrack peak area; mo S represents the area of ​​the initial core matrix peak, which is dimensionless; fo The initial microcrack peak area is dimensionless.

[0061] In this embodiment of the invention, the ratio of microfracture permeation peak area can be determined based on the initial core matrix peak area, the initial microfracture peak area, the target core matrix peak area, and the target microfracture peak area. Referring to the above example, this can be achieved, for instance, through the formula... Determine the area ratio of microcrack infiltration peaks. Among them, P f This represents the proportion of the area of ​​the microcrack infiltration peaks, which is dimensionless.

[0062] In this embodiment of the invention, the dynamic matrix permeation of the core sample can be determined based on the ratio of total permeation to matrix permeation peak area. Combining the above examples, for instance, it can be determined using formula V. m =V·P m Determine the dynamic matrix permeation of the core sample, V m The larger the value, the stronger the matrix absorption capacity of the core sample. Among them, V... m This represents the dynamic absorption of the matrix, expressed in cm³. 3 V represents the total amount of osmosis, in cm³. 3 .

[0063] In this embodiment of the invention, the dynamic permeation amount of the core sample can be determined based on the ratio of the total permeation amount to the permeation peak area of ​​the microfracture. Combining the above examples, for instance, it can be determined using formula V. f =V·P f Determine the dynamic matrix permeation of the core sample, V f The larger the value, the stronger the microfracture absorption capacity of the core sample. Among them, V... f This refers to the dynamic absorption rate of microcracks, expressed in cm³. 3 .

[0064] In this embodiment of the invention, the dynamic permeation of the matrix and the dynamic permeation of the microfractures of the core sample can be determined based on the initial core matrix peak area, the initial microfracture peak area, the total permeation, the target core matrix peak area, and the target microfracture peak area, thus achieving a more accurate test of the permeation capacity of the shale matrix and microfractures.

[0065] Figure 6 This is a flowchart of another shale permeability testing method provided in this embodiment of the invention. This embodiment is an optimization based on the above-described technical solutions. In this embodiment, optionally, determining the test temperature and test confining pressure includes: obtaining the sampling well parameters of the target sampling well, wherein the target sampling well is the sampling well from which core samples were collected; and determining the test temperature and test confining pressure based on the sampling well parameters. The explanations of terms that are the same as or corresponding to those in the above embodiments are not repeated here.

[0066] See Figure 6 The method in this embodiment may specifically include the following steps:

[0067] S210. For core samples collected from the target shale reservoir section, determine the initial core matrix peak area and the initial microfracture peak area of ​​the core samples.

[0068] S220. Obtain the acquisition well parameters of the target acquisition well, where the target acquisition well is the acquisition well from which the core sample was obtained.

[0069] In this embodiment of the invention, the acquisition well parameters may include, for example, the core formation temperature, formation pore pressure, maximum horizontal principal stress, minimum horizontal principal stress, vertical stress, and / or effective stress coefficient of the target acquisition well. For instance, the core formation temperature of the target acquisition well may be 60°C, the formation pore pressure may be 20 MPa, the maximum horizontal principal stress may be 36 MPa, the minimum horizontal principal stress may be 28 MPa, the vertical stress may be 30 MPa, and the effective stress coefficient may be 0.5. Here, the core formation temperature can be understood as the formation temperature of the target shale reservoir section from which the core sample was acquired; the formation pore pressure can be understood as the formation pore pressure of the target shale reservoir section; the maximum horizontal principal stress, minimum horizontal principal stress, vertical stress, and effective stress coefficient can also be the maximum horizontal principal stress, minimum horizontal principal stress, vertical stress, and effective stress coefficient of the target shale reservoir section, respectively; and the vertical stress can also be understood as vertical stress.

[0070] It should be noted that the parameters of the acquisition well can be determined by performing well logging operations on the target acquisition well and by considering the rock mechanics parameters of the area where the target acquisition well is located.

[0071] S230. Determine the test temperature and test confining pressure based on the collected well parameters.

[0072] In this embodiment of the invention, no specific limitation is made on the method of determining the test temperature and test confining pressure based on the well parameters.

[0073] S240. Under the conditions of test temperature and test confining pressure, determine the total amount of permeation of the core sample at the target time, the peak area of ​​the target core matrix, and the peak area of ​​the target microfracture.

