A method and device for identifying interlayers in heated rock mass during in-situ conversion of shale oil

Abstract

The present invention discloses a method and device for identifying interlayers in a heated rock mass in an in-situ conversion section of shale oil. The method comprises: inputting a sensitivity curve of a target well into a lithologic identification model; obtaining binary lithologic data of a zone of organic-rich shale development based on the model output; identifying at least one pseudo-in-situ conversion section based on a set upper limit for the proportion of non-organic-rich shale in the in-situ conversion section and the binary lithologic data; dividing the pseudo-in-situ conversion section into at least one heated rock mass based on the distribution characteristics of the binary lithologic data and the TOC distribution characteristics; identifying a single layer of non-organic-rich shale in the heated rock mass; and identifying the single layer of non-organic-rich shale as an interlayer if its thickness exceeds a lower limit for the thickness of a single layer that constitutes an interlayer in the pseudo-in-situ conversion section. The method can combine the binary logging lithologic interpretation results with organic matter abundance to finely divide the heated rock mass; and convert the lower limit of the hydrocarbon generation potential of the interlayer into a more intuitive and easily accessible lower limit of the interlayer thickness, thereby intuitively identifying interlayers in the heated rock mass.

Description

Technical Field

[0001] The present invention relates to the technical field of geophysics and shale oil development, and in particular to a method and device for identifying heated rock interlayers in an in-situ conversion section of shale oil. Background Art

[0002] my country has conducted extensive research on the in-situ conversion of oil shale and accumulated rich experience. Various in-situ heating methods for shale, including convection heating, electric heating, and microwave heating, have been studied and demonstrated. These findings have laid a solid foundation for further research and development of in-situ conversion technologies for shale oil. In recent years, progress has been made in evaluating and selecting favorable and sweet spots for in-situ conversion of low- to medium-maturity shale oil (Yang Zhi, Zou Caineng, Fu Jinhua, et al. Evaluation of continental shale sites based on in-situ conversion / upgrading technology: A case study of the 7th member of the Yanchang Formation, Triassic, Ordos Basin, 2017; Patent Grant Announcement No.: CN 109113730 B).

[0003] Analysis of previous research reveals a relatively weak understanding of the definition of the vertical heating section for in-situ conversion of low- to medium-maturity, organic-rich shales. In-situ heating development research for oil shale generally and generally focuses on the oil shale layer as the target zone. While research on in-situ conversion of shale oil has deepened the definition of the heating section, only five conditions have been identified (Zhao Wenzhi, Hu Suyun, and Hou Lianhua. The Connotation and Strategic Role of Underground In-situ Conversion of Shale Oil, 2018). Summary of the Invention

[0004] The inventors discovered that due to the complex and changeable geological conditions of the continental shale formations, my country's organic-rich shale sections often show more significant heterogeneity, which is manifested in the high development of non-shale interlayers and the heterogeneity of the quality of shale source rocks. During the in-situ conversion and heating stage of shale oil, non-shale interlayers and low hydrocarbon generation potential interlayers may differ from organic-rich shale in terms of heat transfer efficiency, thermal cracking, hydrocarbon generation, etc.; in the production stage after the in-situ conversion of shale oil to large-scale oil and gas, interlayers may also differ significantly from organic-rich shale in terms of fracture development, physical properties and oil and gas saturation (for example, the poor ability of interlayers to generate fractures acts as a barrier to oil and gas transmission). These differences will have an impact that cannot be ignored on the selection of optimal heating sections, well pattern and well spacing design during the in-situ conversion and development of shale oil. Based on this, it is very necessary to make a detailed division of heating units for the in-situ conversion heating section of shale oil from the two aspects of lithology and hydrocarbon generation potential.

[0005] In order to at least partially solve the technical problems existing in the prior art, the inventors have made the present invention. Through specific implementation methods, a method and device for identifying interlayers in the heated rock mass of the in-situ conversion section of shale oil are provided, and the lithologic spatial distribution and organic matter abundance of the in-situ conversion heating section of shale oil are finely evaluated, and the heated rock mass of the heating section is further divided; on this basis, interlayers are identified based on hydrocarbon generation potential, providing important data basis for realizing efficient development of in-situ conversion of shale oil.

[0006] In a first aspect, an embodiment of the present invention provides a method for identifying interlayers in heated rock mass during an in-situ conversion stage of shale oil, comprising:

[0007] The sensitivity curve of the target well in the shale layer is input into the lithologic identification model. Based on the output of the model, binary lithologic data of the organic-rich shale development section, including organic-rich shale and non-organic-rich shale, is obtained.

[0008] identifying at least one pseudo-in-situ conversion section within the organic-rich shale development section based on a set upper limit for the proportion of non-organic-rich shale in the in-situ conversion section and the binary lithologic data, and dividing the pseudo-in-situ conversion section into at least one heated rock mass based on the distribution characteristics of the binary lithologic properties and TOC distribution characteristics;

[0009] Identify a non-organic-rich shale single layer in the heated rock mass. If the thickness of the non-organic-rich shale single layer is greater than the lower limit of the single layer thickness as an interlayer in the simulated in-situ conversion section, identify the non-organic-rich shale single layer as an interlayer. The lower limit of the single layer thickness is predetermined based on the average hydrocarbon generation potential value of the organic-rich shale single layer in the shale layer and multiple data pairs including the thickness of the non-organic-rich shale single layer and its hydrocarbon generation potential value.

[0010] In a second aspect, an embodiment of the present invention provides a device for identifying interlayers in heated rock mass in an in-situ conversion section of shale oil, the device comprising a binary lithology prediction module, a heated rock mass division module, an interlayer identification module, a lithology identification model establishment module, and an interlayer single layer thickness lower limit determination module;

[0011] The binary lithology prediction module is used to input the sensitivity curve of the shale layer target well into the lithology identification model, and obtain binary lithology data of the organic-rich shale development section, including organic-rich shale and non-organic-rich shale, based on the model output results. The lithology identification model is pre-established by the lithology identification model establishment module;

[0012] The heated rock mass division module is configured to identify at least one pseudo-in-situ conversion section within the organic-rich shale development section based on a set upper limit of the proportion of non-organic-rich shale in the in-situ conversion section and the binary lithologic data, and to divide the pseudo-in-situ conversion section into at least one heated rock mass based on the distribution characteristics of the binary lithologic properties and the TOC distribution characteristics;

[0013] The interlayer identification module is used to identify a non-organic-rich shale single layer in the heated rock mass. If the thickness of the non-organic-rich shale single layer is greater than the lower limit of the single layer thickness of the interlayer in the simulated in-situ conversion section, the non-organic-rich shale single layer is identified as an interlayer. The lower limit of the single layer thickness is predetermined by the interlayer single layer thickness lower limit determination module based on the average hydrocarbon generation potential value of the organic-rich shale single layer in the shale layer and multiple data pairs including the thickness of the non-organic-rich shale single layer and its hydrocarbon generation potential value.

[0014] In a third aspect, an embodiment of the present invention provides a computer storage medium, wherein the computer storage medium stores computer executable instructions, and when the computer executable instructions are executed by a processor, the above-mentioned method for identifying heated rock interlayers in the in-situ conversion section of shale oil is implemented.

[0015] 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 method for identifying heated rock interlayers in the in-situ conversion section of shale oil is implemented.

