Method and equipment for evaluating content of movable oil in shale and storage medium

Abstract

The invention provides a method and equipment for evaluating the content of movable oil in shale and a storage medium, and belongs to the field of shale oil exploration, the evaluation method comprises the following steps: determining a first recovery coefficient based on pyrolysis test data of a to-be-tested sample at different placement times; determining a second recovery coefficient based on the pyrolysis test data of the to-be-tested sample in different sample crushing environments; determining a third recovery coefficient based on pyrolysis test data of the to-be-tested sample under different grinding particle fractions; determining a fourth recovery coefficient based on pyrolysis test data of the to-be-tested sample at different pyrolysis temperatures; determining the product of the first recovery coefficient, the second recovery coefficient, the third recovery coefficient and the fourth recovery coefficient as a light hydrocarbon recovery coefficient; and evaluating the content of the movable oil in the shale based on the light hydrocarbon recovery coefficient. The method provided by the invention has a guiding effect on quantitative evaluation of the oiliness of the shale, and the finally determined free oil content result is slightly different from the actual condition.

Description

Technical Field

[0001] The present invention relates to the technical field of shale oil exploration. Specifically, it relates to a method for evaluating the content of mobile oil in shale, an electronic device for implementing the method for evaluating the content of mobile oil in shale, and a computer-readable storage medium. Background Art

[0002] In shale reservoirs, oil mainly exists in two forms: adsorbed state and free state. Adsorbed oil exists inside and on the surface of organic matter and on the surface of inorganic minerals; free oil exists in pores and fractures, and a small amount of oil can also exist in the hydrocarbon-generation residual pores of oil-wetting organic matter in a dissolved state. The oil content in shale is equal to the sum of the free oil content and the adsorbed and miscible oil content. Since the crude oil in the adsorbed and miscible state in shale is difficult to flow, at present, the development focus of shale oil is the free crude oil in shale. Free oil is an effective contributor to the production capacity of shale oil under the natural elastic energy extraction method.

[0003] Existing quantitative characterization methods for shale free oil and adsorbed oil content include solvent stepwise extraction method, rock pyrolysis method, nuclear magnetic resonance method, three-dimensional fluorescence quantitative analysis method, etc. For example, a Chinese non-patent document with a publication date of July 2018 and a title of "Geochemical Characteristics of Soluble Organic Matter in Different Occurrence States in Low-Maturity Lacustrine Shaly Source Rocks" proposes a method for characterizing the content of free shale oil based on multi-solvent sequential extraction method. This method utilizes the differences in the occurrence space and molecular polarity of shale oil in different occurrence states, and uses appropriate solvents to extract block samples and powder samples respectively. The free shale oil has a large occurrence space and small molecular polarity and is easy to extract; while the adsorbed shale oil has a small occurrence space and large molecular polarity and is difficult to extract. The chloroform bitumen "A" obtained is used for oiliness analysis. However, this method has the following defects: (1) There is light hydrocarbon loss in the properties of the solvent itself and the solvent volatilization process; (2) The occurrence state does not completely correspond to the solvent polarity, and it is difficult to effectively distinguish free and adsorbed shale oil; (3) The analysis process is complex and cumbersome, and the cost is expensive. The extraction solvent is only limited to the scientific research level of typical samples and cannot be applied to production.

[0004] A Chinese non-patent document with a publication date of November 2016 and a title of "Quantitative Characterization Technology and Application Research of Shale Oil in Different Occurrence States" proposes a method for characterizing the content of free shale oil based on multi-temperature-stage fractional pyrolysis method. The basis of this method is that shale oil in different occurrence states has different molecular thermal volatilization capabilities, and the small molecules and free compounds existing in fractures and large pores are relatively easier to thermally release. By carrying out pyrolysis chromatographic analysis of the hydrocarbon components released by thermal decomposition in different temperature segments, S 1-1 is the light component of free oil in the connected pores of mud shale, which is easy to mobilize under current technical conditions; S 1-2They are heavy components in free oil, and it is difficult to exploit them under current technical conditions; the sum of the two is the amount of free oil in shale, that is, the maximum movable oil volume. However, this method has the following defects: (1) It does not consider the light hydrocarbon loss during coring, core placement, and the experiment process; (2) The starting temperature is too high, which does not conform to the actual geological situation; (3) The applicable range is limited, mainly applicable to samples within the oil generation window and highly over-mature shale.

[0005] A Chinese non-patent document with a publication date of September 2020 and a title of "Method for Detecting Oil Content in Shale Oil Reservoirs by T1-T2 Two-Dimensional Nuclear Magnetic Resonance" proposes a method for characterizing the content of free shale oil based on the nuclear magnetic resonance results of shale. This method is based on the differences in the longitudinal relaxation time T1 and T1 / T2 of different fluids, establishes a T1-T2 two-dimensional nuclear magnetic resonance spectrogram, and conducts oil content detection in shale oil reservoirs according to the different positions of fluid components on the T1-T2 spectrogram. However, this method has the following defects: (1) The core and the nuclear magnetic resonance instrument are different, and there are significant differences between the measured results and the idealized interpretation spectrogram, resulting in poor accuracy and popularization; (2) There is currently no mature interpretation model. For example, in medium- to high-maturity shale oil formations, organic pores are not well developed, and shale oil reservoirs may not contain water, which contradicts the current interpretation spectrogram.

[0006] A Chinese non-patent document with a publication date of May 2020 and a title of "Analysis of Oil Content and Mobility of Inter-salt Shale in Qianjiang Formation, Qianjiang Sag, Jianghan Basin" proposes a method for comprehensively evaluating the mobility of inter-salt shale oil based on the use of the oil saturation index (S1 / TOC) combined with pyrolysis movable oil volume (S 1-1 ) and three-dimensional fluorescence quantification and other technical means. This method identifies the oil content of rocks based on the changes in the luminescence color and intensity of oil in the rocks. Specifically, saturated hydrocarbons do not luminesce, and unsaturated hydrocarbons and their derivatives fluoresce. However, this method has high requirements for the particle size, extraction solvent, and extraction method of the samples, and the most ideal standard sample is crude oil from the same depth and the same layer, with poor operability.

[0007] Although these above methods can all study and measure the content of free oil in shale to a certain extent, they do not consider the loss of light hydrocarbons in the samples during sampling, transportation, production, and even experimental operations of the core samples. In addition, the current various methods for preventing light hydrocarbon loss have great uncertainties, and the methods for recovering light hydrocarbon loss are not yet mature, resulting in a large difference between the measured free oil results in the experiment and the actual situation, with poor reliability and credibility, and cannot be used for the evaluation and prediction of shale oil resources.

[0008] Therefore, it is necessary to form a method for determining the content of free oil in shale considering light hydrocarbon loss. Summary of the Invention

[0009] In view of the technical problem that the prior art does not consider the loss of light hydrocarbons in the study and determination methods of shale oil content, the present invention provides a method for evaluating the movable oil content in shale. By using this method, a reasonable light hydrocarbon recovery coefficient can be obtained, which has a guiding role in quantitatively evaluating the oil content of shale.

