A method for obtaining original free hydrocarbon content of a lacustrine mixed carbonate rock shale oil geochemical logging

Abstract

The application provides a method for obtaining original free hydrocarbon content of lacustrine mixed carbonate rock shale oil geochemical logging, comprising obtaining dominant lithology of the lacustrine mixed carbonate rock to be measured and free hydrocarbon content of the dominant lithology at a T moment after the barrel is taken out; according to the free hydrocarbon content of the dominant lithology at the T moment and a preset free hydrocarbon loss recovery model, the original free hydrocarbon content of the dominant lithology is obtained, and the obtaining of the original free hydrocarbon content of the lacustrine mixed carbonate rock shale oil geochemical logging is completed. The method obtains the original free hydrocarbon content of the dominant lithology by analyzing the dominant lithology and combining the free hydrocarbon loss recovery model, and the free hydrocarbon loss correction under different lithologies is more scientific and reasonable. The free hydrocarbon loss recovery model established by the application has good adaptability, high accuracy, good precision and easy operation.

Description

Technical Field

[0001] The present invention belongs to the technical field of free hydrocarbon correction methods for geochemical logging, and relates to a method for obtaining the original free hydrocarbon content in lacustrine mixed-accumulation carbonate shale oil geochemical logging. Background Art

[0002] Shale oil is an important component of unconventional energy. Laminated gray-dolomiaceous shales and layered gray-dolomiaceous shales in lacustrine mixed carbonate rocks are shale oil-rich reservoirs. The sources of samples for geochemical logging analysis mainly include three sampling methods: cuttings logging, sidewall coring, and drill coring. In the process of cuttings logging sampling, the cuttings are affected by factors such as drilling fluid flushing during the process of returning to the wellhead, resulting in the greatest loss of free hydrocarbons and the least accurate measurement. Sidewall coring sampling has a lower degree of free hydrocarbon loss than cuttings logging samples. Drilling coring samples have the least free hydrocarbon loss and are closest to the free hydrocarbon content of the original formation. Therefore, drilling coring samples are the most appropriate for geochemical logging analysis. After coring, logging analysis equipment is often lacking. To ensure the integrity of the core, geochemical analysis cannot be performed immediately at most logging sites. Instead, the core is sampled and analyzed after several days of quiescence (including during transportation). This results in low free hydrocarbon analysis values ​​that do not represent the original formation free hydrocarbon content. Current research on free hydrocarbon loss correction in shale oil geochemical logging primarily focuses on mud shales, and most methods rely on empirical charts, critical point analysis, and univariate linear regression. These methods are significantly affected by human factors, resulting in poor correction results. Furthermore, correction for free hydrocarbons in mixed carbonate rocks is rarely proposed. Summary of the Invention

[0003] In response to the problems existing in the prior art, the present invention provides a method for obtaining the original free hydrocarbon content of lacustrine mixed-accumulation carbonate shale oil geochemical logging, thereby solving the technical problem in the prior art that free hydrocarbons in mixed-accumulation carbonate rocks cannot be corrected.

[0004] The present invention is achieved through the following technical solutions:

[0005] A method for obtaining the original free hydrocarbon content of lacustrine mixed carbonate shale oil geochemical logging comprises the following steps:

[0006] Obtain the dominant lithology of the lacustrine mixed-accumulation carbonate rock to be tested and the free hydrocarbon content of the dominant lithology at the time T after the rock is discharged from the cylinder;

[0007] According to the free hydrocarbon content of the dominant lithology at time T and the preset free hydrocarbon loss recovery model, the original free hydrocarbon content of the dominant lithology is obtained, and the original free hydrocarbon content of the lacustrine mixed carbonate shale oil geochemical logging is completed.

[0008] Preferably, the dominant lithology includes laminated lime-dolomite shale and layered lime-dolomite shale.

