Joint evaluation method and system for continental facies shale oil mobility geological control factors

Abstract

The invention belongs to the technical field of geological exploration, and discloses a continental facies shale oil mobility geological control factor combined evaluation method and system.The continental facies shale oil mobility geological control factor combined evaluation method comprises the steps that a sedimentary structure type and an organic matter type are divided based on a rock sample; comprehensively dividing continental facies shale lithofacies by combining three-end-member lithofacies types; analyzing the saturation of the movable fluid according to the multiphase relaxation time spectrum of the rock sample, and evaluating the mobility of shale oil by using pyrolysis parameters; and analyzing the influence factors of the mobility of shale oil based on the geological control factors. According to the method, aiming at research requirements of continental facies shale oil mobility control factors, in order to solve the problem of how to comprehensively and completely evaluate the shale oil mobility control factors, a multi-scale multi-type qualitative observation technology and a quantitative test technology are combined, a plurality of influence factors of shale oil mobility are comprehensively considered, and a relatively comprehensive evaluation system is established.

Description

Technical Field

[0001] The present invention relates to the field of geological exploration technology, and in particular to a method and system for jointly evaluating geological control factors of continental shale oil mobility. Background Art

[0002] my country is rich in continental shale oil resources, which constitute an important replaceable oil and gas resource. The mobility of shale oil is affected by many factors. The evaluation of geological factors affecting the mobility of shale oil has a far-reaching impact on the effective development, economic feasibility, technological progress and risk management of shale oil, and is a key factor that cannot be ignored in the development of the shale oil industry.

[0003] The academic community has conducted a series of discussions on the factors affecting shale oil mobility. Based on the analysis of the factors affecting shale oil mobility and their mechanisms of action in the aforementioned studies, the factors affecting shale oil mobility mainly include organic factors, mineral composition, sedimentary structure, pore structure and other factors.

[0004] At present, invention patents related to shale oil mobility are mainly centered around the evaluation method of shale oil mobility. A study proposed a shale oil mobility evaluation method based on nuclear magnetic resonance-centrifugation, and combined high-pressure mercury injection and nitrogen adsorption experiments to determine the lower limit of the effective pore size; another technology announced a method based on the evaluation of total shale oil resources, free resources and movable resources. On the basis of clarifying the total resources and free resources, based on the relationship between the movable ratio and the nuclear magnetic centrifugal pressure difference, combined with the existing geological and production data of the oil field, the distribution of shale oil movable resources and its resource amount are clarified. Evaluation model, evaluation method and application; another study proposed an evaluation model based on nuclear magnetic resonance experiments. , multiple supercritical carbon dioxide displacement experiments were carried out on core samples to obtain the nuclear magnetic resonance T2 spectra before and after each displacement, so as to calculate and analyze the corresponding water content characteristics, movable oil saturation characteristics and maturity characteristics, and then evaluate the shale oil mobility; another technology proposed an evaluation method for oil and gas reservoir fluid mobility by combining CT pore size distribution, nuclear magnetic resonance T2 spectrum and error analysis to simulate the fluid mobilization process under different operating systems, and realize the quantitative characterization of the fluid pore throat radius mobilization distribution under different operating systems.

[0005] However, the above technologies all focus on the evaluation methods of shale oil mobility, and most of them revolve around nuclear magnetic resonance experiments. The existing technologies are still insufficient for a comprehensive and complete evaluation of the factors affecting the mobility of shale oil in a certain area. Therefore, how to provide a comprehensive and systematic joint evaluation plan for the geological control factors of shale oil mobility has become a problem that needs to be solved urgently. Summary of the invention

[0006] The embodiments of the present invention provide a method and system for jointly evaluating geological control factors of continental shale oil mobility, so as to solve the problem that most of the existing technologies are centered around nuclear magnetic resonance experiments, and a comprehensive and complete evaluation of factors affecting the mobility of shale oil in a certain area is still insufficient.

[0007] In order to have a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not a general review, nor is it intended to identify key / important components or to describe the scope of protection of these embodiments. Its only purpose is to present some concepts in a simple form as a prelude to the detailed description that follows.

[0008] According to a first aspect of an embodiment of the present invention, a method for jointly evaluating geological control factors of continental shale oil mobility is provided.

[0009] In one embodiment, the combined evaluation method of geological control factors of continental shale oil mobility includes: Based on rock samples, the sedimentary structure type and organic matter type are divided, and the continental shale lithofacies are comprehensively divided by combining the three-terminal lithofacies types; The movable fluid saturation is analyzed based on the relaxation time spectrum of the multiphase state of the rock sample, and the mobility of the shale oil is evaluated using pyrolysis parameters; Based on geological control factors, the factors affecting shale oil mobility are analyzed, and the geological control factors include organic matter, inorganic matter, rock structure and pore structure.

[0010] In one embodiment, based on rock samples, sedimentary structure types and organic matter types are divided, and the continental shale lithofacies are comprehensively divided in combination with three-end-member lithofacies types, including: using X-ray whole-rock quantitative analysis combined with bedding thickness boundaries to divide the sedimentary structure types of rock samples, the sedimentary structure types include laminated structure, layered structure and massive structure; based on the measurement results of total organic carbon content, the organic matter types of rock samples are divided, the organic matter types include high organic matter, medium organic matter and low organic matter; according to the sedimentary structure types and organic matter types, in combination with three-end-member lithofacies types, the continental shale lithofacies of rock samples are comprehensively divided, the three-end-member lithofacies types include felsic minerals, carbonate minerals and clay minerals.

[0011] In one embodiment, the movable fluid saturation is analyzed according to the relaxation time spectrum of the multiphase state of the rock sample, and the mobility of the shale oil is evaluated using the pyrolysis parameters, including: based on the nuclear magnetic resonance technology, the two-dimensional relaxation time spectrum and the transverse relaxation time spectrum of the multiphase rock sample are measured, and the multiphase rock sample includes the dry state, the saturated fluid state and the high-speed centrifugal state of the rock sample; according to the transverse relaxation time spectrum, the movable fluid saturation and related parameters are analyzed; based on the step-by-step pyrolysis experiment results, the pyrolysis parameters of the rock sample powder are measured, and the measured data are corrected to obtain the movable oil content of the rock sample.

[0012] In one embodiment, analyzing movable fluid saturation and related parameters according to the transverse relaxation time spectrum includes: calculating movable fluid saturation, nuclear magnetic porosity and transverse relaxation cutoff time based on the transverse relaxation time spectrum; removing base signals of saturated fluid state and high-speed centrifugal state based on the calculation results; and determining bound fluid and movable fluid in rock samples using movable fluid saturation analysis.

[0013] In one embodiment, based on geological control factors, the factors affecting the mobility of shale oil are analyzed, including: based on organic matter, analyzing the factors affecting the mobility of shale oil; based on inorganic matter, analyzing the factors affecting the mobility of shale oil in combination with three-end member lithofacies types; based on rock structure, analyzing the factors affecting the mobility of shale oil in combination with sedimentary structure types; based on pore structure, analyzing the factors affecting the mobility of shale oil.

[0014] In one embodiment, based on organic matter, analyzing the factors affecting the mobility of shale oil includes: constructing a first scatter plot according to the movable oil content and the total organic carbon content, selecting the rising data points and the falling data points in the first scatter plot as the control group, and calculating the Pearson correlation coefficient of each control group, and analyzing the correlation between the movable oil content and the total organic carbon content according to the calculation results; constructing a second scatter plot according to the movable oil content and the organic matter maturity, selecting the rising data points and the falling data points in the second scatter plot as the control group, and calculating the Pearson correlation coefficient of each control group, and judging the correlation between the organic matter maturity and the movable oil content according to the calculation results; constructing a third scatter plot according to the movable oil content and the highest pyrolysis peak temperature, and verifying the influence of the organic matter maturity on the movable oil content; The expression for calculating the Pearson correlation coefficient of each control group is: , where Cov ( X , Y ) represents the covariance of the control group, Var [ X ] represents the variance of the rising data points in the control group, Var [ Y ] represents the variance of the decreased data points in the control group.