[0010] To achieve the above object, the first aspect of the present invention provides a method for evaluating the movable oil content in shale. The evaluation method includes the following steps: determining a first recovery coefficient considering the influence of the sample placement time based on the pyrolysis test data of the sample to be tested under different placement times; determining a second recovery coefficient considering the influence of the sample crushing environment based on the pyrolysis test data of the sample to be tested under different crushing environments; determining a third recovery coefficient considering the influence of the sample crushing particle size based on the pyrolysis test data of the sample to be tested under different crushing particle sizes; determining a fourth recovery coefficient considering the influence of the sample pyrolysis temperature based on the pyrolysis test data of the sample to be tested under different pyrolysis temperatures; determining the product of the first recovery coefficient, the second recovery coefficient, the third recovery coefficient, and the fourth recovery coefficient as the light hydrocarbon recovery coefficient; and evaluating the movable oil content in shale based on the light hydrocarbon recovery coefficient.

[0011] In an exemplary embodiment of the present invention, the step of determining a first recovery coefficient considering the influence of the sample placement time based on the pyrolysis test data of the sample to be tested under different placement times may include: obtaining the pyrolysis test data of the sample to be tested under different placement times when the sample to be tested has a reasonable particle size and a reasonable pyrolysis temperature; determining the recovery coefficients of the sample to be tested under different placement times based on the pyrolysis test data of the sample to be tested under different placement times; and determining the average value of the recovery coefficients of the sample to be tested under different placement times as the first recovery coefficient.

[0012] In an exemplary embodiment of the present invention, the step of determining a second recovery coefficient considering the influence of the sample crushing environment based on the pyrolysis test data of the sample to be tested under different crushing environments may include: obtaining the pyrolysis test data of the sample to be tested under different crushing environments when the sample to be tested has a reasonable particle size and a reasonable pyrolysis temperature; wherein the different crushing environments include an open environment and a closed environment; determining the recovery coefficients of the sample to be tested under different crushing environments based on the pyrolysis test data of the sample to be tested under different crushing environments; and determining the average value of the recovery coefficients of the sample to be tested under different crushing environments as the second recovery coefficient.

[0013] In an exemplary embodiment of the present invention, determining a third recovery coefficient considering the influence of the sample crushing particle size based on the pyrolysis test data of the sample to be tested under different crushing particle sizes may include: when the sample to be tested is at a reasonable pyrolysis temperature, obtaining the pyrolysis test data of the sample to be tested under different crushing particle sizes, where the different crushing particle sizes include a reasonable particle size and other particle sizes; determining the recovery coefficients of the sample to be tested under different crushing particle sizes based on the pyrolysis test data of the sample to be tested under different crushing particle sizes; and determining the average value of the recovery coefficients of the sample to be tested under different crushing particle sizes as the third recovery coefficient.

[0014] In an exemplary embodiment of the present invention, determining a fourth recovery coefficient considering the influence of the sample pyrolysis temperature based on the pyrolysis test data of the sample to be tested under different pyrolysis temperatures may include: when the sample to be tested is at a reasonable particle size, obtaining the pyrolysis test data of the sample to be tested under different pyrolysis temperatures; where the different pyrolysis temperatures include a reasonable pyrolysis temperature and a conventional pyrolysis temperature; determining the recovery coefficients of the sample to be tested under different pyrolysis temperatures based on the pyrolysis test data of the sample to be tested under different pyrolysis temperatures; and determining the average value of the recovery coefficients of the sample to be tested under different pyrolysis temperatures as the fourth recovery coefficient.

[0015] In an exemplary embodiment of the present invention, the evaluation method may further include: obtaining the porosity test data of different lithology samples under different crushing particle sizes; determining the fitting relationship between porosity and particle size based on the porosity test data of different lithology samples under different crushing particle sizes; and determining a reasonable particle size based on the median value of the effective porosity of the shale samples in the target area through the fitting relationship between porosity and particle size.

[0016] In an exemplary embodiment of the present invention, the evaluation method may further include: obtaining the total hydrocarbon chromatogram image of the crude oil sample in the shale horizontal well, where the crude oil sample and the sample to be tested are in the same stratigraphic horizon; obtaining the total hydrocarbon chromatogram image of the multi-temperature stage pyrolysis hydrocarbons of the sample to be tested in different pyrolysis temperature segments; comparing the total hydrocarbon chromatogram image of the crude oil sample and the total hydrocarbon chromatogram image of the multi-temperature stage pyrolysis hydrocarbons, and determining the part in the total hydrocarbon chromatogram image of the multi-temperature stage pyrolysis hydrocarbons that is similar to the total hydrocarbon chromatogram image of the crude oil sample; and determining the pyrolysis temperature corresponding to the part in the total hydrocarbon chromatogram image of the multi-temperature stage pyrolysis hydrocarbons that is similar to the total hydrocarbon chromatogram image of the crude oil sample as the reasonable pyrolysis temperature.

[0017] In an exemplary embodiment of the present invention, the evaluation method may further include: determining the light hydrocarbon recovery coefficients of the samples to be tested with different Ro values; determining the fitting relationship between the Ro value and the light hydrocarbon recovery coefficient based on the light hydrocarbon recovery coefficients corresponding to different Ro values; and predicting the light hydrocarbon recovery coefficient corresponding to the sample to be tested with a specified Ro value based on the fitting relationship between the Ro value and the light hydrocarbon recovery coefficient.

[0018] In a second aspect of the present invention, an electronic device is provided, which includes a processor and a memory. At least one computer program is stored in the memory, and the at least one computer program is loaded and executed by one or more of the above-mentioned processors, so that a computer can implement the above-mentioned method for evaluating the content of movable oil in shale.

[0019] In a third aspect of the present invention, a computer-readable storage medium is provided. At least one program code is stored in the computer-readable storage medium, and the program code is loaded and executed by a processor, so that a computer can implement the above-mentioned method for evaluating the content of movable oil in shale.

[0020] Through the technical solution provided by the present invention, the present invention has at least the following technical effects:

[0021] (1) Compared with the rock pyrolysis method in the prior art, the method for evaluating the content of movable oil in shale of the present invention fully considers the influence of different factors on the loss of light hydrocarbons, and finally determines a new parameter that can quantitatively characterize the oil-bearing property of shale, that is, the light hydrocarbon recovery coefficient. Using this light hydrocarbon recovery coefficient, the recovery of thermally released hydrocarbon S1 (light hydrocarbon) can be realized, and the pyrolysis measurement value of the complete free oil can be obtained;

[0022] (2) The present invention combines various methods such as airtight sample crushing, GRI porosity testing, and pyrolysis experiments to determine the reasonable particle size and reasonable pyrolysis temperature of the lithological sample, forming experimental parameters closer to the actual geological conditions, which can ensure the rationality of the finally obtained light hydrocarbon recovery coefficient;

[0023] (3) The method for evaluating the content of movable oil in shale of the present invention is instructive for quantitatively evaluating the oil-bearing property of shale oil in the whole area. The finally determined free oil content result has a small difference from the actual situation, and has high reliability and credibility, and can be used for the evaluation and prediction of shale oil resources;

[0024] (4) From the perspective of cost reduction and efficiency improvement, the present invention can directly perform light hydrocarbon recovery on old samples, avoiding the waste of a large number of samples in the early stage; it can predict the light hydrocarbon recovery coefficient of higher maturity and reduce experimental investment.

