Evaluation method and device for hydrocarbon preservation unit

Abstract

An embodiment of the present invention discloses a method and device for evaluating an oil and gas preservation unit. The method for evaluating an oil and gas preservation unit includes: obtaining a tectonic-sedimentary evolution model of the oil and gas preservation unit; obtaining the caprock characteristics and source rock characteristics of the oil and gas preservation unit; obtaining the caprock sealing property based on the caprock characteristics, obtaining the source rock evaluation result based on the source rock characteristics, and obtaining the key tectonic period based on the tectonic-sedimentary evolution model; obtaining the resource amount of oil and gas loss; obtaining the oil and gas resource amount and resource potential based on the caprock sealing property, the source rock evaluation result, the key tectonic period, and the resource amount of oil and gas loss; and evaluating the oil and gas preservation unit based on the oil and gas resource amount and resource potential. The purpose of being able to evaluate the oil and gas preservation units in different regions is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of oil and gas exploration, and more specifically, relates to a method and device for evaluating an oil and gas preservation unit. Background Art

[0002] Oil and gas resource evaluation refers to the process of estimating the underground oil and gas potential (mainly undiscovered oil and gas resources) of a certain trap, a certain zone, a certain basin, a certain country or the whole world in a specific area, which is usually called oil and gas resource evaluation or oil and gas resource prediction. It belongs to petroleum and natural gas geology.

[0003] The discipline that studies the theory and methods of resource prediction is called resource prediction methodology. Oil and gas resource evaluation includes three aspects: geological analysis, engineering evaluation and economic evaluation. Oil and gas resource evaluation is a comprehensive study of the past, present and future conditions of oil and gas under modern technical conditions, using multi-disciplines, multi-means, multi-faceted data results and information, and taking the content of petroleum geological research as the main line under the condition of systematic engineering analysis.

[0004] In recent years, although each oil and gas (sub) company has carried out relevant research work on the evaluation of marine strata oil and gas resources in the study area, there are still great differences in evaluation criteria and methods. In existing basin simulation software, the calculation of hydrocarbon generation amount is based on the theory of kerogen thermal degradation to generate oil and hydrocarbon generation kinetics; in multiple rounds of resource evaluation in China, the genetic methods adopted all take organic carbon, chloroform bitumen "A", and hydrocarbon production rate as the main parameters. In current resource evaluation, the calculation of resource volume is mostly based on the hydrocarbon generation amount and selects the corresponding hydrocarbon generation and accumulation coefficient (oil drainage coefficient * accumulation coefficient) for calculation. In recent years, it has driven the update and development of resource evaluation methods, especially great progress has been made in aspects such as the hydrocarbon expulsion efficiency of different types of source rocks, the accumulation coefficient, and the fine characterization of source rocks.

[0005] In the prior art, due to the complex oil and gas geological conditions and different oil and gas accumulation conditions in different regions, there is a problem that the existing evaluation methods cannot evaluate the oil and gas preservation units in different regions. Summary of the Invention

[0006] In view of this, the embodiments of the present invention provide a method and device for evaluating an oil and gas preservation unit, which at least solve the problem that the existing evaluation methods cannot evaluate the oil and gas preservation units in different regions.

[0007] In a first aspect, the embodiments of the present invention provide a method for evaluating an oil and gas preservation unit, including:

[0008] Obtaining a tectonic-sedimentary evolution model of the oil and gas preservation unit;

[0009] Analyze the types of hydrocarbon preservation units based on the tectonic-sedimentary evolution model, including residual type or reconstructed type. Obtain the caprock characteristics and source rock characteristics of the hydrocarbon preservation units;

[0010] Obtain the caprock sealing property based on the caprock characteristics, obtain the source rock evaluation result based on the source rock characteristics, and obtain the key tectonic periods based on the tectonic-sedimentary evolution model;

[0011] Obtain the resource amount of hydrocarbon loss;

[0012] Obtain the hydrocarbon resource amount and resource potential based on the caprock sealing property, source rock evaluation result, key tectonic periods, and resource amount of hydrocarbon loss;

[0013] Evaluate the hydrocarbon preservation units based on the hydrocarbon resource amount and resource potential.

[0014] Optionally, the method for obtaining the tectonic-sedimentary evolution model of the hydrocarbon preservation unit includes:

[0015] Analyze the types of hydrocarbon preservation units based on the tectonic-sedimentary evolution model;

[0016] The types of the hydrocarbon preservation units include residual type or reconstructed type.