[0015] In one embodiment, the factors affecting the mobility of shale oil are analyzed based on inorganic substances and combined with the three-end member lithofacies types, including: A fourth scatter plot is constructed according to the felsic mineral content and the movable oil content, and a fifth scatter plot is constructed according to the felsic mineral content and the movable fluid saturation, and the rising data points and the falling data points in the fourth scatter plot and the fifth scatter plot are respectively selected as control groups, and the Pearson correlation coefficient of each control group is calculated, and the correlation between the felsic mineral content and the movable oil content and the movable fluid saturation is determined according to the calculation results; A sixth scatter plot is constructed according to the carbonate rock mineral content and the movable oil content, and a seventh scatter plot is constructed according to the carbonate rock mineral content and the movable fluid saturation, and the rising data points and the falling data points in the sixth scatter plot and the seventh scatter plot are respectively selected as control groups, and the Pearson correlation coefficient of each control group is calculated, and the correlation between the carbonate rock mineral content and the movable oil content and the movable fluid saturation is analyzed according to the calculation results; The eighth scatter plot was constructed according to the clay mineral content and the movable oil content, and the ninth scatter plot was constructed according to the clay mineral content and the movable fluid saturation. The rising data points and the falling data points in the eighth scatter plot and the ninth scatter plot were selected as control groups, respectively, and the Pearson correlation coefficient of each control group was calculated. The correlation between the clay mineral content and the movable oil content and the movable fluid saturation was determined based on the calculation results.

[0016] In one embodiment, according to the rock structure and in combination with the sedimentary structure type, the factors affecting the mobility of shale oil are analyzed, including: based on the sedimentary structure type, calculating the average movable oil content of the laminar structure, layered structure and massive structure; based on the sedimentary structure type, calculating the average movable fluid saturation of the laminar structure, layered structure and massive structure; constructing the average movable oil content histogram and the average movable fluid saturation histogram of the laminar structure, layered structure and massive structure, and judging the influence of the rock structure on the mobility of shale oil.

[0017] In one embodiment, based on the pore structure, analyzing the factors affecting the mobility of shale oil includes: constructing advance and retreat mercury curves and pore size distribution diagrams of different lithofacies types based on pore size related parameters of rock samples, wherein the pore size related parameters include average pore size, surface area and pore volume; constructing a tenth scatter plot based on the average pore size and movable oil content, selecting rising data points and falling data points in the tenth scatter plot as a control group, and calculating the Pearson correlation coefficient of each control group, and judging the correlation between the average pore size and the movable oil content according to the calculation results; constructing an eleventh scatter plot based on the surface area and movable oil content, selecting rising data points and falling data points in the eleventh scatter plot as a control group, and calculating the Pearson correlation coefficient of each control group, and judging the correlation between the surface area and the movable oil content according to the calculation results; constructing a twelfth scatter plot based on the pore volume and movable oil content, selecting rising data points and falling data points in the twelfth scatter plot as a control group, and calculating the Pearson correlation coefficient of each control group, and judging the correlation between the pore volume and the movable oil content according to the calculation results.

[0018] According to a second aspect of an embodiment of the present invention, a system for jointly evaluating geological control factors of continental shale oil mobility is provided.

[0019] In one embodiment, the combined evaluation system of geological control factors of continental shale oil mobility includes: The lithofacies feature recognition module is used to classify sedimentary structure types and organic matter types based on rock samples, and to comprehensively classify continental shale lithofacies by combining three-end member lithofacies types; Fluid dynamic analysis module, used to analyze the movable fluid saturation based on the relaxation time spectrum of the multiphase state of the rock sample and evaluate the mobility of shale oil using pyrolysis parameters; The geological factor evaluation module is used to analyze the factors affecting shale oil mobility based on geological control factors.

[0020] According to a third aspect of an embodiment of the present invention, a computer device is provided.

[0021] In one embodiment, the computer device includes a memory and a processor, wherein a computer program is stored in the memory, and the steps of the above method are implemented when the processor executes the computer program.

[0022] According to a fourth aspect of embodiments of the present invention, a computer-readable storage medium is provided.

[0023] In one embodiment, the computer-readable storage medium stores a computer program, which implements the steps of the above method when executed by a processor.

[0024] The technical solution provided by the embodiment of the present invention may have the following beneficial effects: The present invention innovatively proposes a solution to the difficult problem of studying geological control factors of continental shale oil mobility. The solution integrates multiple parameters of organic matter, inorganic matter, sedimentary structure, and pore structure to establish a relatively comprehensive evaluation system for geological control factors of continental shale oil mobility, solving the gap in the analysis of factors affecting shale oil mobility control. It has the advantages of comprehensive consideration of influencing factors, wide recognition of the experiments involved in the industry, strong operability, and good applicability.

[0025] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0027] Figure 1 It is a flow chart of a method for jointly evaluating geological control factors of continental shale oil mobility according to an exemplary embodiment; Figure 2 It is a structural block diagram of a joint evaluation system of geological control factors of continental shale oil mobility according to an exemplary embodiment; Figure 3 It is a specific implementation diagram of a method for jointly evaluating geological control factors of continental shale oil mobility according to an exemplary embodiment; Figure 4 Schematic diagrams of microscopic characteristics of shales of different sedimentary structures in a joint evaluation method of geological control factors of continental shale oil mobility according to an exemplary embodiment, wherein (a) is a schematic diagram of the interaction of different laminae; (b) is another schematic diagram of the interaction of different laminae; (c) is a schematic diagram of the distribution of bands with occasional bright colors under the microscope; (d) is another schematic diagram of the distribution of bands with occasional bright colors under the microscope; (e) is a schematic diagram of the uniform distribution of minerals in fine particles; (f) is another schematic diagram of the uniform distribution of minerals in fine particles; Figure 5 It is a nuclear magnetic resonance T1-T2 spectrum of each hydrogen-containing component of the second lacustrine mud shale in a depression hole in a joint evaluation method of geological control factors of continental shale oil mobility according to an exemplary embodiment; Figure 6 The present invention is a distribution diagram of movable water and irreducible water signals of different structural shales in the second section of a depression hole in a joint evaluation method of geological control factors of continental shale oil mobility according to an exemplary embodiment, wherein (a) is a distribution diagram of movable water and irreducible water signals of laminar shale; (b) is a distribution diagram of movable water and irreducible water signals of layered shale; (c) is a distribution diagram of movable water and irreducible water signals of massive shale; Figure 7 The figure is a histogram comparison diagram of average movable oil content and average movable fluid saturation of different lithofacies in a joint evaluation method of geological control factors of continental shale oil mobility according to an exemplary embodiment, wherein (a) is a histogram of average movable oil content of different lithofacies; (b) is a histogram of average movable fluid saturation of different lithofacies; Figure 8 It is a correlation diagram between movable oil content and TOC content in the second section of a depression hole in a combined evaluation method of geological control factors of continental shale oil mobility according to an exemplary embodiment; Fig. 9 is a correlation diagram between movable oil content and organic matter maturity in a joint evaluation method of geological control factors of continental shale oil mobility according to an exemplary embodiment; Fig.10 is a correlation diagram between movable oil content and Tmax in a joint evaluation method of geological control factors of continental shale oil mobility according to an exemplary embodiment; Fig.11 is a correlation diagram between felsic mineral content and movable oil content in a method for joint evaluation of geological control factors of continental shale oil mobility according to an exemplary embodiment; Fig.12 is a correlation diagram between clay mineral content and movable oil content in a joint evaluation method of geological control factors of continental shale oil mobility according to an exemplary embodiment; Fig.13 The figure is a histogram comparison of average movable oil content and average movable fluid saturation of different rock structures in a joint evaluation method of geological control factors of continental shale oil mobility according to an exemplary embodiment, wherein (a) is a histogram of average movable oil content of different rock structures; (b) is a histogram of average movable fluid saturation of different rock structures; Fig.14 The figure is a histogram comparison of average specific surface area and average pore volume of different lithofacies in a joint evaluation method of geological control factors of continental shale oil mobility according to an exemplary embodiment, wherein (a) is a histogram of average specific surface area of ​​different lithofacies; (b) is a histogram of average pore volume of different lithofacies; Fig.15 1 is a histogram comparison of average mercury intrusion porosity and average mercury removal efficiency of different rock structures and different lithofacies in a joint evaluation method of geological control factors of continental shale oil mobility according to an exemplary embodiment, wherein (a) is a histogram of average mercury intrusion porosity of different rock structures; (b) is a histogram of average mercury removal efficiency of different rock structures; (c) is a histogram of average mercury intrusion porosity of different lithofacies; (d) is a histogram of average mercury removal efficiency of different lithofacies; Fig.16is a scatter plot of movable oil content and average pore size in a combined evaluation method of geological control factors of continental shale oil mobility according to an exemplary embodiment; Fig.17 is a scatter plot of movable oil content and surface area in a combined evaluation method of geological control factors of continental shale oil mobility according to an exemplary embodiment; Fig.18 is a scatter plot of movable oil content and pore volume in a method for jointly evaluating geological control factors of continental shale oil mobility according to an exemplary embodiment; Fig.19 It is a scatter plot of surface area and pore volume in a method for jointly evaluating geological control factors of continental shale oil mobility according to an exemplary embodiment. DETAILED DESCRIPTION

[0028] Figure 1 and Figure 3 An embodiment of a combined evaluation method of geological control factors of continental shale oil mobility according to the present invention is shown.

