Evaluation method and device for conversion process of shale in supercritical water and electronic equipment

Abstract

The invention relates to the technical field of oil and gas geology, and provides an evaluation method and device for the conversion process of shale in supercritical water and electronic equipment, the method comprises the following steps: obtaining initial shale information of a shale sample, including organic rock characteristics, reservoir characteristics, kerogen structures and product compound compositions of the shale sample; carrying out a supercritical water conversion experiment on the shale sample, and collecting the converted shale sample and an oil-gas-water phase product; analyzing the converted shale sample and the oil-gas-water phase product to obtain a product yield and converted shale information; and obtaining an evaluation result of the conversion process of the shale in the supercritical water based on the product yield, the initial shale information before the conversion experiment and the evolution of the converted shale information. According to the method, the change of the conversion process of the shale in the supercritical water can be analyzed from multiple dimensions, and guiding significance is provided for industrial application of a shale supercritical water in-situ conversion technology.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil and gas geology, and particularly relates to a shale conversion process evaluation method and device in supercritical water and electronic equipment. BACKGROUND

[0002] The content of heavy components in low-maturity shale is high, the conversion rate of organic matter is low, and the content of solid kerogen is more than 40%, which makes the extraction and conversion process of shale complex. Traditional shale oil development technologies, such as horizontal drilling and hydraulic fracturing, face the challenges of low efficiency and environmental pollution.

[0003] Supercritical water, as a green and efficient solvent, can promote the cracking of kerogen and heavy oil in shale, thereby improving the conversion efficiency and product quality. In addition, supercritical water effectively reduces the generation of harmful by-products, thereby reducing environmental pollution. In general, supercritical water in-situ conversion technology is considered to be one of the most promising methods to realize large-scale development of low-maturity shale oil.

[0004] Researching the conversion process of shale in supercritical water, including how supercritical water extracts shale oil from shale cores to fracture networks, and how shale organic matter degrades in supercritical water, is of great significance to process parameter optimization and deepening the understanding of the conversion mechanism. However, the existing evaluation methods still face many problems: (1) At the core scale, organic matter is usually present in the form of adsorbed oil, free oil and expelled oil. Under the current technical level, only the expelled oil in the hydraulic fracture network and the free oil in the shale pores can be developed and utilized. However, the existing evaluation methods mainly aim at the total yield of shale oil, and cannot evaluate the yield of shale oil in different states. At the same time, shale is a complex porous medium composed of minerals and organic matter, and its conversion in supercritical water involves the coupling process of organic matter degradation and reservoir evolution. The existing methods cannot evaluate how this coupling process affects the extraction of shale oil from shale cores by supercritical water.

[0005] (2) The existing methods cannot evaluate the evolution stage and path of shale organic matter in supercritical water at the molecular scale. SUMMARY

[0006] The present application provides a shale conversion process evaluation method, device and electronic equipment in supercritical water, to solve the problem that the existing technology cannot objectively and accurately evaluate the conversion process of shale in supercritical water.

[0007] The application provides a shale conversion process in supercritical water evaluation method, comprising: obtaining initial shale information of a shale sample; wherein the initial shale information comprises organic rock characteristics, reservoir characteristics, kerogen structure and product compound composition of the shale sample; performing a supercritical water conversion experiment on the shale sample and collecting the converted shale sample and oil-gas-water phase products; analyzing the converted shale sample and the oil-gas-water phase products to obtain product yield and converted shale information; wherein the product yield comprises retained oil, discharged oil, free oil, adsorbed oil and gas yield; wherein the converted shale information comprises organic rock characteristics, reservoir characteristics, kerogen structure and product compound composition of the converted shale sample; based on the product yield, the initial shale information before the conversion experiment and the evolution of the converted shale information, an evaluation result of the shale conversion process in supercritical water is obtained.

[0008] According to the shale conversion process in supercritical water evaluation method provided by the application, initial shale information of a shale sample is obtained, comprising: using a multifunctional polarizing microscope to characterize the microscopic components and fluorescence characteristics of the shale sample to obtain the organic rock characteristics of the shale sample; using a scanning electron microscope, nitrogen adsorption and an X-ray powder diffractometer to characterize the shale pore and mineral properties to obtain the reservoir characteristics of the shale sample; using group component analysis, Fourier transform ion cyclotron resonance mass spectrometry, comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry and gas chromatography to characterize product compounds to obtain the product compound composition of the shale sample; using organic element analysis, solid 13C nuclear magnetic resonance, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy to characterize the kerogen structure to obtain the kerogen structure of the shale sample.

