Method and device for identifying complex lithologic shale oil in-situ conversion heating section interlayer

Abstract

The invention discloses a complex lithologic shale oil in-situ conversion heating section interlayer identification method and device, and the method comprises the steps: identifying a non-shale layer according to the lithologic data of a to-be-in-situ conversion section in a shale layer; if the non-shale layer is a single lithologic layer and the thickness is greater than the lower limit of the single-layer thickness of the corresponding interlayer, identifying the non-shale layer as an interlayer; if the non-shale layer is a composite lithologic layer, whether the composite lithologic layer is an interlayer or not is determined according to the thicknesses of all types of contained lithologic single layers and the corresponding interlayer single layer thickness lower limit. According to the method, for a specific application scene of an organic matter-rich shale section, the limitation that the interlayer is recognized only by lithology traditionally is broken through, the hydrocarbon generation potential lower limit value of the interlayer is converted into the interlayer thickness lower limit value which is more visual and easier to obtain, the requirement for data is reduced, and interlayer recognition can be achieved only by lithology data.

Description

Technical Field

[0001] The present invention relates to the technical field of geophysical well logging and in-situ production of shale oil, and in particular to a method and device for identifying interlayers in an in-situ conversion heating section of shale oil with complex lithology. Background Art

[0002] Studies have shown that my country's medium- and low-maturity shale oil resources have great potential. If the corresponding exploration and development technology achieves a breakthrough, it will be of great strategic significance for reducing my country's dependence on foreign crude oil. At present, theoretical and technical exploration in this field is in full swing at home and abroad. The organic matter stored in medium- and low-maturity shales mainly includes two categories: generated retained oil and kerogen that has not been converted into hydrocarbons. The existing unconventional oil and gas development methods that rely on horizontal wells and large-scale hydraulic fracturing are usually not able to effectively develop the two types of organic matter. It is necessary to rely on in-situ heating of shale to convert organic matter into light oil and gas with better fluidity before it can be produced. In this process, the organic-rich shale layer to be heated needs to be finely characterized, especially the interlayer that affects the heating and oil and gas conversion efficiency.

[0003] At present, the technical methods for evaluating interlayers in shale layers are mainly aimed at simple lithologic interlayers. For example, non-shale lithologic interlayers such as sandstone, limestone, dolomite, and mixed sedimentary rocks are identified and characterized in shale. In this type of classification scheme, the thickness, proportion, and development degree of individual interlayers have been studied and reported (Zhu Deshun, Wang Yong, Zhu Deyan, et al. Definition criteria and main controlling factors of interlayer shale oil in the first stratum of Shahejie Formation in Bonan Subsag, 2015; Cheng Ming, Luo Xiaorong, Lei Yuhong, et al. Study on the distribution, fractal characteristics and estimation methods of silty interlayers / lamina in Zhangjiatan shale in Ordos Basin, 2015; Liu Yali, Liu Peng. Characteristics and functions of interlayers in continental organic-rich mudstone - taking Jiyang Depression as an example, 2019; Wang Baohua, Li Hao, Lu Jianlin. Quantitative characterization of the development degree of non-mudstone interlayers in continental shale formations, 2019). In previous studies, the presence of interlayers mainly affects the storage, migration and seepage of generated oil and gas, as well as the hydraulic fracturing effect in the subsequent development stage. Therefore, current research on interlayers mainly focuses on the porosity, permeability, oil and gas saturation and mechanical properties of interlayers.

[0004] In terms of patent technology, the evaluation of interlayers in shale formations is also focused on the effects on the seepage, content or later reservoir transformation of generated oil and gas. For example, the quantitative characterization method of the development degree of permeable interlayers in mudstone (authorization publication number: CN 110569512B), the classification of lithofacies combinations of sandstone interlayer development sections in shale formations (application publication number: CN115876974A), the calculation method and system of the oil content index of sandstone interlayers in shale formations (application publication number: CN114894997A), and the evaluation method of brittleness of continental shale gas reservoirs considering interlayer types (authorization publication number: CN115356772B). Summary of the invention

[0005] The inventors found that for the in-situ conversion of shale oil, the target layer to be developed is the organic-rich shale section, and the mining object is the immobile solid organic matter or the non-flowing viscous retained oil. The traditional identification and evaluation of lithologic interlayers has no significant benefit for the in-situ heating development of low-mature shale oil. In contrast, accurately identifying interlayers with poor hydrocarbon generation potential from the perspective of source rock quality is more practical for the efficient development of shale oil in-situ conversion. At present, there are few studies on the identification and evaluation of interlayers based on differences in hydrocarbon generation potential for organic-rich shale formations. In addition, due to the characteristics of most continental shale formations such as rapid lithologic changes, a large number of interlayers, and thin single-layer thickness, it is difficult to achieve high-precision evaluation of interlayers with low hydrocarbon generation potential in organic-rich shale formations.

[0006] In order to at least partially solve the technical problems existing in the prior art, the inventors have made the present invention, and through a specific implementation method, provide a method and device for identifying interlayers in the heating section of complex lithology shale oil in-situ conversion, which can identify interlayers based on hydrocarbon generation potential, and provide important data basis for realizing efficient development of shale oil in-situ conversion.

[0007] In a first aspect, an embodiment of the present invention provides a method for identifying an interlayer in an in-situ conversion heating section of shale oil with complex lithology, comprising:

[0008] Identify non-shale layers based on lithological data of the proposed in-situ conversion zone within the shale layer;

[0009] If the non-shale layer is a single lithology layer, and the thickness of the non-shale layer is greater than the lower limit of the single layer thickness of the corresponding type of lithology layer as the interlayer of the simulated in-situ conversion section, the non-shale layer is identified as an interlayer;

[0010] If the non-shale layer is a composite lithology layer, whether the composite lithology layer is an interlayer is determined based on the thickness of each type of lithology single layer contained in the composite lithology layer and the lower limit of the single layer thickness of each type of lithology single layer as an interlayer of the quasi-in-situ conversion section. The lower limit of the single layer thickness of each type of lithology single layer as an interlayer of the quasi-in-situ conversion section is predetermined based on the average value of the hydrocarbon generation potential of the shale single layer in the shale layer and multiple data pairs containing the thickness of the lithology single layer of this type and its hydrocarbon generation potential value.

