Method and device for determining shale brittleness

Abstract

This specification provides a method and apparatus for determining the brittleness of shale. The method includes: obtaining a target sample of the target area of the shale, performing a nanoindentation experiment on the target sample to obtain the mechanical property data of the target sample and the mechanical property data of the cementation interface of the minerals in the target sample; forming a mechanical property distribution cloud map according to the mechanical property data of the target sample; obtaining the contribution value of the favorable mineral components according to the mechanical property distribution cloud map; obtaining the mechanical property contribution value according to the mechanical property data of the cementation interface of the minerals in the target sample; obtaining the brittleness index of the target sample according to the contribution value of the favorable mineral components, the mechanical property contribution value and the mechanical property data of the cementation interface of the minerals in the target sample; and determining the brittleness of the target sample according to the brittleness index of the target sample. Based on the above method, the brittleness of shale can be determined more comprehensively and accurately.

Description

Technical Field

[0001] The present invention relates to the technical field of drilling in soil layers or rocks, and particularly to a method and device for determining the brittleness of shale. Background Art

[0002] Shale oil and gas is an unconventional natural gas resource extracted from shale formations. The brittleness of shale is a key index for evaluating the mechanical properties of shale oil and gas reservoirs. Accurately and comprehensively determining the brittleness of shale is of great significance for the efficient exploitation of shale oil and gas.

[0003] Currently, the brittleness of shale is mainly determined based on various mineral component contents, Young's modulus, hardness parameters, and rock stress-strain. Among them, determining the brittleness of shale through various mineral component contents does not consider the mechanical properties of the rock, and the determination method of mineral components is mainly obtained through X-ray diffraction experiments and visual inspection. This method has problems such as complex operation and low accuracy; determining the brittleness of shale through Young's modulus, hardness parameters, and rock stress-strain although considers the mechanical properties of the rock, generally, indoor macroscopic experiments need to be carried out to obtain the mechanical properties of the rock, which is costly and has high requirements for the size of the experimental object. It is difficult to obtain the reservoir properties and mechanical characteristics of the deep rock in a short time, and it does not consider that the rock is a non-uniform, multi-medium material, and the mechanical properties of the rock are due to the combined action of multiple mineral components. Therefore, this method cannot accurately determine the brittleness of shale either.

[0004] Aiming at the problem of low accuracy existing in the existing determination of shale brittleness, no effective solution has been proposed yet. Summary of the Invention

[0005] The embodiments of the present specification provide a method and device for determining the brittleness of shale to solve the problem that the brittleness of shale cannot be determined more accurately in the prior art.

[0006] On the one hand, the present application provides a method for determining the brittleness of shale, including:

[0007] Obtain a target sample of the target area of shale, conduct a nanoindentation experiment on the target sample, and obtain the mechanical property data of the target sample and the mechanical property data of the cementation interface of the minerals in the target sample;

[0008] Form a mechanical property distribution cloud map according to the mechanical property data of the target sample;

[0009] Obtain the contribution value of favorable mineral components according to the mechanical property distribution cloud map;

[0010] Obtain the mechanical property contribution value according to the mechanical property data of the cementation interface of the minerals in the target sample;

[0011] Obtain the brittleness index of the target sample based on the contribution value of the favorable mineral components, the contribution value of the mechanical properties, and the mechanical property data of the cementation interface of the minerals in the target sample;

[0012] Determine the brittleness of the target sample according to the brittleness index of the target sample.

[0013] Furthermore, perform a nanoindentation experiment on the target sample to obtain the mechanical property data of the target sample, including:

[0014] Perform a nanoindentation experiment on the target sample to obtain the first load and first displacement data;

[0015] Calculate the mechanical properties of the indentation point based on the first load and first displacement data as the mechanical property data of the target sample.

[0016] Furthermore, perform a nanoindentation experiment on the target sample to obtain the mechanical property data of the cementation interface of the minerals in the target sample, including:

[0017] Determine the cementation interface of the minerals in the target sample;

[0018] Perform a nanoindentation experiment on the cementation interface of the minerals in the target sample to obtain the second load and second displacement data;

[0019] Calculate the mechanical properties of the indentation point based on the second load and second displacement data as the mechanical property data of the cementation interface of the minerals in the target sample.

[0020] Furthermore, the mechanical property data of the cementation interface of the minerals in the target sample also includes: the mechanical property data of the cementation interface of the favorable minerals in the target sample.

[0021] Furthermore, obtaining the contribution value of the favorable mineral components according to the mechanical property distribution nephogram includes:

[0022] Determine the distribution characteristics of the favorable mineral components according to the mechanical property distribution nephogram;

[0023] Determine the proportion of the favorable mineral components in the total mineral components according to the distribution characteristics of the favorable components;

[0024] Take the proportion of the favorable mineral components in the total mineral components as the contribution value of the favorable mineral components.

[0025] Furthermore, obtaining the brittleness index of the target sample according to the contribution value of the favorable mineral components, the contribution value of the mechanical properties, and the mechanical property data of the cementation interface of the minerals in the target sample includes:

[0026] Obtain a first brittleness index based on the contribution value of the favorable mineral components and the contribution value of the mechanical properties;

[0027] Obtain a second brittleness index based on the mechanical property data of the cementation interface of the minerals in the target sample;

[0028] Obtain the brittleness index of the target sample based on the first brittleness index and the second brittleness index.

[0029] Furthermore, the determining the brittleness of the target sample according to the brittleness index of the target sample includes:

[0030] Determine the brittleness index of the target sample according to the first brittleness index and the second brittleness index of the target sample;

[0031] Determine the brittleness of the target sample according to the brittleness index of the target sample.