[0029] In this optional embodiment, the combined evaluation method of geological control factors of continental shale oil mobility includes: Step S101: based on rock samples, the sedimentary structure type and organic matter type are classified, and the continental shale lithofacies are comprehensively classified in combination with the three-end-member lithofacies types; Step S103, analyzing the movable fluid saturation according to the relaxation time spectrum of the multiphase state of the rock sample, and evaluating the mobility of the shale oil using pyrolysis parameters; Step S105: Analyze the factors affecting the mobility of shale oil based on geological control factors, wherein the geological control factors include organic matter, inorganic matter, rock structure and pore structure.

[0030] In this optional embodiment, based on rock samples, the sedimentary structure type and organic matter type are divided, and the continental shale lithofacies are comprehensively divided in combination with the three-end member lithofacies types, including: Step S1011, using X-ray whole-rock quantitative analysis, combined with the bedding thickness boundary, the sedimentary structure type of the rock sample is divided, and the sedimentary structure type includes laminar structure, layered structure and massive structure; specifically, combining core description, thin section observation and X-ray whole-rock quantitative analysis (XRD), the rock type is divided and the mineral composition is clarified. With the bedding thickness of 1mm and 50cm as the boundary, the sedimentary structure is divided into laminar, layered and massive.

[0031] In this example, the samples come from the shale of the second section of Guan 108-8 well, Guandong 12 well and Guandong 14 well in a depression in a basin. First, through core observation and thin section identification, it is identified that the sedimentary structures in the study area are mainly divided into blocky structures, layered structures and laminar structures, with 1 mm and 50 cm as the boundaries. Laminated structures are smaller than 1 mm. Under the microscope, it can be seen that countless fine stratifications are deposited in a regular order. Generally, dark strata rich in clay, strata rich in organic matter and strata dominated by calcium minerals appear alternately, such as Figure 4 As shown in (a) and (b) in the figure, the layer between 1 mm and 50 cm is layered, with thicker layers deposited more evenly and alternating. The color is generally different in depth, and bright strips can occasionally be seen under the microscope. It is generally composed of calcium or silica, such as Figure 4 As shown in (c) and (d) in the figure; those larger than 50 cm are classified as massive. This type of structure has no stratification under the microscope, and the minerals are almost uniformly distributed in small particles, such as Figure 4 As shown in (e) and (f).

[0032] Step S1013, based on the measurement result of total organic carbon content, classify the organic matter type of rock sample, the organic matter type includes high organic matter, medium organic matter and low organic matter; specifically, measure the total organic carbon content (TOC) of the sample, and use the TOC content equal to 1% and 3% as the boundary to classify the sample into high organic matter, medium organic matter and low organic matter.

[0033] In this embodiment, combined with XRD and microscopic observation, it is determined that the target layer section in the study area is mainly composed of minerals such as quartz, feldspar, dolomite, calcite and clay minerals, and contains a small amount of minerals such as analcime and pyrite. Among them, the content of felsic minerals is the highest, with an average of 24.56% for quartz and 13.34% for feldspar minerals. A large number of silt-grade felsic particles can be seen in thin sections, and occasionally large quartz particles or feldspar particles are seen. Felsic particles are often gathered in layers and can form interlayers with clay layers; carbonate minerals are second, among which dolomite accounts for an average of 24.08% of all mineral components, and calcite is less, averaging 7.57%. Carbonate minerals are mostly scattered and evenly distributed, and sometimes they are distributed in layers, which are interlayered with clay-rich layers, or occur with organic matter. Straight-automorphic dolomite crystals can be seen under fluorescence; the clay mineral content is 20.1% on average, mainly including illite / montmorillonite mixed layer, illite and a little chlorite; in addition, it also contains a small amount of special minerals such as analcime, pyrite and siderite. Then, the total organic carbon content (TOC) was determined, and the samples were divided into low organic matter, medium organic matter and high organic matter types with the total organic carbon content of 1% and 3% as the boundary.

[0034] Step S1015: According to the sedimentary structure type and organic matter type, combined with the three-end member lithofacies type, the continental shale lithofacies of the rock sample are comprehensively divided, and the three-end member lithofacies types include felsic minerals, carbonate minerals and clay minerals. Specifically, the three main minerals of clay minerals, carbonate minerals and felsic minerals are used as the "three end members" to define the major lithofacies types, combined with the laminar, layered and massive types divided in step S1011, and the high organic matter, medium organic matter and low organic matter divided in step S1013, the lithofacies are comprehensively analyzed and divided.

[0035] In this embodiment, finally, with clay minerals, carbonate minerals and calcareous minerals as the three end members, combined with organic matter content and sedimentary structure, the lithofacies division scheme was determined and the shale lithofacies types in the study area were comprehensively divided into 8 types: C-low organic massive gray dolomitic shale facies, C1-medium-high organic laminated gray dolomitic shale facies containing felsic, C2-low-medium organic laminated mixed gray dolomitic shale facies, S1-medium-high organic laminated gray dolomitic felsic shale facies, S2-medium-high organic massive mixed felsic shale facies, S3-medium-high organic laminated clay-containing felsic shale facies, M-low-medium organic massive mixed shale facies, M1-medium-high organic laminated mixed shale facies.

[0036] In this optional embodiment, analyzing the movable fluid saturation according to the relaxation time spectrum of the multiphase state of the rock sample and evaluating the mobility of the shale oil using the pyrolysis parameters includes: Step S1031: Based on nuclear magnetic resonance technology, a two-dimensional relaxation time spectrum and a transverse relaxation time spectrum of a multiphase rock sample are measured, wherein the multiphase rock sample includes a dry state, a saturated fluid state, and a high-speed centrifugal state of the rock sample; In this embodiment, firstly, two-dimensional spectrum templates corresponding to kerogen, free water, adsorbed water, free oil, adsorbed oil, etc. are prepared, wherein kerogen is located on the left side of the plate, the high TOC shale signal is stronger, and its T1 / T2 ratio is related to the maturity of organic matter. The T1 / T2 ratio increases with maturity, and the T2 peak is small, about 0.1ms; the T1 and T2 relaxation times of free water are equivalent, and the relaxation signal is located on the line of T1 / T2=1, which is easily affected by experimental conditions, and the central T2 is about 0.7ms; the relaxation characteristics of adsorbed water are similar to those of free water, and its position is lower left than that of free water, and the central T2 is about 0.2ms; after saturation, free oil includes nanopore oil and macropore oil, and its typical feature is a band-like distribution, but the nanopore oil has a strong adsorption and can be classified as adsorbed oil, and the central T2 is about 10ms and 500ms; adsorbed oil, that is, the position of nanopore oil, has a central T2 of about 2ms, such as Figure 5 shown.

[0037] Step S1033, analyzing the movable fluid saturation and related parameters according to the transverse relaxation time spectrum; Specifically, nuclear magnetic resonance experiments are carried out on samples after oil washing and drying, pressurized water saturation and high-speed centrifugation, and the experimental results are imported into the calculation system, so as to calculate parameters such as movable fluid saturation, nuclear magnetic porosity and T2 cutoff value.