[0011] In a second aspect, an embodiment of the present invention provides an interlayer identification device for an in-situ conversion heating section of complex lithology shale oil, including an interlayer single layer thickness lower limit determination module, a non-shale layer identification module and an interlayer identification module;

[0012] The interlayer single layer thickness lower limit determination module is used to predetermine the single layer thickness lower limit of each type of lithology single layer as the interlayer of the pseudo in-situ conversion section based on the average hydrocarbon generation potential value of the shale single layer in the shale layer and a plurality of data pairs containing the thickness of the lithology single layer of this type and its hydrocarbon generation potential value;

[0013] The non-shale layer identification module is used to identify the non-shale layer according to the lithology data of the proposed in-situ conversion heating section in the shale layer;

[0014] The interlayer identification module is used to identify the sandstone single layer as an interlayer if the non-shale layer is a single lithology layer and the thickness of the non-shale layer is greater than the lower limit of the single layer thickness of the corresponding type of lithology single layer as the interlayer of the pseudo-in-situ conversion section; if the non-shale layer is a composite lithology layer, determine whether the composite lithology layer is an interlayer based on the thickness of each type of lithology single layer contained in the composite lithology layer and the lower limit of the single layer thickness of each type of lithology single layer contained as the interlayer of the pseudo-in-situ conversion section.

[0015] In a third aspect, an embodiment of the present invention provides a computer storage medium, in which computer executable instructions are stored. When the computer executable instructions are executed by a processor, the above-mentioned method for identifying interlayers in the in-situ conversion heating section of complex lithology shale oil is implemented.

[0016] In a fourth aspect, an embodiment of the present disclosure provides a server, comprising: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the above-mentioned method for identifying interlayers in the in-situ conversion heating section of complex lithology shale oil is implemented.

[0017] The beneficial effects of the above technical solution provided by the embodiment of the present invention include at least:

[0018] (1) The method for identifying interlayers in the in-situ conversion heating section of complex lithology shale oil provided in an embodiment of the present invention predetermines, for each type of lithology other than shale contained in the shale layer, the lower limit of the single layer thickness of the lithology single layer of this type as the interlayer of the pseudo in-situ conversion section is determined based on the average value of the hydrocarbon generation potential value of the shale single layer in the shale layer and multiple data pairs containing the thickness of the lithology single layer of this type and its hydrocarbon generation potential value; identifies non-shale layers based on the lithology data of the pseudo in-situ conversion section in the shale layer, and determines whether the non-shale layer is an interlayer by using different methods based on the thickness of the lithology single layer and the corresponding lower limit of the single layer thickness as the interlayer according to whether the non-shale layer is a single lithology layer or a composite lithology layer. First, this method is targeted at specific application scenarios of organic-rich shale sections, breaking the limitation of traditional identification of interlayers based solely on lithology, and is more suitable for geological evaluation and related research on in-situ conversion of shale oil; in addition, this method converts the lower limit of hydrocarbon generation potential of interlayers into a more intuitive and easier to obtain lower limit of interlayer thickness, reducing the requirements for data, and only lithology data is needed to identify interlayers in the proposed in-situ conversion section of shale oil. The direct reason for being able to convert the lower limit of hydrocarbon generation potential of interlayers into the lower limit of interlayer thickness in this way is that there is a significant statistical relationship between interlayer thickness and hydrocarbon generation potential of interlayers; and the fundamental reason is that the enrichment of organic matter requires an extremely low deposition rate, and the smaller the thickness of the interlayer single layer, the faster the deposition rate, the more difficult it is to enrich organic matter, and the worse the hydrocarbon generation potential is.

[0019] (2) The method for identifying the interlayers in the in-situ conversion heating section of complex lithology shale oil provided by the embodiment of the present invention, the data relied on for determining the lower limit of the single layer thickness of each type of lithology single layer as the interlayer of the pseudo in-situ conversion section are the average value of the hydrocarbon generation potential of the shale single layer in the shale layer and multiple data pairs including the thickness of the lithology single layer and its hydrocarbon generation potential value of each type of lithology single layer, which are obtained in the following way: according to the centimeter-level core description data of the continuous coring section in the shale layer and the upper limit of the non-shale layer ratio in the in-situ conversion section, the pseudo in-situ conversion is identified from the coring section. The proposed in-situ conversion section is divided into multiple units, and the type of each unit is determined according to the thickness ratio of the proposed in-situ conversion section, and at least one unit is selected from each type of unit; the selected units are described at the millimeter level, and the units are divided into multiple shale monolayers and sandstone monolayers according to the description results. Rock samples are cut from the monolayers, and the hydrocarbon generation potential of the rock samples is determined by pyrolysis test; the average value of the hydrocarbon generation potential of the shale monolayer and multiple data pairs containing the thickness of the lithology monolayer and its hydrocarbon generation potential of each type of lithology monolayer are statistically obtained. Taking into full consideration the geological characteristics of the shale formation, such as the rapid lithology change and thin monolayer thickness, the basic workload is greatly reduced through lithology combination division, multi-level core fine description, and multi-scale sampling layer screening, while taking into account the lithology representativeness and high sampling accuracy of the collected samples.

[0020] (3) The method for identifying the interlayer of the in-situ conversion heating section of complex lithology shale oil provided by the embodiment of the present invention is to cut a rock sample from a unit, including: determining the reference plane direction according to the extension direction of the bedding plane of the screened unit, cutting and leveling the top and bottom surfaces of the unit in a direction parallel to the reference plane, cutting the side surface of the unit in a direction perpendicular to the reference plane, so that the shape of the cross section of the unit parallel to the reference plane is consistent; cutting the unit into a first rock sample and a second rock sample in a direction perpendicular to the reference plane; obtaining an XRF scan of the cut surface of the second rock sample, and obtaining a sequence of dividing lines arranged in an upper and lower order according to the data difference in the scan, wherein the dividing lines are consistent with the bedding plane direction at the corresponding position; cutting the first rock sample in sequence according to the dividing line sequence to obtain multiple rock samples. The continuous section preparation for the microscopic heterogeneity of fine-grained sedimentary rocks improves work efficiency and reduces sample loss rate; the dividing lines are consistent with the bedding plane direction at the corresponding position, the obtained rock samples are of full types, the heterogeneity representativeness is good, and the rock samples are homogeneous, which provides a basis for realizing fast and high-resolution sample property judgment.

[0021] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description, claims, and drawings.