[0032] Furthermore, after determining the brittleness of the target sample according to the brittleness index of the target sample, the method further includes:

[0033] Determine the shale oil and gas exploration process according to the brittleness of the target sample in the shale target area;

[0034] Conduct shale oil and gas exploration according to the exploration process.

[0035] On the other hand, the present application provides a device for determining shale brittleness, including:

[0036] A mechanical data acquisition module, configured to acquire a target sample in a shale target area, perform a nanoindentation experiment on the target sample, and obtain the mechanical property data of the target sample and the mechanical property data of the cementation interface of the minerals in the target sample;

[0037] A brittleness index acquisition module, configured to form a mechanical property distribution cloud map according to the mechanical property data of the target sample, obtain a contribution value of favorable mineral components according to the mechanical property distribution cloud map, obtain a contribution value of mechanical properties according to the mechanical property data of the cementation interface of the minerals in the target sample, and obtain the brittleness index of the target sample according to the contribution value of the favorable mineral components, the contribution value of the mechanical properties, and the mechanical property data of the cementation interface of the minerals in the target sample;

[0038] A brittleness determination module, configured to determine the brittleness of the target sample according to the brittleness index of the target sample.

[0039] On yet another aspect, the present application further provides a computer-readable storage medium, on which computer instructions are stored, and when the computer-readable storage medium executes the instructions, the above method for determining shale brittleness is implemented.

[0040] A method and device for determining shale brittleness provided in this specification obtain a target sample of a shale target area, conduct a nanoindentation experiment on the target sample, and obtain the mechanical property data of the target sample and the mechanical property data of the cementation interface of minerals in the target sample. By more comprehensively considering the microscopic mechanical property differences of different minerals in shale, the accuracy of the determined shale brittleness index is higher. Further, a mechanical property distribution cloud map is formed based on the mechanical property data of the target sample. Then, according to the mechanical property distribution cloud map, the mineral components and their distribution characteristics that are favorable for brittle failure and those that are not are distinguished. Based on the distribution characteristics of each mineral component, the ratio of the distribution of mineral components favorable for brittle failure to the distribution of mineral components unfavorable for brittle failure is determined, and finally, the contribution value of favorable mineral components is obtained, thereby reducing the time and cost of distinguishing mineral components. According to the mechanical property data of the cementation interface of minerals in the target sample, a mechanical property contribution value is obtained. Then, based on the contribution value of favorable mineral components, the mechanical property contribution value, and the mechanical property data of the cementation interface of minerals in the target sample, the brittleness index of the target sample is obtained. Finally, according to the brittleness index of the target sample, the brittleness of the target sample is determined. Through the above solution, the problems of low accuracy and high cost existing in the existing process of determining shale brittleness are solved, and the technical effect of accurately and efficiently determining shale brittleness is achieved. Brief Description of the Drawings

[0041] In order to more clearly illustrate the technical solutions in the embodiments of this specification or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in this specification. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0042] Figure 1 It is a schematic flowchart of an embodiment of a method for determining shale brittleness provided in this specification;

[0043] Figure 2 It is a schematic diagram of a nanoindentation experiment in an embodiment of this specification;

[0044] Figure 3 It is a hardness distribution cloud map in an embodiment of this specification;

[0045] Figure 4 It is a schematic diagram of the structural composition of a device for determining shale brittleness provided in an embodiment of this specification;

[0046] Figure 5 It is a schematic diagram of the structural composition of an electronic device provided in an embodiment of this specification. Detailed Embodiments

[0047] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this specification. Obviously, the described embodiments are only a part of the embodiments of this specification, rather than all the embodiments. Based on the embodiments in this specification, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this specification.

[0048] Considering that when determining shale brittleness based on the contents of various mineral components in the existing methods, the accuracy of mineral component judgment is directly related to the accuracy of shale brittleness index determination, and further affects the accuracy of shale brittleness determination. In the existing technology, mineral components are often obtained through visual inspection or X-ray diffraction experiments. Based on visual inspection to distinguish mineral components, there is a great deal of subjectivity, resulting in inaccurate final judgment results of mineral components. Based on X-ray diffraction experiments, first, representative rock samples need to be selected. Secondly, the rock samples need to be refined in a mortar to the specifications required by the experiment. Then, the rock samples are scanned with an X-ray powder diffractometer to obtain the spectra of corresponding minerals. Finally, spectrum fitting software is used to perform quantitative interpretation and semi-quantitative analysis on the minerals. This method has relatively cumbersome steps for distinguishing mineral components and requires corresponding processing and analysis of the shale samples before and after the experiment to obtain the final judgment result.

[0049] Furthermore, considering that there are ways to determine shale brittleness based on Young's modulus, hardness parameters, and rock stress-strain in the existing methods, but these methods generally obtain the mechanical properties of rocks based on indoor macroscopic experiments. Then, indoor macroscopic experiments have problems such as high cost, non-repeatability, and long experimental periods. There are also some methods that obtain mechanical property data based on microscopic experiments, but they do not consider that rock is a non-uniform and multi-medium material, and the mechanical properties of rocks are due to the combined action of multiple mineral components. They do not consider that the cementation interface of rocks can better reflect the mechanical properties of rocks, so a brittle determination method that comprehensively considers the mechanical property differences of shale micro-components cannot be established.

[0050] Aiming at the problems existing in the existing methods, this specification considers the microscopic mechanical differences of various minerals and introduces a mechanical property cloud map to simply and quickly distinguish various mineral components, introduces the mineral cementation interface to more comprehensively reflect the mechanical property characteristics of various mineral components in the rock, and combines the mechanical property data of the mineral cementation interface to establish a more comprehensive comprehensive shale brittleness index, thereby effectively improving the accuracy and efficiency of shale brittleness determination.