[0017] Optionally, the method for obtaining the caprock sealing property based on the caprock characteristics and the source rock evaluation result based on the source rock characteristics includes:

[0018] Obtain the caprock sealing property at the key tectonic periods through dynamic research on caprock characteristics, obtain the evaluation result of the secondary hydrocarbon generation amount of the source rock at the key tectonic periods based on the source rock characteristics and TSM basin simulation, and obtain the loss amount result based on the diffusion coefficient experiment;

[0019] For the reconstructed hydrocarbon preservation units, obtain the source rock maturity and the retained oil amount of the hydrocarbon preservation unit before the key tectonic transformation period based on the source rock characteristics and TSM basin simulation, and then obtain the secondary hydrocarbon generation amount of kerogen and the secondary hydrocarbon generation amount of the retained oil in the hydrocarbon preservation unit after the key tectonic transformation through TSM basin simulation;

[0020] Obtain the modified TSM basin simulation based on the source rock maturity and the retained oil;

[0021] Obtain the source rock evaluation result based on the parameters in the modified TSM basin simulation.

[0022] Optionally, the parameters in the modified TSM basin simulation include:

[0023] The secondary gas generation amount of kerogen, the late cracking gas generation amount of the retained oil, the hydrocarbon supply amount estimated based on the migration trend analysis, and the late diffusion loss amount.

[0024] Optionally, the residual hydrocarbon preservation unit is:

[0025] The hydrocarbon source rock in the early stage generates hydrocarbon that migrates and accumulates into reservoirs through the processes of burial, maturation, hydrocarbon generation, hydrocarbon expulsion, and migration and accumulation in sequence;

[0026] A hydrocarbon preservation unit in which the hydrocarbon is lost due to later tectonic transformation, diffusion loss, and water-soluble loss, resulting in the destruction of the cap rock.

[0027] Optionally, the reconstructed hydrocarbon preservation unit is:

[0028] The hydrocarbon source rock generates hydrocarbon that migrates and accumulates into reservoirs through the processes of burial, maturation, hydrocarbon generation, hydrocarbon expulsion, and migration and accumulation in sequence during the early sedimentary burial process;

[0029] A hydrocarbon preservation unit that experiences the cessation of hydrocarbon generation due to the uplift of the later strata, and then experiences sedimentary burial depth exceeding the burial depth.

[0030] Optionally, the cap rock characteristics include:

[0031] Dynamic evolution evaluation and analysis of the cap rock burial history, cap rock diagenesis history, and pore evolution history.

[0032] Optionally, the hydrocarbon source rock characteristics include:

[0033] Hydrocarbon source rock burial history, hydrocarbon source rock maturation history, hydrocarbon source rock hydrocarbon generation history, and hydrocarbon migration and accumulation history.

[0034] Optionally, the resource quantity of hydrocarbon loss is:

[0035] The resource quantity of hydrocarbon lost due to tectonic, diffusion, or water-soluble factors.

[0036] In a second aspect, an embodiment of the present invention further provides an evaluation device for a hydrocarbon preservation unit, including:

[0037] Model acquisition unit: used to acquire the tectonic-sedimentary evolution model of the hydrocarbon preservation unit;

[0038] Characteristic acquisition unit: used to acquire the cap rock characteristics and hydrocarbon source rock characteristics of the hydrocarbon preservation unit;

[0039] Characteristic processing unit: used to obtain the cap rock sealing property based on the cap rock characteristics, obtain the evaluation result of the hydrocarbon source rock based on the hydrocarbon source rock characteristics, and obtain the key tectonic period based on the tectonic-sedimentary evolution model;

[0040] Resource quantity acquisition unit: used to acquire the resource quantity of hydrocarbon loss;

[0041] Parameter acquisition unit: used to obtain the hydrocarbon resource quantity and resource potential based on the cap rock sealing property, hydrocarbon source rock evaluation result, key tectonic period, and resource quantity of hydrocarbon loss;

[0042] Evaluation unit: used to evaluate the hydrocarbon preservation unit based on the hydrocarbon resource quantity and resource potential.

[0043] In the present invention, the hydrocarbon resource quantity and resource potential are obtained from the caprock sealing property, the evaluation result of the source rock, the key tectonic period, and the resource quantity of hydrocarbon loss, and the hydrocarbon preservation unit is evaluated based on the hydrocarbon resource quantity and resource potential. In the hydrocarbon resource evaluation, the characteristics of different hydrocarbon preservation units in different regions are fully considered, and different resource evaluation parameters and methods are formulated according to the exploration degree, data basis, tectonic evolution, and differences in hydrocarbon generation, expulsion, migration, and accumulation of the source rock in the region. Thus, the purpose of being able to evaluate the hydrocarbon preservation units in different regions can be achieved.