[0022] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings:

[0024] Figure 1 This is a flow chart of a method for determining the lower limit of the single layer thickness of each type of lithology single layer as an interlayer of a pseudo in-situ conversion section in Example 1 of the present invention;

[0025] Figure 2 This is a flow chart of the method for identifying the interlayer in the heating section of complex lithology shale oil in-situ conversion in the second embodiment of the present invention;

[0026] Figure 3 This is a flow chart of the method for preparing a sample of an organic-rich shale section in Example 3 of the present invention;

[0027] Figure 4 This is an example diagram of a shale section with complex lithological interlayers selected in Example 4 of the present invention;

[0028] Figure 5 It is a schematic diagram of the structure of the interlayer identification device for the in-situ conversion heating section of complex lithology shale oil in an embodiment of the present invention. DETAILED DESCRIPTION

[0029] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0030] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0031] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which the invention belongs. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials related to the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0032] Embodiment 1

[0033] Embodiment 1 of the present invention provides a method for determining the lower limit of the thickness of each type of lithology single layer as an interlayer of a pseudo-in-situ conversion section of a shale layer, specifically determining the lower limit of the thickness of an interlayer identified from a pseudo-in-situ conversion section in a shale layer, i.e., an organic-rich shale development section. Each type of lithology single layer here refers to a lithology single layer of other lithologies contained in a shale layer except shale. Figure 1 As shown, the following steps are included:

[0034] Step S11: Based on the centimeter-level core description data of the continuous coring section in the shale layer and the upper limit of the non-shale layer ratio of the in-situ conversion section, identify the quasi-in-situ conversion section from the coring section, divide the identified quasi-in-situ conversion section into multiple units, determine the type of each unit according to the thickness ratio of the quasi-in-situ conversion section, and screen at least one unit from each type of unit.

[0035] First, typical dissected wells used to identify interlayers with low hydrocarbon generation potential are selected. Generally, typical dissected wells must meet the following requirements:

[0036] (1) The dissecting well must be located in the shale oil in-situ conversion development block, or at least adjacent to the development block;

[0037] (2) at least one well;

[0038] (3) There is a continuous coring section in the shale section to be heated for in-situ conversion of shale oil.

[0039] Based on the lithological description data, the pseudo-in-situ conversion section, that is, the organic-rich shale development section, is identified from the core section of the typical dissecting well.

[0040] For each identified simulated in-situ conversion section, the thickness ratio of the non-shale layer is less than the upper limit of the non-shale layer ratio.

[0041] The upper limit of the non-shale layer ratio in the in-situ conversion section can usually be set to 20%. Optionally, it can also be set to other values ​​according to relevant regulations or actual research needs.

[0042] In some embodiments, the quasi-in-situ conversion section can be divided into multiple units according to the sedimentation cycle, that is, divided into multiple sedimentation cycles, with a single sedimentation cycle as a unit.

[0043] Each unit is classified into one of the following types according to its thickness ratio to the proposed in-situ conversion section:

[0044] (1) The thickness ratio of the proposed in-situ conversion section is less than 1%,

[0045] (2) The thickness ratio of the proposed in-situ conversion section is not less than 1% and not more than 5%,

[0046] (3) The thickness ratio of the proposed in-situ conversion section is greater than 5% and less than 10%,

[0047] (4) The thickness ratio of the proposed in-situ conversion section is greater than 10%.

[0048] The basis for this classification is that the thickness of a single sedimentary cycle is affected by the comprehensive influence of the sedimentary paleoenvironment, which will affect the abundance of organic matter in the lithological combination section.

[0049] Screening the same number of units from each type of unit can be done by screening a typical unit from each type of unit, or by screening multiple units if the research time and conditions permit.

[0050] Step S12: Conduct millimeter-level lithology description on the screened units, divide the units into multiple lithology single layers according to the description results, cut rock samples from the lithology single layers, and determine the hydrocarbon generation potential value of the rock samples through pyrolysis testing.

[0051] (1) Using wire cutting technology, cut each lithologic single layer of each unit (sampling layer) along the lithologic single layer plane, and prepare independent flaky rock samples for each lithologic single layer. The thickness of the rock sample is the thickness of the single layer, and the volume of a single rock sample must meet the mass required for rock pyrolysis (preferably, not less than 5 grams); (2) Conduct rock pyrolysis test on each rock sample; (3) Calculate the sum of free hydrocarbons (S1) (unit: mg / g, the amount of free hydrocarbons in the rock per unit mass) and pyrolysis hydrocarbons (S2) (unit: mg / g, the amount of hydrocarbons generated by pyrolysis of the rock per unit mass) of each pyrolysis rock sample as the hydrocarbon generation potential value of the rock sample.

[0052] Optionally, multiple lithology single-layer rock samples are cut from each unit (sampling layer section), and the method in the following embodiment 3 may also be used.

[0053] Step S13: Statistically obtain the average value of the hydrocarbon generation potential of the shale single layer and a plurality of data pairs including the thickness of each type of lithology single layer and its hydrocarbon generation potential value.

[0054] For each type of lithologic single layer, the following steps S14 and S15 are respectively performed to determine the lower limit of the single layer thickness of the lithologic single layer of this type as the interlayer of the pseudo in-situ conversion section of the shale layer.

[0055] Step S14: For each type of lithologic single layer, multiple sample points are obtained according to the average value of the hydrocarbon generation potential value of the shale single layer in the shale layer and multiple data pairs containing the thickness of the lithologic single layer of this type and its hydrocarbon generation potential value, each sample point containing the ratio of the thickness and hydrocarbon generation potential value of the lithologic single layer of this type to the average value of the hydrocarbon generation potential value of the shale single layer.

[0056] Step S15: Project the sample points into a coordinate system, obtain a fitting trend line by fitting, and determine the ratio of the hydrocarbon generation potential value to the average value of the shale single layer hydrocarbon generation potential value according to the fitting trend line as the single layer thickness corresponding to the set ratio, and determine the thickness as the lower limit of the single layer thickness of the lithology single layer of this type as the interlayer of the quasi-in-situ conversion section.

[0057] The above coordinate system uses the single layer thickness, the ratio of the hydrocarbon generation potential value to the average hydrocarbon generation potential value of the shale single layer (hydrocarbon generation potential value / average hydrocarbon generation potential value of the shale single layer) as coordinate axes.

[0058] The above-mentioned set ratio is usually 38% to 42%; preferably, it is 40%.

[0059] Taking the setting ratio of 40% as an example, 40% of the average hydrocarbon generation potential value of all shale single layers in the quasi-in-situ conversion section is used as the lower limit of the hydrocarbon generation potential of the interlayer of the quasi-in-situ conversion section; then, through the above-mentioned thickness conversion, the lower limit of the single layer thickness of each type of lithology single layer as the interlayer of the quasi-in-situ conversion section is obtained.