[0038] In this embodiment, the T2 spectrum of saturated water and the centrifugal T2 spectrum are processed to remove the base signal and then combined for observation. The T2 cutoff value (dividing movable fluid and bound fluid) is used to roughly characterize the fluid occurrence state of different states. The left side of the T2 cutoff value is used to represent the bound fluid in the rock, and the right side represents the movable fluid in the rock. According to the actual situation, the gray part below is the signal of the centrifugal T2 spectrum without base (dry sample), which represents the bound fluid, and the part between the saturated fluid T2 spectrum represents the movable fluid. It can be seen that there is a large difference in the movable fluid content between different sedimentary structures, such as Figure 6 As shown in (a), (b) and (c) in FIG.

[0039] Step S1035: Based on the step-by-step pyrolysis experiment results, the pyrolysis parameters of the rock sample powder are determined, and the measured data are corrected to obtain the movable oil content of the rock sample.

[0040] Specifically, through step-by-step pyrolysis experiments, the pyrolysis parameters S1-1 indicating the content of light oil components, S1-2 indicating the content of light and medium oil components, S2-1 indicating heavy hydrocarbons and colloid asphalt components, and S2-2 indicating kerogen pyrolysis regeneration hydrocarbons in shale were obtained. By calculating the pyrolysis parameters through data correction, the movable oil content of the sample can be obtained and the shale oil in different occurrence states can be characterized. It is determined that the shale in this area is mainly adsorbed oil, and the free oil content is generally small. And after statistical analysis after correction, it is known that the shales with poor oil and gas content, general, good, very good and excellent oil and gas content account for 22.22%, 7.94%, 22.22%, 26.98% and 20.63% respectively, of which 69.84% of the shales have good oil and gas content.

[0041] In this embodiment, the samples are divided into respective lithofacies types according to the size of organic matter, sedimentary structure type and mineral component content. The average movable oil content and average movable fluid saturation of each lithofacies type are calculated according to the movable oil content measured by step-by-step pyrolysis and the movable fluid saturation measured by nuclear magnetic resonance experiment. A comparative analysis shows that the movable oil content of the medium-high organic matter laminated clay-containing felsic shale phase (S1) and the medium-high organic matter laminated mixed shale phase (M1) are relatively high, averaging 3.86 mg / g and 3.06 mg / g respectively. Although the movable oil content of the medium-high organic matter laminated felsic gray-domelite shale phase (C1) is not as high as the above two phases, it has obvious advantages compared with the other lithofacies, such as Figure 7As shown in (a) in the figure, in terms of movable fluid saturation, the medium-high organic matter laminated clay-bearing felsic shale phase (S1) and the medium-high organic matter laminated mixed shale phase (M1) have the highest values, which are 43.77% and 53.41% respectively, and the mobility advantage is obvious, as shown in Figure 2. Figure 7 As shown in (b) in .

[0042] In this optional embodiment, based on the nuclear magnetic resonance technology, the two-dimensional relaxation time spectrum and the transverse relaxation time spectrum of the multiphase rock sample are measured, and the multiphase rock sample includes the dry state, the saturated fluid state and the high-speed centrifugal state of the rock sample, including: Step S10311, select some samples, and measure the two-dimensional relaxation time spectra (T1-T2 spectra) thereof when dry, when saturated with fluid, and after high-speed centrifugation; It should be noted that in nuclear magnetic resonance (NMR) technology, T1-T2 spectrum is often also called "longitudinal-transverse relaxation time spectrum" or "two-dimensional relaxation time spectrum", that is, a two-dimensional distribution diagram that contains both longitudinal relaxation time (T1) and transverse relaxation time (T2) information. This spectrum can provide detailed information about different components in the sample (such as oil, water, kerogen, etc.), because different substances or fluids have different relaxation characteristics; while T2 spectrum is usually called "transverse relaxation time spectrum".

[0043] Specifically, it includes: (1) setting the temperature to 110℃ and drying the selected samples for 48 hours. Determine the T1-T2 spectrum of the dried samples to obtain the nuclear magnetic resonance signals of kerogen or possible structural water; (2) placing the dried samples in the sample chamber of the pressurized saturation device and vacuumizing them for 8 hours, followed by a saturated water / oil (n-dodecane) experiment, with the pressure set to 20MA and the saturation time being 48 hours. Determine the T1-T2 spectrum of the saturated oil / water samples to obtain the nuclear magnetic resonance signals of free oil and free water; (3) subjecting the saturated fluid samples to high-speed centrifugation, with the centrifugation parameters at 10,000 r / min and the time being 3 hours. Determine the T1-T2 spectrum of the centrifuged samples to obtain the nuclear magnetic resonance signals of adsorbed water / adsorbed oil.

[0044] Step S10313, based on the nuclear magnetic two-dimensional spectrum responses of kerogen, free water, adsorbed water, free oil, and adsorbed oil measured in step S10311, corresponding two-dimensional spectrum templates are established for several major hydrogen nuclear components (kerogen, free water, adsorbed water, free oil, and adsorbed oil) in the reservoir; Step S10315, select samples and measure their T2 spectra when dry, saturated with water, and after high-speed centrifugation. Specifically including: (1) Wash the prepared 3-6 cm diameter columnar core with oil for 10 days, then set the temperature to 110°C and dry for 48 hours. Measure the nuclear magnetic resonance T2 spectrum of the sample after oil washing and drying; (2) Put the dried sample into the sample chamber of the pressurized saturation device, vacuum it for 12 hours, and then use deionized water to perform a saturated water experiment, the pressure is set to 20MA, and the saturation time is 48 hours. Measure the nuclear magnetic resonance T2 spectrum of the saturated water sample; (3) High-speed centrifuge the saturated water sample with a centrifugation parameter of 10000r / min and a time of 3 hours. Measure the nuclear magnetic resonance T2 spectrum of the sample after centrifugation.

[0045] In this optional embodiment, analyzing the movable fluid saturation and related parameters according to the transverse relaxation time spectrum includes: Step S10331, based on the transverse relaxation time spectrum, calculate the movable fluid saturation, nuclear magnetic porosity and transverse relaxation cutoff time; specifically, import the T2 spectrum data measured in step S10315 into the calculation system to calculate and obtain parameters such as movable fluid saturation, nuclear magnetic porosity, T2 cutoff value, etc.

[0046] Step S10333, based on the calculation results, remove the background signals of the saturated fluid state and the high-speed centrifugal state; specifically, perform data processing on the data measured in step S10315 to remove the background signals in the nuclear magnetic resonance T2 spectrum of the saturated water sample and the nuclear magnetic resonance T2 spectrum of the sample after centrifugation (the nuclear magnetic resonance T2 spectrum of the sample after washing oil drying).

[0047] Step S10335: Determine the bound fluid and the movable fluid in the rock sample by using the movable fluid saturation analysis. Specifically, by analyzing the data processed in step S10333, the movable fluid saturation analysis is performed, and the signal of the centrifugal T2 spectrum without the base (dry sample) is used to represent the bound fluid in the rock, and the part between the saturated fluid T2 spectrum represents the movable fluid in the rock.

[0048] In this optional embodiment, based on the step-by-step pyrolysis experimental results, the pyrolysis parameters of the rock sample powder are measured, and the measured data are corrected to obtain the movable oil content of the rock sample, including: Step S10351, grind the selected samples into powder, 50-60 mg per sample; Step S10353, conduct a step-by-step pyrolysis experiment on the powder sample; heat the sample to 200°C, keep the temperature constant for 1 minute, and measure the pyrolysis parameter S1-1; then heat to 350°C at a heating rate of 25°C / min, keep the temperature constant for 1 minute, and measure the pyrolysis parameter S1-2; then heat to 450°C at a heating rate of 25°C / min, and measure the pyrolysis parameter S2-1; finally, heat to 600°C at a heating rate of 25°C / min, and measure the parameter S2-2; Step S10355, correct the data and calculate the movable oil content of all samples; add S1-1×2 plus S1-2 as the movable oil content; S2-1 indicates heavy hydrocarbons and colloidal asphalt components, which represent the adsorbed oil content in shale; S2-2 indicates the kerogen pyrolysis regeneration hydrocarbons in the shale, which represents the remaining hydrocarbon generation potential of the kerogen.