[0016] The beneficial effects of the above technical solutions provided by the embodiments of the present invention include at least:

[0017] (1) The method for identifying interlayers in heated rock masses in the in-situ conversion section of shale oil provided by the present invention identifies the pseudo-in-situ conversion section based on the upper limit of the proportion of non-organic-rich shale in the in-situ conversion section, based on binary lithologic logging interpretation. The pseudo-in-situ conversion section is further subdivided into heated rock masses based on binary lithologic differences and TOC differences, making it possible to adopt different well layouts, heating schemes, and subsequent oil and gas development plans for heated rock masses with different geological and geochemical conditions, thus providing an important geological evaluation tool for the large-scale and efficient development of shale oil in-situ conversion. The field significance of this achievement lies in enabling the refined and differentiated design of in-situ conversion development plans.

[0018] (2) The method for identifying interlayers in heated rock masses in the in-situ conversion section of shale oil provided in an embodiment of the present invention predetermines the lower limit of the thickness of the non-organic-rich shale single layer as an interlayer in the proposed in-situ conversion section based on the average value of the hydrocarbon generation potential of the organic-rich shale single layer in the shale layer and multiple data pairs including the thickness of the non-organic-rich shale single layer and its hydrocarbon generation potential value; if the thickness of the non-organic-rich shale single layer is determined to be greater than the lower limit of the thickness of the single layer as an interlayer, it is determined to be an interlayer. First, this method is targeted at the specific application scenario of the organic-rich shale development section, breaking the limitation of the traditional method of identifying 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 the hydrocarbon generation potential of the interlayer into a more intuitive and easier to obtain lower limit of the thickness of the interlayer, reducing the requirements for data, and only lithology data is needed to realize the identification of interlayers in the proposed in-situ conversion section of shale oil. The direct reason why the lower limit of the hydrocarbon generation potential of the interlayer can be converted into the lower limit of the interlayer thickness in this way is that the interlayer thickness 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 sedimentation rate, and the smaller the thickness of the single interlayer, the faster the sedimentation rate, the more difficult it is to enrich organic matter, and ultimately the worse the hydrocarbon generation potential.

[0019] (3) The method for identifying shale interlayers based on hydrocarbon generation potential and lithologic binarization provided in the embodiment of the present invention determines the data on which the lower limit of the thickness of a non-organic-rich shale monolayer as an interlayer of a pseudo-in-situ conversion section depends, which is the average value of the hydrocarbon generation potential of the organic-rich shale monolayer in the shale layer and a plurality of data pairs including the thickness of the non-organic-rich shale monolayer and its hydrocarbon generation potential value, obtained in the following manner: according to the binary lithologic data of the continuous coring section in the shale layer and the upper limit of the proportion of non-organic-rich shale in the in-situ conversion section, the pseudo-in-situ conversion section is identified from the coring section; according to the sedimentary cycle The identified pseudo-in situ conversion section was divided into multiple units. The type of each unit was determined by its thickness ratio relative to the pseudo-in situ conversion section, and at least one unit of each type was selected. A millimeter-level lithologic description was performed on the selected units. Based on the description results, the units were divided into multiple organic-rich shale single layers and non-organic-rich shale single layers. Rock samples were cut from the single layers and their hydrocarbon generation potentials were determined through pyrolysis testing. The average hydrocarbon generation potential of the organic-rich shale single layers and multiple data pairs containing the thickness and hydrocarbon generation potential of the non-organic-rich shale single layers were statistically obtained. Taking into account the geological characteristics of continental shale formations, such as rapid lithologic changes and thin single layers, the lithologic combination classification, multi-level core characterization, and multi-scale sampling interval screening significantly reduced the workload while ensuring the lithologic representativeness and high sampling accuracy of the collected samples.

[0020] (4) The method for identifying interlayers in heated rock mass in the in-situ conversion section of shale oil provided by the embodiment of the present invention is aimed at the specific scenario of lithologic identification of thin interlayers in the organic-rich shale development section. It abandons the universal pursuit of conventional well logging lithologic interpretation to interpret and characterize various lithologies developed in the study area separately, and limits the lithologic interpretation objects to two types: organic-rich shale and non-organic-rich shale. It reduces the multi-solution of well logging lithologic interpretation and improves the interpretation accuracy. At the same time, it reduces the amount of calculation and improves the recognition speed of batch interpretation of multiple wells.

[0021] (5) The method for identifying interlayers in heated rock mass during the in-situ conversion phase of shale oil provided by the present invention requires only core data from sample wells during the lithologic identification model establishment phase. Once the modeling is complete, only conventional well logging curves are required during the application phase to accurately characterize the lithologic properties of organic-rich shale using binary methods. This significantly reduces the requirements for data quality while ensuring interpretation accuracy.

[0022] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or will be understood by practicing the present invention. The purposes 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.

[0023] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] 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:

[0025] Figure 1 This is a flow chart of a method for determining the lower limit of the thickness of a single layer of non-organic-rich shale as an interlayer in Example 1 of the present invention;

[0026] Figure 2 This is a flow chart of a method for establishing a lithology identification model for an organic-rich shale development section based on lithology binarization in Example 2 of the present invention;

[0027] Figure 3 This is a flow chart of the method for identifying heated rock interlayers in the in-situ conversion section of shale oil in Example 3 of the present invention;

[0028] Figure 4 This is a comprehensive histogram of sample wells selected in Example 4 of the present invention;

[0029] Figure 5 Schematic diagram of the division of the heated rock mass in the shale oil in-situ conversion heating section in Example 4 of the present invention;

[0030] Figure 6 The histogram of a typical dissecting well and the distribution of three sampling points in Example 5 of the present invention are shown below;

[0031] Figure 7 for Figure 6 The millimeter-scale silt interlayer, shale single layer division and sampling plan of "Sampling Point 1";

[0032] Figure 8 for Figure 6 The millimeter-scale silt interlayer and shale single layer division and sampling plan diagram of "Sampling Point 2" and "Sampling Point 3";

[0033] Figure 9 A graph showing the relationship between the ratio of the average value of the hydrocarbon generation potential of a sandstone single layer to that of a shale and the thickness of the sandstone single layer in Example 5 of the present invention;

[0034] Figure 10 for Figure 6 "Sampling point 1" is based on the comparison between the lithologic profile evaluated in this embodiment and the conventional lithologic profile;

[0035] Figure 11 This is a schematic structural diagram of a device for identifying heated rock interlayers in an in-situ conversion section of shale oil in an embodiment of the present invention. DETAILED DESCRIPTION

[0036] Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although 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. Rather, 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.

[0037] It should be understood that the terms described herein are intended only to describe particular embodiments and are not intended to limit the present invention. In addition, for numerical ranges herein, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Each smaller range between any intermediate value within a stated value or stated range and any other stated value or intermediate value within the stated range is also encompassed by the present invention. The upper and lower limits of these smaller ranges may be independently included or excluded within the scope.

[0038] Unless otherwise indicated, all technical and scientific terms used herein have the same meaning 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 any conflict with any incorporated document, the content of this specification shall prevail.

[0039] In the embodiment of the present application, the TOC lower limit of organic-rich shale is used as a standard to classify organic-rich shale and non-organic-rich shale. Specifically, the lithology of rocks with TOC greater than the lower limit is defined as organic-rich shale; the lithology of rocks with TOC not greater than the lower limit is defined as non-organic-rich shale.