[0060] The direct reason why Example 1 of the present application can convert the lower limit value of the hydrocarbon generation potential of the interlayer into the lower limit value of the thickness of the interlayer is that the thickness of the interlayer has a relatively significant statistical relationship with the hydrocarbon generation potential of the interlayer; and the fundamental reason is that the enrichment of organic matter requires an extremely low deposition rate, and the smaller the thickness of the interlayer single layer, the faster the deposition rate, the more difficult it is to enrich the organic matter, and the worse the hydrocarbon generation potential is.

[0061] Embodiment 2

[0062] The second embodiment of the present invention provides a method for identifying interlayers in the in-situ conversion heating section of complex lithology shale oil, which identifies interlayers from the quasi-in-situ conversion section in the shale layer, that is, the organic-rich shale development section. The process is referred to Figure 2 As shown, the following steps are included:

[0063] Step S21: Identify a non-shale single layer based on the lithology data of the proposed in-situ conversion section in the shale layer.

[0064] Lithology data can be data obtained by interpreting conventional logging curves, so its resolution can be consistent with the resolution of the logging curves.

[0065] Step S22: If the non-shale layer is a single lithology layer, and the thickness of the non-shale layer is greater than the lower limit of the single layer thickness of the corresponding type of lithology layer as the interlayer of the proposed in-situ conversion section, the non-shale layer is identified as an interlayer.

[0066] If the thickness of a single lithology layer other than shale is not greater than the lower limit of the single-layer thickness of the corresponding type of lithology as the interlayer of the simulated in-situ conversion section, the non-shale layer is identified as a non-interlayer.

[0067] Step S23: If the non-shale layer is a composite lithology layer, determine whether the composite lithology layer is an interlayer according to the thickness of each type of lithology single layer contained in the composite lithology layer and the lower limit of the single layer thickness of each type of lithology single layer contained as an interlayer of the simulated in-situ conversion section.

[0068] Specifically, it can be divided into the following two situations:

[0069] (1) If the thickness of any type of lithology single layer contained in the composite lithology layer is greater than the lower limit of the single layer thickness of the lithology single layer of this type as an interlayer of the pseudo in-situ conversion section, the composite lithology layer shall be identified as an interlayer.

[0070] If the thickness of any type of lithology single layer is greater than the lower limit of the single layer thickness of this type of lithology single layer as an interlayer of the pseudo in-situ conversion section, then this type of lithology single layer can constitute an interlayer alone; and the composite lithology layer also contains other non-shale lithology single layers, so the composite lithology layer can be identified as an interlayer.

[0071] (2) If the thickness of any type of lithologic single layer contained in the composite lithologic layer is not greater than the lower limit of the single layer thickness of the lithologic single layer of the type as an interlayer of the pseudo-in-situ conversion section, determine the ratio of the thickness of each type of lithologic single layer contained in the composite lithologic layer to the lower limit of the single layer thickness of the corresponding type of lithologic single layer as an interlayer of the pseudo-in-situ conversion section. If the sum of the ratios is greater than 1, the composite lithologic layer is determined to be an interlayer.

[0072]

[0073] In the above formula, H is the composite lithology layer thickness index (i.e. the sum of the above ratios); n is the nth lithology single layer; hn is the thickness of the nth lithology single layer in the composite lithology layer; h0n is the lower limit of the interlayer thickness corresponding to the nth lithology in the composite lithology layer.

[0074] The lower limit of the single-layer thickness of each type of lithologic single layer as the interlayer of the quasi-in-situ conversion section is predetermined based on the average value of the hydrocarbon generation potential of the shale single layer in the shale layer and multiple data pairs containing the thickness of the lithologic single layer of this type and its hydrocarbon generation potential value. The specific determination method is described in the previous embodiment 1 and will not be repeated here.

[0075] The method for identifying interlayers in the in-situ conversion heating section of complex lithology shale oil provided in Example 2 of the present invention predetermines, for each type of lithology other than shale contained in the shale layer, the lower limit of the single layer thickness of the lithology single layer of this type as the interlayer of the proposed in-situ conversion section based on the average value of the hydrocarbon generation potential value of the shale single layer in the shale layer and multiple data pairs containing the thickness of the lithology single layer of this type and its hydrocarbon generation potential value; identifies non-shale layers based on the lithology data of the proposed in-situ conversion section in the shale layer, and determines whether the non-shale layer is an interlayer by using different methods based on the thickness of the lithology single layer and the corresponding lower limit of the single layer thickness as the interlayer, depending on whether the non-shale layer is a single lithology layer or a composite lithology layer. First, this method is targeted at specific application scenarios in organic-rich shale sections, breaking the limitations of traditional reliance on lithology to identify interlayers, and is more suitable for geological evaluation and related research on in-situ conversion of shale oil. In addition, this method converts the lower limit of the hydrocarbon generation potential of the interlayer into a more intuitive and easier to obtain lower limit of the interlayer thickness, reducing the requirements for data, and only lithology data are needed to identify interlayers in the shale oil proposed in-situ conversion section.

[0076] The second embodiment of the present invention provides a method for identifying interlayers in the in-situ conversion heating section of complex lithology shale oil. The data relied on for determining the lower limit of the single-layer thickness of each type of lithology single layer as the interlayer of the quasi-in-situ conversion section are the average value of the hydrocarbon generation potential of the shale single layer in the shale layer and multiple data pairs including the thickness of the lithology single layer and its hydrocarbon generation potential value for each type of lithology single layer. The data are obtained in the following way: based on the centimeter-level core description data of the continuous coring section in the shale layer and the upper limit of the non-shale layer ratio in the in-situ conversion section, the quasi-in-situ conversion section is identified from the coring section, and the identified The pseudo-in-situ conversion section is divided into multiple units according to the sedimentary cycle, and the type of each unit is determined according to the thickness ratio of the pseudo-in-situ conversion section, and at least one unit is selected from each type of unit; millimeter-level lithology description is carried out on the selected units, and the units are divided into multiple shale monolayers and sandstone monolayers according to the description results. Rock samples are cut from the monolayers, and the hydrocarbon generation potential of the rock samples is determined by pyrolysis test; the average value of the hydrocarbon generation potential of the shale monolayer and multiple data pairs containing the thickness of the lithology monolayer and its hydrocarbon generation potential of each type of lithology monolayer are statistically obtained. Taking into full consideration the geological characteristics of the shale formation, such as rapid lithology changes and thin monolayer thickness, the basic workload is greatly reduced through lithology combination division, multi-level core fine description, and multi-scale sampling layer screening, while taking into account the lithology representativeness and high sampling accuracy of the collected samples.

