Method for estimating carbon release of organic carbon in terrestrial lake basin

Abstract

The application discloses a method for estimating carbon release of organic carbon in a continental lake basin, and relates to the technical field of carbon release data operation processing. The method comprises the following steps: obtaining geological data of a target region; determining source rock data and reservoir data respectively according to the geological data; comparing oil sources by using a chromatograph-mass spectrum comparison method according to the source rock data and the reservoir data, and determining the corresponding relationship between the source rock and the reservoir; simulating the hydrocarbon accumulation dynamics process, and determining hydrocarbon generation rate and hydrocarbon expulsion rate data; and calculating the carbon release amount of the organic carbon in the target region according to the source rock data, the reservoir data, the corresponding relationship between the source rock and the reservoir and the hydrocarbon generation rate and hydrocarbon expulsion rate data. The application can effectively improve the accuracy of estimating the carbon release amount of the organic carbon in the continental lake basin.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of carbon release data operation processing, in particular to a carbon release estimation method of terrestrial lake basin organic carbon. BACKGROUND

[0002] Under the background of global warming, carbon cycle has become a research hotspot in the field of earth science. As an important part of carbon cycle, the storage and release process of carbon in terrestrial ecosystem has a profound impact on global climate. Terrestrial lake basin is an important storage place of carbon in terrestrial ecosystem, and the dynamic change of organic carbon in the lake basin is closely related to global climate change. By calculating the release amount of organic carbon in the terrestrial lake basin, the change of carbon dioxide in the geological history can be reflected, and the corresponding explanation of the climate and environmental change in the geological history can be made, and the reference for modern climate change can be provided.

[0003] At present, the existing calculation methods of the carbon release amount of organic carbon mainly include laboratory simulation method, numerical model method and field monitoring method. Among them, for the laboratory simulation method, such as thermal decomposition experiment, the carbon release amount at different temperatures is determined by heating the sample. Although this laboratory simulation method has the advantages of rapidness and good repeatability, it may not be consistent with the actual geological conditions under high temperature conditions, resulting in inaccurate results of the carbon release amount of organic carbon. For the numerical model method, such as geochemical model, a mathematical model is established to simulate the release process of organic carbon based on the kinetics of geochemical reaction of organic carbon in sedimentary rock. The uncertainty of the model parameters of this numerical model method is large, and a large amount of data is needed to support, otherwise the final result of the carbon release amount of organic carbon will be inaccurate. For the field monitoring method, such as gas flux measurement, the carbon release amount is determined by directly measuring the carbon dioxide flux released from the surface of the sedimentary rock. However, this field monitoring method is greatly affected by environmental factors, and the data fluctuates greatly, and the result of the carbon release amount of organic carbon is also generally inaccurate.

[0004] In summary, the existing calculation methods of the carbon release amount of organic carbon generally have the problem of low accuracy, therefore, how to improve the accuracy of estimating the carbon release amount of organic carbon in the terrestrial lake basin has become a technical problem to be solved in the field. SUMMARY

[0005] The purpose of the present application is to provide a carbon release estimation method of terrestrial lake basin organic carbon, which can effectively improve the accuracy of estimating the carbon release amount of organic carbon in the terrestrial lake basin.

[0006] To achieve the above-mentioned purpose, the present application provides the following solutions:

[0007] The present application provides a carbon release estimation method of terrestrial lake basin organic carbon, which comprises the following steps:

[0008] obtaining geological data of a target area;

[0009] determining source rock data and reservoir data respectively according to the geological data; the source rock data and the reservoir data are respectively used to represent source rock horizon and range and reservoir horizon and range;

[0010] determining the corresponding relationship between the source rock and the reservoir by using a chromatogram-mass spectrum comparison method according to the source rock data and the reservoir data;

[0011] determining hydrocarbon generation rate and hydrocarbon expulsion rate data by simulating hydrocarbon accumulation dynamics;

[0012] calculating carbon release amount of organic carbon in the target area according to the source rock data, the reservoir data, the corresponding relationship between the source rock and the reservoir and the hydrocarbon generation rate and hydrocarbon expulsion rate data.

[0013] Optionally, the source rock data and the reservoir data are determined according to the geological data, and specifically include the following steps:

[0014] defining source rock horizon and its spatial distribution profile of the target area and analyzing hydrocarbon generation and expulsion history of the source rock according to geochemical data and logging curve data in the geological data, and obtaining the source rock data;

[0015] dividing and detecting the reservoir of the target area according to geochemical data in the geological data, and obtaining the reservoir data.

[0016] Optionally, the corresponding relationship between the source rock and the reservoir is determined by using a chromatogram-mass spectrum comparison method according to the source rock data and the reservoir data, and specifically includes the following steps:

[0017] determining chromatogram and mass spectrum of various biomarker compounds in crude oil in the target area according to the source rock data and the reservoir data;

[0018] determining the influence of different source rock types and thermal evolution degree on crude oil composition by analyzing chromatographic characteristics and mass spectral characteristics of various biomarker compounds in crude oil by using a chromatogram-mass spectrum comparison method according to the chromatogram and mass spectrum of various biomarker compounds in crude oil in the target area, and comparing retention time, mass spectral characteristics and relative abundance of various biomarker compounds respectively, identifying the type, maturity and generation process of oil source rock in the source rock, realizing oil source correlation, tracing the source of oil and gas, and determining the corresponding relationship between the source rock and the reservoir.