[0009] According to the shale conversion process in supercritical water evaluation method provided by the application, a supercritical water conversion experiment is performed on a shale sample, and the converted shale sample and oil-gas-water phase products are collected, comprising: after the supercritical water conversion experiment is performed on the shale sample, gas products in a gas collector are collected; mixing methylene chloride extraction liquid of a cleaning pipeline and a reaction kettle with oil in a liquid collection pipe; using a rotary evaporator to evaporate methylene chloride solvent in the mixed extraction liquid at 45°C to obtain discharged oil; using methylene chloride to extract the reacted shale sample to obtain residual oil; drying the reacted shale sample as the converted shale sample and performing weighing and sealing preservation; obtaining free oil and adsorbed oil content of the shale sample by a rock pyrolysis instrument , extraction shale pyrolysis parameters S2 and S1.

[0010] The application provides a shale conversion process evaluation method in supercritical water, which is characterized by analyzing shale samples after conversion and oil-gas-water phase products to obtain product yield and shale information after conversion, including: analyzing micro-component, fluorescence, pore and mineral characteristics of shale samples after conversion, characterizing oil-gas-water phase compound composition, and characterizing kerogen molecular structure characteristics to obtain shale information after conversion including organic rock characteristics, reservoir characteristics, kerogen structure and product compound composition of shale samples after conversion.

[0011] The application provides a shale conversion process evaluation method in supercritical water, which is characterized by obtaining shale conversion process evaluation results in supercritical water based on product yield, initial shale information before conversion and evolution of shale information after conversion, including: obtaining core-scale evaluation results by product yield, organic rock characteristics and reservoir characteristics before conversion; wherein the core-scale evaluation results are used to evaluate macro-processes of supercritical water extraction of shale oil from cores; and obtaining molecular-scale evaluation results by evolution of kerogen structure and product compound composition before and after conversion; wherein the molecular-scale evaluation results are used to evaluate micro-conversion processes of organic matter in supercritical water.

[0012] The application provides a shale conversion process evaluation method in supercritical water, which is characterized by obtaining core-scale evaluation results including main paths of shale oil discharge, shale oil yield and quality changes of different occurrence forms; and molecular-scale evaluation results including stages and paths of organic matter conversion.

[0013] The application further provides a shale conversion process evaluation device in supercritical water, which includes: an initial shale information module for obtaining initial shale information of shale samples; wherein the initial shale information includes organic rock characteristics, reservoir characteristics, kerogen structure and product compound composition of shale samples; a conversion experiment module for performing supercritical water conversion experiments on shale samples and collecting shale samples after conversion and oil-gas-water phase products; a shale information after conversion module for analyzing shale samples after conversion and oil-gas-water phase products to obtain product yield and shale information after conversion; wherein the product yield includes retained oil, discharged oil, free oil, adsorbed oil and gas yield; and the shale information after conversion includes organic rock characteristics, reservoir characteristics, kerogen structure and product compound composition of shale samples after conversion; and an evaluation result module for obtaining shale conversion process evaluation results in supercritical water based on product yield, initial shale information before conversion and evolution of shale information after conversion.

[0014] The application further provides an electronic device including a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the shale conversion process evaluation method in supercritical water.

[0015] The application further provides a non-transitory computer-readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the shale conversion process evaluation method in supercritical water according to any one of the above.

[0016] The application further provides a computer program product, which comprises a computer program, and the computer program is executed by a processor to implement the shale conversion process evaluation method in supercritical water according to any one of the above.

[0017] The shale conversion process evaluation method in supercritical water, the device and the electronic equipment provided by the application analyze the changes of the shale conversion process in supercritical water from multiple dimensions, can evaluate the shale conversion process in supercritical water from the core scale to the molecular scale, and cover the macroscopic process of supercritical water extracting shale oil from a core and the microscopic conversion process of organic matter in supercritical water. In addition, the method is also suitable for selecting key engineering parameters such as reaction temperature and pressure, and has important guiding significance for the industrial application of the shale supercritical water in-situ conversion technology. BRIEF DESCRIPTION OF DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the application or prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the application, and other drawings can also be obtained by those skilled in the art without any creative effort.

[0019] Figure 1 is a shale conversion process evaluation method flowchart in supercritical water according to an embodiment of the application; Figure 2 is an experimental flowchart according to an embodiment of the application; Figure 3 is a characteristic image of different shale organic rocks according to an embodiment of the application; Figure 4 is a scanning electron microscope image of different shale according to an embodiment of the application; Figure 5 is a shale oil and gas yield graph according to an embodiment of the application; Figure 6 is a shale kerogen organic element and infrared spectrum image according to an embodiment of the application; Figure 7 is a shale oil group component content graph according to an embodiment of the application; Figure 8 is a shale oil compound species and content graph with a boiling point <300°C according to an embodiment of the application; Figure 9This is a diagram showing the types and contents of heteroatom compounds in shale oil according to one embodiment of the present invention; Figure 10 This is a diagram of shale gas composition and content according to an embodiment of the present invention; Figure 11 This is a macroscopic process diagram of supercritical water extraction of shale oil according to one embodiment of the present invention; Figure 12 This is a microscopic process diagram of organic matter degradation in supercritical water according to an embodiment of the present invention. DETAILED DESCRIPTION

[0020] To make the objectives, technical solutions, and advantages of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below in conjunction with the accompanying drawings. Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0021] The present invention provides a method for evaluating the conversion process of shale in supercritical water. The method evaluates the process of supercritical water extraction of shale oil at the core scale and evaluates the evolution stages and paths of organic matter in supercritical water at the molecular scale, providing guidance for the industrial application of shale supercritical water conversion technology.

