1. The method for evaluating the residual hydrocarbon content of the marine high-over-mature hydrocarbon source rock is characterized by comprising the following steps of:

s100, establishing a hydrocarbon potential evolution section diagram and a hydrocarbon source rock hydrogen index evolution section diagram of the over-mature hydrocarbon source rock;

s200, determining hydrocarbon expulsion critical conditions of over-mature source rocks, and inverting the original hydrocarbon generation potential of the source rocks;

step S300, inverting hydrocarbon-generating critical conditions of over-mature hydrocarbon source rocks;

s400, establishing a model of the residual hydrocarbons generated and discharged by the over-mature hydrocarbon source rock;

step S500, determining the hydrocarbon generation rate, the hydrocarbon discharge rate and the residual hydrocarbon rate of the over-mature hydrocarbon source rock;

and step S600, calculating the residual hydrocarbon strength and the residual hydrocarbon amount of the over-mature source rock.

2. The method for evaluating the residual hydrocarbon content of the marine over-mature hydrocarbon source rock according to claim 1, wherein the establishing method of the step S100 specifically comprises: obtaining a hydrocarbon generation potential index, a hydrogen index and an equivalent environmental plastid reflectivity of the over-mature hydrocarbon source rock according to a hydrocarbon source rock pyrolysis experiment;

in a marine stratum lacking vitrinite, establishing a hydrocarbon-generating potential evolution section map and a hydrocarbon source rock hydrogen index evolution section map of the over-mature hydrocarbon source rock based on the hydrocarbon-generating potential index, the hydrogen index and the equivalent environmental plastid reflectivity; the hydrocarbon-generating potential evolution section map of the hydrocarbon source rock is a relation map of the hydrocarbon-generating potential index and the equivalent environmental plastid reflectivity; the hydrocarbon source rock hydrogen index evolution section diagram is a relation diagram of the hydrogen index and the equivalent environment plastid reflectivity;

the hydrocarbon potential index is(ii) a Wherein the content of the first and second substances,respectively the hydrocarbon amount obtained when the unit mass of the hydrocarbon source rock sample is heated to 300 ℃ to 600 ℃, and the unit is mg HC/g;the total organic carbon content in unit mass of the source rock is unit mg/g;

the hydrogen index is；

The equivalent environmental plastid reflectivity is，(ii) a Wherein the content of the first and second substances,the maximum pyrolysis peak temperature of the pyrolysis experiment of the hydrocarbon source rock.

3. The method for evaluating the residual hydrocarbon content of the marine over-mature source rock according to claim 2, wherein the method for determining the hydrocarbon expulsion critical condition of the marine over-mature source rock comprises the following steps: obtaining a uniform temperature distribution diagram of the fluid inclusion according to an inclusion experiment; determining a primary phase inclusion homogeneous temperature peak based on the fluid inclusion homogeneous temperature profile; acquiring a corresponding minimum value on an isotherm when the uniform temperature main peak of the inclusion in the first period is obtained according to the typical well deposition and burial history and the thermal evolution history chart;namely the critical maturity of hydrocarbon expulsion corresponding to the critical condition of hydrocarbon expulsion.

4. The method for evaluating the residual hydrocarbon content of the marine high-over-mature source rock according to claim 3, wherein the method for inverting the original hydrocarbon generation potential of the high-over-mature source rock is as follows: acquiring hydrocarbon potential index envelope curve according to the hydrocarbon potential evolution profile of the hydrocarbon source rock；+Wherein a, b, c and d are constants;

acquiring the original hydrocarbon generation potential of the over-mature source rock based on the hydrocarbon generation potential index envelope curve and the hydrocarbon discharge critical maturity；。

5. The method for evaluating the residual hydrocarbon content of the sea-phase high-over-mature hydrocarbon source rock according to claim 4, wherein the inversion method of the hydrocarbon-production critical condition of the high-over-mature hydrocarbon source rock is as follows: acquiring a hydrogen index envelope curve based on the hydrocarbon source rock hydrogen index evolution profile；+Wherein e, f, g and h are constants;

obtaining hydrocarbon generation critical conditions of the high over-mature hydrocarbon source rock based on the hydrogen index envelope curve and the original hydrocarbon generation potential of the hydrocarbon source rock(ii) a WhereinAnd the equivalent environmental plastid reflectivity corresponding to the intersection point of the hydrogen index envelope curve and the original hydrocarbon generation potential of the hydrocarbon source rock.