[0044] Other features and advantages of the present invention will be described in detail in the following specific implementation section. Brief Description of the Drawings

[0045] By describing the exemplary embodiments of the present invention in more detail in conjunction with the drawings, the above and other objects, features, and advantages of the present invention will become more obvious. Among them, in the exemplary embodiments of the present invention, the same reference numerals generally represent the same components.

[0046] Figure 1 The flowchart of the method for evaluating the hydrocarbon preservation unit according to an embodiment of the present invention is shown;

[0047] Figure 2 The block diagram of the technical method for evaluating the resources of the residual hydrocarbon preservation unit according to an embodiment of the present invention is shown;

[0048] Figure 3 The block diagram of the technical method for evaluating the resources of the reconstructed hydrocarbon preservation unit according to an embodiment of the present invention is shown;

[0049] Figure 4 The schematic diagram of the Ro isolines at the end of J3 of the Permian source rock in the Jianghan Plain area according to an embodiment of the present invention is shown;

[0050] Figure 5 The schematic diagram of the Ro isolines at the end of E of the Permian source rock in the Jianghan Plain area according to an embodiment of the present invention is shown;

[0051] Figure 6 The schematic diagram of the hydrocarbon generation evolution history of the Permian source rock in the Jianghan Plain area according to an embodiment of the present invention is shown;

[0052] Figure 7 The principle block diagram of the device for evaluating the hydrocarbon preservation unit according to an embodiment of the present invention is shown. Detailed Description of the Invention

[0053] The preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described below, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein.

[0054] An oil and gas preservation unit is a hydrocarbon-bearing geological unit that encloses fluids in a three-dimensional space within a basin.

[0055] TSM basin simulation is a deterministic numerical simulation that is guided by the basin system concept of 3T (environment) - 4S (processes) - 4M (responses), and is carried out under the constraint of the prototype, comprehensively integrating the four historical systems of burial, heat, hydrocarbon generation, and migration and accumulation in a systematic network from the basin to the trap.

[0056] An evaluation method for an oil and gas preservation unit includes:

[0057] Obtaining the tectonic-sedimentary evolution model of the oil and gas preservation unit;

[0058] Obtaining the caprock characteristics and source rock characteristics of the oil and gas preservation unit;

[0059] Obtaining the caprock sealing property based on the caprock characteristics, obtaining the source rock evaluation result based on the source rock characteristics, and obtaining the key tectonic period based on the tectonic-sedimentary evolution model;

[0060] Obtaining the amount of resources lost due to oil and gas dissipation;

[0061] Obtaining the oil and gas resource amount and resource potential based on the caprock sealing property, source rock evaluation result, key tectonic period, and the amount of resources lost due to oil and gas dissipation;

[0062] Evaluating the oil and gas preservation unit based on the oil and gas resource amount and resource potential.

[0063] Optionally, obtaining the tectonic-sedimentary evolution model of the oil and gas preservation unit includes:

[0064] Analyzing the type of the oil and gas preservation unit based on the tectonic-sedimentary evolution model;

[0065] The type of the oil and gas preservation unit includes residual type or reconstructed type.

[0066] Optionally, obtaining the caprock sealing property based on the caprock characteristics and obtaining the source rock evaluation result based on the source rock characteristics includes:

[0067] Obtaining the caprock sealing property during the key tectonic period based on the dynamic study of the caprock characteristics, obtaining the evaluation result of the secondary hydrocarbon generation amount of the source rock during the key tectonic period based on the source rock characteristics and TSM basin simulation, and obtaining the dissipation amount result based on the diffusion coefficient experiment;

[0068] For a reconstructed hydrocarbon preservation unit, based on the characteristics of source rocks and TSM basin simulation, the maturity of source rocks and the retained oil volume of the hydrocarbon preservation unit before the key tectonic transformation period are obtained. Then, the secondary hydrocarbon generation amount of kerogen and the secondary hydrocarbon generation amount of retained oil in the hydrocarbon preservation unit after the key tectonic transformation are obtained through TSM basin simulation;

[0069] Based on the maturity of the source rocks and the retained oil, a modified TSM basin simulation is obtained;

[0070] Based on the parameters in the modified TSM basin simulation, the source rock evaluation results are obtained.

[0071] Optionally, the parameters in the modified TSM basin simulation include:

[0072] The secondary gas generation amount of kerogen, the late cracking gas generation amount of retained oil, the hydrocarbon supply amount estimated based on migration trend analysis, and the late diffusion loss amount.