[0025] Other features and advantages of the present invention will be described in detail in the subsequent specific implementation part. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The drawings are used to provide a further understanding of the embodiments of the present invention, and constitute a part of the specification. Together with the following specific implementation manners, they are used to explain the embodiments of the present invention, but do not constitute a limitation to the embodiments of the present invention. In the drawings:

[0027] Figure 1 is a flowchart of the method for evaluating the content of movable oil in shale provided by the first embodiment of the present invention;

[0028] Figure 2 Flow chart of the method for evaluating the content of movable oil in shale provided by the second embodiment of the present invention;

[0029] Figure 3 Flow chart of the method for evaluating the content of movable oil in shale provided by the third embodiment of the present invention;

[0030] Figure 4 Fitting curve graph of porosity and particle size provided by the third embodiment of the present invention;

[0031] Figure 5 Schematic structural diagram of the electronic device provided by the fourth embodiment of the present invention.

[0032] Description of reference numerals

[0033] 201 - Memory, 202 - Processor. Detailed description of the specific implementation mode

[0034] The following will describe in detail the specific implementation mode of the embodiments of the present invention with reference to the accompanying drawings. It should be understood that the specific implementation mode described here is only used to illustrate and explain the embodiments of the present invention, and is not used to limit the embodiments of the present invention.

[0035] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other.

[0036] In the present invention, unless otherwise stated, the orientation words such as "upper, lower, top, bottom" are usually in the direction shown in the drawings or in terms of the vertical, perpendicular or gravitational direction for describing the relative position relationship of each component. "First", "second", etc. are only for convenience of description and easy distinction, and cannot be understood as indicating or implying relative importance.

[0037] In the prior art, for the research and determination of the content of free oil in shale, rock pyrolysis is one of the most effective methods. However, at present, all the existing rock pyrolysis methods do not consider the light hydrocarbon loss caused during the sampling, transportation, production, and even experimental operation of core samples, resulting in a large difference between the free oil results measured by experiments and the actual situation, with poor reliability and credibility, and cannot be used for the evaluation and prediction of shale oil resources. Therefore, the present invention provides a method for evaluating the content of movable oil in shale to solve the above technical problems.

[0038] The overall technical concept of the present invention is as follows: by conducting analysis on the relationship between the crushing particle size and porosity of experimental samples, the similarity between pyrolysis S1 and petroleum chromatography characteristics at different temperatures, and the control experiment on influencing factors of oil-bearing property, etc., to obtain a reasonable sample crushing particle size and reasonable temperature-stage pyrolysis closer to the actual underground conditions, and then determine the reasonable values of the movable hydrocarbon amount of rock types and its related parameters (such as light hydrocarbon recovery coefficient), so as to accurately evaluate the shale oil resource quantity.

[0039] The present invention will be described in detail below with reference to the drawings and in conjunction with embodiments.

[0040] Embodiment 1

[0041] As Figure 1 shown, the first embodiment of the present invention provides a method for evaluating the movable oil content in shale, and the method includes the following steps:

[0042] Step S101: Based on the pyrolysis test data of the sample to be tested under different placement times, determine the first recovery coefficient K1 considering the influence of the sample placement time.

[0043] For example, different placement times can be determined according to the open placement time of the lithological sample during sampling, transportation, production, and even experimental operation. Specifically, different placement times can be set as 5 min, 30 min, 1 h, 2 h, 4 h, 0.5 day, 1 day, 3 days, 5 days, 15 days, 30 days, etc.

[0044] Step S102: Based on the pyrolysis test data of the sample to be tested under different sample crushing environments, determine the second recovery coefficient K2 considering the influence of the sample crushing environment.

[0045] For example, different sample crushing environments can include open environments and closed environments, etc.

[0046] Step S103: Based on the pyrolysis test data of the sample to be tested under different crushing particle sizes, determine the third recovery coefficient K3 considering the influence of the sample crushing particle size.

[0047] For example, different crushing particle sizes can be set according to the particle size ranges of different rock types. Specifically, different crushing particle sizes can be set as 0.01 mm - 0.3 mm, 0.05 mm - 1.0 mm, 1.5 mm - 3.0 mm, 3.00 mm - 5.00 mm, 5.00 mm - 8.00 mm, etc.

[0048] Step S104: Based on the pyrolysis test data of the sample to be tested under different pyrolysis temperatures, determine the fourth recovery coefficient K4 considering the influence of the sample pyrolysis temperature.

[0049] For example, different pyrolysis temperatures can be determined according to the temperature ranges set in conventional pyrolysis and multi-stage pyrolysis. Specifically, different pyrolysis temperatures can be set at 100°C, 150°C, 200°C, 250°C, 300°C, 350°C, 400°C, etc.

[0050] Step S105: Determine the product of the first recovery coefficient, the second recovery coefficient, the third recovery coefficient, and the fourth recovery coefficient as the light hydrocarbon recovery coefficient.

[0051] Here, it should be noted that the calculation of the light hydrocarbon recovery coefficient needs to consider two parts: The first part is the light hydrocarbon recovery calculation, which mainly involves two experiments, namely the pyrolysis tests under different placement times and different sample crushing environments. Both of these experiments are carried out under reasonable particle sizes and reasonable temperature conditions, and are used to calculate the first recovery coefficient (K1) under different placement times and the second recovery coefficient (K2) under different sample crushing environments respectively; The second part is the calculation of the movable hydrocarbon content, which mainly involves two experiments, namely different crushing particle sizes and different pyrolysis temperatures, and are used to calculate the third recovery coefficient (K3) under different crushing particle sizes and the fourth recovery coefficient (K4) under different pyrolysis temperatures respectively. In addition, since the crushing particle size in this experiment is larger than that in conventional pyrolysis and the pyrolysis temperature is lower than that in conventional pyrolysis, both will cause the movable hydrocarbon content to be less than that in conventional pyrolysis. Therefore, when calculating the amount of movable hydrocarbons, the reduced part needs to be restored to the amount of hydrocarbons generated under conventional conditions, that is, the loss amount needs to be added.

[0052] Finally, the light hydrocarbon recovery coefficient can be obtained through the first recovery coefficient (K1), the second recovery coefficient (K2), the third recovery coefficient (K3), and the fourth recovery coefficient (K4). That is, the calculation formula for the light hydrocarbon recovery coefficient is:

[0053] K = K1 × K2 × K3 × K4

[0054] In the formula, K is the light hydrocarbon recovery coefficient; K1 is the first recovery coefficient; K2 is the second recovery coefficient; K3 is the third recovery coefficient; K4 is the first recovery coefficient.

[0055] Step S106: Evaluate the content of movable oil in the shale based on the light hydrocarbon recovery coefficient.