[0051] Based on the above ideas, this specification proposes a method for determining the brittleness of shale. First, obtain a target sample from the target area of the shale, conduct a nanoindentation experiment on the target sample to obtain the mechanical property data of the target sample and the mechanical property data of the cementation interface of the minerals in the target sample; second, form a mechanical property distribution cloud map based on the mechanical property data of the target sample, obtain the contribution value of favorable mineral components according to the mechanical property distribution cloud map, obtain the mechanical property contribution value according to the mechanical property data of the cementation interface of the minerals in the target sample, and obtain the brittleness index of the target sample according to the contribution value of favorable mineral components, the mechanical property contribution value, and the mechanical property data of the cementation interface of the minerals in the target sample; finally, determine the brittleness of the target sample according to the brittleness index of the target sample. Refer to Figure 1 As shown, the embodiments of this specification provide a method for determining the brittleness of shale. Specifically, when implemented, the method may include the following content.

[0052] S101: Obtain a target sample from the target area of the shale, conduct a nanoindentation experiment on the target sample to obtain the mechanical property data of the target sample and the mechanical property data of the cementation interface of the minerals in the target sample.

[0053] In some embodiments, the above-mentioned target area of the shale may be different reservoir depths of the shale or the shale of different wells, and the target sample may be a cuttings or core sample. The target area and target sample here can be adjusted accordingly according to actual needs, and this specification does not make specific limitations here. The above-mentioned target sample can be obtained in the following way: when drilling different reservoir depths of the shale of the same well or different reservoir depths of the shale of different wells, take the rock debris or core returned to the wellhead corresponding to the reservoir depth of the corresponding well, and simply screen out the cuttings or cores that meet the experimental requirements from them as the target sample for the experiment. For example, during the screening process, eliminate some false cuttings with large size, obvious edges and corners, and blurred hues. These false cuttings will return to the surface together with the true cuttings, and the subsequent nanoindentation experiment data accuracy can be ensured through the elimination operation.

[0054] In some embodiments, the above-mentioned nanoindentation experiment is a microscale mechanical measurement technique. It obtains the load-displacement curve graph of the material by measuring the load acting on the pressure needle and the depth of penetration into the sample surface. Compared with indoor macroscopic experiments, it is difficult to obtain cores that meet the indoor experiment size requirements, it is difficult to study the reservoir structure and mechanical properties of deep shale, and there are disadvantages such as non-repeatability, long experimental period, high cost, and high price. The nanoindentation experiment has advantages such as low requirements for the size of the experimental object, no damage to the test piece, high repeatability, etc., and it has high resolution and can predict the mechanical properties and failure behaviors of rock materials with different compositions, different structures, and anisotropy.

[0055] In some embodiments, the above-mentioned nanoindentation experiment is performed on the target sample to obtain the mechanical property data of the target sample. Specifically, the implementation may include:

[0056] Performing a nanoindentation experiment on the target sample to obtain first load and first displacement data;

[0057] Calculating the mechanical properties of the indentation point based on the first load and first displacement data as the mechanical property data of the target sample.

[0058] In some embodiments, the above-mentioned calculation of the mechanical properties of the indentation point based on the first load and first displacement data as the mechanical property data of the target sample may include:

[0059] S1: Calculate the contact stiffness according to the following formula:

[0060]

[0061] where S represents the contact stiffness, h is the first displacement, h max is the maximum displacement, and p is the first load;

[0062] S2: Calculate the contact depth according to the following formula:

[0063]

[0064] where h c represents the contact depth, P max is the maximum load, and ε is a constant related to the indenter geometry;

[0065] S3: Calculate the contact area according to the following formula:

[0066]

[0067] where A c is the contact area;

[0068] S4: Calculate the elastic modulus and hardness according to the following formula:

[0069]

[0070]

[0071] where E is the elastic modulus and H is the hardness.

[0072] S5: Take the above elastic modulus and hardness as the mechanical property data of the target sample.

[0073] In some embodiments, the above-mentioned nanoindentation experiment is performed on the target sample to obtain the mechanical property data of the cementation interface of the minerals in the target sample. Specifically, the implementation may include:

[0074] Determine the cementation interface of the minerals in the target sample;

[0075] Perform a nanoindentation experiment on the cementation interface of the minerals in the target sample to obtain second load and second displacement data;

[0076] Calculate the mechanical properties of the indentation point based on the second load and second displacement data as the mechanical property data of the cementation interface of the minerals in the target sample.

[0077] In some embodiments, the above-mentioned mechanical property data of the cementation interface of the minerals in the target sample may further include: the mechanical property data of the cementation interface of the favorable minerals in the target sample.

[0078] In some embodiments, the above-mentioned nanoindentation experiment is performed on the target sample to obtain the mechanical property data of the cementation interface of the minerals in the target sample. Specifically, the implementation may further include:

[0079] Determine the cementation interface of the favorable minerals in the target sample;

[0080] Perform a nanoindentation experiment on the cementation interface of the favorable minerals in the target sample to obtain third load and third displacement data;

[0081] Calculate the mechanical properties of the indentation point based on the third load and third displacement data as the mechanical property data of the cementation interface of the favorable minerals in the target sample.

[0082] In some embodiments, the above-mentioned favorable minerals in the target sample refer to the minerals in the target sample that are conducive to brittle failure. The determination method of the minerals in the target sample that are conducive to brittle failure will be described separately later.