[0073] Optionally, the residual hydrocarbon preservation unit is:

[0074] The oil and gas generated by the early source rocks through the processes of burial, maturation, hydrocarbon generation, hydrocarbon expulsion, and migration and accumulation are migrated and accumulated into reservoirs;

[0075] The hydrocarbon preservation unit in which the caprock is damaged due to the loss, diffusion loss, and water-soluble loss during the later tectonic transformation.

[0076] Optionally, the reconstructed hydrocarbon preservation unit is:

[0077] The oil and gas generated by the source rocks through the processes of burial, maturation, hydrocarbon generation, hydrocarbon expulsion, and migration and accumulation during the early sedimentary burial process are migrated and accumulated into reservoirs;

[0078] The hydrocarbon preservation unit that experiences the cessation of hydrocarbon generation due to the uplift of the later strata and then experiences sedimentary burial depth exceeding the burial depth.

[0079] Optionally, the caprock characteristics include:

[0080] Dynamic evolution evaluation and analysis of the caprock burial history, caprock diagenesis history, and pore evolution history.

[0081] Optionally, the source rock characteristics include:

[0082] The source rock burial history, source rock maturity history, source rock hydrocarbon generation history, and oil and gas migration and accumulation history.

[0083] Optionally, the resource volume of hydrocarbon loss is:

[0084] The resource volume of oil and gas lost due to tectonic, diffusion, or water-soluble factors.

[0085] Example 1:

[0086] Such asFigure 1 As shown, a method for evaluating an oil and gas preservation unit comprises:

[0087] Step S101: obtaining a structural-sedimentary evolution model of an oil and gas preservation unit;

[0088] Step S102: Acquire the cap rock characteristics and source rock characteristics of the oil and gas preservation unit;

[0089] Step S103: obtaining the sealing property of the cap rock based on the cap rock characteristics, obtaining the source rock evaluation result based on the source rock characteristics, and obtaining the key tectonic period based on the tectonic-sedimentary evolution model;

[0090] Step S104: Obtaining the amount of lost oil and gas resources;

[0091] Step S105: Obtaining the oil and gas resource volume and resource potential based on the sealing property of the cap rock, the evaluation results of the source rock, the key tectonic period and the resource volume of oil and gas loss;

[0092] Step S106: Evaluate the oil and gas preservation unit based on the oil and gas resource quantity and resource potential.

[0093] Resource evaluation is essentially to evaluate how much resources a region’s source rocks have generated, how much resources have been migrated and accumulated, and how much oil and gas resources can be preserved in different geological periods after later tectonic transformation. However, there are many differences in the hydrocarbon generation and expulsion processes of source rocks and the sealing performance of caprocks in different oil and gas preservation units. Generally speaking, the current marine oil and gas preservation units in southern China can be roughly divided into two types: one is the “residual” oil and gas preservation unit, that is, the early source rocks generated and accumulated oil and gas in the process of burial-maturity-hydrocarbon generation-expulsion-migration and accumulation, and how much oil and gas resources can be left after the destruction of the caprocks due to later tectonic transformation. This type of resource evaluation method is to first calculate the oil and gas generation resources in the key tectonic period according to the conventional resource evaluation method, and focus on calculating the lost resources caused by structural loss, diffusion loss and water dissolution loss due to the later evolution of the cap rock. Finally, the generated oil and gas resources minus the lost oil and gas resources are used to obtain this type of oil and gas resources. The second type is the "reconstructed" oil and gas preservation unit, that is, the source rock undergoes burial-maturity-hydrocarbon generation-hydrocarbon expulsion-migration and accumulation in the early deposition and burial process, and then experiences the uplift of the later strata and the cessation of hydrocarbon generation. Then it experiences sedimentation and burial depth that exceeds the first burial depth, which on the one hand causes secondary hydrocarbon generation by kerogen in the source rock, and on the other hand causes gas generation by late cracking of retained oil. These two hydrocarbon generation and cracking constitute the total resource volume. Generally, in this case, the impact of later cap rock destruction on oil and gas is relatively small. The resource evaluation process should focus on the resource volume of the first hydrocarbon generation, migration and accumulation and the resource volume of the secondary hydrocarbon generation and retained oil cracking, migration and accumulation. These two constitute the resource volume of this type of oil and gas preservation unit.

[0094] Optionally, the method for obtaining the structural-sedimentary evolution model of the hydrocarbon preservation unit includes:

[0095] Analyzing the type of the hydrocarbon preservation unit based on the structural-sedimentary evolution model;

[0096] The type of the hydrocarbon preservation unit includes a residual type or a reconstructed type.

[0097] Optionally, the caprock characteristics include:

[0098] Dynamic evolution evaluation and analysis of the caprock burial history, caprock diagenesis history, and pore evolution history.