[0056] Here, it should be noted that the thermally released hydrocarbon S1 (light hydrocarbon) represents the amount of hydrocarbon remaining in the rock after generation and hydrocarbon expulsion, that is, the movable oil volume. Since light hydrocarbons are volatile, some light hydrocarbons have been lost during sample collection, transportation, and storage. Therefore, the S1 measured by the pyrolysis method currently is not the complete free oil, and S1 recovery is required, that is, the light hydrocarbon recovery coefficient needs to be determined. That is to say, the light hydrocarbon recovery coefficient determined in this application can quantitatively characterize the oil-bearing property of shale. After correcting the S1 measured by the pyrolysis method using this light hydrocarbon recovery coefficient, the measurement result of the complete free oil closer to the actual geological conditions can be obtained.

[0057] In this embodiment, to ensure the accuracy of pyrolysis test data under different influencing factors (i.e., sample crushing environment, placement time, crushing particle size, pyrolysis temperature), when conducting rock pyrolysis experiments under different sample crushing environments and different placement times, the same pyrolysis temperature should be adopted, and the particle size of the sample to be tested should be the same. In addition, when conducting rock pyrolysis tests under different pyrolysis temperatures, the particle size of the sample to be tested should be the same as that used in the rock pyrolysis tests under different sample crushing environments and different placement times; when conducting rock pyrolysis tests under different crushing particle sizes, the pyrolysis temperature should be the same as that used in the rock pyrolysis tests under different sample crushing environments and different placement times.

[0058] Furthermore, the reasonable particle size and reasonable pyrolysis temperature under actual geological conditions can be determined first, and the sample to be tested can be processed into rock fragments with a reasonable particle size, and rock pyrolysis experiments (i.e., sample crushing environment, placement time, crushing particle size, pyrolysis temperature) under different influencing factors can be carried out at a reasonable pyrolysis temperature, and multiple sets of pyrolysis test data can be obtained. Furthermore, the authenticity and rationality of the pyrolysis test data can be ensured, and a reasonable light hydrocarbon recovery coefficient can be obtained.

[0059] Exemplarily, based on the pyrolysis test data of the sample to be tested under different placement times, the process of determining the first recovery coefficient considering the influence of the sample placement time includes, but is not limited to, the following sub-steps S1011 to S1013.

[0060] Sub-step S1011: Under the condition that the sample to be tested is at a reasonable particle size and reasonable pyrolysis temperature, obtain the pyrolysis test data of the sample to be tested under different placement times.

[0061] Sub-step S1012: Based on the pyrolysis test data of the sample to be tested under different placement times, determine the recovery coefficients of the sample to be tested under different placement times.

[0062] Sub-step S1013: Determine the average value of the recovery coefficients of the sample to be tested under different placement times as the first recovery coefficient.

[0063] Exemplarily, the process of determining the second recovery coefficient considering the influence of the sample crushing environment based on the pyrolysis test data of the sample to be tested under different crushing environments includes but is not limited to the following sub-steps S1021 to S1023.

[0064] Sub-step S1021: When the sample to be tested is in a reasonable particle size and reasonable pyrolysis temperature, obtain the pyrolysis test data of the sample to be tested under different crushing environments. Among them, different crushing environments include an open environment and a closed environment.

[0065] Sub-step S1022: Based on the pyrolysis test data of the sample to be tested under different crushing environments, determine the recovery coefficient of the sample to be tested under different crushing environments.

[0066] Sub-step S1023: Determine the average value of the recovery coefficients of the sample to be tested under different crushing environments as the second recovery coefficient.

[0067] Exemplarily, the process of determining the third recovery coefficient considering the influence of the sample crushing particle size based on the pyrolysis test data of the sample to be tested under different crushing particle sizes includes but is not limited to the following sub-steps S1031 to S1033.

[0068] Sub-step S1031: When the sample to be tested is at a reasonable pyrolysis temperature, obtain the pyrolysis test data of the sample to be tested under different crushing particle sizes. Among them, the different crushing particle sizes include a reasonable particle size and other particle sizes.

[0069] Sub-step S1032: Based on the pyrolysis test data of the sample to be tested under different crushing particle sizes, determine the recovery coefficient of the sample to be tested under different crushing particle sizes.

[0070] Sub-step S1033: Determine the average value of the recovery coefficients of the sample to be tested under different crushing particle sizes as the third recovery coefficient.

[0071] Exemplarily, the process of determining the fourth recovery coefficient considering the influence of the sample pyrolysis temperature based on the pyrolysis test data of the sample to be tested under different pyrolysis temperatures includes but is not limited to the following sub-steps S1041 to S1043.

[0072] Sub-step S1041: When the sample to be tested is at a reasonable particle size, obtain the pyrolysis test data of the sample to be tested under different pyrolysis temperatures. Among them, the different pyrolysis temperatures include a reasonable pyrolysis temperature and a conventional pyrolysis temperature.

[0073] Sub-step S1042: Based on the pyrolysis test data of the sample to be tested under different pyrolysis temperatures, determine the recovery coefficient of the sample to be tested under different pyrolysis temperatures.

[0074] Sub-step S1043: Determine the average value of the recovery coefficients of the samples to be tested at different pyrolysis temperatures as the fourth recovery coefficient.

[0075] Here, the reasonable particle size and reasonable pyrolysis temperature can be inferred from the relevant historical measurement data of the actual geology, or can be determined by assigning empirical values according to the pyrolysis test results of rocks with similar lithologies.

[0076] Of course, the present invention is not limited thereto, and the reasonable particle size and reasonable pyrolysis temperature can also be obtained through joint analysis by methods such as nuclear magnetic resonance and chromatographic analysis.

[0077] Exemplarily, the process for determining the reasonable particle size is as follows:

[0078] (a) Obtain the porosity test data of samples with different lithologies at different crushed particle sizes.

[0079] (b) Based on the porosity test data of samples with different lithologies at different crushed particle sizes, determine the fitting relationship between porosity and particle size.

[0080] (c) Based on the median value of the effective porosity of the shale samples in the target area, determine the reasonable particle size through the fitting relationship between porosity and particle size.

[0081] Exemplarily, the process for determining the reasonable pyrolysis temperature is as follows:

[0082] (a) Obtain the total hydrocarbon chromatogram image of the crude oil sample in the shale horizontal well. Among them, the stratigraphic position of the crude oil sample is the same as that of the sample to be tested.

[0083] (b) Obtain the total hydrocarbon chromatogram image of the multi-temperature stage pyrolysis hydrocarbons of the sample to be tested in different pyrolysis temperature ranges.

[0084] (c) Compare the total hydrocarbon chromatogram image of the crude oil sample and the total hydrocarbon chromatogram image of the multi-temperature stage pyrolysis hydrocarbons, and determine the part in the total hydrocarbon chromatogram image of the multi-temperature stage pyrolysis hydrocarbons that is similar to the total hydrocarbon chromatogram image of the crude oil sample.

[0085] (d) Determine the pyrolysis temperature corresponding to the part in the total hydrocarbon chromatogram image of the multi-temperature stage pyrolysis hydrocarbons that is similar to the total hydrocarbon chromatogram image of the crude oil sample as the reasonable pyrolysis temperature.

[0086] It should be noted that the porosity involved in the method for evaluating the content of mobile oil in shale of the present invention represents the movable pore porosity for storing free oil, which corresponds to mobile oil, while adsorbed oil and dead pore oil cannot be exploited under the current engineering conditions, so they are not considered in the present invention.