[0040] The lower limit of TOC of organic-rich shale is flexibly set according to the actual geological conditions of the study area, and can usually be set to 2%, 3% or 5%. Optionally, it can also be set to other values.

[0041] Example 1

[0042] The first embodiment of the present invention provides a method for determining the lower limit of the thickness of a single layer of non-organic-rich shale as an interlayer of a pseudo-in-situ conversion section in a shale layer, specifically determining the lower limit of the thickness of a non-organic-rich shale interlayer identified from a pseudo-in-situ conversion section in a shale layer, referring to Figure 1 As shown, the following steps are included:

[0043] Step S11: Based on the binary lithologic data of the cored section of the target layer of the sample well and the upper limit of the proportion of non-organic-rich shale in the in-situ conversion section, identify the pseudo-in-situ conversion section from the cored section, divide the identified pseudo-in-situ conversion section into multiple units, determine the type of each unit according to the thickness ratio of the pseudo-in-situ conversion section, and select at least one unit from each type of unit.

[0044] First, typical dissected wells are selected to identify interlayers with low hydrocarbon generation potential. Generally, typical dissected wells must meet the following requirements:

[0045] (1) The dissecting well must be located within the shale oil in-situ conversion development block, or at least adjacent to the development block;

[0046] (2) at least one well;

[0047] (3) There is a continuous coring section in the shale oil in-situ conversion section where the shale is to be heated.

[0048] Binary lithologic data of the coring section, including organic-rich shale and non-organic-rich shale, can be obtained from core description data, thin section identification data, and TOC detection data of the coring section of the target layer of the sample well. The acquisition process includes the following description in Example 2.

[0049] Here, the binary lithology data of the core section needs to be centimeter-level lithology data.

[0050] The thickness of the non-organic-rich shale in the simulated in-situ conversion section identified from the coring section is less than the set upper limit of the non-organic-rich shale ratio in the in-situ conversion section.

[0051] The upper limit of the proportion of non-organic-rich shale 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.

[0052] 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.

[0053] Each unit is divided into one of the following types according to its thickness ratio to the proposed in-situ conversion section:

[0054] (1) The thickness ratio of the proposed in-situ conversion section is less than 1%,

[0055] (2) The thickness ratio of the proposed in-situ conversion section is not less than 1% and not more than 5%,

[0056] (3) The thickness ratio of the proposed in-situ conversion section is greater than 5% and not greater than 10%,

[0057] (4) The thickness ratio of the in-situ conversion section is greater than 10%.

[0058] 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 organic matter abundance of the lithologic combination section.

[0059] The same number of units can be screened from each type of unit. One typical unit can be screened from each type of unit. If the research time and conditions permit, multiple units can also be screened.

[0060] Step S12: Perform millimeter-level binary lithologic description on the selected units. Based on the description results, divide the units into multiple organic-rich shale monolayers and non-organic-rich shale monolayers. Cut rock samples from the monolayers and determine the hydrocarbon generation potential of the rock samples through pyrolysis testing.

[0061] Based on the millimeter-level binary lithologic description of the selected units, the following steps are performed:

[0062] (1) Using wire cutting technology, cut each lithologic layer of each unit (sampling layer) along the lithologic layer plane, and prepare an independent flaky rock sample for each lithologic 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 testing 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 after pyrolysis of the rock per unit mass) of each pyrolysis rock sample as the hydrocarbon generation potential value of the rock sample.

[0063] Step S13: Statistically obtain an average value of the hydrocarbon generation potential value of the organic-rich shale single layer and a plurality of data pairs including the thickness of the non-organic-rich shale single layer and its hydrocarbon generation potential value.

[0064] The data used to determine the lower limit of the thickness of a non-organic-rich shale monolayer as an interlayer of a pseudo-in situ conversion section are the average hydrocarbon generation potential of the organic-rich shale monolayer within the shale layer and multiple data pairs including the thickness of the non-organic-rich shale monolayer and its hydrocarbon generation potential. The data are obtained in the following manner: based on the binary lithologic data of consecutive coring sections within the shale layer and the upper limit of the proportion of non-organic-rich shale in 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 multiple units according to the sedimentary cycle, the type of each unit is determined according to the thickness ratio of each unit to the pseudo-in situ conversion section, and at least one unit of each type is selected; the selected units are subjected to millimeter-level lithologic description, and based on the description results, the units are divided into multiple organic-rich shale monolayers and non-organic-rich shale monolayers; rock samples are cut from the monolayers and the hydrocarbon generation potential of the rock samples is determined by pyrolysis testing; and the average hydrocarbon generation potential of the organic-rich shale monolayer and multiple data pairs including the thickness of the non-organic-rich shale monolayer and its hydrocarbon generation potential are statistically obtained. Taking full account of the geological characteristics of the continental shale formations, such as rapid lithologic changes and thin single-layer thickness, the basic workload was greatly reduced through lithologic combination division, multi-level core detailed description, and multi-scale sampling layer screening, while taking into account the lithologic representativeness and high sampling accuracy of the collected samples.

[0065] Step S14: Based on each data pair, a sample point is obtained, which includes the ratio of the thickness of the non-organic-rich shale single layer and the hydrocarbon generation potential value to the average hydrocarbon generation potential value of the organic-rich shale single layer.

[0066] Step S15: Project the sample points into a coordinate system and obtain a trend line by fitting. Based on the trend line, determine the ratio of the hydrocarbon generation potential value to the average hydrocarbon generation potential value of the organic-rich shale single layer as the thickness of the non-organic-rich shale single layer corresponding to the set ratio. This thickness is determined as the lower limit of the single layer thickness of the non-organic-rich shale single layer as the interlayer of the simulated in-situ conversion section.

[0067] The coordinate system uses the thickness of a non-organic-rich shale single layer and the ratio of the hydrocarbon generation potential value of a non-organic-rich shale single layer to the average hydrocarbon generation potential value of a shale single layer (hydrocarbon generation potential value of a non-organic-rich shale single layer / average hydrocarbon generation potential value of a shale single layer) as the coordinate axes.

[0068] The above-mentioned set ratio is usually 38% to 42%; preferably, it is 40%.

[0069] Taking the set ratio of 40% as an example, 40% of the average hydrocarbon generation potential value of all organic-rich shale single layers in the pseudo-in situ conversion section is used as the lower limit of the hydrocarbon generation potential of the interlayer of the pseudo-in situ conversion section; then, through the above-mentioned thickness conversion, the lower limit of the single layer thickness of the non-organic-rich shale single layer as the interlayer of the pseudo-in situ conversion section is obtained.

[0070] 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 ultimately the worse the hydrocarbon generation potential.

[0071] Example 2

[0072] The second embodiment of the present invention provides a method for establishing a lithology identification model for an organic-rich shale development section based on lithology binarization. Figure 2 As shown, the following steps are included:

[0073] Step S21: Determine the lower limit of the GR value of the organic-rich shale based on the binary lithologic data of the core section of the target layer of the sample well.

[0074] Wells cored in the target layer of the study area are selected as sample wells. Optionally, the selected wells can be divided into sample wells and verification wells. The relevant data of the verification wells do not participate in the training of the model and are only used for the later verification of the model.