[0099] Optionally, the source rock characteristics include:

[0100] Source rock burial history, source rock maturity history, source rock hydrocarbon generation history, and hydrocarbon migration and accumulation history.

[0101] Optionally, the resource volume of hydrocarbon loss is:

[0102] The resource volume of hydrocarbon loss due to tectonic, diffusion, or water-soluble factors.

[0103] Optionally, obtaining the caprock sealing property based on the caprock characteristics, obtaining the source rock evaluation result based on the source rock characteristics, and obtaining the key tectonic period based on the structural-sedimentary evolution model includes:

[0104] Obtaining the caprock sealing property at the key tectonic period based on the dynamic research of the caprock characteristics, obtaining the evaluation result of the secondary hydrocarbon generation amount of the source rock at the key tectonic period based on the source rock characteristics and TSM basin simulation, and obtaining the loss amount result based on the diffusion coefficient experiment;

[0105] For the reconstructed hydrocarbon preservation unit, based on the source rock characteristics and TSM basin simulation, obtaining the source rock maturity and the remaining oil volume of the hydrocarbon preservation unit before the key tectonic transformation period, and then obtaining the secondary hydrocarbon generation amount of kerogen and the secondary hydrocarbon generation amount of the remaining oil in the hydrocarbon preservation unit after the key tectonic transformation through TSM basin simulation;

[0106] Obtaining the modified TSM basin simulation based on the source rock maturity and the remaining oil;

[0107] Obtaining the source rock evaluation result based on the parameters in the modified TSM basin simulation.

[0108] Optionally, the parameters in the modified TSM basin simulation include:

[0109] The secondary gas generation amount of kerogen, the late cracking gas generation amount of the remaining oil, the hydrocarbon supply amount estimated based on the migration trend analysis, and the late diffusion loss amount.

[0110] Optionally, the residual hydrocarbon preservation unit is:

[0111] In the early stage, source rocks generate and accumulate oil and gas through burial, maturation, hydrocarbon generation, hydrocarbon expulsion, and migration and accumulation processes in sequence.

[0112] An oil and gas preservation unit where the oil and gas are lost due to late-stage tectonic transformation, diffusion loss, and water-soluble loss, resulting in the destruction of the cap rock.

[0113] Such as Figure 2 As shown, it is the technical method roadmap for resource evaluation of "residual type" oil and gas preservation units. Based on the analysis of the tectonic-sedimentary evolution history, in the first step, through the study of the burial history, maturation history, hydrocarbon generation history, and oil and gas migration and accumulation history of the source rock during the key tectonic period, the source rock evaluation is carried out, and the expected resource volume of the area before loss is calculated; in the second step, through the analysis of the burial history, diagenesis history, pore evolution history, etc. of the cap rock, the sealing property of the cap rock is studied, and thus the resource volume of the oil and gas that may be lost due to factors such as tectonics, diffusion, and water solubility after the formation of oil and gas reservoirs is calculated; in the third step, the final resource volume is further calculated, the resource potential is analyzed, and the zone evaluation and optimization are carried out.

[0114] Optionally, the reconstructed oil and gas preservation unit is:

[0115] In the process of early sedimentary burial, source rocks generate and accumulate oil and gas through burial, maturation, hydrocarbon generation, hydrocarbon expulsion, and migration and accumulation processes in sequence.

[0116] An oil and gas preservation unit that experiences the cessation of hydrocarbon generation due to the uplift of the later strata, and then experiences sedimentary burial depth exceeding the original burial depth.

[0117] Such as Figure 3 As shown, it is the technical method roadmap for resource evaluation of "reconstructed type" oil and gas preservation units. Based on the analysis of the tectonic-sedimentary evolution history, in the first step, through TSM basin simulation, the burial history, maturation history, hydrocarbon generation history, and migration and accumulation history of the source rock are studied, the maturity of the source rock before the key period is studied, the hydrocarbons generated by the source rock at this maturity are calculated, as well as the resource volume of the expelled and accumulated oil and gas reservoirs and the retained oil in the source rock; secondly, after the key tectonic period, due to the re-subsidence caused by the uplift of the strata, the source rock generates hydrocarbons again and the retained oil in the source rock cracks into gas, and the resources of these two parts constitute the final expected resource volume. If the upper cover layer is severely damaged, the loss volume of the oil and gas is calculated, and then the final resource volume is obtained, the resource potential is analyzed, and the zone evaluation and optimization are carried out.