[0009] Preferably, when the dominant lithology is laminated lime-dolomite shale, the preset free hydrocarbon loss recovery model is:

[0010] S 纹层状原始 =S 纹层状，T / e -aT

[0011] Where,

[0012] S 纹层状原始 is the original free hydrocarbon content of the laminated ash dolomite;

[0013] S 纹层状，T is the free hydrocarbon content of the laminated dolomitic shale at time T after the core is taken out of the barrel;

[0014] a is a constant;

[0015] T is the time when the core is left to stand after exiting the barrel.

[0016] Preferably, when the dominant lithology is laminated lime-dolomite shale, the process of establishing the preset free hydrocarbon loss recovery model is specifically as follows:

[0017] Obtain the original free hydrocarbon content of laminated gray-dolomiaceous shale;

[0018] The cores were left at room temperature for several hours, and the free hydrocarbon content of the laminated gray-dolomitic shale was measured at different time points.

[0019] A nonlinear regression analysis method was used to establish a model for the original free hydrocarbon content of the laminated gray-dolominic shale and the free hydrocarbon content of the laminated gray-dolominic shale at time T after the core was taken out of the barrel.

[0020] Preferably, when the dominant lithology is layered lime-dolomite shale, the preset free hydrocarbon loss recovery model is:

[0021] S 层状原始 =S 层状，T +f(φ)

[0022] Where,

[0023] S 层状原始 is the original free hydrocarbon content of the layered limestone;

[0024] S 层状，T is the free hydrocarbon content of the layered limestone at time T after the core is left to stand after exiting the barrel;

[0025] f(φ) is the relationship between the lost free hydrocarbon content and the porosity value φ of the sample to be tested.

[0026] Preferably, when the dominant lithology is layered lime-dolomite shale, the process of establishing the preset free hydrocarbon loss recovery model is specifically as follows:

[0027] Obtaining the original free hydrocarbon content of layered gray-dolomitic shales;

[0028] The samples were subjected to oil washing treatment and the free hydrocarbon values ​​lost by the layered grey-dolomitic shale were obtained;

[0029] Obtain the porosity value of the sample and establish a functional model between the lost free hydrocarbon value and the porosity value through linear regression analysis;

[0030] A model was established to compare the original free hydrocarbon content of layered gray-dolomiaceous shale and the free hydrocarbon content of layered gray-dolomiaceous shale at time T after the core was taken out of the barrel.

[0031] Preferably, the free hydrocarbon content of the dominant lithology of the lacustrine mixed carbonate rock core to be tested is obtained by a geochemical analyzer after the core is left to stand for a time T after exiting the barrel.

[0032] A system for obtaining the original free hydrocarbon content of lacustrine mixed carbonate shale oil geochemical logging, comprising:

[0033] A data acquisition unit, the data acquisition unit is used to obtain the free hydrocarbon content of the laminated lime-dolominic shale and the layered lime-dolominic shale in the lacustrine mixed carbonate rock measured at the time T after the core is left to stand after being taken out of the barrel;

[0034] A data processing unit is used to obtain the original free hydrocarbon content of the dominant lithology based on the free hydrocarbon content of the dominant lithology at time T and a preset free hydrocarbon loss recovery model, thereby completing the acquisition of the original free hydrocarbon content of the lacustrine mixed carbonate shale oil geochemical logging.

[0035] A terminal device comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of the above method when executing the computer program.

[0036] A computer-readable storage medium stores a computer program, which implements the steps of the above method when executed by a processor.

[0037] Compared with the prior art, the present invention has the following beneficial technical effects:

[0038] The present invention provides a method for obtaining the original free hydrocarbon content from geochemical logging of lacustrine mixed carbonate shale oil. By analyzing the dominant lithology and combining it with a free hydrocarbon loss recovery model, the original free hydrocarbon content of the dominant lithology is obtained. This allows for more scientific and reasonable correction of free hydrocarbon losses for different lithologies. The free hydrocarbon loss recovery model established in the present invention has good adaptability, high accuracy, good precision, and is easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without paying any creative work.