[0049] In this optional embodiment, based on geological control factors, the factors affecting the mobility of shale oil include: Step S1051, based on organic matter, analyze the factors affecting the mobility of shale oil; specifically, in this embodiment, by making a scatter plot of movable oil content and TOC content to analyze their correlation, it is determined that the movable oil content and TOC content are significantly correlated, indicating that TOC content can significantly affect the mobility of shale oil. The scatter plot shows that for most samples, especially when TOC>2%, the movable oil content and TOC content are significantly positively correlated, indicating that the movable oil content will increase with the increase of TOC content, proving that TOC content has a significant beneficial effect on the mobility of shale oil, such as Figure 8 shown.

[0050] In the above embodiment, depth is used as a factor affecting thermal maturity (organic matter maturity) instead of Ro for analysis. By drawing a scatter plot of movable oil content and depth, no obvious correlation between movable oil content and depth is found. However, combined with TOC data, it can be seen that since the TOC content of Guan 108-8 well located in the shallow part is relatively high, while the TOC of Guandong 12 well and Guandong 14 well located in the deeper layer is relatively low, but with the increase of depth, the range of movable oil content does not change significantly, indicating that thermal maturity plays a role. With the increase of depth, thermal maturity increases, movable oil content increases, and is positively correlated with thermal maturity. High thermal maturity will promote oil generation, such as Fig. 9 shown.

[0051] When measuring the maximum pyrolysis peak temperature (Tmax) data of the sample and drawing a scatter plot of movable oil content and Tmax, it can be seen that with the increase of Tmax, the movable oil content of shale first increases and then decreases. The movable oil content reaches a peak value when the Tmax value is 438°C, indicating that the movable oil content is the highest at an earlier maturity. It can be determined that the shale oil mobility in this area is best at an earlier maturity period. Fig.10 shown.

[0052] Step S1053, analyzing the factors affecting the mobility of shale oil based on inorganic substances and three-end-member lithofacies types; Specifically, the total content of various feldspar quartz minerals in each sample was calculated based on the measured XRD data, and a scatter plot of the felsic mineral content and the movable oil content was drawn. It can be seen that the felsic mineral content and the movable oil content have a strong correlation, indicating that the felsic minerals have a great influence on the mobility of shale oil. The movable oil content in shale shows a trend of first increasing and then decreasing with the increase of the felsic mineral content, and reaches a peak value when the felsic mineral content reaches 15%. This shows that when the felsic mineral content is low, the felsic minerals have a favorable effect on the mobility of shale oil, and when the felsic mineral content is high, the felsic minerals have an adverse effect on the mobility of shale oil. The reason for the analysis is that the increase in the content of felsic minerals means an increase in the input of terrestrial debris, which will provide a large amount of nutrients for the sedimentary water body, greatly increase the paleoproductivity, and increase the TOC content. When the paleoproductivity reaches its peak, the input of terrestrial debris will dilute the sedimentary organic matter and reduce the TOC content. Since the TOC content is strongly positively correlated with the movable oil content, the correlation between the felsic mineral content and the movable oil content shows a trend of first increasing and then decreasing. Fig.11 shown.

[0053] In the above embodiment, by drawing a scatter plot of clay minerals and movable oil content, it can be seen that the clay mineral content and the movable oil content have a strong correlation, indicating that clay minerals have a greater impact on the mobility of shale oil. With the increase of clay mineral content, the movable oil content has the characteristics of first increasing and then decreasing. Among them, when the clay mineral content is 18%, the movable oil content reaches a peak. It means that when the clay mineral content is low, clay minerals have a favorable effect on the mobility of shale oil, and when the clay mineral content is high, clay minerals have an adverse effect on the mobility of shale oil. The reasons are analyzed and believed to be: when the clay content is high, it will provide good preservation conditions for organic matter enrichment, which is easy to enrich organic matter and the TOC content is relatively high; however, with the continuous increase of clay minerals, the water body it reflects will be in an extremely calm environment, without turbulent water flow to bring nutrients, resulting in the water environment being unsuitable for the growth of aquatic organisms at this time, so the organic matter enrichment degree and TOC content are reduced, while the movable oil content is positively correlated with TOC, then the clay mineral content and the movable oil content will also have a trend of increasing first and then decreasing, such as Fig.12 shown.

[0054] Step S1055: Analyze the factors affecting the mobility of shale oil based on the rock structure and the sedimentary structure type; Specifically, the average movable oil content and the average movable fluid saturation of different rock structures are calculated. By drawing the histogram of the average movable oil content and the average movable fluid saturation of the laminar structure, layered structure and massive structure samples, it can be seen that there are large differences in the movable oil content and movable fluid saturation among the rocks of the three structures, indicating that the rock structure has a greater impact on the mobility of shale oil. Among them, the laminar shale is higher than the layered shale and higher than the massive shale, indicating that the laminar shale is most conducive to the mobility of shale oil, and the massive shale is the least favorable. Analysis shows that: the laminar shale has a larger pore structure, followed by the layered shale, and the massive shale has undeveloped large pores and fracture systems. The larger the slit, the higher the proportion of movable fluid and the better the mobility. Fig.13 As shown in (a) and (b) in .

[0055] Step S1057: Analyze factors affecting the mobility of shale oil based on the pore structure.

[0056] Specifically, through nitrogen adsorption experiments, the pore characteristics of the samples were quantitatively characterized, and the experimental data were statistically analyzed and sorted to obtain parameters such as specific surface area, pore volume and average pore diameter. The data showed that the specific surface area of ​​shale in the study area ranged from 0.4996 to 21.9711 m2 / g, with an average of 5.0812 m2 / g; the pore volume value ranged from 0.0026 to 0.0354 cm3 / g, with an average of 0.0116 cm3 / g; the average pore diameter ranged from 6.6633 to 32.752 nm, with an average of 17.0206 nm. By comparing the surface area and pore volume parameters of various lithofacies, it is identified that the specific surface area and pore volume of the three lithofacies with developed clay minerals, S3 (medium-high organic matter laminated clay-bearing felsic shale phase), M (low-medium organic matter massive mixed shale phase) and M1 (medium-high organic matter laminated mixed shale phase) are larger than those of other lithofacies, and they have relatively developed nanopore reservoir space, indicating that clay minerals provide the main nanopore reservoir space, such as Fig.14 As shown in (a) and (b) in .

[0057] In the above embodiment, the pore characteristics are quantitatively characterized by high-pressure mercury injection experiments, and the mercury advance and retreat curves of shales of different lithofacies are analyzed. The morphologies of the mercury advance and retreat curves of various lithofacies are not much different, and it is judged that the shale reservoir structure in the study area is mainly composed of nano-scale pores, with a small amount of large pores. By analyzing the pore size distribution of high-pressure mercury injection of different lithofacies types, there is no obvious difference in the curve morphology. Almost all of them are distributed in a state of high on the left and low on the right. It is judged that both large and small pores are distributed in the shale reservoir space in the study area as a whole, and nano-scale pores are mostly developed, and micron-scale pores are rarely developed. By comparing the mercury injection porosity, mercury withdrawal efficiency, rock structure, and mineral composition, it is determined that in terms of pore connectivity, laminar>layered>massive, mixed>felsic>cloudy, such as Fig.15 As shown in (a), (b), (c) and (d) in FIG.

[0058] Based on the data obtained from nitrogen adsorption and high-pressure mercury injection, a scatter plot of movable oil content and average pore size was drawn. It can be seen that the movable oil content and the average pore size have a strong correlation, indicating that the average pore size has a significant impact on the mobility of shale oil. The average pore size represents the size of the pores and is significantly positively correlated with the movable oil content, indicating that the increase in the average pore size is beneficial to the mobility of shale oil. The larger the pores, the more movable oil content. Fig.16 As shown; In addition, Fig.16 The box in the lower right corner contains some abnormal data points (indicated by triangular symbols). Compared with the conventional data points (indicated by circular symbols), these abnormal data points reveal the special situation of low movable oil content under high pore size conditions, which provides important clues and directions for subsequent research.

[0059] By drawing a scatter plot of movable oil content and surface area, it can be seen that the movable oil content and surface area have a strong correlation, indicating that the surface area has a significant impact on the mobility of shale oil. The movable oil content of shale decreases with the increase of the specific surface area of ​​pores, and the two are negatively correlated, indicating that the increase of surface area has an adverse effect on the mobility of shale oil. When the pore volume remains unchanged, the larger the specific surface area, the lower the movable oil content. Fig.17 shown.