[0087] In addition, the implementation environment of this embodiment includes at least one terminal and a server, and this method is executed on the terminal or the server respectively. The terminal and the server can be communicatively connected to realize the interactive transmission of information.

[0088] Among them, the terminal can be any kind of electronic product that can perform human-computer interaction with the user through one or more means such as a keyboard, a touchpad, a touch screen, voice interaction, etc., such as a PC (Personal Computer), a PPC (Pocket Personal Computer), a tablet computer, etc.

[0089] The server can be a single server, a server cluster composed of multiple servers, or a cloud server that provides basic cloud computing services such as cloud services, cloud databases, cloud computing, cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, CDN (Content Delivery Network), and big data and artificial intelligence platforms.

[0090] Embodiment 2

[0091] As Figure 2 shown, the second embodiment of the present invention provides a method for evaluating the movable oil content in shale, and the method includes the following steps:

[0092] Step S201: Determine the samples to be tested with different lithologies and determine a reasonable particle size.

[0093] Exemplarily, the process of determining the samples to be tested and determining a reasonable particle size includes but is not limited to the following sub-steps S2011 to S2016.

[0094] Sub-step S2011: First, carry out XRD measurement experiments, select three different lithologies of shale, namely felsic shale, mixed shale, and calcareous shale, as the samples to be tested, and measure the porosity of the three samples to be tested respectively.

[0095] Sub-step S2012: Carry out TOC measurement experiments, and select several different TOC values as the particle size test samples for the samples to be tested.

[0096] For example, felsic shale, mixed shale, and calcareous shale with TOC values of 1.0, 1.5, and 2.0 can be selected as the particle size test samples respectively.

[0097] Sub-step S2013: Perform crushing treatments with different particle sizes on each group of particle size test samples (i.e., the samples to be tested with the same TOC and the same lithology), and use a nuclear magnetic resonance instrument to measure the porosity, so as to obtain the porosity of each group of particle size test samples at different particle sizes.

[0098] Sub-step S2014: Fit the different particle sizes in sub-step S2013 and the corresponding porosities into a regression equation to obtain the porosity-particle size fitting curve for each group of particle size test samples.

[0099] Sub-step S2015: Repeat sub-steps S2013 to S2014 to respectively determine the porosity-particle size fitting curves for 9 groups of particle size test samples.

[0100] Sub-step S2016: Substitute the median value of the effective porosity of the shale samples in the target area into the porosity-particle size fitting curve of the corresponding particle size test samples to determine the reasonable particle sizes of the test samples with different lithologies.

[0101] Here, it should be noted that the median value range of the effective porosity of the shale samples in the target area can be determined by statistically analyzing the normal distribution of the shale porosity in the target area and taking the median value range of this normal distribution as the median value of the effective porosity of the shale samples in the target area.

[0102] Step S202: Determine the reasonable pyrolysis temperature.

[0103] Exemplarily, the process of determining the reasonable pyrolysis temperature includes but is not limited to the following sub-steps S2021 to S2024.

[0104] Sub-step S2021: Select three barrels of crude oil samples with different lithologies for total hydrocarbon chromatographic analysis to respectively obtain the total hydrocarbon chromatographic images of the three crude oil samples.

[0105] Sub-step S2022: After crushing the three test samples into the reasonable particle sizes in step S201, conduct multi-temperature stage pyrolysis experiments to respectively obtain the total hydrocarbon chromatographic images of the multi-temperature stage pyrolysis hydrocarbons of the three test samples in different pyrolysis temperature ranges.

[0106] Among them, for the multi-temperature stage pyrolysis experiment, five temperature ranges closer to the geological conditions should be selected as the pyrolysis temperatures for the experiment.

[0107] Sub-step S2023: For each test sample, compare the total hydrocarbon chromatographic images of the multi-temperature stage pyrolysis hydrocarbons in different pyrolysis temperature ranges with the total hydrocarbon chromatographic images of the crude oil samples, and determine the parts in the total hydrocarbon chromatographic images of the multi-temperature stage pyrolysis hydrocarbons that are similar to the total hydrocarbon chromatographic images of the crude oil samples.

[0108] Sub-step S2024: For each test sample, determine the pyrolysis temperature corresponding to the part in the total hydrocarbon chromatographic image of the multi-temperature stage pyrolysis hydrocarbons that is similar to the total hydrocarbon chromatographic image of the crude oil sample as the reasonable pyrolysis temperature of this test sample.

[0109] Step S203: For each sample to be tested, when the sample to be tested is at a reasonable particle size and a reasonable pyrolysis temperature, conduct the rock pyrolysis experiment of the sample to be tested under different placement times, and determine the first recovery coefficient K1 considering the influence of the sample placement time.

[0110] For example, according to the reasonable particle size determined in step S201 and the reasonable pyrolysis temperature determined in step S202, use the samples to be tested with the same lithology to conduct control pyrolysis experiments with different placement times after crushing the samples respectively, and obtain the recovery coefficient K considering the influence of the sample placement time. 时间 ; Repeat the above steps to conduct multiple groups of control pyrolysis experiments with different placement times, calculate the average value of the recovery coefficients K corresponding to the data of multiple groups of control pyrolysis experiments. 时间 And determine the obtained average value as the final first recovery coefficient K1.

[0111] Step S204: For each sample to be tested, when the sample to be tested is at a reasonable particle size and a reasonable pyrolysis temperature, conduct the rock pyrolysis experiment of the sample to be tested under different sample crushing environments, and determine the second recovery coefficient considering the influence of the sample crushing environment. Among them, different sample crushing environments can include open environments and closed environments, etc.

[0112] For example, according to the reasonable particle size determined in step S201 and the reasonable pyrolysis temperature determined in step S202, use the samples to be tested with the same lithology to conduct control pyrolysis experiments of open crushing and closed crushing respectively, and obtain the recovery coefficient K considering the influence of the sample crushing environment. 开闭 ; Repeat the above steps to conduct multiple groups of control pyrolysis experiments with different sample crushing environments, and calculate the average value of the recovery coefficients K corresponding to the data of multiple groups of control pyrolysis experiments considering the influence of the sample crushing environment. 开闭 And determine the obtained average value as the final second recovery coefficient K2.

[0113] Step S205: For each sample to be tested, when the sample to be tested is at a reasonable pyrolysis temperature, conduct the rock pyrolysis experiment of the sample to be tested under different crushing particle sizes, and determine the third recovery coefficient considering the influence of the sample crushing particle size. Among them, different crushing particle sizes should include reasonable particle sizes and other particle sizes.

[0114] For example, multiple crushing particle sizes can be set according to the reasonable particle size determined in step S201, and referring to the reasonable pyrolysis temperature determined in step S202, use the samples to be tested with the same lithology to conduct control pyrolysis experiments with different crushing particle sizes respectively, and obtain the recovery coefficient K considering the influence of the sample particle size. 粒级 ; Repeat the above steps to conduct multiple groups of control pyrolysis experiments with different crushing particle sizes, and calculate the average value of the recovery coefficients K corresponding to the data of multiple groups of control pyrolysis experiments considering the influence of the sample crushing particle size. 粒级Calculate the average value and determine the obtained average value as the final third recovery coefficient K3.