[0022] See also Figure 1 , Figure 1 1 is a flow chart of a method for evaluating the conversion process of shale in supercritical water according to an embodiment of the present invention. In this embodiment, the method for evaluating the conversion process of shale in supercritical water may include steps S110 to S140, each of which is specifically as follows: S110: Obtaining initial shale information of the shale sample; wherein the initial shale information includes organic rock characteristics, reservoir characteristics, kerogen structure, and product compound composition of the shale sample.

[0023] S120: Conduct supercritical water conversion experiments on shale samples and collect converted shale samples and oil, gas and water phase products.

[0024] S130: Analyze the converted shale samples and oil, gas and water phase products to obtain product yields and converted shale information; the product yields include retained oil, discharged oil, free oil, adsorbed oil and gas yields; the converted shale information includes the organic rock characteristics, reservoir characteristics, kerogen structure and product compound composition of the converted shale samples.

[0025] S140: Based on the product yield, the initial shale information before the conversion experiment, and the evolution of the shale information after the conversion, an evaluation result of the shale conversion process in supercritical water is obtained.

[0026] Supercritical water has unique physicochemical properties, such as density, viscosity, dielectric constant, etc., which are quite different from ordinary water and gas. This makes organic matter in supercritical water environment can occur special chemical reactions, so as to realize the conversion of shale organic matter to shale oil and other products.

[0027] In this embodiment, the initial state of the shale sample is comprehensively characterized by various professional analysis techniques. The organic rock characteristics can understand the type, content and distribution of organic matter in shale; the reservoir characteristics characterization includes pores, minerals, etc., which can reflect the storage and percolation capacity of shale reservoir to fluid; the kerogen structure analysis helps to clarify the chemical composition and molecular structure characteristics of kerogen; the product compound composition analysis can explain the types and contents of organic compounds in shale products at different conversion stages.

[0028] In some embodiments, the step of obtaining initial shale information of the shale sample can specifically include: The microcomponents and fluorescence characteristics of the shale sample are characterized by using a multifunctional polarizing microscope to obtain the organic rock characteristics of the shale sample; scanning electron microscopy (SEM), nitrogen adsorption and X-ray powder diffractometer (XRD) are used to characterize the pore and mineral properties of the shale to obtain the reservoir characteristics of the shale sample; group component analysis, high-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS), comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GCxGC / TOF-MS) and gas chromatography (GC) are used to characterize the product compounds to obtain the product compound composition of the shale sample; organic element analysis (CHONS), solid 13C nuclear magnetic resonance (13C NMR), Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS) are used to characterize the kerogen structure to obtain the kerogen structure of the shale sample.

[0029] In this embodiment, the shale sample is placed in a supercritical water environment, and certain conditions such as temperature, pressure and reaction time are controlled to make the shale undergo chemical conversion reaction, and the converted shale sample and products are collected. This step is the core link of the entire evaluation method, which simulates the actual possible change process of shale under supercritical water conditions.

[0030] In some embodiments, the step of performing supercritical water conversion experiment on the shale sample and collecting the converted shale sample and products can specifically include: After the supercritical water conversion experiment on the shale sample, gas products in the gas collector are collected; methylene chloride (DCM) extraction liquid of the cleaning pipeline and the reaction kettle is mixed with oil in the liquid collection tube; methylene chloride (DCM) solvent in the mixed extraction liquid is evaporated at 45°C by using a rotary evaporator to obtain discharged oil; the shale sample after the reaction is extracted by using methylene chloride (DCM) to obtain residual oil; the shale sample after the reaction is dried as the shale sample after conversion and is sealed for storage after weighing; shale pyrolysis parameters S1 and S2 before and after extraction are obtained by using a rock pyrolysis instrument, to obtain free oil (S1) and adsorbed oil (S2) contents of the shale sample.

[0031] In this embodiment, the collected products are analyzed in detail to obtain product yield and shale information after conversion. The product yield is one of important indexes for measuring the conversion effect, and the analysis of the shale information after conversion compared with the initial shale information can directly show the changes of the shale in the supercritical water conversion process.

[0032] In some embodiments, the step of analyzing the shale sample after conversion and the oil, gas and water phase products to obtain product yield and shale information after conversion can specifically include: analyzing the characteristics of the microcomponents, fluorescence, pores and minerals of the shale sample after conversion, characterizing the compound composition of the gas, water phase oil and the molecular structure characteristics of the kerogen, to obtain the shale information after conversion including the organic rock characteristics, reservoir characteristics, kerogen structure and product compound composition of the shale sample after conversion.