[0118] Example 2:

[0119] Taking the Jianghan Plain area as an example for the "reconstructed type":

[0120] In the Jianghan Plain area, the Mesozoic and Paleozoic basins have undergone strong tectonic deformation and transformation, and the oil and gas preservation conditions have been damaged to varying degrees. In the late stage, Meso-Cenozoic fault-depressed basins were superimposed. On the one hand, it caused secondary hydrocarbon generation of the early source rocks, on the other hand, it retained the cracking of oil to supply gas, and at the same time, the oil and gas preservation system was rebuilt. Take the Permian source rocks in the Jianghan Plain as an example.

[0121] According to the sedimentary tectonic evolution of the Jianghan Basin, the Permian source rocks were continuously deposited from the Sinian to the end of the Jurassic, and the Permian source rocks generated hydrocarbons continuously at one time. The Middle Yanshan Movement in J3-K1 caused strong uplift and erosion of the underlying strata, and the continuous hydrocarbon generation at one time was interrupted. The fault-depression during K2-E deposited several kilometers of sandstone and mudstone, which buried the underlying strata again, and the secondary hydrocarbon generation of the source rocks was initiated.

[0122] By means of basin simulation, predict the initial maturity, initial paleogeothermal temperature before the deep burial of K2-E, the maturity and paleogeothermal temperature distribution at the end of E, and combine the conditions for secondary hydrocarbon generation to delineate the favorable area for secondary hydrocarbon generation of the Permian source rocks in the plain area. As Figure 4 and Figure 5 shown.

[0123] Based on the hydrocarbon generation evolution process of source rocks simulated by burial history and thermal maturity history, using the TSM basin simulation method, the hydrocarbon generation amounts of the Permian source rocks at each stage are obtained. As Figure 6 shown, the main hydrocarbon generation periods of the Permian source rocks are two stages from the end of T2 to the end of J2 and from the end of J to the end of E.

[0124] At this time, the resource quantity calculation consists of two parts. One part is the hydrocarbon expelled from the source rock layer and accumulated into reservoirs, and the other part remains in the source rock layer together with solid bitumen and cracks into gas after secondary burial, supplying hydrocarbons in the late stage.

[0125] By determining the hydrocarbon generation and expulsion patterns of source rocks with different lithologies, it is found that for the Permian source rocks in the study area, when Ro = 0.8, the retained oil reaches 80%, when Ro = 1.0, it reaches 65%, when Ro = 1.3, it reaches 40%, and when Ro = 2.0, it reaches 8%. Thus, through basin simulation, the total amount of retained oil in the Permian source rocks by the end of the Jurassic reaches 8.377 million tons. This part of the retained oil can crack into gas during the secondary deep burial in the late-stage superimposed basin, and according to a reasonable conversion rate, the resource quantity of the retained oil cracking into gas is 6.7 million tons. Finally, based on the secondary evolution hydrocarbon generation of Ro at the end of E, the converted oil and gas quantity of secondary hydrocarbon generation is obtained through basin simulation. Thus, the resource quantity of the Jianghan Plain area can be finally obtained.

[0126] Example 3:

[0127] As Figure 7 shown, an evaluation device for an oil and gas preservation unit includes:

[0128] Model acquisition unit: used to acquire the tectonic-sedimentary evolution model of the hydrocarbon preservation unit;

[0129] Feature acquisition unit: used to acquire the caprock features and source rock features of the hydrocarbon preservation unit;

[0130] Feature processing unit: used to obtain the caprock sealing property based on the caprock features, obtain the source rock evaluation result based on the source rock features, and obtain the key tectonic period based on the tectonic-sedimentary evolution model;

[0131] Resource amount acquisition unit: used to acquire the resource amount of hydrocarbon loss;

[0132] Parameter acquisition unit: used to obtain the hydrocarbon resource amount and resource potential based on the caprock sealing property, source rock evaluation result, key tectonic period, and resource amount of hydrocarbon loss;

[0133] Evaluation unit: used to evaluate the hydrocarbon preservation unit based on the hydrocarbon resource amount and resource potential.

[0134] Optionally, the acquisition of the tectonic-sedimentary evolution model of the hydrocarbon preservation unit includes:

[0135] Analyze the type of the hydrocarbon preservation unit based on the tectonic-sedimentary evolution model;

[0136] The type of the hydrocarbon preservation unit includes residual type or reconstructed type.