[0075] Specifically, the binary lithologic data of the core section, including organic-rich shale and non-organic-rich shale (i.e., interlayer), is obtained by the following steps:

[0076] (1) Based on the thin section identification data of the core section of the target layer of the sample well, the lithologic description data in the core description data is corrected to obtain preliminary lithologic data, which includes mud shale.

[0077] The lithologic descriptions in core data are merely empirical descriptions of the cores made by geologists based on visual observation. Due to the limitations of visual observation and subjective factors, the accuracy of these lithologic descriptions requires further refinement. Thin section identification data can accurately assign lithologic names, but thin section identification data is limited in sampling. Therefore, preliminary lithologic data is obtained based on the lithologic descriptions in the core data and verified with thin section identification data.

[0078] The preliminary description data obtained may include clastic rocks such as shale, coarse sandstone, medium sandstone, fine sandstone and siltstone, and may also include carbonate rocks or other rock types.

[0079] (2) Based on the TOC detection data, the mud shale with a TOC value greater than the preset lower limit of TOC for organic-rich shale in the preliminary lithologic data is determined as organic-rich shale, and the binary lithologic data of the coring section is obtained.

[0080] Thin section identification data can be used to accurately determine lithologic names at the millimeter level. However, thin section identification data cannot distinguish between organic-rich and non-organic-rich shales. In this case, TOC values ​​must be referenced to define shales with TOC values ​​no greater than the lower limit of the TOC of organic-rich shales, as well as other lithologies other than shales, as non-organic-rich shales.

[0081] It can be seen that the organic-rich shale in this embodiment is defined based on the TOC lower limit of organic-rich shale. Shale that meets this lower limit is organic-rich shale; the organic-rich shale development section refers to a rock formation composed of organic-rich shale and its interlayers.

[0082] The lower limit of TOC of organic-rich shale is flexibly set according to the actual geological conditions of the study area, and can usually be set to 2%, 3% or 5%. Optionally, it can also be set to other values.

[0083] Mud shales with TOC values ​​not greater than the lower limit of TOC of organic-rich shales, as well as other lithologies other than mud shales, are identified as non-organic-rich shales.

[0084] Determining the lower limit of the GR value of organic-rich shale can include extracting the lithology and GR values ​​of sampling points with thin section identification data and TOC test data based on lithology data and GR curves of sample wells; and statistically obtaining the lower limit of the GR value of organic-rich shale based on the lithology and GR values ​​of multiple sampling points.

[0085] Since the interlayer identification in this embodiment is based on the well logging curve, the well logging curve of the sample well must first be standardized; after obtaining the preliminary lithologic data or binary lithologic data of the coring section, the standardized well logging curve is depth-relocated.

[0086] The GR values ​​of the above sampling points are extracted from the GR curve after standardization and depth resetting.

[0087] Step S22: taking the binary lithologic data of the coring section and the curve section of the selected sensitivity curve as a sample, and establishing a sample set.

[0088] In some embodiments, after obtaining the binary lithologic data of the coring section, the method further includes screening sensitivity curves of organic-rich shale and non-organic-rich shale from all types of well logging curves of the sample well.

[0089] Step S23: Use the sample set to train the selected neural network model, establish a lithology recognition model, and input the GR value lower limit into the lithology recognition model.

[0090] Example 3

[0091] The third embodiment of the present invention provides a method for identifying interlayers in heated rock mass in the in-situ conversion section of shale oil. Figure 3 As shown, the following steps are included:

[0092] Step S31: Input the sensitivity curve of the target well in the shale layer into the lithologic identification model, and obtain binary lithologic data of the organic-rich shale development section including organic-rich shale and non-organic-rich shale according to the output of the model.

[0093] The lithology identification model is pre-established using the method described in the second embodiment above.

[0094] The lithologic identification model works by initially locating the organic-rich shale development interval based on the GR lower limit of the organic-rich shale and the GR curve of the target well. Based on the neural network learning results of the corresponding sensitive curve segments of the organic-rich shale development interval, the binary lithologic data is determined and output.

[0095] That is, the lower limit of the GR value of organic-rich shale is first used to roughly locate the organic-rich shale development section, and then the lithology identification model is used to perform fine and high-resolution binary lithology prediction for the organic-rich shale development section.

[0096] In some embodiments, before inputting the sensitivity curve of the target well into the lithologic identification model, the process also includes using rock logging data to remove high GR value outliers from the sensitivity curve of the target well, such as those in non-organic-rich shales. For example, interference from high GR values ​​in organic-rich shales caused by specific high GR rocks, such as high-uranium sandstone, can be removed.

[0097] Step S32: identifying at least one pseudo-in-situ conversion section within the organic-rich shale development section according to the set upper limit of the proportion of non-organic-rich shale in the in-situ conversion section and the binary lithologic data.

[0098] That is, the identified pseudo-in-situ conversion section satisfies the requirement that the thickness of the non-organic-rich shale layer is less than the upper limit of the non-organic-rich shale ratio in the in-situ conversion section.

[0099] The upper limit of the proportion of non-organic-rich shale 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.

[0100] Step S33: Divide the quasi-in-situ conversion section into at least one heated rock mass according to the distribution characteristics of the binary lithology and the TOC distribution characteristics.

[0101] Alternatively, a histogram of the binary lithologic profile and TOC profile of the organic-rich shale development section may be established.

[0102] Furthermore, if there is coring data for the organic-rich shale development section of the target well, the lithologic profile is established based on the binary lithologic description data of the coring data; if the binary lithologic description data in the coring data is incomplete, the lithologic data is supplemented in combination with the model output results to establish a binary lithologic profile.

[0103] The TOC profile can be established by using the measured TOC values ​​if there are continuous TOC values ​​(sampling interval is not greater than 0.5 meters) in the organic-rich shale development section of the target well. If there are no or only partial measured TOC values ​​in the organic-rich shale development section of the target well, the measured TOC values ​​are used first, and the interpreted TOC values ​​of the TOC interpretation model are used to supplement the measured TOC data in the remaining sections to establish the TOC profile.

[0104] Specifically, the division of the heated rock mass in the proposed in-situ conversion stage is based on the following principles:

[0105] The TOC difference between the heated rock mass and the adjacent heated rock mass satisfies a first set difference, and / or the lithology combination difference between the heated rock mass and the adjacent heated rock mass satisfies a second set difference.

[0106] Furthermore, the first set difference includes the overall TOC value difference and / or the overall TOC curve morphology difference; the second set difference includes the number of non-organic-rich shale layers and / or the thickness of non-organic-rich shale layers.

[0107] There are three situations in which a shale oil in-situ conversion heated rock mass is different from an adjacent heated rock mass. Situation 1: The heated rock mass and its adjacent heated rock mass have significantly different TOC value curve characteristics, such as overall TOC value differences or overall TOC value curve morphology differences. The specific differences need to be determined in combination with actual conditions in different embodiments. Situation 2: The heated rock mass and its adjacent heated rock mass do not have significantly different TOC value curve characteristics, but have significantly different lithologic combinations, such as the number of interlayers or the thickness of a single interlayer. The specific differences need to be determined in combination with actual conditions in different embodiments. Situation 3: The heated rock mass and its adjacent heated rock mass have both TOC value curve characteristic differences and lithologic combination differences.