6. The method for evaluating the residual hydrocarbon content of the marine high-over-mature hydrocarbon source rock according to claim 5, wherein the method for establishing the model of the residual hydrocarbon generation and discharge of the marine high-over-mature hydrocarbon source rock comprises the following steps: establishing a high over-mature hydrocarbon source rock hydrocarbon generation and discharge residual hydrocarbon model based on the high over-mature hydrocarbon source rock hydrocarbon generation potential evolution profile map, the high over-mature hydrocarbon source rock hydrogen index evolution profile map, the high over-mature hydrocarbon source rock hydrocarbon discharge critical condition, the high over-mature hydrocarbon source rock original hydrocarbon generation potential, the high over-mature hydrocarbon source rock hydrocarbon generation critical condition and MATLAB software, and identifying the high over-mature hydrocarbon source rock hydrocarbon generation and discharge residual hydrocarbon model in the model、、、And。

7. the method for evaluating the residual hydrocarbon content of the marine over-mature hydrocarbon source rock according to claim 6, wherein the step S500 specifically comprises: calculating the hydrocarbon generation rate of the hydrocarbon source rock, the hydrocarbon expulsion rate of the hydrocarbon source rock and the residual hydrocarbon rate of the hydrocarbon source rock based on the over-mature hydrocarbon source rock hydrocarbon expulsion residual hydrocarbon model;

the hydrocarbon generation rate of the hydrocarbon source rock is，；

The hydrocarbon source rock has hydrocarbon discharge rate of，；

The residual hydrocarbon rate of the source rock is，=。

8. The method for evaluating the residual hydrocarbon content of the marine over-mature source rock according to claim 7, wherein the method for calculating the residual hydrocarbon strength of the marine over-mature source rock specifically comprises the following steps: according to the hydrocarbon discharge rate, the organic matter abundance and the thickness and density integral of the hydrocarbon source rock corresponding to different thermal evolution stages, the residual hydrocarbon strength of the hydrocarbon source rock at different thermal evolution stages is obtained；

；

H is the thickness of the source rock;is the density of the source rock;the distribution area of the hydrocarbon source rock;is the original total organic carbon content of the source rock.

9. The method for evaluating the residual hydrocarbon content of a marine high-over-mature hydrocarbon source rock according to claim 8,；

。

10. the method for evaluating the residual hydrocarbon content in the marine high-over-mature hydrocarbon source rock according to claim 9, wherein the total residual hydrocarbon content in each geological period is obtained based on the residual hydrocarbon strength；

。

Background

Huge shale oil and gas resources are reserved in the hydrocarbon source rock stratum system, the residual quantity determines the potential of the shale oil and gas resources, and the residual quantity evaluation has important significance for shale oil and gas resource evaluation and favorable exploration target optimization. How to establish an evaluation model of the residual quantity of the marine over-mature hydrocarbon source rock and calculate the residual hydrocarbon quantity of the marine over-mature hydrocarbon source rock is a problem which is not solved by the geochemistry for a long time, and the fundamental reason is that the marine over-mature hydrocarbon source rock is generally high in maturity, is lack of immature low-mature hydrocarbon source rock and cannot reconstruct a complete hydrocarbon generation, retention and expulsion evolution process of the hydrocarbon source rock.