[0137] Optionally, the obtaining of the caprock sealing property based on the caprock features, the source rock evaluation result based on the source rock features, and the key tectonic period based on the tectonic-sedimentary evolution model includes:

[0138] Obtain the caprock sealing property at the key tectonic period through dynamic research based on the caprock features, obtain the evaluation result of the secondary hydrocarbon generation amount of the source rock at the key tectonic period based on the source rock features and TSM basin simulation, and obtain the loss amount result based on the diffusion coefficient experiment;

[0139] For the reconstructed hydrocarbon preservation unit, obtain the source rock maturity and retained oil amount of the hydrocarbon preservation unit before the key tectonic transformation based on the source rock features and TSM basin simulation, and then obtain the secondary hydrocarbon generation amount of kerogen and the secondary hydrocarbon generation amount of the retained oil in the hydrocarbon preservation unit after the key tectonic transformation through TSM basin simulation;

[0140] Obtain the modified TSM basin simulation based on the source rock maturity and retained oil;

[0141] Obtain the source rock evaluation result based on the parameters in the modified TSM basin simulation.

[0142] Optionally, the parameters in the modified TSM basin simulation include:

[0143] The secondary gas generation volume of kerogen, the late-stage cracking gas of retained oil, and the migration trend.

[0144] Optionally, the residual type of hydrocarbon preservation unit is:

[0145] The hydrocarbon source rocks in the early stage generate hydrocarbons that migrate and accumulate into reservoirs through the processes of burial, maturation, hydrocarbon generation, hydrocarbon expulsion, and migration and accumulation in sequence;

[0146] The hydrocarbon preservation unit in which the hydrocarbons generated by the early-stage hydrocarbon source rocks are lost due to late-stage tectonic transformation, diffusion loss, and water-soluble loss, resulting in the destruction of the cap rock.

[0147] Optionally, the reconstructed type of hydrocarbon preservation unit is:

[0148] The hydrocarbon source rocks generate hydrocarbons that migrate and accumulate into reservoirs through the processes of burial, maturation, hydrocarbon generation, hydrocarbon expulsion, and migration and accumulation in sequence during the early-stage sedimentary burial process;

[0149] The hydrocarbon preservation unit in which hydrocarbon generation stops after the late-stage uplift of the strata, and then experiences sedimentary burial depth and exceeds the burial depth.

[0150] Optionally, the cap rock characteristics include:

[0151] Dynamic evolution evaluation and analysis of the cap rock burial history, cap rock diagenesis history, and pore evolution history.

[0152] Optionally, the hydrocarbon source rock characteristics include:

[0153] The hydrocarbon source burial history, hydrocarbon source maturation history, hydrocarbon source hydrocarbon generation history, and hydrocarbon migration and accumulation history.

[0154] Optionally, the resource volume of hydrocarbon loss is:

[0155] The resource volume of hydrocarbons lost due to tectonic, diffusion, or water-soluble factors.

[0156] This embodiment mainly includes the resource evaluation of "reconstructed type" and "residual type" hydrocarbon preservation units. The former type focuses on considering two parts of resources: the secondary hydrocarbon generation of hydrocarbon source rocks and the gas supply from the cracking of retained oil; the latter type focuses on considering several possible ways of hydrocarbon loss and the loss volume. This method of resource evaluation for different types of preservation units caused by different origins is closer to the actual geological situation and more realistic.

[0157] The embodiments of the present invention have been described above. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments.

Claims

1. A method for evaluating an oil and gas preservation unit, characterized in that Including: Obtaining the structural - sedimentary evolution model of the hydrocarbon preservation unit; Obtaining the caprock characteristics and source rock characteristics of the hydrocarbon preservation unit; Based on the caprock characteristics, obtaining the caprock sealing property, based on the source rock characteristics, obtaining the source rock evaluation result, and based on the structural - sedimentary evolution model, obtaining the key tectonic period; Obtaining the resource amount of hydrocarbon loss; Based on the caprock sealing property, source rock evaluation result, key tectonic period, and the resource amount of hydrocarbon loss, obtaining the hydrocarbon resource amount and resource potential; Evaluating the hydrocarbon preservation unit based on the hydrocarbon resource amount and resource potential; The obtaining of the structural - sedimentary evolution model of the hydrocarbon preservation unit includes: Analyzing the type of the hydrocarbon preservation unit based on the structural - sedimentary evolution model; The types of the hydrocarbon preservation unit include the residual type or the reconstructed type; The obtaining of the caprock sealing property based on the caprock characteristics and the evaluation result based on the source rock characteristics includes: Obtaining the caprock sealing property at the key tectonic period based on the dynamic research of caprock characteristics, obtaining the evaluation result of the secondary hydrocarbon generation amount of the source rock at the key tectonic period based on the source rock characteristics and TSM basin simulation, and obtaining the loss amount result based on the diffusion coefficient experiment; For the reconstructed - type hydrocarbon preservation unit, based on the source rock characteristics and TSM basin simulation, obtaining the source rock maturity and the retained oil amount of the hydrocarbon preservation unit before the key tectonic transformation period, and then obtaining the secondary hydrocarbon generation amount of kerogen and the secondary hydrocarbon generation amount of the retained oil of the hydrocarbon preservation unit after the key tectonic transformation through TSM basin simulation; Obtaining the modified TSM basin simulation based on the source rock maturity and the retained oil; Obtaining the source rock evaluation result based on the parameters in the modified TSM basin simulation; 2. The evaluation method of the oil and gas preservation unit according to claim 1, characterized in that The parameters in the modified TSM basin simulation include: The secondary gas generation amount of kerogen, the late cracking gas amount of the retained oil, the hydrocarbon supply amount estimated based on the migration trend analysis, and the late diffusion loss amount.