[0083] In some embodiments, the above-mentioned cementation interface of the minerals is an interface formed by cementing two or more minerals in the rock. The cementation process is that the rock is affected by pressure, causing some minerals in the rock to slowly dissolve in water, and the aqueous solution containing minerals penetrates into the voids between sediment particles and forms mineral crystals that stick together. The cementation interface of the minerals in the above-mentioned target sample can be determined based on the morphological characteristics of the cementation interface. Since the formation of the mineral cementation interface is mainly affected by pressure, the cementation interfaces of multiple minerals in the rock can better reflect the mechanical properties of the rock, thus laying a data foundation for obtaining an accurate brittleness index subsequently.

[0084] In some embodiments, when performing a nanoindentation experiment on the target sample, multiple sets of load-displacement curves of the target sample can be obtained. From the curves, the corresponding maximum displacement, maximum load, displacement, and load data in each set of load-displacement curves can be determined. In this specification, nanoindentation experiments are respectively performed on the target sample and the cementation interface of the minerals in the target sample, and the corresponding load and displacement data are obtained. When the experimental object changes, the load and displacement data also change accordingly. To avoid ambiguity, the first load, first displacement, second load, and second displacement are used for distinction. Of course, it should be noted that the above-listed first load, first displacement, second load, and second displacement data are only illustrative. In specific implementation, according to the different objects of the nanoindentation experiment, third load, third displacement data, etc. can also be introduced.

[0085] In some embodiments, the calculation methods of the mechanical property data of the cementation interface of the minerals in the target sample and the mechanical property data of the cementation interface of the beneficial minerals in the target sample are the same as those of the mechanical property data of the target sample, which will not be elaborated in this specification.

[0086] S102: Form a mechanical property distribution cloud map according to the mechanical property data of the target sample.

[0087] In some embodiments, when forming a mechanical property distribution cloud map according to the mechanical property data of the target sample, a mechanical property distribution cloud map corresponding to the elastic modulus and hardness data can be formed according to the elastic modulus and hardness data of the target sample. Among them, the formation method of the mechanical property distribution cloud map can be obtained either through manual operation or by using a computer, which is not specifically limited in this specification.

[0088] Considering that rocks are composed of the combined action of multiple minerals and different minerals have different mechanical property characteristics, for this reason, in this example, the mechanical property differences between minerals can be characterized by a mechanical property distribution cloud map. Characterizing the mechanical property differences between minerals by a mechanical property distribution cloud map can more simply and efficiently distinguish mineral components.

[0089] For example: An elastic modulus or hardness distribution cloud map can be formed based on the elastic modulus or hardness data. In the elastic modulus or hardness distribution cloud map, since the elastic modulus or hardness of various minerals is different, in the distribution cloud map, there will be a region where the elastic modulus or hardness is relatively the same, while in other regions it is different. By comparing this mechanical difference, the components and their distribution characteristics of various minerals can be identified, greatly improving the speed of distinguishing mineral components, and thus improving the efficiency of determining shale brittleness.

[0090] In order to achieve efficient determination of brittleness, in this example, the mineral components in the target sample are divided into: mineral components conducive to brittle failure and mineral components not conducive to brittle failure. Among them, the minerals conducive to brittle failure may include: minerals with relatively high hardness such as quartz, dolomite, and calcite, and the minerals not conducive to brittle failure may include: relatively soft minerals such as clay. Through the mechanical property distribution nephogram, the distribution characteristics of the mineral components conducive to brittle failure and the mineral components not conducive to brittle failure can be quickly and efficiently determined.

[0091] S103: Obtain the contribution value of the favorable mineral components according to the mechanical property distribution nephogram;

[0092] Specifically, obtaining the contribution value of the favorable mineral components according to the mechanical property distribution nephogram may include:

[0093] S1: Determine the distribution characteristics of the favorable mineral components according to the mechanical property distribution nephogram;

[0094] S2: Determine the proportion of the favorable mineral components in the total mineral components according to the distribution characteristics of the favorable mineral components;

[0095] S3: Take the proportion of the favorable mineral components in the total mineral components as the contribution value of the favorable mineral components.

[0096] In some embodiments, the above-mentioned favorable mineral components refer to the mineral components conducive to brittle failure, and the distribution characteristics of the above-mentioned favorable mineral components refer to the distribution and proportion of the favorable mineral components in the mechanical property nephogram to the total mineral components.

[0097] In some embodiments, the proportion of the above-mentioned favorable mineral components in the total mineral components can determine the area proportion of the favorable mineral components in the total mineral components based on the distribution and proportion of the favorable mineral components to the total mineral components, and take the area proportion of the favorable mineral components in the total mineral components as the proportion of the favorable mineral components in the total mineral components.

[0098] In some embodiments, taking the proportion of the above-mentioned favorable mineral components in the total mineral components as the contribution value of the favorable mineral components can be specifically determined according to the following formula:

[0099]

[0100] Wherein, W F is the contribution value of the favorable mineral components, W qtz , W cal , W dol and W toc are the area proportions of quartz, dolomite, calcite, and total organic carbon respectively.

[0101] S104: Obtain the mechanical property contribution value according to the mechanical property data of the cementation interface of the minerals in the target sample.

[0102] In some embodiments, the mechanical property data of the cementation interface of the minerals in the above-mentioned target sample includes: the elastic modulus and hardness data of the cementation interface of the beneficial minerals in the target sample and the elastic modulus and hardness data of the cementation interface of the minerals in the target sample. Among them, the beneficial minerals in the target sample are distinguished and obtained according to the mechanical property nephogram, which will not be elaborated here.

[0103] In some embodiments, the above-mentioned mechanical property contribution value can be calculated according to the following formula:

[0104] S1: Calculate the elastic modulus and hardness of the beneficial minerals at the cementation interface to obtain E i 、H i ;

[0105] S2: Calculate the elastic modulus and hardness of the minerals at the cementation interface to obtain E 1 、H 1 ;

[0106] S3: Calculate the mechanical property contribution value according to the following formula:

[0107]

[0108] where S F is the mechanical property contribution value, E i 、H i are the elastic modulus and hardness of the beneficial minerals at the cementation surface respectively, and E 1 、H 1 are the elastic modulus and hardness of the cementation interface.