[0074] S250. Based on the initial core matrix peak area, initial microfracture peak area, total permeation, target core matrix peak area, and target microfracture peak area, determine the dynamic permeation of the core sample matrix and the dynamic permeation of the microfracture.

[0075] In this embodiment of the invention, before determining the test temperature and confining pressure, the porosity and permeability of the core sample can be tested using an automatic helium porosity analyzer and an ultra-low permeability analyzer, respectively. For example, the porosity of the core sample can be tested to be 6.8%, and the permeability to be 0.012 mD. If it is necessary to test the permeability of other shale in the future, and if the well parameters, porosity, and permeability of the other shale are consistent with or similar to those of the core sample, the matrix dynamic permeability and microfracture dynamic permeability of the core sample can be directly used as the matrix dynamic permeability and microfracture dynamic permeability of other shale, thereby saving resources for testing the permeability of shale.

[0076] The technical solution of this invention involves obtaining the parameters of a target acquisition well, where the target acquisition well is the acquisition well from which core samples were collected; and determining the test temperature and test confining pressure based on the acquisition well parameters. This technical solution, by determining the test temperature and test confining pressure based on the acquisition well parameters, allows factors related to the target acquisition well to be considered as influencing factors in shale permeability testing. This solves the problem of conventional spontaneous permeability testing methods being unable to simultaneously consider the influence of multiple factors. The testing method is simple and feasible to operate, reduces testing costs, and the test results are more consistent with actual conditions, thereby improving the accuracy of shale permeability testing.

[0077] An optional technical solution involves obtaining well parameters including the core formation temperature of the target well, and at least one of the formation pore pressure, maximum horizontal principal stress, minimum horizontal principal stress, vertical stress, and effective stress coefficient of the target well; determining the test temperature and test confining pressure based on the well parameters, including: using the core formation temperature as the test temperature; and determining the test confining pressure based on at least one of the formation pore pressure, maximum horizontal principal stress, minimum horizontal principal stress, vertical stress, and effective stress coefficient.

[0078] In this embodiment of the invention, the core formation temperature can be used as the test temperature. For example, when the core formation temperature is 60°C, the test temperature is 60°C. The test confining pressure can be determined based on at least one of the formation pore pressure, maximum horizontal principal stress, minimum horizontal principal stress, vertical stress, and effective stress coefficient. This makes the test temperature for shale permeability testing more closely match the actual formation temperature and the test confining pressure for shale permeability testing more closely match the actual formation confining pressure, thereby further improving the accuracy of shale permeability testing.

[0079] Based on the above scheme, another optional technical solution involves determining the test confining pressure based on at least one of formation pore pressure, maximum horizontal principal stress, minimum horizontal principal stress, vertical stress, and effective stress coefficient. This includes: determining the vertical effective stress based on at least one of vertical stress, effective stress coefficient, and formation pore pressure; determining the maximum horizontal effective principal stress based on at least one of maximum horizontal principal stress, effective stress coefficient, and formation pore pressure; determining the minimum horizontal effective principal stress based on at least one of minimum horizontal principal stress, effective stress coefficient, and formation pore pressure; and determining the test confining pressure based on the vertical effective stress, minimum horizontal effective principal stress, and maximum horizontal effective principal stress.

[0080] The vertical effective stress can be understood as the effective stress in the vertical direction of the target shale reservoir section. The maximum horizontal effective principal stress can be understood as the maximum effective principal stress in the horizontal direction of the target shale reservoir section. The minimum horizontal effective principal stress can be understood as the minimum effective principal stress in the horizontal direction of the target shale reservoir section.