[0033] Further, the oil, gas and water phase products are analyzed to obtain product yield. Optionally, the product yield can include shale oil yield.

[0034] Finally, based on the product yield and the evolution of the shale information before and after the conversion experiment, the effect and characteristics of the shale conversion process in the supercritical water are comprehensively evaluated. Through the analysis and comprehensive consideration of different aspects of information, the evaluation result of the conversion process is finally obtained.

[0035] In some embodiments, the step of obtaining the evaluation result of the shale conversion process in the supercritical water based on the product yield, the initial shale information before the conversion experiment and the evolution of the shale information after the conversion can specifically include: the core scale evaluation result is obtained through the product yield, the changes of the organic rock characteristics and the reservoir characteristics before and after the conversion experiment; wherein the core scale evaluation result is used to evaluate the macro process of the supercritical water extraction of shale oil from the core; the molecular scale evaluation result is obtained through the evolution of the kerogen structure and the product compound composition before and after the conversion experiment; wherein the molecular scale evaluation result is used to evaluate the micro conversion process of the organic matter in the supercritical water.​​

[0036] Further, according to the core-scale evaluation result and the molecule-scale evaluation result, the final evaluation result of the shale in the supercritical water conversion process can be obtained.

[0037] In some embodiments, the core-scale evaluation result includes the main path of the shale oil discharge, the shale oil production of different occurrence forms and the quality change; and the molecule-scale evaluation result includes the stage and path of the organic matter conversion.

[0038] Based on the above embodiments, the present application obtains the initial and converted shale sample information in multiple aspects, including the organic rock characteristics, the reservoir characteristics, the kerogen structure and the product compound composition, and the information is complementary to each other, which can comprehensively reflect the state change of the shale before and after the conversion from different angles, and provides sufficient data support for accurately evaluating the conversion process.

[0039] It should be further noted that, during the supercritical water conversion experiment, the temperature, the pressure, the reaction time and other conditions have important influences on the shale conversion effect. The present embodiment is optimized and adjusted according to the properties of the shale and the expected conversion target.

[0040] In order to more clearly explain the above method for evaluating the shale in the supercritical water conversion process, each step will be described in detail below.

[0041] In step S210, the organic rock characteristics, the reservoir pore and mineral, the kerogen structure and the shale oil composition of the selected shale sample are characterized.

[0042] The microcomponents and the fluorescence characteristics of the shale are characterized by using a multifunctional polarizing microscope; the shale pore and mineral properties are characterized by using a scanning electron microscope (SEM), nitrogen adsorption and an X-ray powder diffractometer (XRD); the shale oil product is comprehensively characterized by using group component analysis, high-resolution Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS), comprehensive two-dimensional gas chromatography-time-of-flight mass spectrometry (GCxGC / TOF-MS) and gas chromatography (GC); and the kerogen structure is characterized in detail by using organic element analysis (CHONS), solid 13C nuclear magnetic resonance (13C NMR), Fourier transform infrared spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS).

[0043] In step S220, a series of time supercritical water conversion experiments are carried out by using an intermittent high-temperature and high-pressure reaction kettle, and the converted shale sample and the product are collected.

[0044] A series of time supercritical water conversion experiments are conducted using a batch autoclave. First, the gaseous products are collected in a gas collector. Then, the dichloromethane (DCM) extract from the purge line and the reactor is mixed with the oil from the liquid collection line. The dichloromethane (DCM) solvent is evaporated from the mixed extract using a rotary evaporator at 45 °C to obtain the drained oil. Next, the reacted shale sample is extracted using dichloromethane (DCM) to obtain the residual oil. Finally, the reacted shale sample is dried, weighed, and sealed for storage; the shale pyrolysis parameters are obtained using a Rock-Eval pyrolysis instrument. , the shale pyrolysis parameters S2 and S1 after extraction, to obtain the free oil (S1) and adsorbed oil (S2) content of the shale sample.

[0045] Step S230, characterization of the petrographic and reservoir characteristics of the reacted shale sample, and the kerogen structure and product chemical composition.

[0046] Using similar means as in step S210, the reacted shale sample is analyzed for the characteristics of the maceral, fluorescence, porosity, and minerals, and the chemical composition of the oil, gas, and water phases, and the molecular structure of the kerogen.

[0047] Step S240, evaluation of the supercritical water conversion process of the shale from the core scale to the molecular scale by the evolution of the shale oil yield, organic rock characteristics, reservoir characteristics, kerogen structure, and product molecular composition before and after the reaction.

[0048] By the changes in the shale oil yield and occurrence state, organic rock characteristics, and reservoir characteristics before and after the reaction, the macroscopic process of the supercritical water extraction of the shale oil from the core is evaluated at the core scale (millimeter to micrometer scale), including the main path of the shale oil drainage, the yield and quality changes of the shale oil in different occurrence forms. By the evolution of the kerogen structure and product chemical composition, the microscopic conversion process of the organic matter in the supercritical water is evaluated, including the stages and paths of the organic matter conversion.