[0109] S105: Obtain the brittleness index of the target sample according to the beneficial mineral component contribution value, the mechanical property contribution value and the mechanical property data of the cementation interface of the minerals in the target sample.

[0110] Specifically, the brittleness index of the target sample can be obtained through the following steps:

[0111] S1: Obtain the first brittleness index according to the beneficial mineral component contribution value and the mechanical property contribution value;

[0112] S2: Obtain the second brittleness index according to the mechanical property data of the cementation interface of the minerals in the target sample;

[0113] S3: Obtain the brittleness index of the target sample according to the first brittleness index and the second brittleness index.

[0114] In some embodiments, according to the favorable mineral component contribution value and the mechanical property contribution value, the first brittleness index can be determined according to the following formula:

[0115] B 1 =W F S F (8)

[0116] Wherein, B 1 is the first brittleness index, W F is the favorable mineral component contribution value, and S F is the mechanical property contribution value.

[0117] In some embodiments, obtaining the second brittleness index according to the mechanical property data of the cementation interface of the minerals in the target sample may include:

[0118] S1: Calculate the standard deviation of the hardness and elastic modulus of different components of the shale according to the following formula:

[0119]

[0120]

[0121] Wherein, S H is the standard deviation of hardness, S E is the standard deviation of elastic modulus, H i is the hardness of the favorable mineral at the cementation surface, E i is the elastic modulus of the favorable mineral at the cementation surface, is the average value of the hardness of the cementation interface, is the average value of the elastic modulus of the cementation interface;

[0122] S2: Determine the second brittleness index according to the following formula:

[0123]

[0124] Wherein, B 2 is the second brittleness index, S H is the standard deviation of hardness, S E is the standard deviation of elastic modulus.

[0125] In some embodiments, obtaining the brittleness index of the target sample according to the first brittleness index and the second brittleness index may include: determining the brittleness index of the target sample according to the following formula:

[0126] B S =B 1 ·B 2 (12)

[0127] Wherein, B Sis the brittleness index of the target sample, B 1 is the first brittleness index, B 2 is the second brittleness index.

[0128] S106: Determine the brittleness of the target sample according to the brittleness index of the target sample.

[0129] In some embodiments, the above determining the brittleness of the target sample according to the brittleness index of the target sample includes:

[0130] Determine the brittleness index of the target sample according to the first brittleness index and the second brittleness index;

[0131] Determine the brittleness of the target sample according to the brittleness index of the target sample.

[0132] In some embodiments, the above first brittleness index, second brittleness index and the above target brittleness index are positively correlated, that is, the larger the first brittleness and the second brittleness index, the larger the brittleness index of the target sample, and the smaller the first brittleness and the second brittleness index, the smaller the brittleness index of the target sample. For example, after determining the values of the first brittleness index and the second brittleness index according to the established first and second brittleness index equations, the product of these two brittleness index values is used as the basis for determining the brittleness index of the target sample. The larger the product, the larger the brittleness index of the target sample. For example, if the brittleness index product is A1 = 20, A2 = 40, then the brittleness index of the target sample is A2 greater than A1, and the larger the brittleness index of the target sample, the more brittle the target sample is.

[0133] In some embodiments, after the above determining the brittleness of the target sample according to the brittleness index of the target sample, the shale oil and gas exploration process can be determined according to the brittleness of the target sample in the shale target area; shale oil and gas exploration is carried out according to the exploration process. That is, the determined brittleness can be applied to actual oil and gas exploration to improve the efficiency of oil and gas exploration.

[0134] The above method will be described below in conjunction with a specific embodiment. However, it should be noted that this specific embodiment is only for better explaining the present application and does not constitute an improper limitation of the present application.

[0135] Before specific implementation, first obtain the target samples in the shale target area, secondly conduct nanoindentation experiments on the target samples to obtain the load and displacement data of the nanoindentation experiments, and finally calculate the mechanical property data of the target samples and the mechanical property data of the cementation interfaces of the minerals in the target samples based on the load and displacement data. During specific implementation, first form a mechanical property distribution nephogram based on the mechanical property data of the target samples, distinguish the mineral components that are conducive to brittle failure and the mineral components that are not conducive to brittle failure according to the mechanical property distribution nephogram, then obtain the distribution characteristics of the mineral components that are conducive to brittle failure and the mineral components that are not conducive to brittle failure based on the mechanical property nephogram and calculate the distribution ratio of the mineral components that are conducive to brittle failure in the total mineral components, use the distribution ratio to obtain the area ratio of the mineral components conducive to brittle failure in the total mineral components, and take the area ratio as the contribution value of the favorable mineral components. Secondly, distinguish the mineral components that are conducive to brittle failure in the mineral cementation interfaces according to the mechanical property nephogram, conduct nanoindentation experiments on the mineral cementation interfaces again, and the mechanical property data of the mineral cementation interfaces in the target samples can be obtained, including the mechanical property data of the mineral cementation interfaces that are conducive to brittle failure. Based on the mechanical property data of the mineral cementation interfaces that are conducive to brittle failure, obtain the mechanical property contribution value. Further, determine the first brittleness index according to the contribution value of the favorable mineral components and the mechanical property contribution value, determine the second brittleness index according to the standard deviation of the mechanical property data of the target samples, and then determine the brittleness index of the target samples according to the first brittleness index and the second brittleness index. Finally, determine the brittleness of the target samples according to the brittleness index of the target samples. Through the above method, the brittleness of shale can be accurately, quickly and comprehensively determined, and the exploration efficiency of shale oil and gas can be improved.