[0019] Optionally, the hydrocarbon accumulation dynamics process can be simulated to determine the hydrocarbon generation and expulsion rates, specifically including the following steps:

[0020] The BaseinMod software was used to simulate the hydrocarbon accumulation dynamics process to determine the hydrocarbon generation and expulsion history, tectonic subsidence history, burial history, thermal evolution history and hydrocarbon charging history, and to determine the hydrocarbon distribution characteristics and patterns.

[0021] Based on the oil and gas distribution characteristics and patterns, the hydrocarbon generation and expulsion history is reconstructed to obtain the hydrocarbon generation rate and hydrocarbon expulsion rate data.

[0022] Optionally, based on the source rock data, the reservoir data, the correspondence between the source rock and the reservoir, and the hydrocarbon generation and expulsion rate data, the carbon release of organic carbon in the target area is calculated, specifically including the following steps:

[0023] Based on the source rock data, the reservoir data, the correspondence between the source rock and the reservoir, and the hydrocarbon generation rate and hydrocarbon expulsion rate data, the total hydrocarbon generation of the source rock and the geological reserves of the reservoir are calculated respectively.

[0024] Calculate the total hydrocarbon release based on the total hydrocarbon generation from the source rock and the geological reserves of the reservoir.

[0025] Based on the total hydrocarbon release and the source rock data, the organic carbon content of the total hydrocarbons released into the environment is calculated.

[0026] The carbon release amount of organic carbon in the target area is calculated based on the total hydrocarbon release amount and the organic carbon content of the total hydrocarbons released into the environment.

[0027] Optionally, the total hydrocarbon generation from the source rock can be calculated using the following formula:

[0028] Q = S × H × ρ × TOC 残留 ×K c ×β×10 -3 ;

[0029] K c =TOC 原始 / TOC 残留 ;

[0030] Where Q is the total hydrocarbon generation from the source rock; S is the area of ​​the source rock; H is the thickness of the source rock; ρ is the density of the source rock; TOC 残留 This represents the current organic carbon content; TOC 原始 Initial organic carbon content; K c β is the organic carbon recovery coefficient; β is the hydrocarbon production rate.

[0031] Optionally, the reservoir geological reserves include crude oil geological reserves and natural gas geological reserves.

[0032] The crude oil geological reserves and the natural gas geological reserves are respectively calculated by the following formula:

[0033]

[0034] Wherein, N is the crude oil geological reserves; G is the natural gas geological reserves; A is the oil / gas bearing area; h is the effective thickness of the oil / gas layer; is the effective porosity of the oil / gas layer; S oi is the original oil saturation of the oil layer; S gi is the original gas saturation of the gas layer; ρ o is the density of the degassed crude oil on the ground; B oi is the volume coefficient of the original crude oil; B gi is the volume coefficient of the original natural gas.

[0035] Optionally, the total amount of hydrocarbon released is calculated by the following formula:

[0036] T = Q - N(G);

[0037] Wherein, T is the total amount of hydrocarbon released; Q is the total hydrocarbon generation amount of the source rock; N is the crude oil geological reserves; G is the natural gas geological reserves.

[0038] Optionally, the organic carbon content of the total hydrocarbon released into the environment is calculated by the following formula:

[0039] TOC 释放 = T / (S x H x ρ x K c x β x 10 -3 );

[0040] Wherein, TOC 释放 is the organic carbon content of the total hydrocarbon released into the environment; T is the total amount of hydrocarbon released; S is the area of the source rock; H is the thickness of the source rock; ρ is the density of the source rock; K c is the recovery coefficient of organic carbon; β is the hydrocarbon generation rate.

[0041] Optionally, the total carbon release amount of the organic carbon in the target area is calculated by the following formula:

[0042] C = TOC 释放 x T;

[0043] Wherein, T is the total amount of hydrocarbon released; TOC 释放 is the organic carbon content of the total hydrocarbon released into the environment; C is the total carbon release amount.

[0044] According to the specific embodiments provided in the present application, the present application has the following technical effects:

[0045] The application provides a carbon release estimation method for organic carbon in a continental lake basin. First, source rock data and reservoir data are determined according to geological data, and then oil source correlation is compared by using a chromatogram-mass spectrum comparison method, so as to determine the corresponding relationship between the source rock and the reservoir. Then, the hydrocarbon generation rate and the hydrocarbon expulsion rate data are determined by simulating the hydrocarbon accumulation dynamics process. Finally, the carbon release amount of the target region is calculated according to the source rock data, the reservoir data, the corresponding relationship between the source rock and the reservoir, and the hydrocarbon generation rate and the hydrocarbon expulsion rate data. The carbon release amount of the continental lake basin region can be systematically and comprehensively estimated. The processes of oil and gas generation, migration, storage and discharge in the continental lake basin region are comprehensively considered, the accuracy of estimating the carbon release amount of the organic carbon in the continental lake basin can be effectively improved, the limitations and low precision of the laboratory simulation method, the numerical model method and the field monitoring method are solved, and the development of carbon release analysis, ecological balance and environmental protection in the continental lake basin region is facilitated. BRIEF DESCRIPTION OF DRAWINGS

[0046] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed in the embodiments will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0047] Figure 1 It is an application environment diagram of a carbon release estimation method for organic carbon in a continental lake basin according to an embodiment of the present application.