[0081] In this embodiment of the invention, the effective vertical stress can be determined based on the vertical stress, effective stress coefficient, and formation pore pressure; the maximum effective horizontal principal stress can be determined based on the maximum horizontal principal stress, effective stress coefficient, and formation pore pressure; the minimum effective horizontal principal stress can be determined based on the minimum horizontal principal stress, effective stress coefficient, and formation pore pressure; and the test confining pressure can be determined based on the effective vertical stress, minimum effective horizontal principal stress, and maximum effective horizontal principal stress. For example, it can be determined using the formula σ. z '=σ z -αP p The effective vertical stress can be determined using the formula σ. H '=σ H -αP p The maximum effective horizontal principal stress can be determined using the formula σ. h '=σ h -αP p The minimum effective principal stress can be determined using the formula σ. c =(σ z '+σ H '+σh ') / 3 determines the test confining pressure. Combining this with the example of the acquired well parameters mentioned above, the effective vertical stress can be calculated to be 20 MPa, the maximum effective horizontal principal stress to be 16 MPa, the minimum effective horizontal principal stress to be 18 MPa, and the test confining pressure to be 18 MPa. Where σ z ' is the effective vertical stress, in MPa; σ z P represents vertical stress, in MPa; α is the effective stress coefficient, which can be a decimal; p Formation pore pressure, in MPa; σ H ' is the maximum effective horizontal principal stress, in MPa; σ H σ represents the maximum horizontal principal stress, in MPa. h ' is the minimum effective principal stress at the horizontal level, in MPa; σ h σ represents the minimum horizontal principal stress, in MPa. c For testing confining pressure, the unit is MPa.

[0082] In this embodiment of the invention, the method for determining the effective vertical stress based on at least one of vertical stress, effective stress coefficient, and formation pore pressure is not specifically limited; the method for determining the maximum effective horizontal principal stress based on at least one of maximum horizontal principal stress, effective stress coefficient, and formation pore pressure is not specifically limited; the method for determining the minimum effective horizontal principal stress based on at least one of minimum horizontal principal stress, effective stress coefficient, and formation pore pressure is not specifically limited; and the method for determining the test confining pressure based on the effective vertical stress, minimum effective horizontal principal stress, and maximum effective horizontal principal stress is not specifically limited.

[0083] In this embodiment of the invention, the test confining pressure can be determined based on at least one of formation pore pressure, maximum horizontal principal stress, minimum horizontal principal stress, vertical stress, and effective stress coefficient, thereby improving the accuracy of the obtained test confining pressure.

[0084] Figure 7 This is a flowchart of another shale permeability testing method provided in this embodiment of the invention. This embodiment is based on and optimized from the above-mentioned technical solutions. In this embodiment, optionally, determining the total permeation of the core sample at a target time under the conditions of test temperature and test confining pressure includes: determining the initial liquid level of the fracturing fluid in the metering tube connected to the core sample at the initial time, under the conditions of test temperature and test confining pressure; and determining the total permeation of the core sample at the target time based on the initial liquid level. The explanations of terms that are the same as or corresponding to those in the above embodiments are not repeated here.

[0085] See Figure 7The method in this embodiment may specifically include the following steps:

[0086] S310. For core samples collected from the target shale reservoir section, determine the initial core matrix peak area and the initial microfracture peak area of ​​the core samples.

[0087] S320. Determine the test temperature and test confining pressure, and under the conditions of the core sample being at the test temperature and test confining pressure, determine the initial liquid level height of the fracturing fluid in the metering tube connected to the core sample at the initial time.

[0088] The initial liquid level can be understood as the height of the fracturing fluid in the metering tube at the initial time; the initial liquid level can also be understood as the height of the fracturing fluid in the metering tube before it is absorbed by the core sample.

[0089] In this embodiment of the invention, the initial time can be the time when the fracturing fluid has been placed into the metering tube, but the core sample has not yet begun to absorb the fracturing fluid. For example, the initial time can be the time when the fracturing fluid has been placed into the metering tube and is in contact with the core sample, but the core sample has not yet begun to absorb the fracturing fluid; another example is any time when the fracturing fluid has been placed into the metering tube and there is an interval between the fracturing fluid and the core sample, preventing direct contact.

[0090] For example, a core sample can be tested using a permeability testing device. This device can include at least a core holder for holding the core sample, a metering tube connected to the core holder that allows fracturing fluid in the metering tube to contact the core sample, a confining pressure pump, and a heating chamber. The core sample can be loaded into the core holder, and the heating chamber can heat both the core sample and the core holder to the test temperature. The confining pressure pump can then apply pressure to the test confining pressure. Under the conditions of the core sample at the test temperature and test confining pressure, the initial fluid level in the metering tube connected to the core sample can be determined at an initial time.