[0040] Figure 1 Schematic diagram of a process for obtaining the original free hydrocarbon content of lacustrine mixed carbonate shale oil geochemical logging in the present invention;

[0041] Figure 2 Well logging diagrams for laminated gray-dolomiaceous shale and layered gray-dolomiaceous shale in a certain area;

[0042] Figure 3 This is a curve fitting diagram of free hydrocarbon S1 and standing time T in the oil-bearing core of laminated gray-dolomitic shale in a certain area (the oil content level is fluorescence and oil spots);

[0043] Figure 4 The free hydrocarbon value of the oil-bearing core (oil content is fluorescence and oil spots) of the lamellar-layered gray-dolomitic shale in a well in the area was measured just after being taken out of the barrel and after being left for 5 days. Figure 3 The curve fitting diagram of the free hydrocarbon value after the relationship is restored, the square points in the figure are the restored values, and the straight line is the fitting curve;

[0044] Figure 5 This is a curve fitting diagram of the free hydrocarbon S1 loss and porosity φ in the oil-bearing core of the layered gray-dolomitic shale in a certain area (the oil-bearing level is fluorescence and oil spots);

[0045] Figure 6 The free hydrocarbon S1 value of the oil-bearing core of the layered gray-dolomitic shale (oil-bearing grade is fluorescence and oil spots) just out of the tube is compared with that after standing for 5 days. Figure 3 The curve fitting diagram after the relationship is restored. The dots in the diagram are the restored values, and the straight line is the fitting curve.

[0046] Figure 7 The figure is a schematic structural diagram of a system for obtaining the original free hydrocarbon content in geochemical logging of lacustrine mixed carbonate shale oil in the present invention. DETAILED DESCRIPTION

[0047] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0048] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0049] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0050] In the description of the embodiments of the present invention, it should be noted that if the terms "upper," "lower," "horizontal," "inner," etc. appear, the orientation or positional relationship indicated is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the inventive product is typically placed when in use. These terms are merely for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or component referred to must have a specific orientation, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. In addition, the terms "first," "second," etc. are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0051] In addition, if the term "horizontal" appears, it does not mean that the component must be absolutely horizontal, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0052] In the description of the embodiments of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0053] The present invention is described in further detail below with reference to the accompanying drawings:

[0054] like Figure 1 As shown, the present invention provides a method for obtaining the original free hydrocarbon content of lacustrine mixed carbonate shale oil geochemical logging, comprising the following steps:

[0055] The dominant lithology of the lacustrine mixed carbonate rock to be tested and the free hydrocarbon content of the dominant lithology after the core is left standing for T time after being ejected from the barrel are obtained; specifically, the free hydrocarbon content of the dominant lithology of the lacustrine mixed carbonate rock to be tested after the core is left standing for T time after being ejected from the barrel is obtained by a geochemical analyzer.

[0056] According to the free hydrocarbon content of the dominant lithology at time T and the preset free hydrocarbon loss recovery model, the original free hydrocarbon content of the dominant lithology is obtained, and the original free hydrocarbon content of the lacustrine mixed carbonate shale oil geochemical logging is completed.

[0057] In practice, the dominant lithologies mainly include laminated gray-dolominic shale and layered gray-dolominic shale.

[0058] When the dominant lithology is laminated lime-dolomite shale, the preset free hydrocarbon loss recovery model is:

[0059] S 纹层状原始 =S 纹层状测量 / e -aT

[0060] Where,

[0061] S 纹层状原始 is the original free hydrocarbon content of the laminated ash dolomite;

[0062] S 纹层状测量 is the free hydrocarbon content of the laminated dolomitic shale at time T after the core is taken out of the barrel;

[0063] a is a constant;

[0064] T is the time when the core is left to stand after exiting the barrel.

[0065] When the dominant lithology is laminated lime-dolomite shale, the process of establishing the preset free hydrocarbon loss recovery model is specifically as follows:

[0066] Obtain the original free hydrocarbon content of laminated gray-dolomiaceous shale;

[0067] The cores were left at room temperature for several hours, and the free hydrocarbon content of the laminated gray-dolomitic shale was measured at different time points.