[0048] Figure 2 It is a flowchart of a carbon release estimation method for organic carbon in a continental lake basin according to an embodiment of the present application.

[0049] Figure 3 It is a judgment flowchart of whether carbon is released under stratum uplift and denudation according to an embodiment of the present application. DETAILED DESCRIPTION

[0050] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.

[0051] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the present application will be further described in detail below with reference to the drawings and specific embodiments.

[0052] The land facies lake basin organic carbon carbon release estimation method provided in the embodiments of the present application can be applied in the application environment as shown in Figure 1 The terminal 102 communicates with the server 104 through a network. The data storage system can store geological data required to be processed by the server 104. The data storage system can be separately arranged, integrated on the server 104, or placed on a cloud or other server. The terminal 102 can send the geological data to be processed to the server 104. After receiving the geological data to be processed, the server 104 determines hydrocarbon source rock data and reservoir data according to the geological data. The server 104 compares the oil source by using a chromatogram-mass spectrum comparison method according to the hydrocarbon source rock data and the reservoir data, determines the corresponding relationship between the hydrocarbon source rock and the reservoir, simulates the oil and gas accumulation dynamics process, and determines the hydrocarbon generation rate and the hydrocarbon expulsion rate data. The server 104 calculates the carbon release amount of the organic carbon in the target area according to the hydrocarbon source rock data, the reservoir data, the corresponding relationship between the hydrocarbon source rock and the reservoir, and the hydrocarbon generation rate and the hydrocarbon expulsion rate data. The server 104 can feed back the carbon release amount of the organic carbon in the target area to the terminal 102. In addition, in some embodiments, the land facies lake basin organic carbon carbon release estimation method can also be implemented by the server 104 or the terminal 102 alone. For example, the terminal 102 can directly calculate the carbon release amount of the geological data to be processed, or the server 104 can obtain the geological data to be processed from the data storage system and calculate the carbon release amount of the geological data to be processed.

[0053] The terminal 102 can be, but is not limited to, various desktop computers, notebook computers, smart phones, tablet computers, Internet of Things devices, and portable wearable devices. The Internet of Things device can be a smart speaker, a smart television, a smart air conditioner, a smart vehicle device, etc. The portable wearable device can be a smart watch, a smart bracelet, a head-mounted device, etc. The server 104 can be implemented by an independent server or a server cluster composed of multiple servers, and can also be a cloud server.

[0054] In an exemplary embodiment, as shown in Figure 2 A land facies lake basin organic carbon carbon release estimation method is provided. The method is executed by a computer device, specifically by a terminal or a server, or by both a terminal and a server. In the embodiments of the present application, the method is applied to the server 104 in Figure 1 The following steps S1 to S5 are included. Wherein:

[0055] Step S1, obtaining geological data of a target area.

[0056] In this embodiment, the geological data of the target region can be obtained by geological monitoring of the target region. The geological data includes but is not limited to geochemical data, well logging curve data and various types of data.

[0057] In step S2, the source rock data and reservoir data are determined respectively according to the geological data.

[0058] In this embodiment, the source rock data and reservoir data are determined respectively according to the geological data in step S2, which specifically includes the following steps:

[0059] In step S21, the source rock horizon and its spatial distribution profile of the target region are defined according to the geochemical data and well logging curve data in the geological data, and the hydrocarbon generation and expulsion history of the source rock is analyzed to obtain the source rock data.

[0060] In step S22, the reservoirs in the target region are divided and detected according to the geochemical data in the geological data to obtain the reservoir data.

[0061] The step S2 in this embodiment is mainly used to determine the source rock data and reservoir data, and the source rock data is mainly related to the parameters of the source rock horizon and range. Based on the geochemical data and well logging curve information, the source rock horizon and its spatial distribution profile are accurately defined, the hydrocarbon generation and expulsion history is deeply analyzed, the carbon release node is determined, and the foundation for calculating the total hydrocarbon generation amount of the source rock is built. Specifically, the horizon and lower limit of the source rock are accurately anchored by using geochemical data, and then the distribution range and effective thickness thereof are clarified; by means of backtracking of the hydrocarbon generation and expulsion history, the hydrocarbon generation and expulsion ratios at different sedimentary stages are obtained, thereby providing key parameter support for comprehensively mastering the hydrocarbon generation potential and dynamic process of the source rock, and ensuring the accuracy and scientificity of subsequent calculation of the total hydrocarbon generation amount of the source rock.

[0062] In this embodiment, the horizon and lower limit of the source rock are accurately anchored by using geochemical data, and the specific process and indexes of accurate anchoring are as follows:

[0063] (1) Organic matter abundance index:

[0064] (1) Total organic carbon (TOC): By analyzing the TOC of rock samples at different horizons, a curve of TOC change with depth or horizon can be drawn. The horizon where the TOC content significantly increases and reaches a certain threshold in the curve can be preliminarily determined as the source rock horizon.

[0065] Chloroform bitumen "A": Combined with TOC analysis, if the content of chloroform bitumen "A" at a certain horizon is high and has a good positive correlation with TOC, it can further prove that the horizon is a source rock.

[0066] Hydrocarbon-generating potential (Pg): Obtained by rock pyrolysis experiment, representing the potential amount of hydrocarbons that can be generated in source rocks. Higher Pg values usually correspond to the layer where source rocks are developed.