[0091] S330. Based on the initial liquid level, determine the total amount of permeation of the core sample at the target time.

[0092] Based on the above example, for instance, after determining the initial liquid level of the fracturing fluid in the metering tube connected to the core sample at an initial time, the core sample can be made to begin absorbing the fracturing fluid. The liquid level of the fracturing fluid at a target time can be determined, and the difference between the initial liquid level and the liquid level of the fracturing fluid at the target time can be used as the total amount of absorbing fluid.

[0093] S340. Under the conditions of test temperature and test confining pressure, determine the target core matrix peak area and the target microcrack peak area of ​​the core sample at the target time.

[0094] S350. Based on the initial core matrix peak area, initial microfracture peak area, total permeation, target core matrix peak area, and target microfracture peak area, determine the dynamic permeation of the core sample matrix and the dynamic permeation of the microfracture.

[0095] The technical solution of this invention determines the initial liquid level of the fracturing fluid in a metering tube connected to the core sample at an initial time, under the conditions of test temperature and test confining pressure. Based on the initial liquid level, the total amount of permeation of the core sample at a target time is determined. This technical solution determines the total amount of permeation of the core sample at a target time by using the initial liquid level of the fracturing fluid in the metering tube connected to the core sample at an initial time. This allows for a relatively simple determination of the total permeation based on changes in the fracturing fluid metering, thereby reducing the difficulty of testing shale permeability.

[0096] An optional technical solution involves determining the total amount of fracturing fluid absorbed by a core sample at a target time based on an initial fluid level, including: determining the target fluid level of the fracturing fluid in the metering tube at the target time; and determining the total amount of fracturing fluid absorbed by the core sample at the target time based on the initial fluid level and the target fluid level.

[0097] The target fluid level can be understood as the height of the fracturing fluid in the metering tube at the target time; the target fluid level can also be understood as the height of the fracturing fluid in the metering tube at the target time before it has been absorbed by the core sample.

[0098] In this embodiment of the invention, the target liquid level height of the fracturing fluid in the metering tube at the target time can be determined; based on the difference between the initial liquid level height and the target liquid level height, the total amount of permeation of the core sample at the target time can be determined, for example, the difference between the initial liquid level height and the target liquid level height can be used as the total amount of permeation.

[0099] In this embodiment of the invention, by determining the total amount of permeation of the core sample at the target time based on the initial liquid level and the target liquid level, the total amount of permeation can be determined more simply based on the metering changes of the fracturing fluid, thereby further reducing the difficulty of testing the permeation capacity of shale.

[0100] To better understand the technical solutions of the above embodiments of the present invention, an optional example is provided herein. For example, see... Figure 8The core sample can be tested using a permeability testing device. The permeability testing device may include a metering tube 1, a sealing liquid 2, a fracturing fluid 3, a suction tube 4, a core holder 6 for holding the core sample 5, a nuclear magnetic resonance device 7, an insulation jacket 8, a heating box 9, a confining pressure pump 10, a cylindrical pad 11, and a core holder outlet valve 12. The core sample 5 can be placed in the core holder 6; one end face of the core sample 5 can contact the fracturing fluid 3 and other fluids, and the other end face can contact the cylindrical pad 11; the confining pressure pump 10 can be used to apply confining pressure to the core sample 5; the heating box 9 can be used to heat the core sample 5; the insulation jacket 8 can be used to maintain a constant temperature; the nuclear magnetic resonance equipment can be used to monitor the permeation capacity of the matrix and microfractures of the core sample online; the cylindrical pad 11 has a flow guide groove on the contact surface with the core sample 5; the center of the circular pad 11 has an orifice 11-1 for the flow of the fracturing fluid 3 and other fluids, and the fluid can flow through the orifice 11-1 to the outlet valve 12 of the core holder; the maximum loading temperature of the permeation capacity testing device can be 150℃; the maximum stress of the permeation capacity testing device can be 50MPa; the stress control accuracy of the permeation capacity testing device can be 0.01MPa, and the stress holding time of the permeation capacity testing device can be greater than 24h.