[0136] In a specific scenario example, the nanoindentation experiment provided in this specification can be applied to conduct indentation experiments on the target samples, and then obtain the mechanical property distribution nephogram based on the data obtained from the indentation experiments, and obtain the mechanical property data of the target samples therefrom. Among them, the nanoindentation experiment on the target samples is as shown in Figure 2 Shown, select a square lattice on the surface of the rock sample and conduct nanoindentation experiments. The points of the indentation are represented by the Figure 2 triangles in, and the spacing is at least kept 30 times the maximum indentation depth to prevent the mutual influence of the indentation stress fields. The 3D mechanical property imaging method conducts a 20×20 indentation lattice, with a total of 400 indentations at different positions, and the test area is 1520×855μm. Figure 3 is the mechanical nephogram of hardness distribution, as shown in Figure 3 Shown, the horizontal and vertical coordinates represent positions, the vertical coordinate represents the hardness value, and the area with high hardness (the rectangular frame part in the figure) represents favorable minerals, and the area with low hardness represents unfavorable minerals.

[0137] Although this specification provides the following embodiments or appendices Figure 4The method operation steps or device structures shown, but based on routine or non-creative labor, the method or device may include more or fewer operation steps or module units after partial combination. In steps or structures where there is no necessary causal relationship logically, the execution order of these steps or the module structure of the device is not limited to the execution order or module structure shown in the embodiments or drawings of this specification. When the method or module structure is applied to actual devices, servers, or terminal products, it can be executed sequentially or in parallel according to the method or module structure shown in the embodiments or drawings (for example, in an environment of parallel processors or multi-threaded processing, and even including an implementation environment of distributed processing and server clusters).

[0138] Based on the above method for determining shale brittleness, this specification also presents an embodiment of a device for determining shale brittleness. As Figure 4 shown, the device for determining shale brittleness may specifically include the following modules:

[0139] The mechanical data acquisition module 401 may specifically be used to obtain a target sample of the target area of the shale, perform a nanoindentation experiment on the target sample, and obtain the mechanical property data of the target sample and the mechanical property data of the cementation interface of the minerals in the target sample;

[0140] The brittleness index acquisition module 402 may specifically be used to form a mechanical property distribution cloud map based on the mechanical property data of the target sample, obtain the contribution value of the favorable mineral components according to the mechanical property distribution cloud map, obtain the mechanical property contribution value according to the mechanical property data of the cementation interface of the minerals in the target sample, and obtain the brittleness index of the target sample according to the contribution value of the favorable mineral components, the mechanical property contribution value, and the mechanical property data of the cementation interface of the minerals in the target sample;

[0141] The brittleness determination module 403 may specifically be used to determine the brittleness of the target sample according to the brittleness index of the target sample.

[0142] In some embodiments, the above mechanical data acquisition module 401 may specifically be used to perform a nanoindentation experiment on the target sample to obtain the first load and first displacement data; calculate the mechanical properties of the indentation point according to the first load and first displacement data as the mechanical property data of the target sample; perform a nanoindentation experiment on the target sample to obtain the mechanical property data of the cementation interface of the minerals in the target sample, including: determining the cementation interface of the minerals in the target sample; performing a nanoindentation experiment on the cementation interface of the minerals in the target sample to obtain the second load and second displacement data; and calculating the mechanical properties of the indentation point according to the second load and second displacement data as the mechanical property data of the cementation interface of the minerals in the target sample.

[0143] In some embodiments, the above-mentioned brittleness index acquisition module 402 may specifically be configured to determine the distribution characteristics of favorable mineral components according to the mechanical property distribution cloud map; determine the proportion of the favorable mineral components in the total mineral components according to the distribution characteristics of the favorable components; use the proportion of the favorable mineral components in the total mineral components as the contribution value of the favorable mineral components; obtain a first brittleness index according to the contribution value of the favorable mineral components and the contribution value of the mechanical properties; obtain a second brittleness index according to the mechanical property data of the cementation interface of the minerals in the target sample; and obtain the brittleness index of the target sample according to the first brittleness index and the second brittleness index.

[0144] In some embodiments, the above-mentioned brittleness determination module 403 may specifically be configured to determine the magnitude of the brittleness index of the target sample according to the magnitudes of the first brittleness index and the second brittleness index of the target sample; and determine the brittleness of the target sample according to the magnitude of the brittleness index of the target sample.

[0145] In some embodiments, after determining the brittleness of the target sample according to the brittleness index of the target sample, when the device is specifically implemented, it may further be configured to determine the shale oil and gas exploration process according to the brittleness of the target sample in the shale target area; and perform shale oil and gas exploration according to the exploration process.

[0146] It should be noted that the units, devices, or modules described in the above embodiments may specifically be implemented by computer chips or entities, or by products with certain functions. For the convenience of description, the above devices are described by dividing them into various modules according to functions. Of course, when implementing this specification, the functions of each module may be implemented in the same or multiple software and / or hardware, or the modules implementing the same function may be implemented by a combination of multiple sub-modules or sub-units. The device embodiments described above are merely illustrative. For example, the division of the units is only a logical function division, and there may be other division methods in actual implementation. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other may be through some interfaces, and the indirect couplings or communication connections of the devices or units may be in electrical, mechanical, or other forms.

[0147] As can be seen from the above, based on the device for determining shale brittleness provided in the embodiments of this specification, it is possible to accurately, efficiently, simply, and comprehensively determine the shale brittleness of the target sample in the target area with a relatively low data processing volume and low cost, thereby effectively guiding shale oil and gas exploration.