[0067] (2) Organic matter maturity indicators:

[0068] Vitrinite reflectance (Ro): According to the change of Ro value with depth or layer, the layer and depth limit of source rocks entering the hydrocarbon generation stage can be determined.

[0069] Pyrolysis peak temperature (Tmax): Tmax value is positively correlated with organic matter maturity. Layers with higher Tmax values may be the layer where source rocks with higher maturity are located.

[0070] (3) Biomarker indicators:

[0071] Normal alkane distribution: Different sources and sedimentary environments of source rocks have different distribution characteristics of normal alkane. For example, source rocks dominated by aquatic organisms are usually dominated by low-carbon number normal alkane, while source rocks dominated by terrestrial higher plants are relatively rich in high-carbon number normal alkane. By analyzing the carbon number distribution and main peak carbon position of normal alkane, the type and sedimentary environment of source rocks can be determined, which can assist in determining the layer of source rocks.

[0072] Steranes and terpanes: Their composition and distribution have strong biological source specificity. For example, the relative content and isomerization degree of regular steranes can reflect the maturity and source of organic matter, and the gamma wax index can indicate the salinity of the sedimentary environment. By using the characteristics of these indicators, different layers of source rocks can be distinguished and their layer attribution can be determined.

[0073] The present embodiment obtains the hydrocarbon generation and expulsion rates of different sedimentary stages by backtracking the hydrocarbon generation and expulsion history. Specifically, different lithological compositions are formed based on the diversity of sedimentary environments, which in turn results in different organic matter abundances and occurrences, forming different hydrocarbon generation patterns. The source rock in a salinization environment has the characteristics of efficient hydrocarbon generation and expulsion. According to the recovery results of the paleosalinity and the comprehensive analysis of the paleoclimate environment, the appropriate salinity range makes the biological explosion, and the paleoproductivity level is significantly improved to reach the super eutrophication level. Stable terrigenous organic matter input and high paleoproductivity provide the material basis for the formation of source rock, and the intermittent reducing environment provides the guarantee for the formation of high-quality source rock. The fresh water environment mainly generates high-wax content light to medium mature oil and a small amount of low mature oil. The high-quality source rock has strong hydrocarbon generation capacity, and at the same evolution stage, it has high hydrocarbon content, providing more material basis for hydrocarbon expulsion, and the hydrocarbon generation pressurization is an effective mechanism for the formation of abnormal pressure. In terms of lithology, high-quality source rock has high plasticity, is easy to form undercompaction, and is also conducive to the formation of abnormal flow pressure. At the same time, the lamination and organic network of high-quality source rock are developed, which is conducive to the formation of good migration channels, making the hydrocarbon expulsion conditions more sufficient. The hydrocarbon expulsion of source rock is jointly determined by the basin evolution and its own characteristics. If the same basin evolution conditions are experienced, the nature of the source rock itself becomes an important factor affecting the expulsion, so each set of source rock also has a different expulsion pattern.

[0074] In the present embodiment, the reservoirs are divided by core observation, thin section observation, resistivity logging, acoustic time difference logging, seismic facies analysis and geochemical logging, so as to obtain reservoir data.

[0075] In the present embodiment, the source rock data mainly includes various parameters related to source rock, for characterizing the source rock horizon and range. The source rock data mainly includes source rock area, source rock thickness, source rock density, current organic carbon content and initial organic carbon content. The reservoir data mainly includes various parameters related to reservoirs, such as oil / gas area, oil / gas layer effective thickness, oil / gas layer effective porosity, oil layer original oil saturation, gas layer original gas saturation, surface degassed crude oil density, original crude oil volume coefficient and original natural gas volume coefficient.

[0076] Step S3, according to the source rock data and the reservoir data, oil source correlation is carried out by chromatogram mass spectrum comparison method to determine the corresponding relationship between the source rock and the reservoir.

[0077] In the present embodiment, step S3 determines the corresponding relationship between the source rock and the reservoir by oil source correlation according to the source rock data and the reservoir data by chromatogram mass spectrum comparison method, specifically including the following steps:

[0078] Step S31, according to the hydrocarbon source rock data and the reservoir data, determining the chromatogram and mass spectrum of various biomarker compounds in the crude oil in the target area.

[0079] Step S32, according to the chromatogram and mass spectrum of various biomarker compounds in the crude oil in the target area, using the chromatogram-mass spectrum comparison method, analyzing the chromatographic characteristics and mass spectral characteristics of various biomarker compounds in the crude oil, determining the influence of different hydrocarbon source rock types and thermal evolution degree on the composition of the crude oil, and comparing the retention time, mass spectral characteristics and relative abundance of various biomarker compounds respectively, identifying the type, maturity and generation process of the oil source rock in the hydrocarbon source rock, realizing oil source correlation, and tracing the source of oil and gas, and determining the corresponding relationship between the hydrocarbon source rock and the reservoir.

[0080] The chromatogram-mass spectrum comparison method is a method for comparing chromatograms and mass spectra to determine the influence of different hydrocarbon source rock types and thermal evolution degree on the composition of the crude oil. Through the process of oil source correlation, the organic geochemical indicators such as biomarker compounds are analyzed, and different oil sources are accurately compared, so as to ensure the accurate relationship between each hydrocarbon source rock and the corresponding reservoir. On this premise, two key geological phenomena can be clearly identified: one is "one source and multiple storage", that is, the hydrocarbons generated by the same layer of hydrocarbon source rock are distributed and gathered in multiple reservoirs; the other is "one reservoir and multiple sources", that is, the hydrocarbons in one reservoir are derived from multiple different hydrocarbon source rocks.