[0049] It should be noted that although the operations of the method of the present application are described in a specific order in the above embodiments and drawings, this does not require or imply that the operations must be performed in this specific order, or that all of the shown operations must be performed to achieve the desired results. Additionally or alternatively, certain steps can be omitted, multiple steps can be combined into one step, and / or one step can be divided into multiple steps.

[0050] In order to more clearly explain the above method for evaluating the supercritical water conversion process of the shale, a specific embodiment will be described below, however, it should be noted that this embodiment is only used to better illustrate the present application, and does not constitute an improper limitation on the present application. ​

[0051] Taking a typical low-mature shale in a certain basin as an example, the shale sample selected has a total organic carbon content TOC = 21.0%, a vitrinite reflectance Ro = 0.69%, a pyrolysis parameter hydrogen index HI = 595.29 mg / g TOC, and a shale oil content of 35.2 mg / g TOC.

[0052] Referring to the steps shown in Figure 1 and Figure 2 , the experimental flowchart shown in Figure 2 is an experimental flowchart of an embodiment of the present application.

[0053] The organic rock characteristics, reservoir porosity and minerals, kerogen structure and shale oil composition of the selected shale sample are characterized. On this basis, a series of time supercritical water conversion experiments are carried out using an intermittent high-temperature high-pressure reaction kettle, and the converted shale samples and oil, gas and water phase products are collected. Further, the organic petrology and reservoir characteristics of the converted shale samples, and the kerogen structure and product compound composition are characterized. Finally, by comparing the shale oil yield before and after the reaction with the occurrence state, the evolution of the organic rock characteristics, reservoir characteristics, kerogen structure and product molecular composition, the conversion process of shale in supercritical water is evaluated from the core scale to the molecular scale.

[0054] The organic rock characteristics, reservoir porosity and minerals, kerogen structure and shale oil composition of the shale before conversion are characterized. As shown in Figure 3 , Figure 3 is a characteristic image of different shale organic rock characteristics of an embodiment of the present application.

[0055] The kerogen maceral is mainly sapropel, containing rich lamellar algae, structural algae and amorphous organic matter, and a small amount of oil showing blue-green fluorescence.

[0056] As shown in Figure 4 , Figure 4 is a scanning electron microscope image of different shale samples of an embodiment of the present application.

[0057] The organic matter developed in the shale is combined with the clay mineral composite layer, and the inorganic micropore is the main pore type, such as intercrystalline pore and feldspar dissolution pore.

[0058] This embodiment uses an intermittent high-temperature high-pressure reaction kettle to carry out 4 groups of time sequence experiments, and the experimental time is 12h, 24h, 36h and 48h respectively. In each experiment, the fluid pressure and the hydrocarbon discharge pressure are set to 23 MPa and 25 MPa respectively, the reaction temperature is 375°C, and the water rock volume ratio is 0.7. After the conversion is completed, the oil, gas and water products are collected in turn.

[0059] The organic petrology and reservoir characteristics of the converted shale samples, and the kerogen structure and product compound composition are characterized. As shown in Figure 5 ,Figure 5 is a shale oil and gas yield chart according to an embodiment of the present application.

[0060] The total oil yield was increased by 18.2 to 11 times and the gas yield showed a continuous upward trend when the reaction was carried out in supercritical water for 12 to 48 h. The retained oil yield in the shale gradually decreased, and the discharge oil yield reached a peak at 36 h. The kerogen conversion rate was increased from 83.3% to 94.5%, and the proportion of free oil was increased.

[0061] As shown in Figure 3 , under the action of supercritical water, the micro-components of kerogen decomposed to generate asphaltenes and hydrocarbons.

[0062] As shown in Figure 3 and Figure 4 , by 48 h, the content of black coke increased significantly, causing the micro-pores of the shale to be blocked. The feldspar and calcite minerals in the shale were dissolved, the cementation effect was weakened, and a large number of cracks and micron-sized pores were formed, providing an effective channel for the discharge of shale oil.

[0063] Please refer to Figure 6 , Figure 6 is a shale kerogen organic element and infrared spectrum image according to an embodiment of the present application.

[0064] As shown in Figure 6 a, in the first 12 h, the kerogen mainly underwent dehydration reaction. In 12 to 36 h, the kerogen mainly underwent dealkylation. In 36 to 48 h, the kerogen mainly underwent deoxidation.

[0065] As shown in Figure 6 b, before the reaction, the kerogen contained a large amount of aliphatic carbon mainly in the form of methylene. With the extension of the reaction time, the content of aliphatic carbon in the kerogen gradually decreased, and the content of aromatic carbon gradually increased. Correspondingly, the length of the aliphatic chain of the kerogen was shortened, and the degree of polycondensation was enhanced. By 48 h, the increase of dehydrogenation and aromatization caused the absorption peak of unsaturated C=C to weaken.