[0101] Specifically, the core sample can be loaded into the core holder 6, and a preset initial confining pressure can be applied to the core sample using the confining pressure pump 10. The initial confining pressure can be, for example, 5 MPa. The core sample and the core holder 6 are heated to the test temperature using the heating box 9. The core sample and the core holder 6 are then loaded to the test confining pressure using the confining pressure pump 10. The fracturing fluid 3 is sucked into the metering tube 1 through the suction pipe 4. When the liquid level of the fracturing fluid 3 reaches a preset position, for example, around the 0 mark, the suction pipe 4 is closed, and oil or other fluids are used as the sealing liquid 2. The time when the suction pipe 4 is closed and oil or other fluids are used as the sealing liquid 2 is taken as the initial time. The initial liquid level height of the fracturing fluid in the metering tube at the initial time is determined. For example, the height of the fracturing fluid 3 reaching the 0 mark can be taken as the initial liquid level height. The target liquid level height of the fracturing fluid in the metering tube at the target time is determined. This target time can be preset after the initial time. The time intervals are preset, for example, 0.5 hours. The target time is the time every 0.5 hours after the initial time. The liquid level of the fracturing fluid in the metering tube is recorded every 0.5 hours as the target liquid level. The difference between the target liquid level corresponding to each target time and the target liquid level corresponding to the adjacent target time or the initial liquid level is the total permeation of the core sample at the target time. Under the test temperature and test confining pressure, the core sample can be monitored online in real time using nuclear magnetic resonance technology to test the target T2 spectrum curves corresponding to each target time. Based on the target T2 spectrum curves, the target core matrix peak area and the target microfracture peak area of ​​the core sample at the target time are determined. Based on the initial core matrix peak area, the initial microfracture peak area, the total permeation, the target core matrix peak area, and the target microfracture peak area, the dynamic permeation of the matrix and the dynamic permeation of the microfracture of the core sample are determined.

[0102] To better understand the technical solutions of the above embodiments of the present invention, an optional example is provided here. For example, for core samples collected from a target shale reservoir section, the initial core matrix peak area and the initial microfracture peak area of ​​the core sample at the initial time are determined; the test temperature and test confining pressure are determined, and at the times corresponding to 5 hours and 10 hours after the core sample reaches the test temperature, test confining pressure, and target time (preset time), the matrix permeation peak area ratio is determined based on the initial core matrix peak area, the initial microfracture peak area, the target core matrix peak area, and the target microfracture peak area; and the microfracture permeation peak area ratio is determined based on the initial core matrix peak area, the initial microfracture peak area, the target core matrix peak area, and the target microfracture peak area. The data obtained from the above tests are shown in Table 1 below.

[0103] Table 1. Data obtained from tests at different target times.

[0104]

[0105] With the target time being 5 hours after the preset time, the dynamic matrix permeation of the core sample was determined to be 1.47 cm³ based on the total permeation volume and the ratio of matrix permeation peak area. 3 Based on the total permeate volume and the ratio of permeate peak area in microfractures, the dynamic permeate volume in the core sample was determined to be 0.03 cm. 3 With the target time being 10 hours after the preset time, the dynamic matrix permeation of the core sample was determined to be 3.45 cm³ based on the total permeation and the ratio of matrix permeation peak area. 3 Based on the total amount of infiltration and the ratio of the infiltration peak area of ​​the microfractures, the dynamic infiltration amount of the core sample in the microfractures was determined to be 0.15 cm3.

[0106] The above test results of shale permeability show that the contribution of matrix pores to permeability in core samples is much higher than that of microfractures, and the permeability of core samples, i.e., dynamic permeability, changes with time.

[0107] Figure 9 This is a structural block diagram of a shale permeability testing device provided in an embodiment of the present invention. This device is used to execute the shale permeability testing method provided in any of the above embodiments. This device and the shale permeability testing methods of the above embodiments belong to the same inventive concept. Details not described in detail in the embodiments of the shale permeability testing device can be found in the embodiments of the above shale permeability testing methods. See also... Figure 9 The device may specifically include: an initial microcrack peak area determination module 410, a target microcrack peak area determination module 420, and a microcrack dynamic permeation determination module 430.

[0108] Among them, the initial microfracture peak area determination module 410 is used to determine the initial core matrix peak area and the initial microfracture peak area of ​​the core sample obtained from the target shale reservoir section.