[0108] Step S34: Identify a non-organic-rich shale single layer in the heated rock mass. If the thickness of the non-organic-rich shale single layer is greater than the lower limit of the single layer thickness as an interlayer in the simulated in-situ conversion section, identify the non-organic-rich shale single layer as an interlayer.

[0109] The lower limit of the single layer thickness is predetermined based on the average hydrocarbon generation potential value of the organic-rich shale single layer in the shale layer and multiple data pairs including the thickness of the non-organic-rich shale single layer and its hydrocarbon generation potential value. The specific determination method is described in Example 1.

[0110] The third embodiment of the present application provides a method for identifying interlayers in heated rock masses within the in-situ conversion zone of shale oil. The working principle of the binary lithologic interpretation method is as follows: Based on the fact that organic-rich shales form in reducing environments that facilitate uranium precipitation, resulting in high uranium and high natural gamma ray characteristics that distinguish them from other lithologies, the method utilizes natural gamma ray combined with conventional rock logging to eliminate interference from other non-shale, high-GR rocks (such as sandstone-type uranium deposits) and identify the vertical distribution of high-GR organic-rich shale development zones. Within the identified organic-rich shale development zones, the correlation between various conventional well logging curves and the organic-rich shale is automatically calculated, and the curve with the best correlation is directly selected as the input curve. A neural network method is then used to automatically establish a lithologic identification model for organic-rich shale and non-organic-rich shale. The lithologic identification model is continuously and iteratively verified in calibration wells to ensure that the interpretation results are consistent with the actual results. Ultimately, the front-end inputs various conventional well logging curves, and the terminal automatically generates a high-precision lithologic profile containing both organic-rich and non-organic-rich shale.

[0111] The third embodiment of the present invention provides a method for identifying interlayers in heated rock masses within the in-situ conversion zone of shale oil. Based on binary lithologic logging interpretation, the method identifies the simulated in-situ conversion zone according to the upper limit of the proportion of non-organic-rich shale within the in-situ conversion zone. Within the simulated in-situ conversion zone, the method further subdivides the heated rock masses based on binary lithologic and TOC differences. This enables the adoption of different well placement methods, heating schemes, and subsequent oil and gas development plans for heated rock masses with varying geological and geochemical conditions, providing an important geological evaluation tool for the large-scale and cost-effective development of in-situ conversion of shale oil. The practical significance of this achievement lies in enabling the refined and differentiated design of in-situ conversion development plans.

[0112] The method for identifying interlayers in heated rock masses in the in-situ conversion section of shale oil provided in Example 3 of the present invention predetermines the lower limit of the thickness of the non-organic-rich shale single layer as an interlayer in the proposed in-situ conversion section based on the average value of the hydrocarbon generation potential of the organic-rich shale single layer in the shale layer and multiple data pairs including the thickness of the non-organic-rich shale single layer and its hydrocarbon generation potential value; if the thickness of the non-organic-rich shale single layer is determined to be greater than the lower limit of the thickness of the single layer as an interlayer, it is determined to be an interlayer. First, this method is targeted at specific application scenarios of organic-rich shale development sections, breaking the limitations of traditional methods of identifying interlayers solely by 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 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 is needed to realize the identification of interlayers in the proposed in-situ conversion section of shale oil. The direct reason why the lower limit of the hydrocarbon generation potential of the interlayer can be converted into the lower limit of the interlayer thickness in this way is that the interlayer thickness 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 sedimentation rate, and the smaller the thickness of the single interlayer, the faster the sedimentation rate, the more difficult it is to enrich organic matter, and ultimately the worse the hydrocarbon generation potential.

[0113] The method for identifying interlayers in heated rock masses in the in-situ conversion section of shale oil provided in Example 3 of the present invention is aimed at the specific scenario of identifying the lithologic properties of thin interlayers in the organic-rich shale development section. It abandons the universal pursuit of conventional well logging lithologic interpretation to interpret and characterize various lithologies developed in the study area separately, and limits the lithologic interpretation objects to two types: organic-rich shale and interlayers (non-organic-rich shale). This reduces the multi-solution nature of well logging lithologic interpretation and improves the interpretation accuracy; at the same time, it reduces the amount of calculation and improves the identification speed of batch interpretation of multiple wells.

[0114] The method for identifying intercalated layers in heated rock mass during the in-situ conversion phase of shale oil, provided in Example 3 of the present invention, requires only core data from sample wells during the lithologic identification model establishment phase. Once the model is complete, conventional well logging curves are sufficient for high-precision characterization of the binary lithologic properties of organic-rich shale. This significantly reduces the requirements for data quality while ensuring interpretation accuracy.

[0115] The method for identifying heated rock interlayers in the in-situ conversion section of shale oil provided in Example 3 of the present invention adopts artificial intelligence methods such as neural networks to eliminate human influence as much as possible and further improve the reliability of lithologic interpretation.

[0116] Example 4

[0117] The fourth embodiment of the present invention provides a specific application of a method for dividing a heated rock mass in an in-situ conversion stage of shale oil, comprising the following steps:

[0118] S1: The shale oil in-situ conversion heating section in the sample well selected in the example has continuous core samples, complete conventional logging curves, and systematic sampling and TOC testing have been carried out in the shale section. Figure 4 shown.

[0119] S2: Standardize the well logging curves of the sample wells. After performing lithologic identification and TOC testing on the heated shale section, the lithology of this section is binarized into two categories: organic-rich shale and interlayer. Core and well logging curve depth regression, binary lithologic sensitivity curve screening, and well logging lithologic identification model establishment are sequentially performed. In this example, the binary lithologic sensitivity curves determined are natural gamma ray (GR), neutron compensation (CNL), and acoustic transit time (AC).

[0120] S3: A TOC logging interpretation model was established using continuous TOC detection data (sampling interval of 0.1m to 0.2m) from the organic-rich shale development section of the sample well, as well as deep resistivity (RD), natural gamma ray (GR), and density (DEN) logging curve data.

[0121] S4: Using the lithologic identification model and TOC logging interpretation model established in steps S2 and S3, a heated rock mass partitioning histogram including a binary lithologic profile and a TOC profile is established. Figure 4 shown.

[0122] S5: Determine the heating rock mass division scheme based on the histogram established in step S4. In this embodiment, the shale oil in-situ conversion heating section is subdivided into three heating rock masses: T1, T2, and T3. The shale in the T1 section is pure, without interlayers, and has a high overall TOC; the T2 section has two sets of sand interlayers locally developed, and the TOC is relatively high overall; the T3 section has mixed shale and sandstone interlayers, with relatively developed sandstone interlayers, and the shale TOC is the lowest among the three. Figure 5 shown.

[0123] Example 5

[0124] A fifth embodiment of the present invention provides a specific application of a method for identifying heated rock interlayers in a shale oil pseudo-in-situ conversion zone based on hydrocarbon generation potential. The method includes identifying sandstone interlayers in a pseudo-in-situ conversion zone within a shale layer, including the following steps:

[0125] S1: A well with continuous coring in an organic-rich shale interval was selected as a typical dissection well ( Figure 6 ).