[0081] In this embodiment, the organic geochemical indicators such as biomarker compounds are analyzed, which specifically includes the following analysis steps:

[0082] 1) Geochemical indicators:

[0083] Carbon isotope: The carbon isotope composition of organic matter of different sources is different. Generally speaking, the carbon isotope of marine-derived organic matter is relatively heavy, and the carbon isotope of terrestrial-derived organic matter is relatively light. By comparing the carbon isotope values of crude oil and source rock, if they are close, it may indicate the same source.

[0084] n-alkanes: The carbon number distribution range, main peak carbon number and distribution pattern of n-alkanes can be used as "fingerprint" for oil source correlation. The n-alkanes in the organic matter of clastic rock series rich in terrigenous material are mainly C27, C29 and C31, with odd-even advantage, while the n-alkanes from aquatic organisms are mainly C15 and C17, with no obvious odd-even advantage.

[0085] 2) Common biomarker compounds

[0086] Sterane compounds:

[0087] Source and structural characteristics document download: C27 steranes are mainly derived from algae and other lower plankton, C28 is mainly derived from diatom, C29 is derived from higher plants or algae. It has a specific tetracyclic steroidal nucleus structure, which is relatively stable in the process of geological evolution.

[0088] 3) Oil source correlation application: analyze the carbon number distribution and isomerization parameters of steranes in crude oil and possible source rocks. For example, if C27 steranes dominate in the crude oil, and the C27 sterane content in a certain source rock is also high, and other related parameters also match, it may indicate that the crude oil has a close relationship with the source rock. In addition, the maturity of organic matter can also be reflected by the isomerization parameters such as 20S / (20S+20R) of steranes, and similar maturity is also an important basis for oil source correlation.

[0089] 4) Analysis method

[0090] Gas chromatography (GC): can separate and analyze various organic compounds in oil, get the carbon number distribution curve of n-alkanes and other compounds, and judge the similarity of oil sources by comparing the shape of the curve, the carbon position of the main peak, etc.

[0091] Gas chromatography-mass spectrometry (GC-MS): can more accurately identify and quantify biomarker compounds. The specific types and relative contents of biomarker compounds such as steranes and terpanes can be analyzed, providing more abundant and accurate data for oil source correlation.

[0092] In this embodiment, in the sterane series compounds, the relative abundance of C27, C28 and C29 regular steranes can indicate the parent input of organic matter in the source rock. The principle of using the relative content of n-alkanes in source rocks and crude oil for oil source correlation is that due to the differences in organic matter type and thermal evolution degree of different source rocks, the distribution characteristics of n-alkanes generated in crude oil are unique. By comparing the relative content of n-alkanes in different oil reservoirs, the source of the crude oil can be inferred, and the same or different source rocks can be distinguished, thereby providing a strong basis for oil source analysis and oil and gas exploration work.

[0093] This embodiment uses chromatograms and mass spectra to carry out oil source correlation. By deeply analyzing the chromatographic characteristics and mass spectral characteristics of biomarker compounds in crude oil, the influence of different types of source rocks and thermal evolution degree on the composition of crude oil is revealed. Crude oil from different sources has characteristic biomarker compound spectra (including chromatograms and mass spectra). By comparing the retention time, mass spectrum and relative abundance of various biomarker compounds in the crude oil sample, the type, maturity and generation process of the source rock can be identified, thereby realizing oil source correlation and tracing the source of oil and gas.

[0094] Step S4, simulate the oil and gas accumulation dynamics process to determine the data of hydrocarbon generation rate and hydrocarbon expulsion rate.

[0095] In this embodiment, step S4 simulates the hydrocarbon accumulation dynamics process to determine the hydrocarbon generation rate and expulsion rate data, specifically including the following steps:

[0096] Step S41, the BasinMod software is used to simulate the hydrocarbon accumulation dynamics process to determine the hydrocarbon generation and expulsion history, tectonic subsidence history, burial history, thermal evolution history and oil and gas charging history, and determine the oil and gas distribution characteristics and mode.

[0097] Step S42, based on the oil and gas distribution characteristics and mode, the hydrocarbon generation and expulsion history is restored to obtain the hydrocarbon generation rate and expulsion rate data.

[0098] The step S4 of this embodiment is mainly the simulation of hydrocarbon accumulation dynamics. The BasinMod software is used to simulate the hydrocarbon accumulation dynamics process to accurately determine the hydrocarbon generation and expulsion history, tectonic subsidence history, burial history, thermal evolution history and oil and gas charging history, and further determine the oil and gas distribution characteristics and mode. Specifically, by restoring the hydrocarbon generation and expulsion history, the hydrocarbon generation rate and expulsion rate data of different sedimentary stages can be accurately obtained. In the process of reconstructing the tectonic subsidence history and burial history, it is determined whether the stratum uplift and erosion phenomenon occurs in a specific period. At the same time, by restoring the thermal evolution history and oil and gas charging history, it can be determined whether the source rock meets the hydrocarbon generation condition and whether the oil and gas reservoir is subjected to uplift and erosion, thereby providing a solid theoretical basis and scientific guidance for oil and gas exploration and development.