[0115] Step S206: For each sample to be tested, conduct a rock pyrolysis experiment on the sample to be tested at different pyrolysis temperatures to determine the fourth recovery coefficient considering the influence of the sample pyrolysis temperature. Among them, different pyrolysis temperatures should include reasonable pyrolysis temperatures and other pyrolysis temperatures.

[0116] For example, based on the reasonable particle size determined in step S201 and referring to the reasonable pyrolysis temperature determined in step S202, set multiple groups of pyrolysis temperatures (such as conventional pyrolysis and multi-temperature stage pyrolysis), conduct control pyrolysis experiments of conventional pyrolysis and multi-temperature stage pyrolysis respectively using the samples to be tested with the same lithology, and obtain the recovery coefficient K considering the influence of the sample pyrolysis temperature. 常规多温 ; Repeat the above steps to conduct multiple groups of control pyrolysis experiments with different crushing particle sizes, and calculate the average value of the recovery coefficient K considering the influence of the sample pyrolysis temperature corresponding to the data of multiple groups of control pyrolysis experiments. 常规多温 Calculate the average value and determine the obtained average value as the final fourth recovery coefficient K4.

[0117] Step S207: Based on the recovery coefficients corresponding to the rock pyrolysis experiments under different influencing factors, determine the light hydrocarbon recovery coefficient of the sample to be tested.

[0118] Perform a product calculation on the above four recovery coefficients to obtain the light hydrocarbon recovery coefficient K of the sample to be tested, that is, K = K1 × K2 × K3 × K4.

[0119] Step S208: Repeat steps S203 - S207 to conduct control experiments on samples with different Ro values, and determine the light hydrocarbon recovery coefficients of the samples to be tested with the same lithology at different Ro values.

[0120] For example, for each sample to be tested, use testing means such as an MPV - SP microphotometer and a multifunctional microscope, and select samples with Ro values of 0.6, 0.7, 0.8, and 0.9 respectively as the samples to be tested for maturity.

[0121] Step S209: Based on the light hydrocarbon recovery coefficients corresponding to different Ro values, determine the fitting relationship between the Ro value and the light hydrocarbon recovery coefficient.

[0122] Step S210: Based on the fitting relationship between the Ro value and the light hydrocarbon recovery coefficient, predict the light hydrocarbon recovery coefficient corresponding to the sample to be tested at any other Ro value.

[0123] Since the Ro value of the lithologic samples used in the pyrolysis experiment is generally less than 0.9, and it is difficult to obtain samples with a higher Ro value, the light hydrocarbon recovery coefficient of samples with a higher Ro value can be obtained by data fitting, and finally the light hydrocarbon recovery coefficients of different evolution degrees can be determined. For example, according to the fitting relationship between Ro and the light hydrocarbon recovery coefficient, the K value corresponding to the sample to be tested when Ro is 1.0 - 1.2 can be predicted.

[0124] In this embodiment, it should be noted that TOC refers to the total organic carbon content, that is, the mass of organic carbon in the rock per unit mass, usually expressed by mass fraction (%).

[0125] Ro refers to the vitrinite reflectance, which is an important index to characterize the maturity of source rocks. Generally, the evolution of organic matter can be divided into three stages according to the change of vitrinite reflectance. When Ro ≤ 0.5%, the organic matter is in the immature stage; when 0.5% < Ro < 1.6%, the sample is in the mature stage, which is conducive to the formation of oil and gas. Among them, when Ro is 0.5% - 0.8%, it enters the initial stage of the mature stage; when Ro is 0.8% - 1.2%, it is in the middle stage of the mature stage; when Ro is 1.2% - 1.6%, it is in the late stage of the mature stage. However, when Ro ≥ 1.6%, it belongs to the over-maturity stage, and no more oil and gas are formed. The organic matter maturity of each set of source rocks in the basin is directly related to whether they can generate oil and gas, so it is one of the key factors for the evaluation of oil and gas resources in the basin.

[0126] Embodiment Three

[0127] As Figure 3 shown, the third embodiment of the present invention provides a method for evaluating the movable oil content in shale, and the method includes the following steps:

[0128] Step S301: Take three lithologic samples and measure their porosities respectively.

[0129] In step S301, for the felsic shale in the second member of the Kongdian Formation in the Cangdong Sag, the mixed shale in the upper part of the third member of the Shahejie Formation in the Qikou Sag, and the dolomitic shale in the lower part of the first member of the Shahejie Formation, 24 large pieces of samples of different lithologies from three horizons in two regions are taken respectively, a total of 72 pieces of shale. The diameter of each rock sample is generally not less than 10 cm in length, not less than 6 cm in width, and not less than 6 cm in height.

[0130] In step S301, take 1 piece of each of the three lithologic samples for nuclear magnetic pore measurement to obtain the corresponding porosity of the core sample, and the process enters step 302.

[0131] Step S302: Select rock samples with TOC of 1.0, 1.5, and 2.0 as the samples to be tested.

[0132] In step S302, 72 samples are crushed into powder samples of about 200 mesh, with a dosage of 1 g, and experiments are carried out about 72 times using an X-ray diffractometer SmartLab or TTR to determine the true lithology (felsic shale, mixed shale, calcareous shale) of the 72 samples.

[0133] After crushing 72 rock samples separately, sieve the samples through a sieve smaller than 0.2 mm with a sample amount of not less than 5 g, and carry out experiments about 72 times on different rock samples using a CS-i carbon-sulfur analyzer and a CS230 carbon-sulfur analyzer to determine the TOC values of different rock samples. Finally, select rock samples with TOC values of 1.0, 1.5, and 2.0 respectively as the samples to be tested, and the process enters step 303.

[0134] Step S303: Crush the samples to be tested into 8 particle sizes and measure the porosity.

[0135] In step S303, select samples with the same TOC and the same lithology, crush and mix them evenly, pick out one and crush it into different particle sizes (set 8 crushing particle sizes: 0.08 mm, 0.15 mm, 0.3 mm, 0.6 mm, 1.0 mm, 1.5 mm, 3 mm, 8 mm). Use a nuclear magnetic resonance instrument to measure the porosity of the samples with different particle sizes, obtain the porosity of the samples at different particle sizes, and the process enters step 304.

[0136] Step S304: Fit the relationship between porosity and particle size and obtain a reasonable particle size.

[0137] In step S304, fit the porosity and particle size in step S303 into a regression equation, obtain a curve related to porosity and particle size, and substitute the porosity of the three rock samples to approximately obtain the corresponding reasonable particle sizes. Figure 4 Shows the fitting curve of porosity and particle size. As Figure 4 shown, based on the currently measured effective porosity of 2% - 4%, it can be considered that the crushing particle size above 1 mm is more reasonable, that is, the reasonable particle size is 1 mm.

[0138] Step S305: Carry out full hydrocarbon chromatographic analysis on the crude oil samples of the three lithologies.

[0139] In step S305, take 1 bottle of crude oil samples corresponding to the three shale types, about 5 ml for each bottle, carry out full hydrocarbon chromatographic analysis on the three crude oil samples, use an HP-7890 gas chromatograph, measure the mass fractions of each component of n-alkanes, pristane, and phytane in the crude oil, obtain the full hydrocarbon chromatogram of the crude oil samples, and the process enters step S306.