In the process of evaluating the residual quantity of the hydrocarbon source rock, the most important parameters comprise the determination of hydrocarbon generation critical conditions and the change of the potential of residual hydrocarbon with the thermal evolution degree. In order to solve the problem when evaluating the residual hydrocarbon content of the over-mature hydrocarbon source rock, the following methods are mainly adopted: 1) empirically, critical conditions for hydrocarbon production, e.g. degree of thermal evolution(i.e., vitrinite reflectance) of 0.4%, 0.5%, 0.6%, etc.; 2) immature low-maturity marine phase hydrocarbon source rocks of a shallow layer of a new stratum in the same basin and immature low-maturity marine phase hydrocarbon source rocks of stratums in the same generation in different basins are used for making up for the lack of immature low-maturity hydrocarbon source rock samples in a research area, and the residual hydrocarbon amount is calculated based on a hydrocarbon potential generation method.

The above method has the following disadvantages: firstly, the critical conditions for hydrocarbon discharge of different types of hydrocarbon source rocks are different, and the hydrocarbon generation critical conditions determined by different scholars are different from person to person, so that the method is subjective, lacks scientificity and cannot be widely applied; secondly, the search for a substituted immature low-maturity source rock sample is difficult, immature low-maturity source rocks are not found in the ancient marine stratum of China, and the shortage of immature low-maturity source rocks in the ancient marine stratum is a common phenomenon; in addition, the problem that immature low-maturity samples of a new shallow layer of the same basin or different basins are used as supplementary samples is large, the deposition environment, the organic phase, the organic matter type and the organic matter enrichment condition of the samples are different greatly, and the important influence factor of hydrocarbon source rock retention and hydrocarbon discharge evolution is achieved. The characteristics of the residual hydrocarbon of the hydrocarbon source rock are not known clearly, so that the potential of shale oil and gas resources is difficult to be scientifically predicted from the cause, and finally the evaluation of the shale oil and gas exploration target selected area is influenced.

Disclosure of Invention

In order to solve the problems in the prior art, namely to solve the problems that the existing evaluation method for the residual hydrocarbon content of the high-over-mature hydrocarbon source rock is poor in precision and depends on an immature low-mature sample, the invention provides an evaluation method for the residual hydrocarbon content of the sea-phase high-over-mature hydrocarbon source rock, which comprises the following steps: s100, establishing a hydrocarbon potential evolution section diagram and a hydrocarbon source rock hydrogen index evolution section diagram of the over-mature hydrocarbon source rock; s200, determining hydrocarbon expulsion critical conditions of over-mature source rocks, and inverting the original hydrocarbon generation potential of the source rocks; step S300, inverting hydrocarbon-generating critical conditions of over-mature hydrocarbon source rocks; s400, establishing a model of the residual hydrocarbons generated and discharged by the over-mature hydrocarbon source rock; step S500, determining the hydrocarbon generation rate, the hydrocarbon discharge rate and the residual hydrocarbon rate of the over-mature hydrocarbon source rock; and step S600, calculating the residual hydrocarbon strength and the residual hydrocarbon amount of the over-mature source rock.

In some preferred embodiments, the establishing method of step S100 specifically includes: and obtaining a hydrocarbon generation potential index, a hydrogen index and an equivalent environmental plastid reflectivity according to a source rock pyrolysis experiment.

In a marine stratum lacking vitrinite, establishing a hydrocarbon-generating potential evolution section map and a hydrocarbon source rock hydrogen index evolution section map of the over-mature hydrocarbon source rock based on the hydrocarbon-generating potential index, the hydrogen index and the equivalent environmental plastid reflectivity; the hydrocarbon-generating potential evolution profile map of the high over-mature hydrocarbon source rock is a relation map of the hydrocarbon-generating potential index and the equivalent environmental plastid reflectivity; the evolution section diagram of the hydrogen index of the over-mature hydrocarbon source rock is a relation diagram of the hydrogen index and the equivalent environment plastid reflectivity.