[0068] A nonlinear regression analysis method was used to establish a model for the original free hydrocarbon content of the laminated gray-dolominic shale and the free hydrocarbon content of the laminated gray-dolominic shale at time T after the core was taken out of the barrel.

[0069] When the dominant lithology is layered lime-dolomite shale, the preset free hydrocarbon loss recovery model is:

[0070] S 层状原始 =S 层状测量 +f(φ)

[0071] Where,

[0072] S 层状原始 is the original free hydrocarbon content of the layered limestone;

[0073] S 层状测量 is the free hydrocarbon content of the layered limestone at time T after the core is left to stand after exiting the barrel;

[0074] f(φ) is the relationship between the lost free hydrocarbon content and the porosity value φ of the sample to be tested.

[0075] When the dominant lithology is layered lime-dolomite shale, the specific process of establishing the preset free hydrocarbon loss recovery model is as follows:

[0076] Obtaining the original free hydrocarbon content of layered gray-dolomitic shales;

[0077] The samples were subjected to oil washing treatment and the free hydrocarbon values ​​lost by the layered grey-dolomitic shale were obtained;

[0078] Obtain the porosity value of the sample and establish a functional model between the lost free hydrocarbon value and the porosity value through linear regression analysis;

[0079] A model was established to compare the original free hydrocarbon content of layered gray-dolomiaceous shale and the free hydrocarbon content of layered gray-dolomiaceous shale at time T after the core was taken out of the barrel.

[0080] The present invention provides a method for obtaining the original free hydrocarbon content of lacustrine mixed carbonate shale oil geochemical logging. By analyzing the dominant lithology and combining it with a free hydrocarbon loss recovery model, the original free hydrocarbon content of the dominant lithology is obtained, and the correction of free hydrocarbon loss under different lithologies is more scientific and reasonable. For laminated gray-dolomite shale, the relationship between free hydrocarbons in the core and time is established according to the recovery model. When establishing the relationship, the regression analysis method in data mining is used. By using a nonlinear regression analysis method, a functional relationship between the measured value and the original value is established, and finally the original free hydrocarbon content of the formation is obtained, and free hydrocarbon loss recovery correction is achieved. For layered gray-dolomite shale, the relationship between the free hydrocarbon loss in the core and porosity is established according to the recovery model. When establishing the relationship, the regression analysis method in data mining is used. By using a linear regression analysis method, a functional relationship between the measured value and the original value is established, and finally the original free hydrocarbon content of the formation is obtained, and free hydrocarbon loss recovery correction is achieved. The correction of free hydrocarbon loss under different lithologies is more scientific and reasonable. In the past, the empirical chart method and univariate linear regression method commonly used in shale to recover hydrocarbon losses were greatly affected by human factors. At the same time, the univariate linear regression analysis method was relatively simple and incomplete. The free hydrocarbon loss recovery model established using this method has good adaptability, high accuracy, good precision, and is easy to operate.

[0081] Example 2

[0082] In order to further explain the present invention, this embodiment is described.

[0083] A method for correcting free hydrocarbon S1 in geochemical logging of lacustrine mixed carbonate shale oil, comprising:

[0084] Step 1: Identify the lithology of lacustrine mixed carbonate rocks. Use X-ray diffraction analysis, element logging, and lithologic scanning logging to identify the main lithology. Use resistivity imaging logging to identify the lithologic structure and structural characteristics. The dominant reservoir lithology is identified as laminated gray-dolominic shale and layered gray-dolominic shale.