[0126] S2: Based on the centimeter-level core description, the organic-rich shale section is divided into 10 sedimentary cycles. Each sedimentary cycle has a positive rhythm, that is, the bottom is a set of siltstone or silty mud shale, and the sediment grain size becomes finer and the lithology gradually changes to shale upwards. In terms of sedimentary genesis, the siltstone or silty mud shale at the bottom of each cycle in this embodiment is a phase of gravity flow deposition. According to the different ratios of the thickness of a single sedimentary cycle to the total thickness of the intended heating section, this embodiment defines the four types of lithologic combinations with ratios below 1%, 1% (inclusive) to 5% (inclusive), 5% to 10% (inclusive), and greater than 10% as Type I (0), Type II (1), Type III (4), and Type IV (5), as shown in detail. Figure 6 In this example, lithologic combination sections No. 1, No. 5, and No. 9 were selected as sample collection sections.

[0127] S3: Select millimeter-scale core description and sample collection points for the type II, type III and type IV lithologic combinations developed in this example ( Figure 6 ). The details are as follows: In the No. 1 lithologic combination section, select a sample collection point and code it as "sampling point 1" ( Figure 6 In the 5th and 9th lithologic combination sections, one sampling point was selected and named as “sampling point 2” ( Figure 6 2 in the figure) and “sampling point 3” ( Figure 6 Large thin sections were made for the samples collected at the three sampling points. The lithology of the three sampling points was described at the millimeter level using the large thin sections. A total of 24 lithologic single layers were divided at "sampling point 1" (as shown in Figure 3). Figure 7 shown), Figure 7 1-24 in the figure represent a single lithologic layer, and 12 and 4 single lithologic layers are divided in “sampling point 2” and “sampling point 3” respectively (e.g. Figure 8 As shown in the figure, the lithologic layers of "sampling point 2" include ① to ③ of "sampling point 2-1", ① and ② of "sampling point 2-2", ① to ③ of "sampling point 2-3", and ① to ④ of "sampling point 2-4", for a total of 12; the lithologic layers of "sampling point 3" include ① to ④, for a total of 4. In this embodiment, the lithologic types of all lithologic layers include shale and silt interlayer.

[0128] S4: All monolayers were sampled using wire cutting technology. After each monolayer sample was prepared, a pyrolysis experiment was performed, and the sum of the pyrolysis free hydrocarbons S1 and the pyrolysis hydrocarbons S2 was used as the hydrocarbon generation potential value of the monolayer.

[0129] S5: Count the hydrocarbon generation potentials of all shale layers and calculate their average value. 40% of the average hydrocarbon generation potential of all shale layers is used as the lower limit of the hydrocarbon generation potential of the shale interlayer for in-situ conversion heating of shale oil. The remaining layers are considered silty interlayers.

[0130] S6: The ratio of the hydrocarbon generation potential of the 15 silty interlayers at the three sampling points to the average hydrocarbon generation potential of the shale single layer, as well as the thickness of each interlayer are put into the same coordinate system in the form of a scatter plot. Since the lithology of the non-shale interlayer in this embodiment is only the silty interlayer, only one scatter plot plate needs to be made. In this embodiment, the ordinate is the ratio of the hydrocarbon generation potential of the silty interlayer to the average hydrocarbon generation potential of the shale single layer, and the abscissa is the thickness of the single layer of each interlayer. Set a trend line for 15 data points, and take the thickness corresponding to the intersection of the trend line and the horizontal line with a ordinate value of 40% as the lower limit of the thickness of the low hydrocarbon generation potential interlayer. That is, in this embodiment, siltstone and silty mud shale with a single layer thickness of no more than 10 mm are all considered to have a large hydrocarbon generation potential and are not considered as interlayers; siltstone and silty mud shale with a single layer thickness of more than 10 mm are all considered as interlayers ( Figure 9 ).

[0131] S7: For organic-rich shale sections, a multi-dimensional screening method of sensitivity curves is used to select lithologic sensitivity curves. Specifically, it includes: screening sample wells for selecting lithologic sensitivity curves; preparing data based on sample wells, including logging curve data and lithologic data; establishing a logging lithologic calibration chart containing standard lithologic columns and all curves; using all logging curves of sample wells as candidates for lithologic sensitivity curves to avoid missing sensitive curves, and calculating the numerical distribution range of each curve; setting a one-dimensional vertical axis for each curve, and arranging the axes corresponding to all curves horizontally; the top scale of all axes should be greater than the maximum value of the corresponding curve, and the bottom scale should be less than the minimum value of the corresponding curve, to ensure that the values ​​of all curves are distributed on the axis; unifying the Vertical length; connect the numerical projections of the same logging curve data acquisition point on each axis from left to right; the lithology of each logging curve data acquisition point is determined according to the logging lithology calibration plate; each lithology is marked with a unique color; connect the numerical projections of all logging curve data acquisition points on different logging curve axes one by one to form a lithology distribution vein line; statistically analyze the distribution patterns of different lithologies on each axis in the lithology sensitivity curve synchronous comparison and screening coordinate system; the more convergent the vein line of a certain lithology on a certain axis, and the more obvious the difference from the vein lines of other lithologies, the more sensitive the logging curve corresponding to the axis is to the lithology, and vice versa. After screening, GR, CNL and AC are determined to be the sensitive curves in this embodiment, as shown in the figure. Figure 5 shown.

[0132] S8: In the embodiment, the lithologic interpretation sensitivity curves GR, CNL and AC are used as input curves to establish a logging lithologic identification model based on the three sensitivity curves, and the interpretation model is further used to establish a lithologic profile ( Figure 10 ).

[0133] S9: Identify and determine the interlayers in the shale oil in situ conversion heating shale section according to the lower limit of the interlayer thickness described in step S6. Take the core section of "sampling point 1" in this embodiment as an example to reconstruct the lithologic profile. All silty interlayers with a thickness of less than 10 mm are considered to be shale. Finally, a lithologic profile of the shale oil in situ conversion shale section based on hydrocarbon generation potential is established, as shown in the figure. Figure 10 As shown. Figure 10 and Figure 6 The comparison shows that Figure 6 Many silt interlayers are Figure 10 This approach of ignoring lithologic interlayers is exactly what is needed for in-situ conversion of shale oil, because these ignored interlayers can also generate hydrocarbons and do not need to be considered as interlayers.

[0134] Based on the inventive concept of the present invention, the embodiment of the present invention also provides a shale oil in-situ conversion section heated rock interlayer identification device, the structure of the device is as follows: Figure 11 As shown, it includes a binary lithology prediction module 111, a heated rock mass division module 112, an interlayer identification module 113, a lithology identification model establishment module 114 and an interlayer single layer thickness lower limit determination module 115;

[0135] A binary lithology prediction module 111 is configured to input the sensitivity curve of the target well in the shale layer into a lithology identification model and obtain binary lithology data of the organic-rich shale development section, including organic-rich shale and non-organic-rich shale, based on the model output. The lithology identification model is pre-established by the lithology identification model establishment module 114;

[0136] A heated rock mass division module 112 is configured to identify at least one pseudo-in-situ conversion section within the organic-rich shale development section based on a set upper limit of the proportion of non-organic-rich shale in the in-situ conversion section and the binary lithologic data, and to divide the pseudo-in-situ conversion section into at least one heated rock mass based on the distribution characteristics of the binary lithologic data and the TOC distribution characteristics;

[0137] The interlayer identification module 113 is used to identify a non-organic-rich shale single layer in the heated rock mass. If the thickness of the non-organic-rich shale single layer is greater than the lower limit of the single layer thickness of the interlayer in the simulated in-situ conversion section, the non-organic-rich shale single layer is identified as an interlayer. The lower limit of the single layer thickness is predetermined by the interlayer single layer thickness lower limit determination module 115 based on the average hydrocarbon generation potential value of the organic-rich shale single layer in the shale layer and multiple data pairs including the thickness of the non-organic-rich shale single layer and its hydrocarbon generation potential value.