The hydrocarbon potential index is(ii) a Wherein the content of the first and second substances,respectively the hydrocarbon amount obtained when the unit mass of the hydrocarbon source rock sample is heated to 300 ℃ to 600 ℃, and the unit is mg HC/g;is the total organic carbon content in the hydrocarbon source rock per unit mass, and the unit is mg/g.

The hydrogen index is。

The equivalent environmental plastid reflectivity is，(ii) a Wherein the content of the first and second substances,the maximum pyrolysis peak temperature of the pyrolysis experiment of the hydrocarbon source rock.

In some preferred embodiments, the method for determining the hydrocarbon expulsion critical condition of the over-mature source rock is as follows: obtaining a uniform temperature distribution diagram of the fluid inclusion according to an inclusion experiment; determining a primary phase inclusion homogeneous temperature peak based on the fluid inclusion homogeneous temperature profile; acquiring the corresponding minimum value on the isotherm when the uniform temperature main peak of the inclusion in the first period is obtained according to the typical well deposition and burial history and the thermal evolution history chart(ii) a This value isNamely the critical maturity of hydrocarbon expulsion corresponding to the critical condition of hydrocarbon expulsion.

In some preferred embodiments, the inversion method of the original hydrocarbon-producing potential of the high over-mature source rock is as follows: acquiring hydrocarbon potential index envelope curve according to the hydrocarbon potential evolution profile of the hydrocarbon source rock；+Wherein a, b, c and d are constants.

Acquiring the original hydrocarbon generation potential of the source rock based on the hydrocarbon generation potential index envelope curve and the hydrocarbon discharge critical maturity；。

In some preferred embodiments, the inversion method of the hydrocarbon-producing critical conditions of the high over-mature hydrocarbon source rock is as follows: acquiring a hydrogen index envelope curve based on the hydrocarbon source rock hydrogen index evolution profile；+Wherein e, f, g and h are constants.

Based on the hydrogen index envelope curve of the rock of the high over-mature hydrocarbon source and the high over-mature hydrocarbon sourceThe original hydrocarbon generation potential of the rock and the hydrocarbon generation critical condition of the rock with high over-mature hydrocarbon source(ii) a WhereinAnd the equivalent environmental plastid reflectivity corresponding to the intersection point of the hydrogen index envelope curve and the original hydrocarbon generation potential of the over-mature source rock is obtained.

In some preferred embodiments, the method for establishing the model of the residual hydrocarbons generated by the over-mature hydrocarbon source rock comprises the following steps: establishing a high over-mature hydrocarbon source rock hydrocarbon generation and discharge residual hydrocarbon model based on the high over-mature hydrocarbon source rock hydrocarbon generation potential evolution profile map, the high over-mature hydrocarbon source rock hydrogen index evolution profile map, the high over-mature hydrocarbon source rock hydrocarbon discharge critical condition, the high over-mature hydrocarbon source rock original hydrocarbon generation potential, the high over-mature hydrocarbon source rock hydrocarbon generation critical condition and MATLAB software, and identifying the high over-mature hydrocarbon source rock hydrocarbon generation and discharge residual hydrocarbon model in the model、、、And。

in some preferred embodiments, step S500 specifically includes: and calculating the hydrocarbon generation rate, the hydrocarbon discharge rate and the residual hydrocarbon rate of the high over-mature hydrocarbon source rock based on the model of the high over-mature hydrocarbon source rock for generating and discharging residual hydrocarbon.

The hydrocarbon generation rate of the hydrocarbon source rock is，。

The hydrocarbon source rock has hydrocarbon discharge rate of，。

The residual hydrocarbon rate of the source rock is，=。

In some preferred embodiments, the method for calculating the residual hydrocarbon strength of the source rock is specifically as follows: according to the hydrocarbon discharge rate, the organic matter abundance and the thickness and density integral of the hydrocarbon source rock corresponding to different thermal evolution stages, the residual hydrocarbon strength of the hydrocarbon source rock at different thermal evolution stages is obtained。

。

H is the thickness of the source rock;is the density of the source rock;the distribution area of the hydrocarbon source rock;is the original total organic carbon content of the source rock.