[0085] Step 2: Use YQ-VIII geochemical analyzer to analyze the core just out of the barrel to obtain the geochemical analysis parameters of laminar and layered gray-dolomitic shale cores, free hydrocarbon S 纹层状原始 and S 层状原始 Value, at this time S 纹层状原始 and S 层状原始 The value is closest to the original hydrocarbon content of the formation;

[0086] Step 3: For the laminar dolomitic shale sample, the free hydrocarbon S of the laminar dolomitic shale is measured at different time points of 1 hour, 2 hours, 5 hours, 10 hours, 24 hours, 120 hours, and 240 hours. 纹层状，T The value of

[0087] Step 4: Establish the free hydrocarbon value S in the laminar gray-dolomitic shale by nonlinear regression analysis method. 纹层状，T The scatter relationship between the two points changes over time, and the S 纹层状，T With S 纹层状原始 And the functional relationship with time T:

[0088] S 纹层状原始 =S 纹层状，T / e -aT

[0089] Where,

[0090] S 纹层状原始 is the original free hydrocarbon content of the laminated ash dolomite, mg / g;

[0091] S 纹层状，T is the free hydrocarbon content of the laminated dolomitic shale at time T after the core is taken out of the barrel, mg / g;

[0092] a is a constant, which can be obtained by function fitting;

[0093] T is the time when the core is left to stand after exiting the barrel, h.

[0094] Step 5: For the layered gray-dolomitic shale sample, the YQ-VIII type geochemical analyzer is used to analyze the geochemical analysis parameters of the layered gray-dolomitic shale core just out of the barrel. 层状原始 value;

[0095] Step 6: Wash each sample with oil to fully remove the free hydrocarbon value ΔS that is easy to lose. 层状 The porosity value φ of each sample was measured using a nuclear magnetic resonance instrument, and ΔS was established through linear regression analysis. 层状 Functional relationship between ΔS and φ: 层状 =f(φ), thus establishing the functional relationship between the original value of free hydrocarbons in layered gray-dolomitic shale and porosity:

[0096] S 层状原始 =S 层状，T +f(φ)

[0097] Where,

[0098] S 层状原始 is the original free hydrocarbon content of the layered limestone, mg / g;

[0099] S 层状，T is the free hydrocarbon content of the layered limestone at time T after the core is taken out of the barrel, mg / g;

[0100] f(φ) is the relationship between the lost free hydrocarbon content and the porosity value φ of the sample to be tested, which can be obtained by data fitting;

[0101] φ is the porosity of the layered dolomitic shale test sample in %.

[0102] Example 3

[0103] Furthermore, the method of the present invention is further explained using the data of a certain well in a certain area. The well logging diagrams of the laminated gray-dolomiaceous shale and the layered gray-dolomiaceous shale in this area are shown in FIG. Figure 2 Specifically, cores were obtained from the upper strata of a well in a certain area for testing. The free hydrocarbon S1 parameter of the laminar gray-dolicholithic shale and layered gray-dolicholithic shale core samples was obtained from the analysis results of the YQ-VIII geochemical analyzer. A total of 36 oil-bearing core samples (oil content level is fluorescence and oil spots) were analyzed, including 12 laminar gray-dolicholithic shale core samples. The free hydrocarbon values ​​S1 of the 12 samples were measured when they were just out of the barrel. 纹层状原始 After the sample was left to stand for 5 days, the free hydrocarbon value S of the sample was measured. 纹层状，5天 , where the fitting relationship between different standing times and free hydrocarbon measurement values ​​is shown in Figure 3 , S 纹层状，5天 Substitute the value into the recovery formula of free hydrocarbons in laminated gray-dolomitic shale core:

[0104] S 纹层状原始 =S 纹层状，T / e -aT

[0105] Calculated S 纹层状原始 Fitting with the measured raw free hydrocarbon values ​​(see Figure 4 ),from Figure 4 It can be seen that the calculated S 纹层状原始 , that is, the free hydrocarbon recovery value of laminated gray-dolomitic shale ( Figure 4 The horizontal axis shows the difference between the measured original free hydrocarbon value, i.e. the original free hydrocarbon value of the laminated gray-dolomitic shale ( Figure 4 There are some deviations, but the overall trend is basically consistent. The calculation model can meet the demand for free hydrocarbons in the core of laminated gray-dolomitic shale;