[0060] In this optional embodiment, the factors affecting the mobility of shale oil analyzed based on organic matter include: Step S10511, constructing a first scatter plot according to the movable oil content and the total organic carbon content, selecting the rising data points and the falling data points in the first scatter plot as a control group, calculating the Pearson correlation coefficient of each control group, and analyzing the correlation between the movable oil content and the total organic carbon content according to the calculation results; Specifically, first, based on the movable oil content and total organic carbon content measured by the step-by-step pyrolysis experiment, the first scatter plot is made with the movable oil content as the ordinate and the TOC content as the abscissa. Then, the correlation between the movable oil content and the TOC content is analyzed according to the trend of the first scatter plot. First, it is judged whether the correlation between the movable oil content and the TOC content is obvious, and whether the scatter plot drawn has a situation such as the data points gradually rising first and then gradually falling or vice versa. If this situation exists, the data with an upward trend (increasing data points) and the data with a downward trend (decreasing data points) are regarded as two groups of data for subsequent analysis. The Pearson correlation coefficient of each group of data is calculated. When the absolute value of the correlation coefficient r>0.5, the correlation is considered to be strong, otherwise the correlation is considered to be weak. If the correlation is poor, it means that the TOC content has a low effect on the mobility of shale oil; if the correlation is strong, it means that the TOC content has a significant effect on the mobility of shale oil, where a positive correlation indicates that the TOC content has a favorable effect on the mobility of shale oil, and a negative correlation indicates that it has an adverse effect. Determine the sample vitrinite reflectance Ro and maximum pyrolysis peak temperature (Tmax) data.

[0061] Step S10513, constructing a second scatter plot according to the movable oil content and the organic matter maturity, selecting the rising data points and the falling data points in the second scatter plot as the control group, and calculating the Pearson correlation coefficient of each control group, and judging the correlation between the organic matter maturity and the movable oil content according to the calculation results; Specifically, based on the movable oil content measured by the step-by-step pyrolysis experiment and the measured vitrinite reflectance Ro, the vitrinite reflectance Ro is used as the ordinate and the movable oil content is used as the abscissa to make a second scatter plot. When the depth range of the study area is large (>1000m) and there is no major tectonic movement transformation in the stratum, there is often a good positive correlation between depth and Ro, and depth can be used as a factor affecting thermal maturity instead of Ro for analysis.

[0062] According to the second scatter plot drawn, determine whether the correlation between organic matter maturity (thermal maturity) and movable oil content is obvious, and observe whether the scatter plot drawn has a situation such as data points gradually rising first and then gradually falling or vice versa. If this situation exists, the data with an upward trend and the data with a downward trend are regarded as two groups of data for subsequent analysis. The Pearson correlation coefficient of each group of data is calculated. When the absolute value of the correlation coefficient r>0.5, the correlation is considered to be strong, otherwise the correlation is considered to be weak. If the correlation is poor, it means that the organic matter maturity has a low impact on the mobility of shale oil; if the correlation is strong, it means that the organic matter maturity has a significant impact on the mobility of shale oil, where a positive correlation indicates that the organic matter maturity has a favorable effect on the mobility of shale oil, and a negative correlation indicates an adverse effect.

[0063] Step S10515, constructing a third scatter plot according to the movable oil content and the highest pyrolysis peak temperature, and verifying the effect of organic matter maturity on the movable oil content; The expression for calculating the Pearson correlation coefficient of each control group in step S1051, step S1053 and step S1057 is the same, and the expression for calculating the Pearson correlation coefficient of each control group is: , where Cov ( X , Y ) represents the covariance of the control group, Var [ X ] represents the variance of the rising data points in the control group, Var [ Y ] represents the variance of the decreased data points in the control group.

[0064] Based on the movable oil content and Tmax data measured by the step-by-step pyrolysis experiment, a third scatter plot was drawn with the movable oil content as the ordinate and the highest pyrolysis peak temperature (Tmax) as the abscissa. According to the third scatter plot, the influence of organic matter maturity on the movable oil content was further verified. As the maturity increases, the generated oil will reach the in-situ adsorption, swelling, water solubility and pore residual limits and oil displacement will occur, so the movable oil content gradually increases before hot pressing. When the shale reaches the hydrocarbon expulsion threshold, oil expulsion will occur, and liquid oil may also begin to crack, resulting in a decrease in the movable oil content. By comparing the changing trend of the movable oil content with the increase of Tmax, after excluding the abnormal data points that are obviously discrete from the whole, it is determined that the organic matter evolution period corresponding to the Tmax with the highest movable oil content is the organic matter evolution period that is most conducive to the mobility of shale oil.

[0065] In this optional embodiment, the factors affecting the mobility of shale oil are analyzed based on inorganic substances and combined with the three-end member lithofacies types, including: Step S10531, constructing a fourth scatter plot according to the felsic mineral content and the movable oil content, constructing a fifth scatter plot according to the felsic mineral content and the movable fluid saturation, selecting the rising data points and the falling data points in the fourth scatter plot and the fifth scatter plot as control groups, respectively, and calculating the Pearson correlation coefficient of each control group, and judging the correlation between the felsic mineral content and the movable oil content and the movable fluid saturation according to the calculation results; Based on the measured XRD data, X-ray whole-rock quantitative analysis, the content of felsic minerals, carbonate minerals, and clay minerals in each sample are statistically analyzed. According to the statistical felsic mineral content and the measured movable oil content and movable fluid saturation, two scatter plots are drawn, the fourth scatter plot and the fifth scatter plot, with movable oil content and movable fluid saturation as the ordinate and felsic mineral content as the abscissa. According to the fourth and fifth scatter plots drawn, it is judged whether the correlation between the felsic mineral content and the movable oil content and movable fluid saturation is obvious, and whether the drawn scatter plots have the situation that the data points gradually rise first and then gradually fall or vice versa. If this situation exists, the data with an upward trend and the data with a downward trend are regarded as two groups of data for subsequent analysis. The Pearson correlation coefficient of each group of data is calculated. When the absolute value of the correlation coefficient r>0.5, the correlation is considered to be strong, otherwise the correlation is considered to be weak. If the correlation is poor, it means that the effect of felsic minerals on the mobility of shale oil is small; if the correlation is strong, it means that the content of felsic minerals has a significant effect on the mobility of shale oil, among which a positive correlation indicates that the content of felsic minerals has a favorable effect on the mobility of shale oil, and a negative correlation indicates that it has an adverse effect.

[0066] Step S10533: construct a sixth scatter plot according to the carbonate rock mineral content and the movable oil content, construct a seventh scatter plot according to the carbonate rock mineral content and the movable fluid saturation, select the rising data points and the falling data points in the sixth scatter plot and the seventh scatter plot as control groups, respectively, calculate the Pearson correlation coefficient of each control group, and analyze the correlation between the carbonate rock mineral content and the movable oil content and the movable fluid saturation according to the calculation results; According to the statistical carbonate mineral content and the measured movable oil content and movable fluid saturation, two scatter plots are drawn, the sixth scatter plot and the seventh scatter plot, with movable oil content and movable fluid saturation as the ordinate and carbonate mineral content as the abscissa. According to the sixth and seventh scatter plots, it is judged whether the correlation between carbonate mineral content and movable oil content and movable fluid saturation is obvious, and whether the drawn scatter plots have the situation that the data points gradually rise first and then gradually fall or vice versa. If this situation exists, the data with an upward trend and the data with a downward trend are regarded as two groups of data for subsequent analysis. The Pearson correlation coefficient of each group of data is calculated. When the absolute value of the correlation coefficient r>0.5, the correlation is considered to be strong, otherwise the correlation is considered to be weak. If the correlation is poor, it means that carbonate rock minerals have little effect on the mobility of shale oil; if the correlation is strong, it means that the carbonate rock mineral content has a significant impact on the mobility of shale oil, among which a positive correlation indicates that the carbonate rock mineral content has a favorable effect on the mobility of shale oil, and a negative correlation indicates that it has an adverse effect.

[0067] Step S10535: construct an eighth scatter plot based on the clay mineral content and the movable oil content, and construct a ninth scatter plot based on the clay mineral content and the movable fluid saturation, select the rising data points and the falling data points in the eighth scatter plot and the ninth scatter plot as control groups, respectively, and calculate the Pearson correlation coefficient of each control group, and determine the correlation between the clay mineral content and the movable oil content and the movable fluid saturation according to the calculation results.