[0138] In some embodiments, the lithology identification model building module 114 is used to pre-build a lithology identification model in the following manner:

[0139] The GR value lower limit of organic-rich shale is determined based on the binary lithologic data of the coring section of the target layer of the sample well; the binary lithologic data of the coring section and the curve segment of the selected sensitivity curve are used as a sample to establish a sample set; the selected neural network model is trained using the sample set to establish a lithologic identification model, and the GR value lower limit is input into the lithologic identification model. The GR value lower limit is used to locate the organic-rich shale development section.

[0140] In some embodiments, the heated rock mass division module 112 is configured to divide the quasi-in-situ conversion section into at least one heated rock mass according to the following principles:

[0141] The TOC difference between the heated rock mass in the in-situ conversion section of shale oil and the adjacent heated rock mass meets the first set difference, and / or the lithology combination difference with the adjacent heated rock mass meets the second set difference.

[0142] In some embodiments, the lithology identification model building module 114 is configured to obtain binary lithology data of the core section of the target layer of the sample well in the following manner:

[0143] Based on the thin section identification data of the core sampling section of the target layer of the sample well, the lithologic description data in the core description data is corrected to obtain preliminary lithologic data, wherein the preliminary lithologic data includes mud shale; based on the TOC detection data, the mud shale in the preliminary lithologic data having a TOC value greater than a preset lower limit of the TOC of organic-rich shale is determined to be organic-rich shale, thereby obtaining binary lithologic data of the core sampling section.

[0144] In some embodiments, the lithology identification model establishment module 114 is used to extract the lithology and GR value of the sampling points with thin section identification data and TOC detection data based on the binary lithology data and GR curve of the sample well; and statistically obtain the lower limit of the GR value of organic-rich shale based on the lithology and GR values ​​of multiple sampling points.

[0145] In some embodiments, the binary lithology prediction module 111 is further configured to:

[0146] Using cuttings logging data, the sensitivity curve of the target well is used to eliminate outliers with high GR values ​​of non-organic-rich shales.

[0147] In some embodiments, the interlayer single layer thickness lower limit determination module 115 is used to predetermine the single layer thickness lower limit of the interlayer serving as the proposed in-situ conversion section by:

[0148] Based on each of the data pairs, a sample point is obtained, including the thickness of the non-organic-rich shale single layer and the ratio of the hydrocarbon generation potential value to the average hydrocarbon generation potential value of the organic-rich shale single layer; the sample point is projected into a coordinate system, and a trend line is obtained by fitting. Based on the trend line, the ratio of the hydrocarbon generation potential value to the average hydrocarbon generation potential value of the organic-rich shale single layer is determined to be the thickness of the non-organic-rich shale single layer corresponding to the set ratio, and this thickness is determined as the lower limit of the single layer thickness of the non-organic-rich shale single layer as an interlayer in the simulated in situ conversion section.

[0149] In some embodiments, the interlayer single layer thickness lower limit determination module 115 is configured to obtain an average hydrocarbon generation potential value of an organic-rich shale single layer in the shale layer and a plurality of data pairs including the thickness of a non-organic-rich shale single layer and its hydrocarbon generation potential value by:

[0150] Based on centimeter-level core description data of continuous coring sections within a shale layer, a pseudo-in situ conversion section is identified from the coring section, and the identified pseudo-in situ conversion section is divided into multiple units according to sedimentary cycles. The type of each unit is determined according to its thickness ratio to the pseudo-in situ conversion section, and at least one unit of each type is screened; a millimeter-level binary lithologic description is performed on the screened units, and based on the description results, the units are divided into multiple organic-rich shale single layers and non-organic-rich shale single layers. Rock samples are cut from the single layers, and the hydrocarbon generation potential of the rock samples is determined through pyrolysis testing; and the average hydrocarbon generation potential of the organic-rich shale single layers and multiple data pairs including the thickness of the non-organic-rich shale single layers and their hydrocarbon generation potential values ​​are statistically obtained.

[0151] In some embodiments, the interlayer single layer thickness lower limit determination module 115 is configured to:

[0152] Each unit is classified into one of the following types:

[0153] 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%.

[0154] Regarding the apparatus 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.

[0155] 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 heated rock interlayers in the in-situ conversion section of shale oil is implemented.

[0156] 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 runnable on the processor, wherein when the processor executes the program, the above-mentioned method for identifying heated rock interlayers in the in-situ conversion section of shale oil is implemented.

[0157] Unless otherwise specifically stated, terms such as process, calculate, compute, determine, display, and the like may refer to the actions and / or processes of one or more processing or computing systems, or similar devices, that manipulate 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 the 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 referred to throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, light fields or particles, or any combination thereof.

[0158] It should be understood that the specific order or hierarchy of steps in the disclosed processes 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 the present disclosure. The accompanying method claims present elements of the various steps in an exemplary order and are not intended to be limited to the specific order or hierarchy described.

[0159] In the foregoing 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 embodiments of the claimed subject matter require more features than are recited in each claim. On the contrary, as reflected in the appended claims, the invention comprises less than all the features of any individual disclosed embodiment. 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.

[0160] 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 may be implemented as electronic hardware, computer software, or a combination thereof. In order to clearly illustrate the interchangeability between hardware and software, the various illustrative components, blocks, modules, circuits, and steps described above are generally described around their functions. Whether such functions are implemented as hardware or software depends on the specific application and the design constraints imposed on the entire system. A skilled person may implement the described functions in an adaptable manner for each specific application, but such implementation decisions should not be interpreted as departing from the scope of protection of this disclosure.

[0161] The steps of the methods or algorithms described in conjunction with the embodiments herein may be directly embodied as hardware, software modules executed by a processor, or a combination thereof. The software module may be located in a RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, register, hard disk, removable disk, 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 write information to the storage medium. Of course, the storage medium may also be an integral part of the processor. The processor and storage medium may be located in an ASIC. The ASIC may be located in a user terminal. Of course, the processor and storage medium may also be present in a user terminal as discrete components.

[0162] For software implementation, the techniques described in this application can be implemented using 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 external to the processor. In the latter case, it is communicatively coupled to the processor via various means, which are well known in the art.