[0077] Embodiment 3

[0078] Embodiment 3 of the present invention provides a method for cutting and preparing a core unit sample of an organic-rich shale section, referring to Figure 3 As shown, the following steps are included:

[0079] Step S31: Determine the reference plane direction according to the extension direction of the sample's bedding plane, cut the top and bottom surfaces of the sample parallel to the reference plane, and cut the side surfaces of the sample perpendicular to the reference plane so that the shape of the cross section of the sample parallel to the reference plane is consistent.

[0080] The top and bottom surfaces of the sample are two end surfaces perpendicular to the axial direction of the coring section.

[0081] The reference plane direction is perpendicular to the dominant bedding plane direction and can be determined by either of the following two methods:

[0082] (1) Count the bedding plane directions of the samples and determine the direction with the most bedding planes as the reference plane direction.

[0083] (2) Based on the directions of the bedding planes of the sample, the reference plane direction is obtained by cluster analysis.

[0084] For example, the reference plane direction finally determined is the direction with the smallest sum of differences with each reference plane, and the difference with each reference plane is determined respectively, and the direction with the smallest sum of differences is determined as the reference plane direction.

[0085] Taking the direction of the reference plane as P and the direction perpendicular to the reference plane as V as an example, the side of the sample is cut along the direction perpendicular to the reference plane so that the shape of the cross section of the sample parallel to the reference plane is consistent. This can be done by using the sample minimum cross-sectional area polygon parallel to P or any shape smaller than the minimum cross-sectional area polygon as the boundary, set as Z, and cutting the sample polygon Z along vector V so that the cross-sectional area of ​​the sample along the direction of vector P is equal.

[0086] Step S32: cutting the sample into a first rock sample and a second rock sample along a direction perpendicular to the reference plane.

[0087] Grind the cut section to make it level with a height difference of no more than 1mm.

[0088] The first rock sample is used as a scanning and reference rock sample, and the second rock sample is used as a cut rock sample, so the volume of the first rock sample does not need to be too large. Preferably, the volume ratio of the first rock sample to the second rock sample is greater than 10.

[0089] Step S33: Obtain an XRF scan of the cut surface of the second rock sample, and obtain a segmentation line sequence arranged in an upper and lower order according to data differences in the scan.

[0090] The second rock sample is placed in the Micro-XRF (micro-area X-ray fluorescence spectrometer) instrument, and the profile is adjusted to a horizontal state; the profile is scanned using Micro-XRF to generate an XRF scan image (data), which is a content distribution map of multiple set elements.

[0091] The conditions for performing XRF scanning along vector V may be: a resolution of 5 microns, a scanning width W = 1 to 2 cm (correspondingly, the width of the cutting surface of the second rock sample is required to be 1 to 5 cm), and a scanning length H, where H is the length of the sample within the range required for heterogeneity research, preferably 1 cm to 30 cm, and the maximum does not exceed HMax or the upper limit of the sample bin of the XRF scanner. HMax is the maximum height of the rock sample, which is the vertical distance between the top and bottom surfaces of the sample.

[0092] In some embodiments, obtaining the segmentation line sequence may include:

[0093] For each XRF scan image, the points whose content change rate of the corresponding element is higher than the set threshold are identified to obtain a scatter point set. Through the scatter point clustering analysis method, multiple possible segmentation lines are obtained from the scatter point set, and the two endpoints of each possible segmentation line are respectively on the two opposite sides of the cutting surface of the second rock sample; through the line clustering analysis method, the possible segmentation lines obtained according to each XRF scan image are clustered and analyzed to obtain a segmentation line sequence arranged in upper and lower order.

[0094] The dividing line determined by the above method is a line formed by points whose corresponding element content change rates of the horizontally matched positions are higher than the set threshold value, so the dividing line is consistent with the direction of the bedding plane at the corresponding position; specifically, each dividing line is located on a bedding plane and is the line where the bedding plane intersects the cutting plane.

[0095] After obtaining the segmentation line sequence by the image method, it can also include determining whether the distance between two adjacent segmentation lines is less than a set distance threshold; if so, deleting one of the segmentation lines, or merging two adjacent segmentation lines whose distance is less than the set distance threshold according to the merging rule of the clustering analysis similarity principle to obtain a new segmentation line.

[0096] The above-mentioned set distance threshold is usually set to 0.2 mm.

[0097] Step S34: cutting the first rock sample in sequence according to the segmentation line sequence to obtain a plurality of rock samples.

[0098] The first rock sample can be cut according to the cutting line sequence by using a diamond wire cutting instrument.

[0099] Furthermore, since the dividing line is consistent with the direction of the bedding plane at the corresponding position, but not necessarily parallel to the reference plane, and the dividing lines are not necessarily parallel to each other, after completing the cutting of the first rock sample according to the dividing line sequence, the cut rock sample can be cut again according to the principle of maximum volume, so that the top and bottom surfaces of the rock sample are parallel; optionally, if the rock type is only used for rock pyrolysis testing, because the rock sample needs to be ground into powder, it is not necessary to level the top and bottom surfaces.

[0100] In the same vertical direction, multiple rock samples can be cut according to research needs. Therefore, in some embodiments, it can include: determining at least one cutting direction perpendicular to the reference plane according to research needs, and completing vertical cutting of the first rock sample according to each cutting direction; wrapping the cut first rock sample with a set material (industrial wax can be used for wrapping), and cutting the wrapped first rock sample in sequence according to the dividing line sequence to obtain multiple rock samples.

[0101] Furthermore, the cut rock sample can be further cut according to the principle of maximum volume so that the top and bottom surfaces of the rock sample are parallel.

[0102] Finally, multiple shale samples and sandstone samples were obtained.

[0103] The sample preparation method provided in Example 3 of the present invention is aimed at the continuous slice preparation of organic-rich shale sections, which improves work efficiency and reduces sample loss rate; the dividing line is consistent with the direction of the bedding plane at the corresponding position, the prepared rock samples are of full types, the heterogeneity is well represented, and the rock samples are homogeneous, which provides a basis for achieving fast and high-resolution sample property judgment.

[0104] Embodiment 4

[0105] Embodiment 4 of the present invention provides a specific application of a method for identifying an interlayer in an in-situ conversion heating section of complex lithology shale oil, which identifies an interlayer from a proposed in-situ conversion section in a shale layer, i.e., an organic-rich shale section, including the following steps:

[0106] S1: The typical dissected well selected in the embodiment is located in the mixed shale development area, and the organic-rich shale section is continuously cored. 10.3 m of the coring section 3185.3 m to 3195.6 m is selected for the demonstration of this embodiment ( Figure 4 ).