[0066] As shown in Figure 7 , the content of the main components of the shale oil is shown in Figure 7 is a shale oil group component content chart according to an embodiment of the present application.

[0067] At 12 h, the shale oil was mainly asphaltenes, and with the extension of the reaction time, the asphaltenes content in the discharge oil and the retained oil gradually decreased, and the content of saturated hydrocarbons and aromatic hydrocarbons correspondingly increased. The main difference between the two is that the content of saturated hydrocarbons in the discharge oil is higher, and the content of asphaltenes in the retained oil is higher.

[0068] As shown in Figure 8 , the content of the main components of the shale oil is shown in Figure 8is a shale oil compound species and content diagram of one embodiment of the present application.

[0069] The content of hydroxyl and carboxylic acid compounds increased significantly in the retentate oil from 12 to 24 h. At 36 h, low-boiling point NSO heteroatomic compounds became the main component. By 48 h, the fatty structure of kerogen was further removed, and small molecule NSO heteroatomic compounds were gradually decomposed, and the retentate oil was mainly composed of aliphatic hydrocarbons. Because supercritical water has high solubility for nonpolar compounds, the discharged oil is mainly composed of aliphatic hydrocarbons.

[0070] As shown in Figure 9 , Figure 9 is a shale oil compound species and content diagram of one embodiment of the present application.

[0071] During 12 to 36 h, kerogen decomposition generated a large amount of NSO heteroatomic compounds. By 48 h, these heteroatomic compounds were further decomposed and converted into N, O and NO heteroatomic compounds. The discharged oil is mainly composed of N heteroatomic compounds.

[0072] As shown in Figure 10 , Figure 10 is a shale gas composition and content diagram of one embodiment of the present application.

[0073] During 12 to 24 h, mainly through water gas shift reaction and decarboxylation reaction. After 24 h, the occurrence of methanation reaction leads to and yield decline. With the further progress of the reaction, the concentration of alkyl and hydrogen radicals continues to increase, prompting the yield of hydrocarbon gas and hydrogen to continue to rise.

[0074] Through the evolution of shale oil yield before and after the reaction, occurrence state, organic rock characteristics, reservoir characteristics, kerogen structure and product molecular composition from core scale to molecular scale, the conversion process of shale in supercritical water is evaluated.

[0075] As shown in Figure 11 , Figure 11 is a macroscopic process mode diagram of supercritical water extraction of shale oil of one embodiment of the present application.

[0076] The macroscopic process of supercritical water extraction of shale oil includes: shale organic matter first degrades to generate macromolecular substances such as asphaltene. With the continuous reaction, the amount of coke gradually increases and blocks the micropore. However, micron-sized pores and layered cracks are formed in the shale, providing a main channel for the release of shale oil. The generation of coke also leads to the decrease of shale oil production. In comparison, the water-rich phase has stronger hydrogen supply capacity and reactivity, and supercritical water has higher selective extraction capacity for aliphatic hydrocarbons; at the same time, the adsorption of kerogen and minerals on asphaltene and the steric effect of nanopores together lead to a higher content of saturated hydrocarbons and aromatic hydrocarbons in the discharged oil.

[0077] As shown in Figure 12 , Figure 12 is a microcosmic process mode diagram of degradation of organic matter in supercritical water according to an embodiment of the present application.

[0078] The microcosmic process of degradation of organic matter in supercritical water includes: first, the low-energy bridge bond or C-C bond in kerogen is broken to generate macromolecular substances such as asphaltene, and the oil phase is enriched in NSO type heteroatomic compounds; second, the residual kerogen and asphaltene macromolecules are further decomposed, and the oil phase is enriched in low-boiling-point NSO compounds; finally, with the enhancement of dehydrogenation and aromatization, the oil phase is enriched in N, NO and SO type heteroatomic compounds with high condensation degree, and the polycyclic aromatic hydrocarbon units condense to form coke.

[0079] The above, the method provided by the embodiment of the present application can evaluate the conversion process of shale under supercritical water conditions from the core scale to the molecular scale, covering the macroscopic process of supercritical water extracting shale oil from the core and the microcosmic conversion process of organic matter in supercritical water. In addition, the method is also suitable for selecting key engineering parameters such as reaction temperature and pressure, and has important guiding significance for the industrial application of shale supercritical water in-situ conversion technology.

[0080] The present application also provides an evaluation device for the conversion process of shale in supercritical water. The evaluation device for the conversion process of shale in supercritical water provided by the present application is described below, and the evaluation device for the conversion process of shale in supercritical water described below can be mutually corresponding and referred to the evaluation method for the conversion process of shale in supercritical water described above.

[0081] The evaluation device for the conversion process of shale in supercritical water can include an initial shale information module, a conversion experiment module, a post-conversion shale information module and an evaluation result module.