[0163] 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 will be appreciated by those skilled in the art that the various embodiments may be further combined and arranged. Therefore, the embodiments described herein are intended to encompass 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 encompassed in a manner similar to the term "including," as explained in terms of "including," used as a transitional word in the claims. In addition, any term "or" used in the specification of the claims is intended to mean "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 heated rock mass during in-situ conversion of shale oil, characterized in that: include: The sensitivity curve of the target well in the shale layer is input into the lithologic identification model. Based on the output of the model, binary lithologic data of the organic-rich shale development section, including organic-rich shale and non-organic-rich shale, is obtained. identifying at least one pseudo-in-situ conversion section within the organic-rich shale development section based on a set upper limit for the proportion of non-organic-rich shale in the in-situ conversion section and the binary lithologic data, and dividing the pseudo-in-situ conversion section into at least one heated rock mass based on the distribution characteristics of the binary lithologic properties and TOC distribution characteristics; A non-organic-rich shale single layer in the heated rock mass is identified. If the thickness of the non-organic-rich shale single layer is greater than the lower limit of the thickness of the single layer as an interlayer in the pseudo-in situ conversion section, the non-organic-rich shale single layer is identified as an interlayer. The lower limit of the thickness of the non-organic-rich shale single layer as the interlayer in the pseudo-in situ conversion section is predetermined by: obtaining a sample point based on each data pair, including the thickness of the non-organic-rich shale single layer and the ratio of the hydrocarbon generation potential value to the average hydrocarbon generation potential value of the organic-rich shale single layer; projecting the sample point into a coordinate system, obtaining a trend line by fitting, and determining, based on the trend line, the ratio of the hydrocarbon generation potential value to the average hydrocarbon generation potential value of the organic-rich shale single layer as the corresponding non-organic-rich shale single layer when the ratio is the set ratio. This thickness is determined as the lower limit of the thickness of the non-organic-rich shale single layer as the interlayer in the pseudo-in situ conversion section.

2. The method according to claim 1, characterized in that The lithology identification model is pre-established in the following manner: Based on the binary lithologic data of the core section of the target layer in the sample well, the lower limit of the GR value of organic-rich shale is determined; The binary lithologic data of the core section and the curve section of the selected sensitive curve are taken as a sample to establish a sample set; The sample set is used to train a selected neural network model to establish a lithology identification model, and the GR value lower limit is input into the lithology identification model. The GR value lower limit is used to locate the organic-rich shale development section.

3. The method according to claim 2, characterized in that The model output result is obtained from the lithology identification model in the following way: Locating the organic-rich shale development section according to the GR value lower limit and the GR curve of the target well; According to the neural network learning result of the sensitive curve segment corresponding to the organic-rich shale development segment, the binary lithologic data thereof is determined to obtain a result for output.

4. The method according to claim 2, characterized in that The binary lithologic data of the core section of the target layer of the sample well is obtained by the following method: According to the thin section identification data of the core section of the target layer of the sample well, the lithology description data in the core description data is corrected to obtain preliminary lithology data, wherein the preliminary lithology data includes mud shale; According to the TOC detection data, the mud shale with a TOC value greater than a preset lower limit of TOC of organic-rich shale in the preliminary lithological data is determined as organic-rich shale, and the binary lithological data of the coring section is obtained.

5. The method according to claim 4, characterized in that Determining the lower limit of the GR value of organic-rich shale includes: Based on the binary lithologic data and GR curve of the sample well, the lithologic properties and GR values ​​of the sampling points with thin section identification data and TOC detection data are extracted; Based on the lithology and GR values ​​of multiple sampling points, the lower limit of the GR value of organic-rich shale was obtained statistically.

6. The method according to claim 1, characterized in that The step of dividing the quasi-in-situ conversion section into at least one heated rock mass comprises: The quasi-in-situ conversion section is divided into at least one heated rock mass according to the following principles: The TOC difference between the heated rock mass and the adjacent heated rock mass satisfies a first set difference, and / or the lithology combination difference between the heated rock mass and the adjacent heated rock mass satisfies a second set difference.

7. The method according to claim 6, characterized in that The first set difference includes an overall TOC value difference and / or an overall TOC curve morphology difference; The second set difference includes a difference in the number of non-organic-rich shale layers and / or a difference in the thickness of the non-organic-rich shale layers.

8. The method according to claim 2, characterized in that The average value of the hydrocarbon generation potential value of a single layer of organic-rich shale in the shale layer and a plurality of data pairs including the thickness of a single layer of non-organic-rich shale and its hydrocarbon generation potential value are obtained by the following method: Based on the binary lithologic data of the cored section of the target layer of the sample well and the upper limit of the proportion of non-organic-rich shale in the in-situ conversion section, a pseudo-in-situ conversion section is identified from the cored 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 each unit to the pseudo-in-situ conversion section, and at least one unit is selected from each type of unit; Conduct millimeter-level binary lithologic descriptions on the selected units. Based on the description results, the units are divided into multiple organic-rich shale layers and non-organic-rich shale layers. Rock samples are cut from the layers and their hydrocarbon generation potential is determined through pyrolysis testing. The average value of the hydrocarbon generation potential value of the organic-rich shale single layer and multiple data pairs including the thickness of the non-organic-rich shale single layer and its hydrocarbon generation potential value are statistically obtained.

9. The method according to claim 8, characterized in that The method of determining the type of each unit according to the thickness ratio of the proposed in-situ conversion section includes: 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%.

10. The method according to any one of claims 1 to 9, characterized in that: The hydrocarbon generation potential value is the sum of free hydrocarbons S1 and pyrolysis hydrocarbons S2 per unit mass of rock.

11. The method according to any one of claims 1 to 9, characterized in that: Before inputting the sensitivity curve of the shale target well into the lithology identification model, the method further includes: Using cuttings logging data, the sensitivity curve of the target well is used to eliminate outliers with high GR values ​​of non-organic-rich shales.

12. The method according to any one of claims 1 to 9, characterized in that: The upper limit of the proportion of non-organic-rich shale in the in-situ conversion section is 20%.

13. A device for identifying interlayers in heated rock mass in an in-situ conversion section of shale oil, characterized in that: The device includes a binary lithology prediction module, a heated rock mass division module, an interlayer identification module, a lithology identification model establishment module and an interlayer single layer thickness lower limit determination module; The binary lithology prediction module is used to input the sensitivity curve of the shale layer target well into the lithology identification model, and obtain binary lithology data of the organic-rich shale development section, including organic-rich shale and non-organic-rich shale, based on the model output results. The lithology identification model is pre-established by the lithology identification model establishment module; The heated rock mass division module is configured to identify at least one pseudo-in-situ conversion section within the organic-rich shale development section based on a set upper limit of the proportion of non-organic-rich shale in the in-situ conversion section and the binary lithologic data, and to divide the pseudo-in-situ conversion section into at least one heated rock mass based on the distribution characteristics of the binary lithologic properties and the TOC distribution characteristics; The interlayer identification module is used to identify a non-organic-rich shale single layer in the heated rock mass. If the thickness of the non-organic-rich shale single layer is greater than the lower limit of the single layer thickness for the interlayer in the pseudo-in-situ conversion section, the non-organic-rich shale single layer is identified as an interlayer. The lower limit of the single layer thickness is predetermined by the interlayer single layer thickness lower limit determination module in the following manner: a sample point is obtained based on each data pair, including the thickness of the non-organic-rich shale single layer and the ratio of the hydrocarbon generation potential value to the average hydrocarbon generation potential value of the organic-rich shale single layer; the sample point is projected into a coordinate system, and a trend line is obtained by fitting. Based on the trend line, the ratio of the hydrocarbon generation potential value to the average hydrocarbon generation potential value of the organic-rich shale single layer is determined to be the non-organic-rich shale single layer thickness corresponding to the set ratio, and the thickness is determined as the lower limit of the single layer thickness for the non-organic-rich shale single layer as the interlayer in the pseudo-in-situ conversion section.

14. 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 heated rock interlayers in the in-situ conversion section of shale oil according to any one of claims 1 to 12.

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