[0107] S2: After centimeter-level core description, the coring section in the embodiment is divided into four lithology combination sections according to lithology differences. The first lithology combination section is a mixed shale section, which is composed of shale and various non-shale lithology interlayers; the second lithology combination section is a dolomitic shale section, which is mainly composed of dolomitic interlayers and shale; the third lithology combination section is a sandy shale section, which is mainly composed of sandstone interlayers and shale of different particle sizes and sand content; the fourth lithology combination section is a gray shale section, which is mainly composed of graystone interlayers and shale ( Figure 4 ). In this embodiment, the first lithology combination section is selected as the sample collection section.

[0108] S3: Millimeter-scale core description of the first lithology combination section. The results show that there are 11 single layers and 9 lithologies constituting the non-shale interlayer. The specific lithologies are as follows: Figure 4 shown.

[0109] S4: Cut and sample various non-shale interlayers and shale layers in the first lithology combination section, and conduct analysis and testing on each layer to determine the hydrocarbon generation potential.

[0110] S5: Calculate the average hydrocarbon generation potential value of all shale monolayers in the sampling layer. In this embodiment, 40% of the average hydrocarbon generation potential value of all shale monolayers in the shale section to be heated is used as the lower limit of the hydrocarbon generation potential of the interlayer of the shale section heated by in-situ conversion of shale oil.

[0111] S6: There are 4 points that require special attention in this step: (1) The percentage of hydrocarbon generation potential of each of the 9 lithology layers in the non-shale interlayer to the average hydrocarbon generation potential of the shale layer must be counted. The statistical scope includes the entire typical dissected well, that is, the same lithology in other lithology combination sections with millimeter-level core description is also counted. For each lithology, a relationship chart of the percentage of hydrocarbon generation potential of each lithology layer to the average hydrocarbon generation potential of the shale layer and the thickness of the layer is established; (2) When determining the thickness of the non-shale interlayer layer, since there is no shale layer separating the various non-shale interlayer layers in the first lithology combination section, this 11-layer ( Figure 4(1-11) of the 11 lithology sections are merged into a single layer, namely a “merged single layer”; (3) when the thickness of any single layer among the 11 single layers exceeds the upper limit of the thickness of the hydrocarbon generation potential interlayer of its corresponding lithology, the entire “merged single layer” is considered to be an interlayer with low hydrocarbon generation potential regardless of the thickness of other lithology single layers; (4) when all 11 single layers exceed the upper limit of the thickness of the low hydrocarbon generation potential interlayer of their corresponding lithology, and the “merged single layer thickness index (H)” of the entire “merged single layer” reaches or exceeds 1, the entire “merged single layer” is considered to be an interlayer with low hydrocarbon generation potential; otherwise, the “merged single layer” is considered to be an in-situ converted shale section.

[0112] Based on the inventive concept of the present invention, the embodiment of the present invention also provides a device for identifying the interlayer of the in-situ conversion heating section of complex lithology shale oil. The structure of the device is as follows: Figure 5 As shown, it includes a single layer thickness lower limit determination module 51 for interlayers, a non-shale layer identification module 52 and an interlayer identification module 53;

[0113] The interlayer single layer thickness lower limit determination module 51 is used to predetermine the single layer thickness lower limit of each type of lithology single layer as the interlayer of the pseudo in-situ conversion section based on the average hydrocarbon generation potential value of the shale single layer in the shale layer and a plurality of data pairs containing the thickness of the lithology single layer of this type and its hydrocarbon generation potential value;

[0114] A non-shale layer identification module 52 is used to identify the non-shale layer according to the lithology data of the proposed in-situ conversion heating section in the shale layer;

[0115] The interlayer identification module 53 is used to identify the sandstone single layer as an interlayer if the non-shale layer is a single lithology layer and the thickness of the non-shale layer is greater than the lower limit of the single layer thickness of the corresponding type of lithology single layer as the interlayer of the pseudo-in-situ conversion section; if the non-shale layer is a composite lithology layer, determine whether the composite lithology layer is an interlayer based on the thickness of each type of lithology single layer contained in the composite lithology layer and the lower limit of the single layer thickness of each type of lithology single layer contained as the interlayer of the pseudo-in-situ conversion section.

[0116] In some embodiments, the interlayer identification module 53 is used to:

[0117] If the thickness of any type of lithological single layer contained in the composite lithology layer is greater than the lower limit of the single layer thickness of the lithological single layer of this type as an interlayer of the pseudo-in-situ conversion section, the composite lithology layer is identified as an interlayer; otherwise, determine the ratio of the thickness of each type of lithological single layer contained in the composite lithology layer to the lower limit of the single layer thickness of the corresponding type of lithological single layer as an interlayer of the pseudo-in-situ conversion section, and if the sum of the ratios is greater than 1, the composite lithology layer is determined to be an interlayer.

[0118] In some embodiments, the interlayer single layer thickness lower limit determination module 51 is used to predetermine the single layer thickness lower limit of each type of lithology single layer as the interlayer of the pseudo in-situ conversion section in the following manner:

[0119] For each type of lithologic single layer, multiple sample points are obtained according to the average hydrocarbon generation potential value of the shale single layer in the shale layer and multiple data pairs containing the thickness of the lithologic single layer of this type and its hydrocarbon generation potential value, each sample point containing the ratio of the thickness of the lithologic single layer of this type and the hydrocarbon generation potential value to the average hydrocarbon generation potential value of the shale single layer; the sample points are projected into a coordinate system to obtain a fitting trend line, and the ratio of the hydrocarbon generation potential value to the average hydrocarbon generation potential value of the shale single layer is determined according to the fitting trend line as the single layer thickness corresponding to the set ratio, and the thickness is determined as the lower limit of the single layer thickness of the lithologic single layer of this type as the interlayer of the pseudo-in-situ conversion section.