In some of the preferred embodiments, the first and second,。

。

in some preferred embodiments, the total amount of residual hydrocarbons for each geological time period is obtained based on the residual hydrocarbon strength。

。

1) The invention establishes a new model of the residual hydrocarbon of the over-mature source rock, and the model does not depend on an immature low-mature sample and can research the characteristics of the residual hydrocarbon of the over-mature source rock.

2) The invention forms a new method and a process for evaluating the residual hydrocarbon amount of the marine high-maturity source rock, can more scientifically calculate the residual hydrocarbon amount of the marine source rock of the stratum lacking in the immature low-maturity sample, provides scientific basis for evaluating shale oil gas resources in a development area of the high-maturity source rock, and provides powerful theoretical guidance and technical support for evaluating the target selection area of shale oil gas exploration.

Drawings

Other features, objects and advantages of the present application will become more apparent upon reading of the following detailed description of non-limiting embodiments thereof, made with reference to the accompanying drawings.

FIG. 1 is a schematic flow diagram of an embodiment of the present invention.

FIG. 2 is a conceptual model diagram of the residual hydrocarbons produced by the highly over-mature hydrocarbon source rock in the invention.

FIG. 3 is an evolution section of hydrocarbon generation potential and hydrogen index of a hydrocarbon source rock of a marine algae nephrite in the Szechwan basin seismic denier system.

FIG. 4 is a histogram of the uniform temperature distribution of the fluid inclusions of the mudstone in the seismic denier system of the Sichuan basin.

FIG. 5 is a graph of the history of deposition and burial and thermal evolution history of the Moxi 8 well in the Sichuan basin.

FIG. 6 is a model of the hydrocarbon source rock-derived row residue of the algae cloud rock in the Szechuan basin of seismic denier system.

FIG. 7 is a graph of the present residual hydrocarbon strength of a hydrocarbon source rock of the algae cloud in the Szechwan basin seismic denier system.

Detailed Description

Preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only for explaining the technical principle of the present invention, and are not intended to limit the scope of the present invention.

The invention provides a method for evaluating the residual hydrocarbon content of a marine high-over-mature hydrocarbon source rock, which comprises the following steps of: s100, establishing a hydrocarbon potential evolution section diagram and a hydrocarbon source rock hydrogen index evolution section diagram of the over-mature hydrocarbon source rock; the method specifically comprises the following steps: obtaining a hydrocarbon potential index (from a source rock pyrolysis experiment)) Hydrogen index (f)) And equivalent environmental plastid reflectivity(ii) a Establishing a hydrocarbon potential evolution section map of a hydrocarbon source rock and a hydrogen index evolution section map of the hydrocarbon source rock on the basis of the hydrocarbon potential index, the hydrogen index and the equivalent environment plastid reflectivity in a marine stratum lacking vitrinite; wherein, the hydrocarbon-generating potential evolution section diagram of the hydrocarbon source rock is a relation diagram of a hydrocarbon-generating potential index and an equivalent environmental plastid reflectivity; the hydrocarbon source rock hydrogen index evolution section diagram is a relation diagram of the hydrogen index and the equivalent environment plastid reflectivity.