[0140] Step S306: Carry out multi-temperature stage pyrolysis on the three lithology samples and carry out full hydrocarbon chromatographic analysis.

[0141] In step S306, the three lithology samples are crushed into a reasonable particle size determined in step S304, and multi-temperature-stage pyrolysis is carried out at five temperature segments closer to geological conditions. The temperature segments are 150 °C constant temperature for 1 min, 150 - 200 °C constant temperature for 1 min, 200 - 250 °C constant temperature for 1 min, 250 - 300 °C constant temperature for 1 min, and 300 - 350 °C constant temperature for 1 min. The heating rate is 25 °C / min. The total hydrocarbon chromatographic analysis is completed respectively to obtain the total hydrocarbon chromatographic images of the multi-temperature-stage pyrolysis hydrocarbons, and the process proceeds to step S307.

[0142] Step S307: Compare chromatograms to determine the reasonable pyrolysis temperature.

[0143] In step S307, the total hydrocarbon chromatographic images of the multi-temperature-stage pyrolysis hydrocarbons of each lithology sample at different temperature segments are compared with the total hydrocarbon chromatogram of the crude oil sample. The part of the total hydrocarbon chromatographic image of the multi-temperature-stage pyrolysis hydrocarbons that is more similar to the total hydrocarbon chromatogram of the crude oil sample is determined, and the temperature corresponding to the part is determined as the reasonable pyrolysis temperature of the lithology sample. The process proceeds to step S308.

[0144] Step S308: Conduct four groups of control experiments under different conditions to obtain the light hydrocarbon recovery coefficient.

[0145] In step S308, according to the reasonable particle size obtained in step S304 and the reasonable pyrolysis temperature obtained in step S307, control pyrolysis experiments are carried out under four different conditions, namely open and closed sample crushing, different crushing particle sizes, different placement times after sample crushing, and conventional pyrolysis and multi-temperature-stage pyrolysis, using samples of the same lithology.

[0146] Among them, the process of the control pyrolysis experiment for the placement time after sample crushing is as follows: Use 1 large block of each of the three different lithology rock samples. Divide each of them into two groups. After crushing into a reasonable particle size, for one group, conduct the pyrolysis experiment after placing it for 24 h, and for the other group, conduct the pyrolysis experiment immediately to obtain two different S1s. To obtain more reliable experimental data, repeat this step to do 1 more group of experiments. Finally, obtain the S1 data of 2 different placement times and 2 groups of recovery coefficients. Take the average of the 2 groups of recovery coefficients as the more reliable first recovery coefficient (K1) considering the influence of different placement times.

[0147] Among them, the process of the open and sealed sample crushing control pyrolysis experiment is as follows: Use 1 large piece of rock samples of three different lithologies, crush them and divide them into two groups, conduct open sample crushing and sealed liquid nitrogen freezing sample crushing respectively, then crush them into a reasonable particle size obtained in step S304, use a pyrolysis instrument, and keep it at a constant temperature for 3 minutes at the reasonable pyrolysis temperature obtained in step S307 to obtain a set of S1. In order to obtain more reliable experimental data, repeat this step to conduct 1 more group of experiments, finally obtain 2 groups of S1 data under different sample crushing environments, and obtain 2 groups of recovery coefficients. Take the average of the 2 groups of recovery coefficients as a more reliable second recovery coefficient (K2) considering the influence of different sample crushing environments.

[0148] Among them, the process of the crushed particle size control pyrolysis experiment is as follows: Use 1 large piece of rock samples of three different lithologies, crush them into a reasonable particle size obtained in step S304 and the particle size used in conventional pyrolysis respectively to conduct pyrolysis experiments, and keep it at a constant temperature for 3 minutes at the reasonable pyrolysis temperature obtained in step S307 to obtain a new set of S1. In order to obtain more reliable experimental data, repeat this step to conduct 1 more group of experiments, finally obtain 2 groups of S1 data under different crushed particle sizes, and obtain 2 groups of recovery coefficients. Take the average of the 2 groups of recovery coefficients as a more reliable third recovery coefficient (K3) considering the influence of different crushed particle sizes.

[0149] Among them, the process of the conventional and multi-temperature stage pyrolysis control pyrolysis experiment is as follows: Use 1 large piece of each of the three different lithology rock samples, divide them into two groups, after crushing them into a reasonable particle size, one group conducts conventional pyrolysis S1, and one group conducts multi-temperature stage pyrolysis at a reasonable temperature to obtain two different sets of S1. In order to obtain more reliable experimental data, repeat this step to conduct 1 more group of experiments, finally obtain 2 groups of S1 data under different pyrolysis programs, and obtain 2 groups of recovery coefficients. Take the average of the 2 groups of recovery coefficients as a more reliable fourth recovery coefficient (K4) considering the influence of different pyrolysis temperatures.

[0150] Finally, perform a product calculation on the four recovery coefficients K1, K2, K3, and K4 to obtain the light hydrocarbon recovery coefficient K, and the process enters step S309.

[0151] Step S309: Select samples with Ro values of 0.6, 0.7, 0.8, and 0.9 respectively.

[0152] In step S309, use an MPV-SP microphotometer and a multifunctional microscope to judge the maturity of the samples by measuring the percentage of the reflected light intensity to the perpendicular incident light intensity of the vitrinite polished surface at a wavelength of 546 nm ± 5 nm (green light). Make the treated kerogen samples into polished sections for measuring the vitrinite reflectance. Finally, select samples with Ro values of 0.6, 0.7, 0.8, and 0.9 respectively (i.e., the lithology samples after restoring the reasonable particle size), and the process enters step S310.

[0153] Step S310: Obtain K through a control experiment, fit K and Ro, and predict the light hydrocarbon recovery coefficient corresponding to a high Ro.

[0154] In step S310, samples of the same lithology with different Ro values (one set for each lithology), such as samples with maturities of 0.5, 0.6, 0.7, 0.8, etc., are used to conduct the above four groups of control experiments respectively, so as to obtain K1, K2, K3, and K4 corresponding to different Ro values, and then obtain the light hydrocarbon recovery coefficient K. Then, the K and Ro curves are fitted to obtain the relationship between Ro and K, so as to predict the K value corresponding to Ro of 1.0 - 1.2.

[0155] Example 4

[0156] The fourth embodiment of the present invention provides an electronic device. Refer to Figure 5 , the electronic device includes a processor 201 and a memory 202. At least one computer program is stored in the memory, and the at least one computer program is loaded and executed by one or more of the above-mentioned processors to enable the computer to implement the method for evaluating the movable oil content in shale as described above.

[0157] Of course, the electronic device may also have components such as a wired or wireless network interface, a keyboard, and an input / output interface for input / output. The electronic device may also include other components for implementing the various functions of the device, which will not be elaborated here.

[0158] The fourth embodiment of the present invention also provides a computer-readable storage medium. At least one program code is stored in the computer-readable storage medium, and the program code is loaded and executed by the processor to enable the computer to implement the method for evaluating the movable oil content in shale as described above.