[0120] In some embodiments, the interlayer single layer thickness lower limit determination module 51 is used to obtain the average hydrocarbon generation potential value of the shale single layer in the shale layer and multiple data pairs including the thickness of each type of lithology single layer and its hydrocarbon generation potential value in the following manner:

[0121] According to the centimeter-level core description data of the continuous coring section in the shale layer and the upper limit of the non-shale layer ratio of the in-situ conversion section, the quasi-in-situ conversion section is identified from the coring section, the identified quasi-in-situ conversion section is divided into multiple units according to the sedimentary cycle, the type of each unit is determined according to the thickness ratio of the quasi-in-situ conversion section, and at least one unit of each type of unit is screened; the screened units are subjected to millimeter-level lithological description, and the units are divided into multiple lithological single layers according to the description results, rock samples are cut from the lithological single layers, and the hydrocarbon generation potential values ​​of the rock samples are determined through pyrolysis tests; the average value of the hydrocarbon generation potential values ​​of the shale single layers and multiple data pairs of each type of lithological single layer, including the thickness of the lithological single layer and its hydrocarbon generation potential value, are statistically obtained.

[0122] In some embodiments, the interlayer single layer thickness lower limit determination module 51 is used to classify the type of each unit into one of the following types:

[0123] The thickness ratio of the proposed in-situ conversion section is less than 1%, the thickness ratio of the proposed in-situ conversion section is not less than 1% and not more than 5%, the thickness ratio of the proposed in-situ conversion section is greater than 5% and not more than 10%, and the thickness ratio of the proposed in-situ conversion section is greater than 10%.

[0124] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0125] Based on the inventive concept of the present invention, an embodiment of the present invention further provides a computer storage medium, in which computer executable instructions are stored. When the computer executable instructions are executed by a processor, the above-mentioned method for identifying interlayers in the in-situ conversion heating section of complex lithology shale oil is implemented.

[0126] Based on the inventive concept of the present invention, an embodiment of the present invention also provides a server, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the above-mentioned method for identifying interlayers in the in-situ conversion heating section of complex lithology shale oil is implemented.

[0127] Unless otherwise specifically stated, terms such as processing, computing, calculating, determining, displaying, etc. may refer to the actions and / or processes of one or more processing or computing systems, or similar devices, which operate and convert data represented as physical (e.g., electronic) quantities within registers or memories of a processing system into other data similarly represented as physical quantities within memories, registers, or other such information storage, transmission, or display devices of the processing system. Information and signals may be represented using any of a variety of different techniques and methods. For example, data, instructions, commands, information, signals, bits, symbols, and chips mentioned throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, light fields or particles, or any combination thereof.

[0128] It should be understood that the specific order or hierarchy of steps in the disclosed process is an example of an exemplary method. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the process can be rearranged without departing from the scope of protection of the present disclosure. The attached method claims present the elements of the various steps in an exemplary order and are not intended to be limited to the specific order or hierarchy described.

[0129] In the above detailed description, various features are grouped together in a single embodiment to simplify the disclosure. This method of disclosure should not be interpreted as reflecting an intention that an embodiment of the claimed subject matter requires more features than those set forth in each claim. On the contrary, as reflected in the appended claims, the invention is in a state of having less than all the features of the disclosed individual embodiments. Therefore, the appended claims are hereby expressly incorporated into the detailed description, with each claim standing on its own as a separate preferred embodiment of the invention.

[0130] Those skilled in the art will also appreciate that the various illustrative logic blocks, modules, circuits, and algorithmic steps described in conjunction with the embodiments herein can all be implemented as electronic hardware, computer software, or a combination thereof. In order to clearly illustrate the interchangeability between hardware and software, various illustrative components, blocks, modules, circuits, and steps are generally described above around their functions. Whether such functions are implemented as hardware or software depends on specific applications and the design constraints imposed on the entire system. A skilled person can implement the described functions in an alternative manner for each specific application, but such implementation decisions should not be interpreted as departing from the scope of protection of the present disclosure.

[0131] The steps of the method or algorithm described in conjunction with the embodiments herein may be directly embodied as hardware, a software module executed by a processor, or a combination thereof. The software module may be located in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, a register, a hard disk, a mobile disk, a CD-ROM, or any other form of storage medium well known in the art. An exemplary storage medium is connected to the processor so that the processor can read information from the storage medium and can write information to the storage medium. Of course, the storage medium may also be an integral part of the processor. The processor and the storage medium may be located in an ASIC. The ASIC may be located in a user terminal. Of course, the processor and the storage medium may also be present in a user terminal as discrete components.

[0132] For software implementation, the techniques described in this application can be implemented with modules (e.g., procedures, functions, etc.) that perform the functions described in this application. These software codes can be stored in a memory unit and executed by a processor. The memory unit can be implemented within the processor or outside the processor. In the latter case, it is coupled to the processor in a communication manner via various means, which are well known in the art.

[0133] The above description includes examples of one or more embodiments. Of course, it is impossible to describe all possible combinations of components or methods for the purpose of describing the above embodiments, but it should be recognized by those skilled in the art that the various embodiments can be further combined and arranged. Therefore, the embodiments described herein are intended to cover all such changes, modifications and variations that fall within the scope of protection of the appended claims. In addition, with respect to the term "comprising" used in the specification or claims, the word is covered in a manner similar to the term "including", just as "including," explained as a transitional word in the claims. In addition, any term "or" used in the specification of the claims is intended to represent "non-exclusive or". The terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance.

Claims

1. A method for identifying interlayers in the in-situ conversion heating section of complex lithology shale oil, characterized in that: include: Identify non-shale layers based on lithological data of the proposed in-situ conversion zone within the shale layer; If the non-shale layer is a single lithology layer, and the thickness of the non-shale layer is greater than the lower limit of the single layer thickness of the corresponding type of lithology layer as the interlayer of the simulated in-situ conversion section, the non-shale layer is identified as an interlayer; If the non-shale layer is a composite lithology layer, whether the composite lithology layer is an interlayer is determined based on the thickness of each type of lithology single layer contained in the composite lithology layer and the lower limit of the single layer thickness of each type of lithology single layer as an interlayer of the quasi-in-situ conversion section. The lower limit of the single layer thickness of each type of lithology single layer as an interlayer of the quasi-in-situ conversion section is predetermined based on the average value of the hydrocarbon generation potential of the shale single layer in the shale layer and multiple data pairs containing the thickness of the lithology single layer of this type and its hydrocarbon generation potential value.

2. The method according to claim 1, characterized in that The step of determining whether the composite lithology layer is an interlayer according to the thickness of each type of lithology single layer contained in the composite lithology layer and the lower limit of the single layer thickness of each type of lithology single layer contained as an interlayer of the pseudo in-situ conversion section includes: If the thickness of any type of lithology single layer contained in the composite lithology layer is greater than the lower limit of the single layer thickness of the lithology single layer of the type as the interlayer of the pseudo in-situ conversion section, the composite lithology layer is identified as an interlayer; Otherwise, determine the ratio of the thickness of each type of lithology single layer contained in the composite lithology layer to the lower limit of the single layer thickness of the corresponding type of lithology single layer as the interlayer of the pseudo-in-situ conversion section; if the sum of the ratios is greater than 1, determine that the composite lithology layer is an interlayer.