[0099] Step S5, according to the source rock data, the reservoir data, the correspondence between the source rock and the reservoir and the hydrocarbon generation rate and expulsion rate data, the carbon release amount of the organic carbon in the target area is calculated.

[0100] The step S5 of this embodiment is mainly to calculate the carbon release amount. On the basis of the source rock data and reservoir data obtained in step S2, the correspondence between the source rock and the reservoir obtained in step S3 and the hydrocarbon generation rate and expulsion rate data obtained in step S4, the carbon release amount of the organic carbon in the target area is calculated.

[0101] After the source rock generates and expels hydrocarbon, the organic carbon migrates into the reservoir to form a hydrocarbon reservoir. For the case without stratum uplift and erosion, the difference between the total hydrocarbon generation amount of the source rock and the geological reserves of the reservoir is the amount of hydrocarbon discharged to the environment during migration, and the carbon release amount can be obtained by inverse calculation. The carbon released to the air is mainly the carbon lost to the air through faults during oil and gas migration, so the difference between the hydrocarbon in the source rock and the reservoir is the amount of hydrocarbon released.

[0102] In this embodiment, by restoring the burial history and tectonic subsidence history, the evolution process of the stratum can be reconstructed, so that the stratum which has experienced uplift and denudation in the geological history can be identified. In combination with the thermal evolution history and the hydrocarbon accumulation process, it can be further judged whether the source rock and the reservoir have experienced denudation. If the source rock has already generated hydrocarbon or the reservoir has experienced uplift and denudation, there will be carbon release, and if there is no uplift and denudation, there will be no carbon release. The judgment process of whether there is carbon release under the stratum uplift and denudation is shown in Figure 3 , wherein the stratum uplift and denudation mainly considers the source rock and the reservoir, and when the source rock has already generated hydrocarbon (thermal evolution), it is judged that there is carbon release, otherwise, it is judged that there is no carbon release. When judging whether the reservoir has experienced denudation, if the reservoir has already accumulated oil and gas (experienced uplift and denudation), it is judged that there is carbon release, otherwise, it is judged that there is no carbon release.

[0103] On the basis of the source rock data, the reservoir data, the corresponding relationship between the source rock and the reservoir, and the data of the hydrocarbon generation rate and the hydrocarbon expulsion rate, in combination with the volumetric method and the parameters such as the organic carbon recovery coefficient and the hydrocarbon production rate, the total hydrocarbon generation amount of the source rock and the geological reserves of the reservoir can be calculated. Through the difference between the total hydrocarbon generation amount of the source rock and the geological reserves of the reservoir, the total hydrocarbon release amount can be obtained, and further calculation can estimate the carbon release amount of the organic carbon in the target region, that is, the total carbon release amount.

[0104] Therefore, the step S5 specifically includes the following steps.

[0105] Step S51, according to the source rock data, the reservoir data, the corresponding relationship between the source rock and the reservoir, and the data of the hydrocarbon generation rate and the hydrocarbon expulsion rate, the total hydrocarbon generation amount of the source rock and the geological reserves of the reservoir are calculated respectively. The geological reserves of the reservoir include the geological reserves of crude oil and the geological reserves of natural gas.

[0106] In this embodiment, the calculation formula of the total hydrocarbon generation amount of the source rock is:

[0107] Q=S×H×ρ×TOC 残留 ×K c ×β×10 -3 (1)。

[0108] K c =TOC 原始 / TOC 残留 (2)。

[0109] Wherein, Q is the total hydrocarbon generation amount of the source rock, the unit is kg or m 3 ; S is the source rock area, the unit is m 2 ; H is the source rock thickness, the unit is m; ρ is the source rock density, the unit is kg / m 3 ; TOC 残留TOC is the current organic carbon content, a decimal number; TOC 原始 K is the initial organic carbon content, a decimal number; K c β is the recovery coefficient of organic carbon, which can be obtained by calculating Ro, and has no unit; β is the hydrocarbon production rate, which is derived from the data of hydrocarbon generation rate and hydrocarbon expulsion rate, and has the unit of kg / tTOC or m 3 / tTOC.

[0110] In this embodiment, the data of hydrocarbon generation rate and hydrocarbon expulsion rate are mainly used to determine the hydrocarbon production rate and the like. The hydrocarbon generation rate refers to the rate of hydrocarbon generated by the source rock per unit time. The hydrocarbon expulsion rate refers to the ratio of the amount of hydrocarbon expelled to the amount of hydrocarbon generated. Since the hydrocarbon expulsion rate is equal to the ratio of the amount of hydrocarbon expelled to the amount of hydrocarbon generated, the hydrocarbon production rate refers to the hydrocarbon generation capacity of the source rock, which is an important parameter for calculating the amount of hydrocarbon generated. Therefore, the hydrocarbon production rate is closely related to the data of hydrocarbon generation rate and hydrocarbon expulsion rate. In this embodiment, the value of the hydrocarbon production rate can be obtained according to the data of hydrocarbon generation rate and hydrocarbon expulsion rate, so as to calculate the total amount of hydrocarbon generated by the source rock and the like.