[0109] The target microfracture peak area determination module 420 is used to determine the test temperature and test confining pressure, and under the test temperature and test confining pressure, determine the total amount of permeation of the core sample, the target core matrix peak area, and the target microfracture peak area at the target time.

[0110] The microfracture dynamic permeation determination module 430 is used to determine the matrix dynamic permeation and microfracture dynamic permeation of the core sample based on the initial core matrix peak area, the initial microfracture peak area, the total permeation, the target core matrix peak area, and the target microfracture peak area.

[0111] Optionally, the target microcrack peak area determination module 420 may include:

[0112] The well parameter acquisition unit is used to acquire the well parameters of the target well, which is the well from which core samples were collected.

[0113] The test confining pressure determination unit is used to determine the test temperature and test confining pressure based on the data acquisition well parameters.

[0114] Optionally, based on the above-mentioned device, the acquisition well parameters include the core formation temperature of the target acquisition well, and at least one of the formation pore pressure, maximum horizontal principal stress, minimum horizontal principal stress, vertical stress, and effective stress coefficient of the target acquisition well.

[0115] The test confining pressure determination unit may include:

[0116] The test temperature is used as a sub-unit to take the core formation temperature as the test temperature;

[0117] The test confining pressure determination sub-unit is used to determine the test confining pressure based on at least one of the formation pore pressure, maximum horizontal principal stress, minimum horizontal principal stress, vertical stress, and effective stress coefficient.

[0118] Optionally, based on the above-mentioned device, a test confining pressure determination subunit can be used, specifically for:

[0119] The effective vertical stress is determined based on at least one of the vertical stress, effective stress coefficient, and formation pore pressure.

[0120] The maximum effective horizontal principal stress is determined based on at least one of the maximum horizontal principal stress, the effective stress coefficient, and the formation pore pressure.

[0121] The minimum effective principal stress is determined based on at least one of the minimum horizontal principal stress, the effective stress coefficient, and the formation pore pressure.

[0122] The test confining pressure is determined based on the vertical effective stress, the minimum horizontal effective principal stress, and the maximum horizontal effective principal stress.

[0123] Optionally, the target microcrack peak area determination module 420 may include:

[0124] The initial liquid level determination unit is used to determine the initial liquid level of the fracturing fluid in the metering tube connected to the core sample at the initial time, under the conditions of test temperature and test confining pressure.

[0125] The total permeation determination unit is used to determine the total permeation of a core sample at a target time based on the initial liquid level.

[0126] Optionally, based on the above-described apparatus, the total amount of permeation determination unit may include:

[0127] The target fluid level determination subunit is used to determine the target fluid level of the fracturing fluid in the metering tube at a target time.

[0128] The total permeation determination subunit is used to determine the total permeation of the core sample at the target time based on the initial liquid level and the target liquid level.

[0129] Optionally, the target microcrack peak area determination module 420 may include:

[0130] The target T2 spectrum curve determination unit is used to determine the target T2 spectrum curve of the core sample at the target time under the test temperature and test confining pressure conditions.

[0131] The target microfracture peak area determination unit is used to determine the target core matrix peak area and target microfracture peak area of ​​the core sample at the target time based on the target T2 spectrum curve.

[0132] Optionally, the initial microcrack peak area determination module 410 may include:

[0133] The peak area determination unit is used to determine the initial T2 spectrum curve of the core sample and to determine the peak area corresponding to at least one peak in the initial T2 spectrum curve.

[0134] The initial microfracture peak area determination unit is used to determine the initial core matrix peak area and the initial microfracture peak area of ​​the core sample based on the peak areas corresponding to at least one peak.

[0135] Optionally, the microcrack dynamic absorption determination module 430 may include:

[0136] The matrix permeation peak area ratio determination unit is used to determine the matrix permeation peak area ratio based on the initial core matrix peak area, the initial microfracture peak area, the target core matrix peak area, and the target microfracture peak area.

[0137] The fracture permeation peak area ratio determination unit is used to determine the microfracture permeation peak area ratio based on the initial core matrix peak area, the initial microfracture peak area, the target core matrix peak area, and the target microfracture peak area.

[0138] The matrix dynamic permeation determination unit is used to determine the matrix dynamic permeation of the core sample based on the total permeation and the ratio of matrix permeation peak area.