[0082] The initial shale information module is used to obtain the initial shale information of the shale sample; wherein the initial shale information includes the organic rock characteristics, reservoir characteristics, kerogen structure and product compound composition of the shale sample.

[0083] a conversion experiment module, configured to perform a supercritical water conversion experiment on the shale sample, and collect the shale sample after conversion and oil, gas and water phase products;

[0084] a post-conversion shale information module, configured to analyze the shale sample after conversion and the oil, gas and water phase products, to obtain shale oil yield and post-conversion shale information; wherein the product yield includes retained oil, discharged oil, free oil, adsorbed oil and gas yield; and the post-conversion shale information includes organic rock characteristics, reservoir characteristics, kerogen structure and product compound composition of the shale sample after conversion.

[0085] an evaluation result module, configured to obtain an evaluation result of the conversion process of the shale in supercritical water based on the product yield, the initial shale information before the conversion experiment and the evolution of the post-conversion shale information.

[0086] In another aspect, the embodiments of the present application also provide an electronic device, which can include a memory, a processor and a computer program stored in the memory and executable on the processor. The processor can implement the evaluation method of the conversion process of the shale in supercritical water when executing the program, and the method can include: obtaining initial shale information of a shale sample; wherein the initial shale information includes organic rock characteristics, reservoir characteristics, kerogen structure and product compound composition of the shale sample; performing a supercritical water conversion experiment on the shale sample, and collecting the shale sample after conversion and oil, gas and water phase products; analyzing the shale sample after conversion and the oil, gas and water phase products, to obtain shale oil yield and post-conversion shale information; wherein the product yield includes retained oil, discharged oil, free oil, adsorbed oil and gas yield; and the post-conversion shale information includes organic rock characteristics, reservoir characteristics, kerogen structure and product compound composition of the shale sample after conversion; and obtaining an evaluation result of the conversion process of the shale in supercritical water based on the product yield, the initial shale information before the conversion experiment and the evolution of the post-conversion shale information.

[0087] Optionally, the electronic device can further include a communication bus and a communication interface (Communications Interface), wherein the processor, the communication interface and the memory complete mutual communication through the communication bus. The processor can invoke the computer program in the memory to execute the evaluation method of the conversion process of the shale in supercritical water provided by the above-mentioned methods.

[0088] Furthermore, the logical instructions in the aforementioned memory can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, or the portion that contributes to the prior art, or a portion of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions for enabling a computer device (which can be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in various embodiments of the present invention. The aforementioned storage media include various media capable of storing program code, such as USB flash drives, mobile hard drives, read-only memories (ROMs), random access memories (RAMs), magnetic disks, or optical disks.

[0089] On the other hand, the present invention also provides a computer program product, which includes a computer program. The computer program can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the evaluation method of the shale conversion process in supercritical water provided by the above methods. The steps and principles of the evaluation method have been introduced in detail in the above methods and will not be repeated here.

[0090] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon. When the computer program is executed by a processor, it is implemented to perform the evaluation method of the shale conversion process in supercritical water provided by the above methods. The steps and principles of the evaluation method have been introduced in detail in the above methods and will not be repeated here.

[0091] The non-transitory computer-readable storage medium can be any available medium or data storage device that can be accessed by the processor, including but not limited to magnetic storage (such as floppy disks, hard disks, magnetic tapes, magneto-optical disks (MO), etc.), optical storage (such as CDs, DVDs, BDs, HVDs, etc.), and semiconductor storage (such as ROMs, EPROMs, EEPROMs, non-volatile memories (NANDFLASH), solid-state drives (SSDs)), etc.

[0092] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one location or distributed across multiple network units. Some or all of the modules may be selected based on actual needs to achieve the objectives of the present embodiment. Persons of ordinary skill in the art will be able to understand and implement the present invention without inventive effort.

[0093] Those skilled in the art can clearly understand the technical solutions of the various embodiments from the above description of the embodiments, and the various embodiments can be implemented by means of software with the necessary general hardware platforms, and of course, can also be implemented by hardware. Based on such understanding, the above technical solutions, essentially or in other words, the part of the prior art that makes a contribution, can be embodied in the form of a software product, which can be stored in a computer readable storage medium, such as a ROM / RAM, a magnetic disk, an optical disk, and the like, and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in the various embodiments or some parts of the embodiments.

[0094] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing embodiments, or make equivalent replacement for some technical features therein; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A method for evaluating the conversion process of shale in supercritical water, characterized in that: include: Obtaining initial shale information of the shale sample; wherein the initial shale information includes organic rock characteristics, reservoir characteristics, kerogen structure and product compound composition of the shale sample; Performing a supercritical water conversion experiment on the shale sample, and collecting the converted shale sample and oil, gas and water phase products; Analyzing the converted shale sample and the oil, gas, and water phase products to obtain product yields and converted shale information; wherein the product yields include retained oil, expelled oil, free oil, adsorbed oil, and gas yields; and the converted shale information includes organic rock characteristics, reservoir characteristics, kerogen structure, and product compound composition of the converted shale sample; Based on the product yield, the initial shale information before the conversion experiment, and the evolution of the shale information after the conversion, an evaluation result of the shale conversion process in supercritical water is obtained.