[0111] In this embodiment, since the reservoir geological reserves include crude oil geological reserves and natural gas geological reserves, the calculation formulae of the crude oil geological reserves and the natural gas geological reserves in the reservoir geological reserves are respectively as follows:

[0112]

[0113] N is the crude oil geological reserves, with the unit of 10 4 t; G is the natural gas geological reserves, with the unit of 10 8 m 3 ; A is the oil / gas bearing area, with the unit of km 2 ; h is the effective thickness of the oil / gas layer, with the unit of m; S is the effective porosity of the oil / gas layer, a decimal number; S oi S is the original oil saturation of the oil layer, a decimal number; S gi S is the original gas saturation of the gas layer, a decimal number; ρ o is the density of the degassed crude oil on the ground, with the unit of t / m 3 ; B oi is the original crude oil volume coefficient, without unit; B gi is the original natural gas volume coefficient, without unit.

[0114] In step S52, the total amount of hydrocarbon released is calculated according to the total amount of hydrocarbon generated by the source rock and the reservoir geological reserves.

[0115] In this embodiment, the calculation formula of the total amount of hydrocarbon released is as follows:

[0116] T=Q-N(G) (5).

[0117] T is the total amount of hydrocarbon released, with the unit of kg or m3 ; Q is the total hydrocarbon generation amount of the source rock, in kg or m 3 ; N is the geological reserves of crude oil, in 10 4 t; G is the geological reserves of natural gas, in 10 8 m 3 .

[0118] It should be noted that in this embodiment, the total amount of hydrocarbon release is calculated by the difference between the total hydrocarbon generation amount of the source rock and the geological reserves of the reservoir, and the geological reserves of the reservoir in the target area of this embodiment include both the geological reserves of crude oil and the geological reserves of natural gas, i.e., the geological reserves of crude oil and natural gas. Therefore, when calculating the total amount of hydrocarbon release by using formula (5), the difference between the total hydrocarbon generation amount of the source rock and the geological reserves of crude oil, and the difference between the total hydrocarbon generation amount of the source rock and the geological reserves of natural gas can be calculated respectively, and then the total amount of hydrocarbon release is obtained by comprehensively considering the two aspects. In addition, the geological reserves of crude oil and natural gas in the reservoir corresponding to one of them and the total amount of hydrocarbon release can be calculated according to actual needs.

[0119] Step S53, according to the total amount of hydrocarbon release and the source rock data, the organic carbon content of the total hydrocarbon released into the environment is calculated.

[0120] In this embodiment, the calculation formula of the organic carbon content of the total hydrocarbon released into the environment is:

[0121] TOC 释放 = T / (S x H x p x K c x b x 10 -3 ) (6).

[0122] Wherein, TOC 释放 is the organic carbon content of the total hydrocarbon released into the environment, which is a decimal number; T is the total amount of hydrocarbon release, in kg or m 3 ; S is the area of the source rock, in m 2 ; H is the thickness of the source rock, in m; p is the density of the source rock, in kg / m 3 ; K c is the organic carbon recovery coefficient, which can be calculated from Ro, and has no unit; b is the hydrocarbon generation rate, in kg / tTOC or m 3 / tTOC.

[0123] Step S54, according to the total amount of hydrocarbon release and the organic carbon content of the total hydrocarbon released into the environment, the carbon release amount of the organic carbon in the target area is calculated.

[0124] In this embodiment, the calculation formula of the carbon release amount of the organic carbon in the target area (i.e., the total amount of carbon release) is:

[0125] C = TOC 释放 x T (7).

[0126] wherein T is the total amount of hydrocarbon released, in kg or m 3 ; TOC 释放 is the organic carbon content of the total hydrocarbon released into the environment, which is a decimal number; C is the total amount of carbon released, in kg or m 3 .

[0127] The embodiment can systematically and comprehensively estimate the carbon release amount in the continental lacustrine basin area by determining the hydrocarbon source rock horizon and range, oil source correlation, oil and gas accumulation dynamics simulation and carbon release amount calculation formula, accurately positioning, focusing on the carbon release amount in a certain area, high accuracy, and comprehensively considering the processes of oil and gas generation, migration, accumulation and discharge in the continental lacustrine basin area, which can effectively improve the accuracy of estimating the carbon release amount of organic carbon in the continental lacustrine basin, and is beneficial to the development of carbon release analysis, ecological balance and environmental protection in the continental lacustrine basin area.

[0128] The technical features of the above embodiments can be combined arbitrarily, and to make the description concise, all possible combinations of the technical features in the above embodiments are not described, however, as long as the combinations of the technical features do not exist contradictory, they should be considered as the scope of the present application.

[0129] The principles and implementation modes of the present application are described by applying specific examples in the present application, and the above embodiment description is only used to help understand the method of the present application and its core idea; at the same time, for those skilled in the art, according to the idea of the present application, the specific implementation mode and application range will be changed. In conclusion, the content of the present application should not be understood as a limitation.