[0159] Optionally, the computer-readable storage medium may be a read-only memory (ROM), a random access memory (RAM), a compact disc read-only memory (CD-ROM), magnetic tape, a floppy disk, and an optical disc data storage device, etc. Those skilled in the art can understand that all or part of the steps in implementing the methods of the above embodiments can be completed by a program instructing relevant hardware. The program is stored in a storage medium and includes several instructions for causing a single-chip microcomputer, a chip, or a processor to execute all or part of the steps of the methods described in various embodiments of the present application. The foregoing storage medium includes: various media such as a USB flash drive, a mobile hard disk, a read-only memory (ROM, Read-Only Memory), a random access memory (RAM, Random Access Memory), a magnetic disk, or an optical disc that can store program codes.

[0160] The preferred embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0161] In addition, it should be noted that, among the various specific technical features described in the above specific embodiments, without conflict, they can be combined in any appropriate manner. To avoid unnecessary repetition, the present invention will not separately describe various possible combination methods.

[0162] In addition, any combination can be made among various different embodiments of the present invention, as long as it does not violate the idea of the present invention, and it should also be regarded as the content disclosed by the present invention.

Claims

1. A method for evaluating the content of mobile oil in shale, characterized in that The evaluation method includes: Based on the pyrolysis test data of the sample to be tested at different placement times, determine the first recovery coefficient considering the influence of the sample placement time; Based on the pyrolysis test data of the sample to be tested in different sample crushing environments, determine the second recovery coefficient considering the influence of the sample crushing environment; Based on the pyrolysis test data of the sample to be tested at different crushing particle sizes, determine the third recovery coefficient considering the influence of the sample crushing particle size; Based on the pyrolysis test data of the sample to be tested at different pyrolysis temperatures, determine the fourth recovery coefficient considering the influence of the sample pyrolysis temperature; Determine the product of the first recovery coefficient, the second recovery coefficient, the third recovery coefficient, and the fourth recovery coefficient as the light hydrocarbon recovery coefficient; Based on the light hydrocarbon recovery coefficient, evaluate the content of mobile oil in shale.

2. The method for evaluating the movable oil content in shale according to claim 1, wherein The step of determining the first recovery coefficient considering the influence of the sample placement time based on the pyrolysis test data of the sample to be tested at different placement times includes: When the sample to be tested is at a reasonable particle size and a reasonable pyrolysis temperature, obtain the pyrolysis test data of the sample to be tested at different placement times; Based on the pyrolysis test data of the sample to be tested at different placement times, determine the recovery coefficients of the sample to be tested at different placement times; Determine the average value of the recovery coefficients of the sample to be tested at different placement times as the first recovery coefficient.

3. The method for evaluating the movable oil content in shale according to claim 1, wherein The step of determining the second recovery coefficient considering the influence of the sample crushing environment based on the pyrolysis test data of the sample to be tested in different sample crushing environments includes: When the sample to be tested is at a reasonable particle size and a reasonable pyrolysis temperature, obtain the pyrolysis test data of the sample to be tested in different sample crushing environments; wherein, the different sample crushing environments include an open environment and a closed environment; Based on the pyrolysis test data of the sample to be tested in different sample crushing environments, determine the recovery coefficients of the sample to be tested in different sample crushing environments; Determine the average value of the recovery coefficients of the sample to be tested at different crushing particle sizes as the second recovery coefficient.

4. The method for evaluating the movable oil content in shale according to claim 1, wherein, The step of determining the third recovery coefficient considering the influence of the sample crushing particle size based on the pyrolysis test data of the sample to be tested at different crushing particle sizes includes: When the sample to be tested is at a reasonable pyrolysis temperature, obtain the pyrolysis test data of the sample to be tested at different crushing particle sizes, wherein the different crushing particle sizes include a reasonable particle size and other particle sizes; Based on the pyrolysis test data of the sample to be tested at different crushing particle sizes, determine the recovery coefficients of the sample to be tested at different crushing particle sizes; Determine the average value of the recovery coefficients of the sample to be tested at different crushing particle sizes as the third recovery coefficient.

5. The method for evaluating the movable oil content in shale according to claim 1, wherein The step of determining the fourth recovery coefficient considering the influence of the sample pyrolysis temperature based on the pyrolysis test data of the sample to be tested at different pyrolysis temperatures includes: When the sample to be tested is at a reasonable particle size, obtain the pyrolysis test data of the sample to be tested at different pyrolysis temperatures; wherein, the different pyrolysis temperatures include a reasonable pyrolysis temperature and a conventional pyrolysis temperature; Based on the pyrolysis test data of the sample to be tested at different pyrolysis temperatures, determine the recovery coefficients of the sample to be tested at different pyrolysis temperatures; Determine the average value of the recovery coefficients of the sample to be tested at different pyrolysis temperatures as the fourth recovery coefficient.

6. The method for evaluating the movable oil content in shale according to any one of claims 2 to 5, characterized in that The evaluation method further includes: Obtain porosity test data of different lithology samples under different crushing particle sizes; Based on the porosity test data of different lithology samples under different crushing particle sizes, determine the fitting relationship between porosity and particle size; Based on the median value of the effective porosity of the shale samples in the target area, determine the reasonable particle size through the fitting relationship between porosity and particle size.

7. The method for evaluating the movable oil content in shale according to any one of claims 2 to 5, characterized in that The evaluation method further includes: Obtain the total hydrocarbon chromatogram image of the crude oil sample in the shale horizontal well, wherein the crude oil sample has the same stratigraphic horizon as the sample to be tested; Obtain the total hydrocarbon chromatogram images of the multi-temperature stage pyrolysis hydrocarbons of the sample to be tested in different pyrolysis temperature ranges; Compare the total hydrocarbon chromatogram image of the crude oil sample and the total hydrocarbon chromatogram images of the multi-temperature stage pyrolysis hydrocarbons, and determine the part in the total hydrocarbon chromatogram images of the multi-temperature stage pyrolysis hydrocarbons that is similar to the total hydrocarbon chromatogram image of the crude oil sample; Determine the reasonable pyrolysis temperature as the pyrolysis temperature corresponding to the part in the total hydrocarbon chromatogram images of the multi-temperature stage pyrolysis hydrocarbons that is similar to the total hydrocarbon chromatogram image of the crude oil sample.

8. The method for evaluating the movable oil content in shale according to claim 1, wherein The evaluation method further includes: Determine the light hydrocarbon recovery coefficients of the samples to be tested with different Ro values; Based on the light hydrocarbon recovery coefficients corresponding to different Ro values, determine the fitting relationship between Ro value and light hydrocarbon recovery coefficient; Based on the fitting relationship between Ro value and light hydrocarbon recovery coefficient, predict the light hydrocarbon recovery coefficient corresponding to the sample to be tested with a specified Ro value.

9. An electronic device, characterized in that, The electronic device includes a processor and a memory, and at least one computer program is stored in the memory. The at least one computer program is loaded and executed by one or more of the above processors, so that the computer implements the method for evaluating the content of mobile oil in shale according to any one of claims 1 to 8.

10. A computer-readable storage medium, characterized in that, At least one program code is stored in the computer-readable storage medium, and the program code is loaded and executed by the processor, so that the computer implements the method for evaluating the content of mobile oil in shale according to any one of claims 1 to 8.

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