3. The method according to claim 1, characterized in that The lower limit of the thickness of each type of lithology single layer as the interlayer of the proposed in-situ conversion section is predetermined by the following method: For each type of lithologic single layer, a plurality of sample points are obtained according to the average value of the hydrocarbon generation potential value of the shale single layer in the shale layer and a plurality of data pairs including the thickness of the lithologic single layer of the type and its hydrocarbon generation potential value, wherein each sample point includes the ratio of the thickness and hydrocarbon generation potential value of the lithologic single layer of the type to the average value of the hydrocarbon generation potential value of the shale single layer; The sample points are projected into a coordinate system to obtain a fitting trend line. According to the fitting trend line, the ratio of the hydrocarbon generation potential value to the average value of the hydrocarbon generation potential value of the shale single layer is determined as the single layer thickness corresponding to the set ratio. The thickness is determined as the lower limit of the single layer thickness of the lithology single layer of this type as the interlayer of the pseudo-in-situ conversion section.

4. The method according to claim 3, characterized in that The set ratio is 38% to 42%.

5. The method according to claim 1, characterized in that The average value of hydrocarbon generation potential of shale single layers in the shale layer and a plurality of data pairs including the thickness of each type of lithology single layer and its hydrocarbon generation potential value are obtained by the following method: According to the centimeter-level core description data of the continuous coring section in the shale layer and the upper limit of the non-shale layer ratio of the in-situ conversion section, the pseudo-in-situ conversion section is identified from the coring section, the identified pseudo-in-situ conversion section is divided into a plurality of units according to the sedimentary cycle, the type of each unit is determined according to the thickness ratio of the pseudo-in-situ conversion section, and at least one unit is selected from each type of unit; Carry out millimeter-level lithology description on the selected units, divide the units into multiple lithology layers according to the description results, cut rock samples from the lithology layers, and determine the hydrocarbon generation potential of the rock samples through pyrolysis test; The average value of the hydrocarbon generation potential of the shale single layer and multiple data pairs including the thickness of the lithology single layer and its hydrocarbon generation potential value for each type of lithology single layer are statistically obtained.

6. The method according to claim 5, characterized in that The type of each unit is determined according to the thickness ratio of the proposed in-situ conversion section, including: Each unit is classified into one of the following types: The thickness ratio of the proposed in-situ conversion section is less than 1%, the thickness ratio of the proposed in-situ conversion section is not less than 1% and not more than 5%, the thickness ratio of the proposed in-situ conversion section is greater than 5% and not more than 10%, and the thickness ratio of the proposed in-situ conversion section is greater than 10%.

7. The method according to claim 5, characterized in that The method of carrying out millimeter-level lithology description on the screened units, dividing the units into a plurality of lithology single layers according to the description results, and cutting rock samples from the lithology single layers also includes: Determine the direction of the reference plane according to the extension direction of the bedding plane of the screened unit, cut and level the top and bottom surfaces of the unit in a direction parallel to the reference plane, and cut the side surfaces of the unit in a direction perpendicular to the reference plane so that the shapes of the cross sections of the unit parallel to the reference plane are consistent; cutting the unit into a first rock sample and a second rock sample along a direction perpendicular to the reference plane; Obtaining an XRF scan of the cut surface of the second rock sample, and obtaining a sequence of segmentation lines arranged in a vertical order according to data differences in the scan, wherein the segmentation lines are consistent in direction with the bedding planes at corresponding positions; The first rock sample is cut in sequence according to the segmentation line sequence to obtain a plurality of rock samples.

8. The method according to claim 7, characterized in that The XRF scans are multiple distribution diagrams of the content of set elements. The segmentation line sequence arranged in a vertical order is obtained according to the data differences in the scans, including: For each XRF scan image, points whose content change rate of the corresponding element is higher than a set threshold are identified to obtain a scattered point set, and multiple possible segmentation lines are obtained from the scattered point set by a scattered point clustering analysis method, wherein two endpoints of each possible segmentation line are respectively on two opposite sides of the cut surface of the second rock sample; By using the line clustering analysis method, possible segmentation lines obtained from each XRF scanning image are clustered and analyzed to obtain a segmentation line sequence arranged in an upper and lower order.

9. The method according to claim 8, characterized in that Also includes: Determine whether the distance between two adjacent segmentation lines is less than the set distance threshold; If so, delete one of the segmentation lines, or merge two adjacent segmentation lines whose distance is less than the set distance threshold according to the merging rule of the cluster analysis similarity principle to obtain a new segmentation line.

10. The method according to claim 1, characterized in that The hydrocarbon generation potential value is the sum of free hydrocarbon S1 and pyrolysis hydrocarbon S2 per unit mass of rock.

11. A device for identifying interlayers in the heating section of complex lithology shale oil in-situ conversion, characterized in that: The device comprises a single layer thickness lower limit determination module for interlayers, a non-shale layer identification module and an interlayer identification module; The interlayer single layer thickness lower limit determination module is used to predetermine the single layer thickness lower limit of each type of lithology single layer as the interlayer of the pseudo in-situ conversion section based on the average hydrocarbon generation potential value of the shale single layer in the shale layer and a plurality of data pairs containing the thickness of the lithology single layer of this type and its hydrocarbon generation potential value; The non-shale layer identification module is used to identify the non-shale layer according to the lithology data of the proposed in-situ conversion heating section in the shale layer; The interlayer identification module is used to identify the sandstone single layer as an interlayer if the non-shale layer is a single lithology layer and the thickness of the non-shale layer is greater than the lower limit of the single layer thickness of the corresponding type of lithology single layer as the interlayer of the pseudo-in-situ conversion section; if the non-shale layer is a composite lithology layer, determine whether the composite lithology layer is an interlayer based on the thickness of each type of lithology single layer contained in the composite lithology layer and the lower limit of the single layer thickness of each type of lithology single layer contained as the interlayer of the pseudo-in-situ conversion section.

12. A computer storage medium, characterized in that: The computer storage medium stores computer executable instructions, which, when executed by a processor, implement the method for identifying interlayers in the in-situ conversion heating section of complex lithology shale oil as described in any one of claims 1 to 10.

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