3. The evaluation method of the oil and gas preservation unit according to claim 1, wherein The residual - type hydrocarbon preservation unit is: The hydrocarbons generated and migrated and accumulated during the processes of burial, maturation, hydrocarbon generation, hydrocarbon expulsion, and migration and accumulation of the early - stage source rock; The hydrocarbon preservation unit in which the caprock is damaged due to the loss, diffusion loss, and water - soluble loss caused by the later - stage tectonic transformation.

4. The evaluation method of the oil and gas preservation unit according to claim 1, wherein The reconstructed - type hydrocarbon preservation unit is: The hydrocarbons generated and migrated and accumulated during the processes of burial, maturation, hydrocarbon generation, hydrocarbon expulsion, and migration and accumulation of the source rock during the early - stage sedimentary burial process; The hydrocarbon preservation unit that experiences the stop of hydrocarbon generation due to the uplift of the later - stage strata and then experiences sedimentary burial depth exceeding the burial depth.

5. The evaluation method of the oil and gas preservation unit according to claim 1, characterized in that The caprock characteristics include: The dynamic evolution evaluation and analysis of the caprock burial history, caprock diagenetic history, and pore evolution history.

6. The evaluation method of the oil and gas preservation unit according to claim 1, wherein The source rock characteristics include: The source rock burial history, source rock maturation history, source rock hydrocarbon generation history, and hydrocarbon migration and accumulation history.

7. The evaluation method of the oil and gas preservation unit according to claim 1, wherein The resource amount of hydrocarbon loss is: The resource amount of hydrocarbon loss due to tectonic, diffusion, or water - soluble factors.

8. An evaluation device for an oil and gas preservation unit, characterized in that, Including: Model acquisition unit: used to obtain the structural - sedimentary evolution model of the hydrocarbon preservation unit; Characteristic acquisition unit: used to obtain the caprock characteristics and source rock characteristics of the hydrocarbon preservation unit; Characteristic processing unit: used to obtain the caprock sealing property based on the caprock characteristics, obtain the source rock evaluation result based on the source rock characteristics, and obtain the key tectonic period based on the structural - sedimentary evolution model; Resource quantity acquisition unit: used to acquire the resource quantity of hydrocarbon loss; Parameter acquisition unit: used to obtain the hydrocarbon resource quantity and resource potential based on the caprock sealing property, source rock evaluation result, key tectonic period, and the resource quantity of hydrocarbon loss; Evaluation unit: used to evaluate the hydrocarbon preservation unit based on the hydrocarbon resource quantity and resource potential; The structural - sedimentary evolution model for obtaining the hydrocarbon preservation unit includes: Analyzing the type of hydrocarbon preservation unit based on the structural - sedimentary evolution model; The types of the hydrocarbon preservation unit include residual type or reconstructed type; The obtaining of the caprock sealing property based on the caprock characteristics and the evaluation result based on the source rock characteristics includes: Obtaining the caprock sealing property at the key tectonic period through dynamic research on caprock characteristics, obtaining the evaluation result of the secondary hydrocarbon generation quantity of the source rock at the key tectonic period based on source rock characteristics and TSM basin simulation, and obtaining the loss quantity result through diffusion coefficient experiment; For the reconstructed - type hydrocarbon preservation unit, obtaining the maturity of the source rock and the retained oil quantity of the hydrocarbon preservation unit before the key tectonic transformation period based on source rock characteristics and TSM basin simulation, and then obtaining the secondary hydrocarbon generation quantity of kerogen and the secondary hydrocarbon generation quantity of the retained oil in the hydrocarbon preservation unit after the key tectonic transformation through TSM basin simulation; Obtaining the modified TSM basin simulation based on the maturity of the source rock and the retained oil; Obtaining the source rock evaluation result based on the parameters in the modified TSM basin simulation.

Images