[0106] Among the samples, there are 24 layered gray-dolomitic shale core samples. First, the porosity φ of the 24 core samples was measured using a nuclear magnetic resonance instrument. Among them, the free hydrocarbon loss ΔS 层状 The curve fitting diagram of porosity φ is shown in Figure 5 Then measure the free hydrocarbon value S of 24 samples just after they come out of the barrel. 1层状原始 After the sample was left to stand for 5 days, the free hydrocarbon value S of the sample was measured. 层状，5天 , S 层状，5天 Substitute the value into the recovery formula of free hydrocarbons in layered gray-dolomitic shale core:

[0107] S 层状原始 =S 层状，T +f(φ)

[0108] Calculated S 层状原始 Fitting with the actual measured raw free hydrocarbon values ​​(see Figure 6 ),from Figure 6 It can be seen that the calculated S 层状原始 , that is, the free hydrocarbon recovery value of layered lime-dolomitic shale ( Figure 6 The horizontal axis shows the difference between the measured original free hydrocarbon value, i.e. the original free hydrocarbon value of the layered lime-dolomitic shale ( Figure 6 ordinate), there are some deviations, but the overall trend is basically consistent, and the calculation model can meet the demand for free hydrocarbons in layered gray-dolomitic shale cores;

[0109] pass Figure 4 and Figure 6 The fitting of the recovered values ​​and the original values ​​revealed that there was a very good correlation between the free hydrocarbon calculation results calculated by the invented recovery formula and the original free hydrocarbon values ​​of the core samples, thereby verifying the accuracy of the calculation results of a correction calculation model for free hydrocarbon S1 in lacustrine mixed carbonate shale oil geochemical logging.

[0110] Example 4

[0111] like Figure 7 As shown, the present invention also provides a system for obtaining the original free hydrocarbon content of lacustrine mixed carbonate shale oil geochemical logging, comprising:

[0112] A data acquisition unit, the data acquisition unit is used to obtain the free hydrocarbon content of the laminated lime-dolominic shale and the layered lime-dolominic shale in the lacustrine mixed carbonate rock measured at the time T after the core is left to stand after being taken out of the barrel;

[0113] A data processing unit is used to obtain the original free hydrocarbon content of the dominant lithology based on the free hydrocarbon content of the dominant lithology at time T and a preset free hydrocarbon loss recovery model, thereby completing the acquisition of the original free hydrocarbon content of the lacustrine mixed carbonate shale oil geochemical logging.

[0114] Furthermore, a schematic diagram of a terminal device is provided in one embodiment of the present invention. The terminal device in this embodiment includes: a processor, a memory, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, the steps of each of the aforementioned method embodiments are implemented. Alternatively, when the processor executes the computer program, the functions of each module / unit in each of the aforementioned device embodiments are implemented.

[0115] The computer program may be divided into one or more modules / units, which are stored in the memory and executed by the processor to accomplish the present invention.

[0116] The terminal device may be a computing device such as a desktop computer, a notebook computer, a PDA, a cloud server, etc. The terminal device may include, but is not limited to, a processor and a memory.

[0117] The processor can be a central processing unit (CPU), or other general-purpose processors, digital signal processors (DSP), application-specific integrated circuits (ASIC), field-programmable gate arrays (FPGA) or other programmable logic devices, discrete gate or transistor logic devices, discrete hardware components, etc.

[0118] The memory may be used to store the computer programs and / or modules, and the processor implements various functions of the terminal device by running or executing the computer programs and / or modules stored in the memory and calling the data stored in the memory.