Claims

1. A method for estimating carbon release of organic carbon in a terrestrial lake basin, characterized by, The method for estimating carbon release of organic carbon in the continental lake basin comprises the following steps: Obtaining geological data of a target area; According to the geological data, determining source rock data and reservoir data respectively; the source rock data and the reservoir data are respectively used to represent the horizons and ranges of source rocks and reservoirs; According to the source rock data and the reservoir data, oil-source correlation is carried out by using a chromatogram-mass spectrum comparison method to determine the corresponding relationship between the source rocks and the reservoirs; Simulating the process of oil and gas accumulation dynamics to determine the data of hydrocarbon generation rate and hydrocarbon expulsion rate; wherein, the process of oil and gas accumulation dynamics is simulated by using the BasinMod software to determine the history of hydrocarbon generation and expulsion, the history of tectonic subsidence, the history of burial, the history of thermal evolution and the history of oil and gas filling, and to determine the characteristics and patterns of oil and gas distribution; based on the characteristics and patterns of oil and gas distribution, the history of hydrocarbon generation and expulsion is restored to obtain the data of hydrocarbon generation rate and hydrocarbon expulsion rate; According to the source rock data, the reservoir data, the corresponding relationship between the source rocks and the reservoirs and the data of hydrocarbon generation rate and hydrocarbon expulsion rate, the amount of carbon release of organic carbon in the target area is calculated; wherein, according to the source rock data, the reservoir data, the corresponding relationship between the source rocks and the reservoirs and the data of hydrocarbon generation rate and hydrocarbon expulsion rate, the total hydrocarbon generation amount of source rocks and the geological reserves of reservoirs are calculated respectively; according to the total hydrocarbon generation amount of source rocks and the geological reserves of reservoirs, the total amount of hydrocarbon release is calculated; according to the total amount of hydrocarbon release and the source rock data, the organic carbon content of total hydrocarbon released into the environment is calculated; according to the total amount of hydrocarbon release and the organic carbon content of total hydrocarbon released into the environment, the amount of carbon release of organic carbon in the target area is calculated.

2. The method according to claim 1, wherein, According to the geological data, the source rock data and the reservoir data are determined respectively, specifically comprising: According to the geochemical data and logging curve data in the geological data, the horizons and spatial distribution profiles of source rocks in the target area are defined, and the processes of hydrocarbon generation and expulsion of source rocks are analyzed to obtain the source rock data; According to the geochemical data in the geological data, the reservoirs in the target area are divided and detected to obtain the reservoir data.

3. The method according to claim 1, wherein, According to the source rock data and the reservoir data, oil-source correlation is carried out by using a chromatogram-mass spectrum comparison method to determine the corresponding relationship between the source rocks and the reservoirs, specifically comprising: According to the source rock data and the reservoir data, the chromatograms and mass spectra of various biomarker compounds in crude oil in the target area are determined; According to the chromatograms and mass spectra of various biomarker compounds in crude oil in the target area, the chromatographic characteristics and mass spectral characteristics of various biomarker compounds in crude oil are analyzed by using a chromatogram-mass spectrum comparison method to determine the influence of different source rock types and thermal evolution degrees on the composition of crude oil, and the retention time, mass spectral characteristics and relative abundance of various biomarker compounds are compared respectively to identify the types, maturity and generation process of oil-source rocks in source rocks, realize oil-source correlation, trace the source of oil and gas, and determine the corresponding relationship between the source rocks and the reservoirs.

4. The method according to claim 1, wherein, The total hydrocarbon generation amount of source rocks is calculated by using the following formula: Q ＝ S × H × ρ × TOC 残留 × Kc × β ×10 -3 ； K c ＝ TOC 原始 / TOC 残留 ； wherein, Q is the total hydrocarbon generation amount of the source rock; S is the source rock area; H is the source rock thickness; ρ is the source rock density; TOC 残留 is the current organic carbon content; TOC 原始 is the initial organic carbon content; K c is the organic carbon recovery coefficient; β is the hydrocarbon generation rate.

5. The method according to claim 4, wherein, The reservoir geological reserves include crude oil geological reserves and natural gas geological reserves; The crude oil geological reserves and the natural gas geological reserves are respectively calculated by using the following formula: N ＝100× A × h × φ × S oi × ρ o / B oi ； G ＝0.01× A × h × φ × S gi / B gi ； wherein, N is the geological reserves of crude oil; G is the geological reserves of natural gas; A is the oil / gas-bearing area; h is the effective thickness of the oil / gas layer; φ is the effective porosity of the oil / gas layer; S oi is the original oil saturation of the oil layer; S gi is the original gas saturation of the gas layer; ρ o is the density of the surface degassed crude oil; B oi is the original crude oil volume coefficient; B gi is the original natural gas volume coefficient.

6. The method according to claim 5, wherein, The total amount of the released hydrocarbons is calculated by using the following formula: T ＝ Q － N ( G )； wherein, T is the total amount of hydrocarbons released; Q is the total amount of hydrocarbons generated from the source rock; N is the geological reserves of crude oil; G is the geological reserves of natural gas.

7. The method according to claim 6, wherein, The organic carbon content of the total hydrocarbons released into the environment is calculated by using the following formula: TOC release = T ( S x H x ρ x Kc x β x 10 -3 ); wherein, TOC 释放 is the organic carbon content of the total hydrocarbons released to the environment; T is the total amount of hydrocarbons released; S is the area of the source rock; H is the thickness of the source rock; ρ is the density of the source rock; K c is the recovery coefficient of the organic carbon; β is the hydrocarbon production rate.

8. The method according to claim 7, wherein, The carbon release amount of the organic carbon in the target area is calculated by using the following formula: C ＝ TOC 释放 × T ； wherein, T is the total amount of hydrocarbons released; TOC 释放 is the organic carbon content of the total hydrocarbons released to the environment; C is the total amount of carbon released.

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