[0148] An embodiment of this specification also provides an electronic device, including a processor and a memory for storing instructions executable by the processor. When specifically implemented, the processor may execute the following steps according to the instructions: obtaining a target sample of a shale target area, performing a nanoindentation experiment on the target sample to obtain mechanical property data of the target sample and mechanical property data of the cementation interface of minerals in the target sample; forming a mechanical property distribution cloud map according to the mechanical property data of the target sample; obtaining a contribution value of favorable mineral components according to the mechanical property distribution cloud map; obtaining a mechanical property contribution value according to the mechanical property data of the cementation interface of minerals in the target sample; obtaining a brittleness index of the target sample according to the contribution value of favorable mineral components, the mechanical property contribution value, and the mechanical property data of the cementation interface of minerals in the target sample; and determining the brittleness of the target sample according to the brittleness index of the target sample.

[0149] To be able to more accurately complete the above instructions, refer to Figure 5 As shown, an embodiment of this specification also provides another specific electronic device. Among them, the electronic device includes a network communication port 501, a processor 502, and a memory 503. The above structures are connected by internal cables so that each structure can perform specific data interactions.

[0150] Among them, the network communication port 501 can specifically be used to obtain a target sample of a shale target area, perform a nanoindentation experiment on the target sample to obtain mechanical property data of the target sample and mechanical property data of the cementation interface of minerals in the target sample.

[0151] The processor 502 can specifically be used to form a mechanical property distribution cloud map according to the mechanical property data of the target sample; obtain a contribution value of favorable mineral components according to the mechanical property distribution cloud map; obtain a mechanical property contribution value according to the mechanical property data of the cementation interface of minerals in the target sample; obtain a brittleness index of the target sample according to the contribution value of favorable mineral components, the mechanical property contribution value, and the mechanical property data of the cementation interface of minerals in the target sample; and determine the brittleness of the target sample according to the brittleness index of the target sample.

[0152] The memory 503 can specifically be used to store corresponding instruction programs.

[0153] In this embodiment, the network communication port 501 can be bound to different communication protocols, so as to send or receive different data, such as a virtual port. For example, the network communication port can be a port responsible for web data communication, or a port responsible for FTP data communication, or a port responsible for mail data communication. In addition, the network communication port can also be a physical communication interface or communication chip. For example, it can be a wireless mobile network communication chip, such as GSM, CDMA, etc.; it can also be a Wifi chip; it can also be a Bluetooth chip.

[0154] In this embodiment, the processor 502 can be implemented in any suitable manner. For example, the processor can take the form of, for example, a microprocessor or a processor, and a computer-readable medium storing computer-readable program code (such as software or firmware) executable by the (micro)processor, logic gates, switches, application specific integrated circuit (ASIC), programmable logic controller, and embedded microcontroller, etc. This specification does not make any limitations.

[0155] In this embodiment, the memory 503 can include multiple levels. In a digital system, anything that can store binary data can be a memory; in an integrated circuit, a circuit with a storage function without a physical form is also called a memory, such as RAM, FIFO, etc.; in a system, a storage device with a physical form is also called a memory, such as a memory module, TF card, etc.

[0156] The embodiment of this specification also provides a computer storage medium based on the above method for determining shale brittleness. The computer storage medium stores computer program instructions, which when executed, implement: obtaining a target sample of a shale target area, performing a nanoindentation experiment on the target sample to obtain the mechanical property data of the target sample and the mechanical property data of the cementation interface of the minerals in the target sample; forming a mechanical property distribution cloud map according to the mechanical property data of the target sample; obtaining a contribution value of favorable mineral components according to the mechanical property distribution cloud map; obtaining a mechanical property contribution value according to the mechanical property data of the cementation interface of the minerals in the target sample; obtaining a brittleness index of the target sample according to the contribution value of favorable mineral components, the mechanical property contribution value, and the mechanical property data of the cementation interface of the minerals in the target sample; and determining the brittleness of the target sample according to the brittleness index of the target sample.

[0157] In this embodiment, the storage medium includes, but is not limited to, Random Access Memory (RAM), Read-Only Memory (ROM), Cache, Hard Disk Drive (HDD), or Memory Card. The memory can be used to store computer program instructions. The network communication unit can be set according to the standards specified by the communication protocol and is used as an interface for network connection communication.

[0158] Although this specification provides method operation steps as described in the embodiments or flowcharts, more or fewer operation steps may be included based on conventional or non-creative means. The step order listed in the embodiments is only one way among the execution orders of numerous steps and does not represent the only execution order. When the actual device or client product is executing, it can be executed in the order shown in the embodiments or the drawings or in parallel (for example, in a parallel processor or multi-threaded processing environment, or even in a distributed data processing environment). The term "comprising", "including" or any other variation thereof is intended to cover non-exclusive inclusion, such that a process, method, product or device comprising a series of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, product or device. Without further limitation, there is no exclusion of additional identical or equivalent elements in the process, method, product or device comprising the said elements. The terms first, second, etc. are used to denote names and do not denote any particular order.

[0159] This specification can be described in the general context of computer-executable instructions executed by a computer, such as program modules. Generally, program modules include routines, programs, objects, components, data structures, classes, etc. that perform specific tasks or implement specific abstract data types. This specification can also be practiced in a distributed computing environment where tasks are performed by remote processing devices connected through a communication network. In a distributed computing environment, program modules can be located in local and remote computer storage media including storage devices.

[0160] From the descriptions of the above embodiments, those skilled in the art can clearly understand that this specification can be implemented by means of software plus a necessary general hardware platform. Based on such an understanding, the technical solution of this specification can essentially be embodied in the form of a software product, and this computer software product can be stored in a storage medium, such as ROM / RAM, magnetic disk, optical disk, etc., including several instructions to enable a computer device (which can be a personal computer, mobile terminal, server, or network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments of this specification.