[0119] If the module / unit integrated in the terminal device is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present invention implements all or part of the process in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by a processor, it can implement the steps of each of the above-mentioned method embodiments. The computer program includes computer program code, which can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, USB flash drive, mobile hard disk, magnetic disk, optical disk, computer memory, read-only memory (ROM), random access memory (RAM), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0120] The above merely describes the preferred embodiments of the present application, and is not used to limit the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A method for obtaining the original free hydrocarbon content of lacustrine mixed carbonate shale oil geochemical logging, characterized in that: The following steps are involved: Obtain the dominant lithology of the lacustrine mixed-accumulation carbonate rock to be tested and the free hydrocarbon content of the dominant lithology at the time T after the cylinder is left standing; According to the free hydrocarbon content of the dominant lithology at time T and a preset free hydrocarbon loss recovery model, the original free hydrocarbon content of the dominant lithology is obtained, thereby completing the acquisition of the original free hydrocarbon content of the lacustrine mixed carbonate shale oil geochemical logging; The dominant lithologies include laminated gray-dolomitic shale and layered gray-dolomitic shale; When the dominant lithology is laminated lime-dolomite shale, the preset free hydrocarbon loss recovery model is: Where, is the original free hydrocarbon content of the laminated ash dolomite; is the free hydrocarbon content of the laminated dolomitic shale at time T after the core is taken out of the barrel; a is a constant; T is the time when the core is left to stand after exiting the barrel; When the dominant lithology is layered lime-dolomite shale, the preset free hydrocarbon loss recovery model is: Where, is the original free hydrocarbon content of the layered limestone; is the free hydrocarbon content of the layered limestone at time T after the core is left to stand after exiting the barrel; is the lost free hydrocarbon content and the porosity value of the sample to be tested relationship.

2. The method for obtaining the original free hydrocarbon content of lacustrine mixed carbonate shale oil geochemical logging according to claim 1, characterized in that: When the dominant lithology is laminated lime-dolomite shale, the process of establishing the preset free hydrocarbon loss recovery model is specifically as follows: Obtain the original free hydrocarbon content of laminated gray-dolomiaceous shale; The cores were left at room temperature for several hours, and the free hydrocarbon content of the laminated gray-dolomitic shale was measured at different time points. A nonlinear regression analysis method was used to establish a model for the original free hydrocarbon content of the laminated gray-dolominic shale and the free hydrocarbon content of the laminated gray-dolominic shale at time T after the core was taken out of the barrel.

3. The method for obtaining the original free hydrocarbon content of lacustrine mixed carbonate shale oil geochemical logging according to claim 1, characterized in that: When the dominant lithology is layered lime-dolomite shale, the process of establishing the preset free hydrocarbon loss recovery model is specifically as follows: Obtaining the original free hydrocarbon content of layered gray-dolomitic shales; The samples were subjected to oil washing treatment and the free hydrocarbon values ​​lost by the layered grey-dolomitic shale were obtained; Obtain the porosity value of the sample and establish a functional model between the lost free hydrocarbon value and the porosity value through linear regression analysis; A model was established to compare the original free hydrocarbon content of layered gray-dolomiaceous shale and the free hydrocarbon content of layered gray-dolomiaceous shale at time T after the core was taken out of the barrel.

4. The method for obtaining the original free hydrocarbon content of lacustrine mixed carbonate shale oil geochemical logging according to claim 1, characterized in that: The free hydrocarbon content of the dominant lithology at the time T after the core of the lacustrine mixed carbonate rock to be tested is left to stand after exiting the barrel is obtained by a geochemical analyzer.

5. A system for obtaining the original free hydrocarbon content of lacustrine mixed carbonate shale oil geochemical logging, characterized in that: A method for obtaining the original free hydrocarbon content of lacustrine mixed carbonate shale oil geochemical logging as described in any one of claims 1 to 4, comprising: A data acquisition unit, the data acquisition unit is used to obtain the free hydrocarbon content of the laminated lime-dolominic shale and the layered lime-dolominic shale in the lacustrine mixed carbonate rock measured at the time T after the core is left to stand after being taken out of the barrel; A data processing unit is used to obtain the original free hydrocarbon content of the dominant lithology based on the free hydrocarbon content of the dominant lithology at time T and a preset free hydrocarbon loss recovery model, thereby completing the acquisition of the original free hydrocarbon content of the lacustrine mixed carbonate shale oil geochemical logging.

6. A terminal device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 4 are implemented.

7. A computer-readable storage medium storing a computer program, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 4 are implemented.

Images