[0068] Specifically, according to the statistical clay (clay) mineral content and the measured movable oil content and movable fluid saturation, two scatter plots are made with movable oil content and movable fluid saturation as the ordinate and clay (clay) mineral content as the abscissa, the eighth scatter plot and the ninth scatter plot. According to the eighth and ninth scatter plots drawn in the steps, it is judged whether the correlation between the clay mineral content and the movable oil content and movable fluid saturation is obvious, and whether the drawn scatter plot has a situation such as the data points gradually rising first and then gradually falling or vice versa. If this situation exists, the data with an upward trend and the data with a downward trend are regarded as two groups of data for subsequent analysis. The Pearson correlation coefficient of each group of data is calculated. When the absolute value of the correlation coefficient r>0.5, it is considered that the correlation is strong, otherwise it is considered that the correlation is weak. If the correlation is poor, it means that the effect of clay minerals on the mobility of shale oil is small; if the correlation is strong, it means that the clay mineral content has a significant effect on the mobility of shale oil, among which a positive correlation indicates that the clay mineral content has a favorable effect on the mobility of shale oil, and a negative correlation indicates that it has an adverse effect.

[0069] In this optional embodiment, according to the rock structure and in combination with the sedimentary structure type, the factors affecting the mobility of shale oil are analyzed, including: Step S10551, based on the sedimentary structure type, calculating the average movable oil content of the laminar structure, layered structure and massive structure; Step S10553, based on the sedimentary structure type, calculating the average movable fluid saturation of the laminar structure, layered structure and massive structure; Specifically, according to the structure of the rock samples, the samples were divided into laminar structure, layered structure and massive structure with 1 mm and 50 cm as the boundaries, and the average movable oil content and average movable fluid saturation of the three structures were calculated.

[0070] Step S10555: construct the average movable oil content histogram and the average movable fluid saturation histogram of the laminar structure, layered structure and massive structure, and determine the impact of the rock structure on the mobility of shale oil.

[0071] Specifically, the average movable oil content and average movable fluid saturation histograms of laminar, layered and massive structure samples are drawn. If the difference between the highest and lowest average movable oil content of samples with different structures exceeds 1%, and the difference between the highest and lowest average movable fluid saturation of samples with different structures exceeds 10%, it is determined that the rock structure has a significant impact on the mobility of shale oil. The structure with the highest average movable oil content and average movable fluid saturation is most conducive to the mobility of shale oil, and the structure with the lowest average movable oil content and average movable fluid saturation is the least conducive to the mobility of shale oil. On the contrary, it means that the rock structure has a low impact on the mobility of shale oil.

[0072] In this optional embodiment, based on the pore structure, the factors affecting the mobility of shale oil include: Step S10571, constructing mercury advance and retreat curves and pore size distribution diagrams of different lithofacies types based on pore size related parameters of the rock sample, wherein the pore size related parameters include average pore size, surface area and pore volume; Specifically, ① crush the selected samples to a size of 20-40 mesh, perform oil washing treatment for 10 days, and then set the temperature to 110℃ for drying for 24 hours; ② conduct a low-temperature nitrogen adsorption experiment on the above samples, the experimental temperature is set to 77K, the equilibrium time is 10s, the relative pressure (P / P0) is 0.002-0.991, and the specific surface area, pore volume and average pore size of the samples are measured. ③ Cut the selected samples into small cubes with a specification of 1cm3, perform oil washing treatment for 14 days, and set the temperature to 110℃ for drying for 24 hours. ④ Perform a high-pressure mercury injection experiment on the samples to measure the sample pore volume, pore size and other parameters, and draw the mercury advance and retreat curves and pore size distribution diagrams of shales of different lithofacies types.

[0073] Step S10573, constructing a tenth scatter plot according to the average pore size and the movable oil content, selecting the rising data points and the falling data points in the tenth scatter plot as control groups, and calculating the Pearson correlation coefficient of each control group, and judging the correlation between the average pore size and the movable oil content according to the calculation results; Specifically, a tenth scatter plot is made with movable oil content as the ordinate and average pore size as the abscissa. Based on the tenth scatter plot, determine whether the correlation between the average pore size and the movable oil content is obvious, and observe whether the scatter plot has a situation where the data points gradually rise and then gradually fall, or vice versa. If this situation exists, the data with an upward trend and the data with a downward trend are regarded as two groups of data for subsequent analysis. The Pearson correlation coefficient of each group of data is calculated. When the absolute value of the correlation coefficient r>0.5, the correlation is considered to be strong, otherwise the correlation is considered to be weak. If the correlation is poor, it means that the average pore size has little effect on the mobility of shale oil; if the correlation is strong, it means that the average pore size has a significant effect on the mobility of shale oil, where a positive correlation indicates that the average pore size has a favorable effect on the mobility of shale oil, and a negative correlation indicates that it has an adverse effect.

[0074] Step S10575, constructing an eleventh scatter plot according to the surface area and the movable oil content, selecting the rising data points and the falling data points in the eleventh scatter plot as control groups, and calculating the Pearson correlation coefficient of each control group, and judging the correlation between the surface area and the movable oil content according to the calculation results; Specifically, the eleventh scatter plot is made with the movable oil content as the ordinate and the surface area as the abscissa. According to the eleventh scatter plot, it is judged whether the correlation between the surface area and the movable oil content is obvious, and whether the scatter plot has a situation where the data points gradually rise and then gradually fall, or vice versa. If this situation exists, the data with an upward trend and the data with a downward trend are regarded as two groups of data for subsequent analysis. The Pearson correlation coefficient of each group of data is calculated. When the absolute value of the correlation coefficient r>0.5, the correlation is considered to be strong, otherwise the correlation is considered to be weak. If the correlation is poor, it means that the surface area has little effect on the mobility of shale oil; if the correlation is strong, it means that the surface area has a significant effect on the mobility of shale oil, where a positive correlation indicates that the surface area has a favorable effect on the mobility of shale oil, and a negative correlation indicates that it has an adverse effect.

[0075] Step S10577, construct a twelfth scatter plot based on the pore volume and the movable oil content, select the rising data points and the falling data points in the twelfth scatter plot as the control group, and calculate the Pearson correlation coefficient of each control group, and determine the correlation between the pore volume and the movable oil content based on the calculation results.

[0076] Specifically, a twelfth scatter plot is made with movable oil content as the ordinate and pore volume as the abscissa. Based on the drawn twelfth scatter plot, determine whether the correlation between pore volume and movable oil content is obvious, and observe whether the drawn scatter plot has a situation where the data points gradually rise and then gradually fall, or vice versa. If this situation exists, the data with an upward trend and the data with a downward trend are regarded as two groups of data for subsequent analysis. The Pearson correlation coefficient of each group of data is calculated. When the absolute value of the correlation coefficient r>0.5, the correlation is considered to be strong, otherwise the correlation is considered to be weak. If the correlation is poor, it means that the pore volume has little effect on the mobility of shale oil; if the correlation is strong, it means that the pore volume has a significant effect on the mobility of shale oil, where a positive correlation indicates that the pore volume has a favorable effect on the mobility of shale oil, and a negative correlation indicates an adverse effect.

[0077] Figure 2 An embodiment of a system for jointly evaluating geological control factors of continental shale oil mobility according to the present invention is shown.

[0078] In this optional embodiment, the combined evaluation system of geological control factors of continental shale oil mobility includes: The lithofacies feature identification module 201 is used to classify the sedimentary structure type and organic matter type based on the rock sample, and to comprehensively classify the continental shale lithofacies by combining the three-end member lithofacies types; The fluid dynamic analysis module 203 is used to analyze the movable fluid saturation according to the relaxation time spectrum of the multiphase state of the rock sample and evaluate the mobility of the shale oil using the pyrolysis parameters; The geological factor evaluation module 205 is used to analyze the factors affecting the mobility of shale oil based on geological control factors, wherein the geological control factors include organic matter, inorganic matter, rock structure and pore structure.

[0079] The present invention innovatively proposes a solution to the difficult problem of studying geological control factors of continental shale oil mobility. The solution integrates multiple parameters of organic matter, inorganic matter, sedimentary structure, and pore structure to establish a relatively comprehensive evaluation system for geological control factors of continental shale oil mobility, solving the gap in the analysis of factors affecting shale oil mobility control. It has the advantages of comprehensive consideration of influencing factors, wide recognition of the experiments involved in the industry, strong operability, and good applicability.