2. The method for evaluating the shale conversion process in supercritical water according to claim 1, characterized in that: The initial shale information of the shale sample is obtained, including: Characterizing the microscopic components and fluorescence characteristics of the shale sample using a multifunctional polarizing microscope to obtain organic rock characteristics of the shale sample; Scanning electron microscopy, nitrogen adsorption, and X-ray powder diffraction were used to characterize the shale pores and mineral properties to obtain reservoir characteristics of the shale samples; Characterizing the product compounds by group component analysis, Fourier transform ion cyclotron resonance mass spectrometry, comprehensive two-dimensional gas chromatography-time of flight mass spectrometry, and gas chromatography to obtain the product compound composition of the shale sample; The kerogen structure was characterized using organic element analysis, solid-state ¹³C nuclear magnetic resonance, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy to obtain the kerogen structure of the shale sample.

3. The method for evaluating the shale conversion process in supercritical water according to claim 1, characterized in that: The supercritical water conversion experiment is performed on the shale sample, and the converted shale sample and oil, gas and water phase products are collected, including: After performing a supercritical water conversion experiment on the shale sample, collecting gas products in a gas collector; Mix the dichloromethane extract from the cleaning lines and reactor with the oil in the liquid collection tube; The dichloromethane solvent in the mixed extract was evaporated using a rotary evaporator at 45°C to obtain the discharged oil; The shale sample after the reaction was extracted with dichloromethane to obtain residual oil; drying the shale sample after the reaction as the converted shale sample, weighing it, and sealing it for storage; Obtaining advance shale pyrolysis parameters through rock pyrolysis instrument , the shale pyrolysis parameters S2 and S1 after extraction, and the free oil and adsorbed oil contents of the shale sample are obtained.

4. The method for evaluating the shale conversion process in supercritical water according to claim 1, characterized in that: The analysis of the converted shale sample and the oil, gas and water phase products to obtain product yields and converted shale information includes: The microscopic components, fluorescence, pore and mineral characteristics of the converted shale samples are analyzed to characterize the compound composition of the oil, gas and water phases, and the kerogen molecular structure characteristics, so as to obtain the converted shale information including the organic rock characteristics, reservoir characteristics, kerogen structure and product compound composition of the converted shale samples.

5. The method for evaluating the shale conversion process in supercritical water according to claim 1, characterized in that: The evaluation results of the shale conversion process in supercritical water are obtained based on the product yield, the initial shale information before the conversion experiment, and the evolution of the shale information after the conversion, including: A core-scale evaluation result is obtained based on the product yield, organic rock characteristics before and after the conversion experiment, and reservoir characteristics. The core-scale evaluation result is used to evaluate the macroscopic process of supercritical water extraction of shale oil from the core. The molecular-scale evaluation results are obtained by analyzing the evolution of kerogen structure and product compound composition before and after the conversion experiment; wherein the molecular-scale evaluation results are used to evaluate the microscopic conversion process of organic matter in supercritical water.

6. The method for evaluating the shale conversion process in supercritical water according to claim 5, characterized in that: The core-scale evaluation results include the main pathways of shale oil discharge, shale oil production and quality changes in different occurrence forms; The molecular-scale evaluation results include the stages and pathways of organic matter transformation.

7. An evaluation device for shale conversion in supercritical water, characterized in that: include: An initial shale information module is used to obtain initial shale information of a shale sample; wherein the initial shale information includes organic rock characteristics, reservoir characteristics, kerogen structure, and product compound composition of the shale sample; A conversion experiment module, used to perform a supercritical water conversion experiment on the shale sample and collect the converted shale sample and oil, gas and water phase products; A converted shale information module is used to analyze the converted shale samples and oil, gas and water phase products to obtain product yields and converted shale information; wherein the product yields include retained oil, expelled oil, free oil, adsorbed oil and gas yields; the converted shale information includes organic rock characteristics, reservoir characteristics, kerogen structure and product compound composition of the converted shale samples; An evaluation result module is used to obtain an evaluation result of the shale conversion process in supercritical water based on the product yield, the initial shale information before the conversion experiment, and the evolution of the shale information after the conversion.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and running on the processor, characterized in that: When the processor executes the computer program, the method for evaluating the shale conversion process in supercritical water as claimed in any one of claims 1 to 6 is implemented.

9. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for evaluating the shale conversion process in supercritical water as claimed in any one of claims 1 to 6 is implemented.

10. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the method for evaluating the shale conversion process in supercritical water as claimed in any one of claims 1 to 6 is implemented.

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