[0139] The microfracture dynamic permeation determination unit is used to determine the dynamic permeation of the core sample based on the total permeation and the ratio of the microfracture permeation peak area.

[0140] The shale permeability testing device provided in this invention includes an initial microfracture peak area determination module, used to determine the initial core matrix peak area and initial microfracture peak area of ​​core samples collected from target shale reservoir sections; a target microfracture peak area determination module, used to determine the test temperature and test confining pressure, and under these conditions, to determine the total permeability, target core matrix peak area, and target microfracture peak area of ​​the core sample at a target time; and a microfracture dynamic permeability determination module, based on the initial core matrix peak area, initial microfracture peak area, total permeability, target core matrix peak area, and target microfracture peak area, to determine the dynamic permeability of the core sample's matrix and microfractures. This device, by using the initial core matrix peak area, initial microfracture peak area, total permeability, target core matrix peak area, and target microfracture peak area as determining factors for the dynamic permeability of the core sample's matrix and microfractures, achieves the testing of the permeability of shale's matrix and microfractures.

[0141] The shale permeability testing device provided in this embodiment of the invention can execute the shale permeability testing method provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects of the method.

[0142] It is worth noting that in the embodiments of the above-mentioned shale permeability testing device, the various units and modules included are only divided according to functional logic, but are not limited to the above division, as long as the corresponding functions can be achieved; in addition, the specific names of each functional unit are only for easy differentiation and are not used to limit the scope of protection of the present invention.

[0143] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0144] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for testing the wicking capacity of shale, characterized in that, The method comprises the following steps: determining an initial core matrix peak area and an initial micro-fracture peak area of an initial T2 spectrum curve of a core sample collected from a target shale reservoir section, wherein the initial T2 spectrum curve is obtained by scanning the core sample that has not been tested by a nuclear magnetic resonance device, the initial core matrix peak area represents a total hydrogen atom signal value of a matrix portion in the core sample that has not been tested, and the initial micro-fracture peak area represents a total hydrogen atom signal value of a micro-fracture portion in the core sample that has not been tested; determining a test temperature and a test confining pressure, and determining a total imbibition amount of the core sample at a target time, a target core matrix peak area and a target micro-fracture peak area of a target T2 spectrum curve of the core sample when the core sample is at the test temperature and the test confining pressure, wherein the target T2 spectrum curve is obtained by scanning the core sample at the target time by the nuclear magnetic resonance device, the target core matrix peak area represents a total hydrogen atom signal value of a matrix portion in the core sample at the target time, and the target micro-fracture peak area represents a total hydrogen atom signal value of a micro-fracture portion in the core sample at the target time; determining a matrix dynamic imbibition amount and a micro-fracture dynamic imbibition amount of the core sample according to the initial core matrix peak area, the initial micro-fracture peak area, the total imbibition amount, the target core matrix peak area, and the target micro-fracture peak area.

2. The method of claim 1, wherein, The method further comprises the following steps: obtaining a collection well parameter of a target collection well, wherein the target collection well is a collection well from which the core sample is collected; determining the test temperature and the test confining pressure according to the collection well parameter.

3. The method of claim 2, wherein, The collection well parameter comprises a core formation temperature of the target collection well, and at least one of a formation pore pressure, a maximum horizontal principal stress, a minimum horizontal principal stress, a vertical stress, and an effective stress coefficient of the target collection well. The method further comprises the following steps: taking the core formation temperature as the test temperature; determining the test confining pressure according to at least one of the formation pore pressure, the maximum horizontal principal stress, the minimum horizontal principal stress, the vertical stress, and the effective stress coefficient.

4. The method of claim 3, wherein, The method further comprises the following steps: determining a vertical effective stress according to at least one of the vertical stress, the effective stress coefficient, and the formation pore pressure; determining a maximum horizontal effective principal stress according to at least one of the maximum horizontal principal stress, the effective stress coefficient, and the formation pore pressure; determining a minimum horizontal effective principal stress according to at least one of the minimum horizontal principal stress, the effective stress coefficient, and the formation pore pressure; determining the test confining pressure according to the vertical effective stress, the minimum horizontal effective principal stress, and the maximum horizontal effective principal stress.