[0161] Although this specification is depicted through embodiments, those of ordinary skill in the art know that this specification has many variations and changes without departing from the spirit of this specification, and it is hoped that the appended claims will cover these variations and changes without departing from the spirit of this specification.

Claims

1. A method for determining the brittleness of shale, characterized in that, the method includes: obtaining a target sample from the target area of shale, conducting a nano-indentation experiment on the target sample to obtain the mechanical property data of the target sample and the mechanical property data of the cementation interface of the minerals in the target sample, the mechanical property data of the target sample including the elastic modulus and hardness of the target sample, and the mechanical property data of the cementation interface of the minerals in the target sample including the elastic modulus and hardness of the cementation interface of the minerals in the target sample; forming a mechanical property distribution cloud map according to the mechanical property data of the target sample; obtaining the contribution value of favorable mineral components according to the mechanical property distribution cloud map; obtaining the mechanical property contribution value according to the mechanical property data of the cementation interface of the minerals in the target sample; obtaining the brittleness index of the target sample according to the contribution value of favorable mineral components, the mechanical property contribution value, and the mechanical property data of the cementation interface of the minerals in the target sample; determining the brittleness of the target sample according to the brittleness index of the target sample; wherein, the obtaining the contribution value of favorable mineral components according to the mechanical property distribution cloud map includes: determining the distribution characteristics of favorable mineral components according to the mechanical property distribution cloud map; determining the proportion of the favorable mineral components in the total mineral components according to the distribution characteristics of the favorable mineral components; taking the proportion of the favorable mineral components in the total mineral components as the contribution value of the favorable mineral components; the obtaining the brittleness index of the target sample according to the contribution value of favorable mineral components, the mechanical property contribution value, and the mechanical property data of the cementation interface of the minerals in the target sample includes: obtaining a first brittleness index according to the contribution value of favorable mineral components and the mechanical property contribution value; obtaining a second brittleness index according to the mechanical property data of the cementation interface of the minerals in the target sample; obtaining the brittleness index of the target sample according to the first brittleness index and the second brittleness index.

2. The method according to claim 1, characterized in that, the conducting a nano-indentation experiment on the target sample to obtain the mechanical property data of the target sample includes: conducting a nano-indentation experiment on the target sample to obtain first load and first displacement data; calculating the mechanical property of the indentation point according to the first load and first displacement data as the mechanical property data of the target sample.

3. The method according to claim 2, characterized in that, the conducting a nano-indentation experiment on the target sample to obtain the mechanical property data of the cementation interface of the minerals in the target sample includes: determining the cementation interface of the minerals in the target sample; conducting a nano-indentation experiment on the cementation interface of the minerals in the target sample to obtain second load and second displacement data; calculating the mechanical property of the indentation point according to the second load and second displacement data as the mechanical property data of the cementation interface of the minerals in the target sample.

4. The method according to claim 3, characterized in that, the mechanical property data of the cementation interface of the minerals in the target sample further includes: the mechanical property data of the cementation interface of the favorable minerals in the target sample.

5. The method according to claim 1, wherein, determining the brittleness of the target sample according to the brittleness index of the target sample includes: determining the brittleness index of the target sample according to the first brittleness index and the second brittleness index of the target sample; determining the brittleness of the target sample according to the brittleness index of the target sample.

6. The method according to claim 1, wherein, after determining the brittleness of the target sample according to the brittleness index of the target sample, the method further includes: determining a shale oil and gas exploration process according to the brittleness of the target sample in the shale target area; conducting shale oil and gas exploration according to the exploration process.

7. A device for determining shale brittleness, wherein, comprising: a mechanical data acquisition module, configured to acquire a target sample in a shale target area, perform a nanoindentation experiment on the target sample, and obtain mechanical property data of the target sample and mechanical property data of the cementation interface of minerals in the target sample, the mechanical property data of the target sample including the elastic modulus and hardness of the target sample, and the mechanical property data of the cementation interface of minerals in the target sample including the elastic modulus and hardness of the cementation interface of minerals in the target sample; a brittleness index acquisition module, configured to form a mechanical property distribution cloud map according to the mechanical property data of the target sample, obtain a contribution value of favorable mineral components according to the mechanical property distribution cloud map, obtain a mechanical property contribution value according to the mechanical property data of the cementation interface of minerals in the target sample, and obtain the brittleness index of the target sample according to the contribution value of favorable mineral components, the mechanical property contribution value, and the mechanical property data of the cementation interface of minerals in the target sample; a brittleness determination module, configured to determine the brittleness of the target sample according to the brittleness index of the target sample; wherein, obtaining the contribution value of favorable mineral components according to the mechanical property distribution cloud map includes: determining the distribution characteristics of favorable mineral components according to the mechanical property distribution cloud map; determining the proportion of the favorable mineral components in the total mineral components according to the distribution characteristics of the favorable mineral components; taking the proportion of the favorable mineral components in the total mineral components as the contribution value of the favorable mineral components; obtaining the brittleness index of the target sample according to the contribution value of favorable mineral components, the mechanical property contribution value, and the mechanical property data of the cementation interface of minerals in the target sample includes: obtaining a first brittleness index according to the contribution value of favorable mineral components and the mechanical property contribution value; obtaining a second brittleness index according to the mechanical property data of the cementation interface of minerals in the target sample; obtaining the brittleness index of the target sample according to the first brittleness index and the second brittleness index.

8. A computer-readable storage medium, wherein, computer instructions are stored thereon, and when the instructions are executed by a processor, the steps of the method according to any one of claims 1 to 6 are implemented.

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