[0080] The present invention is not limited to the structures which have been described above and shown in the drawings, and various modifications and changes may be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A method for jointly evaluating geological control factors of continental shale oil mobility, characterized in that: The combined evaluation method of geological control factors of continental shale oil mobility includes: Based on rock samples, the sedimentary structure type and organic matter type are divided, and the continental shale lithofacies are comprehensively divided by combining the three-terminal lithofacies types; The movable fluid saturation is analyzed based on the relaxation time spectrum of the multiphase state of the rock sample, and the mobility of the shale oil is evaluated using pyrolysis parameters; Based on geological control factors, the factors affecting shale oil mobility are analyzed, and the geological control factors include organic matter, inorganic matter, rock structure and pore structure.

2. A combined evaluation method for geological control factors of continental shale oil mobility according to claim 1, characterized in that: The classification of sedimentary structure types and organic matter types based on rock samples, and the comprehensive classification of continental shale lithofacies in combination with three-end member lithofacies types include: Using X-ray whole-rock quantitative analysis and combining bedding thickness boundaries, the sedimentary structure types of rock samples are classified, including laminar structure, layered structure and massive structure; Based on the determination result of total organic carbon content, the organic matter type of the rock sample is classified, and the organic matter type includes high organic matter, medium organic matter and low organic matter; The continental shale lithofacies of the rock samples are comprehensively classified according to the sedimentary structure type and organic matter type, combined with the three-end-member lithofacies types, which include felsic minerals, carbonate minerals and clay minerals.

3. The combined evaluation method of geological control factors of continental shale oil mobility according to claim 1 is characterized in that: The method of analyzing the movable fluid saturation according to the relaxation time spectrum of the multiphase state of the rock sample and evaluating the mobility of the shale oil by using the pyrolysis parameters includes: Based on nuclear magnetic resonance technology, the two-dimensional relaxation time spectrum and the transverse relaxation time spectrum of the multiphase rock sample are measured, and the multiphase rock sample includes the dry state, the saturated fluid state and the high-speed centrifugal state of the rock sample; Analyze movable fluid saturation and related parameters based on transverse relaxation time spectrum; Based on the results of the step-by-step pyrolysis experiment, the pyrolysis parameters of the rock sample powder were determined, and the measured data were corrected to obtain the movable oil content of the rock sample.

4. A combined evaluation method of geological control factors of continental shale oil mobility according to claim 3, characterized in that: The analysis of movable fluid saturation and related parameters according to the transverse relaxation time spectrum includes: Based on the transverse relaxation time spectrum, the movable fluid saturation, nuclear magnetic porosity and transverse relaxation cutoff time are calculated; Based on the calculation results, the base signals of saturated fluid state and high-speed centrifugal state are removed; The movable fluid saturation analysis is used to determine the bound and movable fluids in the rock sample.

5. The combined evaluation method of geological control factors of continental shale oil mobility according to claim 1, characterized in that: The factors affecting the mobility of shale oil based on geological control factors include: Analyze the factors affecting the mobility of shale oil based on organic matter; According to inorganic substances and combined with three-end-member lithofacies types, the factors affecting the mobility of shale oil are analyzed; Analyze the factors affecting the mobility of shale oil based on rock structure and sedimentary structure type; Based on the pore structure, the factors affecting the mobility of shale oil are analyzed.

6. A combined evaluation method of geological control factors of continental shale oil mobility according to claim 5, characterized in that: The factors affecting the mobility of shale oil based on organic matter include: A first scatter plot is constructed according to the movable oil content and the total organic carbon content, the rising data points and the falling data points in the first scatter plot are selected as control groups, and the Pearson correlation coefficient of each control group is calculated, and the correlation between the movable oil content and the total organic carbon content is analyzed according to the calculation results; A second scatter plot is constructed based on movable oil content and organic matter maturity, and rising data points and falling data points in the second scatter plot are selected as control groups, and the Pearson correlation coefficient of each control group is calculated, and the correlation between organic matter maturity and movable oil content is determined based on the calculation results; The third scatter plot was constructed based on the movable oil content and the highest pyrolysis peak temperature, and the effect of organic matter maturity on the movable oil content was verified; The expression for calculating the Pearson correlation coefficient of each control group is: , where Cov ( X,Y ) represents the covariance of the control group, Var [ X ] represents the variance of the rising data points in the control group, Var [Y] represents the variance of the falling data points in the control group.

7. A combined evaluation method of geological control factors of continental shale oil mobility according to claim 5, characterized in that: The factors affecting the mobility of shale oil analyzed based on inorganic substances and combined with the three-end member lithofacies types include: A fourth scatter plot is constructed according to the felsic mineral content and the movable oil content, and a fifth scatter plot is constructed according to the felsic mineral content and the movable fluid saturation, and the rising data points and the falling data points in the fourth scatter plot and the fifth scatter plot are respectively selected as control groups, and the Pearson correlation coefficient of each control group is calculated, and the correlation between the felsic mineral content and the movable oil content and the movable fluid saturation is determined according to the calculation results; A sixth scatter plot is constructed according to the carbonate rock mineral content and the movable oil content, and a seventh scatter plot is constructed according to the carbonate rock mineral content and the movable fluid saturation, and the rising data points and the falling data points in the sixth scatter plot and the seventh scatter plot are respectively selected as control groups, and the Pearson correlation coefficient of each control group is calculated, and the correlation between the carbonate rock mineral content and the movable oil content and the movable fluid saturation is analyzed according to the calculation results; The eighth scatter plot was constructed according to the clay mineral content and the movable oil content, and the ninth scatter plot was constructed according to the clay mineral content and the movable fluid saturation. The rising data points and the falling data points in the eighth scatter plot and the ninth scatter plot were selected as control groups, respectively, and the Pearson correlation coefficient of each control group was calculated. The correlation between the clay mineral content and the movable oil content and the movable fluid saturation was determined based on the calculation results.

8. A combined evaluation method of geological control factors of continental shale oil mobility according to claim 5, characterized in that: The factors affecting the mobility of shale oil analyzed based on rock structure and sedimentary structure type include: Based on the sedimentary structure type, the average movable oil content of laminar, layered and massive structures is calculated; Based on the sedimentary structure type, the average movable fluid saturation of laminar, layered and massive structures is calculated; The average movable oil content histogram and average movable fluid saturation histogram of laminar, layered and massive structures are constructed to determine the effect of rock structure on the mobility of shale oil.

9. A combined evaluation method of geological control factors of continental shale oil mobility according to claim 5, characterized in that: The factors affecting the mobility of shale oil based on pore structure include: Based on the pore size related parameters of the rock samples, construct the mercury advance and retreat curve diagram and pore size distribution diagram of different lithofacies types, wherein the pore size related parameters include average pore size, surface area and pore volume; A tenth scatter plot is constructed according to the average pore size and the movable oil content, the rising data points and the falling data points in the tenth scatter plot are selected as control groups, and the Pearson correlation coefficient of each control group is calculated, and the correlation between the average pore size and the movable oil content is determined according to the calculation results; An eleventh scatter plot is constructed based on the surface area and the movable oil content, the rising data points and the falling data points in the eleventh scatter plot are selected as control groups, and the Pearson correlation coefficient of each control group is calculated, and the correlation between the surface area and the movable oil content is determined based on the calculation results; A twelfth scatter plot is constructed based on the pore volume and the movable oil content, the rising data points and the falling data points in the twelfth scatter plot are selected as control groups, and the Pearson correlation coefficient of each control group is calculated. The correlation between the pore volume and the movable oil content is determined based on the calculation results.

10. A joint evaluation system for geological control factors of continental shale oil mobility, characterized in that: The combined evaluation system of geological control factors of continental shale oil mobility includes: The lithofacies feature recognition module is used to classify sedimentary structure types and organic matter types based on rock samples, and to comprehensively classify continental shale lithofacies by combining three-end member lithofacies types; Fluid dynamic analysis module, used to analyze the movable fluid saturation based on the relaxation time spectrum of the multiphase state of the rock sample and evaluate the mobility of shale oil using pyrolysis parameters; The geological factor evaluation module is used to analyze the factors affecting shale oil mobility based on geological control factors.

Images