5. The method of claim 1, wherein, The total imbibition amount of the core sample at a target time is determined under the condition that the core sample is at the test temperature and the test confining pressure, and the total imbibition amount of the core sample at the target time is determined based on the initial liquid level height in the metering pipe connected with the core sample. The initial liquid level height of the fracturing fluid in the metering pipe connected with the core sample at an initial time is determined under the condition that the core sample is at the test temperature and the test confining pressure. The total imbibition amount of the core sample at a target time is determined based on the initial liquid level height.

6. The method of claim 5, wherein, The total imbibition amount of the core sample at a target time is determined based on the initial liquid level height. The target liquid level height of the fracturing fluid in the metering pipe at a target time is determined. The total imbibition amount of the core sample at the target time is determined according to the initial liquid level height and the target liquid level height.

7. The method of claim 1, wherein, The target core matrix peak area and the target micro-fracture peak area of the core sample at a target time are determined under the condition that the core sample is at the test temperature and the test confining pressure, and the target core matrix peak area and the target micro-fracture peak area of the core sample at the target time are determined based on the target T2 spectrum curve of the core sample at the target time. The target T2 spectrum curve of the core sample at the target time is determined under the condition that the core sample is at the test temperature and the test confining pressure. The initial core matrix peak area and the initial micro-fracture peak area of the core sample are determined based on the initial T2 spectrum curve of the core sample and the peak areas corresponding to the at least one peak in the initial T2 spectrum curve.

8. The method of claim 1, wherein, The initial T2 spectrum curve of the core sample is determined, and the peak areas corresponding to the at least one peak in the initial T2 spectrum curve are determined. The initial core matrix peak area and the initial micro-fracture peak area of the core sample are determined according to the peak areas corresponding to the at least one peak. The matrix dynamic imbibition amount and the micro-fracture dynamic imbibition amount of the core sample are determined according to the initial core matrix peak area, the initial micro-fracture peak area, the total imbibition amount, the target core matrix peak area, and the target micro-fracture peak area.

9. The method of claim 1, wherein, The matrix imbibition peak area ratio is determined according to the initial core matrix peak area, the initial micro-fracture peak area, the target core matrix peak area, and the target micro-fracture peak area. The micro-fracture imbibition peak area ratio is determined according to the initial core matrix peak area, the initial micro-fracture peak area, the target core matrix peak area, and the target micro-fracture peak area. The matrix dynamic imbibition amount of the core sample is determined according to the total imbibition amount and the matrix imbibition peak area ratio. The micro-fracture dynamic imbibition amount of the core sample is determined according to the total imbibition amount and the micro-fracture imbibition peak area ratio. It comprises:

10. A shale wicking capacity testing device characterized by, ​ The initial micro-fracture peak area determination module is configured to determine an initial core matrix peak area and an initial micro-fracture peak area of an initial T2 spectrum curve of a core sample collected from a target shale reservoir section, wherein the initial T2 spectrum curve is obtained by scanning the core sample that is not tested by a nuclear magnetic resonance device, the initial core matrix peak area represents a total hydrogen atom signal value of a matrix portion in the core sample that is not tested, and the initial micro-fracture peak area represents a total hydrogen atom signal value of a micro-fracture portion in the core sample that is not tested; The target micro-fracture peak area determination module is configured to determine a test temperature and a test confining pressure, and determine a total imbibition amount of the core sample at a target time, a target core matrix peak area and a target micro-fracture peak area of a target T2 spectrum curve of the core sample when the core sample is at the test temperature and the test confining pressure, wherein the target T2 spectrum curve is obtained by scanning the core sample at the target time by the nuclear magnetic resonance device, the target core matrix peak area represents a total hydrogen atom signal value of a matrix portion in the core sample at the target time, and the target micro-fracture peak area represents a total hydrogen atom signal value of a micro-fracture portion in the core sample at the target time; The micro-fracture dynamic imbibition amount determination module is configured to determine a matrix dynamic imbibition amount and a micro-fracture dynamic imbibition amount of the core sample according to the initial core matrix peak area, the initial micro-fracture peak area, the total imbibition amount, the target core matrix peak area, and the target micro-fracture peak area.

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