S200, determining hydrocarbon discharge critical conditions of the over-mature source rocks, and inverting the original hydrocarbon generation potential of the over-mature source rocks; wherein the critical condition for hydrocarbon expulsion is determined byObtaining a uniform temperature distribution diagram of the fluid inclusion according to an inclusion experiment; determining a primary peak value of the uniform temperature of the inclusion in the first period based on the obtained uniform temperature distribution map of the fluid inclusion; acquiring the corresponding minimum value on the isotherm when the uniform temperature main peak of the inclusion in the first period is obtained according to the typical well deposition and burial history and the thermal evolution history chart(ii) a This value isNamely the critical maturity of hydrocarbon expulsion corresponding to the critical condition of hydrocarbon expulsion. The inversion method of the original hydrocarbon generation potential of the source rock comprises the following steps: acquiring hydrocarbon potential index envelope curve according to hydrocarbon source rock hydrocarbon potential evolution profile；+Wherein a, b, c and d are constants; acquiring original hydrocarbon generation potential of the source rock based on hydrocarbon generation potential index envelope curve and hydrocarbon discharge critical maturity；。

Step S300, inverting hydrocarbon-generating critical conditions of over-mature hydrocarbon source rocks; specifically, the method comprises the step of acquiring a hydrogen index envelope curve based on a hydrogen index evolution profile of a high-over-mature hydrocarbon source rock(ii) a Based on the hydrogen index envelope curve and the original hydrocarbon generation potential of the hydrocarbon source rock, obtaining the equivalent environment plastid reflectivity corresponding to the intersection point of the hydrogen index envelope curve and the original hydrocarbon generation potential of the hydrocarbon source rock, namely the hydrocarbon generation critical condition of the hydrocarbon source rock。

S400, establishing a model of the residual hydrocarbons generated and discharged by the over-mature hydrocarbon source rock; the method specifically comprises the step of establishing a high-over-mature hydrocarbon source rock hydrocarbon generation and expulsion residual hydrocarbon model based on a high-over-mature hydrocarbon source rock hydrocarbon generation potential evolution profile, a high-over-mature hydrocarbon source rock hydrogen index evolution profile, a high-over-mature hydrocarbon expulsion critical condition, a high-over-mature hydrocarbon source rock original hydrocarbon generation potential, a high-over-mature hydrocarbon source rock hydrocarbon generation critical condition and MATLAB software.

Step S500, determining the hydrocarbon generation rate, the hydrocarbon discharge rate and the residual hydrocarbon rate of the over-mature hydrocarbon source rock; specifically, the method comprises the step of calculating the hydrocarbon generation rate of the hydrocarbon source rock based on a model of the residual hydrocarbon generated and discharged by the highly over-mature hydrocarbon source rockHydrocarbon-expelling rate of hydrocarbon source rockAnd residual hydrocarbon fraction of source rock(ii) a Wherein the content of the first and second substances,；；=。

step S600, calculating the residual hydrocarbon strength and the residual hydrocarbon amount of the over-mature source rock; specifically, the method comprises the step of obtaining the residual hydrocarbon strength of the hydrocarbon source rock at different thermal evolution stages according to the corresponding hydrocarbon discharge rate, organic matter abundance, thickness of the hydrocarbon source rock and density integral at different thermal evolution stages(ii) a Obtaining the total amount of residual hydrocarbon in each geological period based on the intensity of the residual hydrocarbon。

。

。

。

。

The method can establish a model which is independent of low-maturity samples and is suitable for evaluating the residual hydrocarbon of the high-over-mature source rock, forms an evaluation method for the residual hydrocarbon amount of the marine high-over-mature source rock, provides scientific basis for shale oil and gas resource evaluation, and provides powerful theoretical guidance and technical support for shale oil and gas exploration target area selection evaluation.

The invention is further described below with reference to the accompanying drawings in conjunction with embodiments of the Sichuan basin.

The Sichuan basin is located in the middle of China, and the basin area is about 19 multiplied by 10⁴ km²Is one of the main natural gas producing areas in China. The Sichuan basin is a typical overlapped basin containing oil and gas, and is subjected to multi-cycle structure movement and overlapped transformation of various basins to form a plurality of sets of raw storage cover combinations, and has the characteristic of multi-layer system containing oil and gas. The earthquake denier system of the Sichuan basin to the lower three-fold system is a marine carbonate stratum, the layer of the research target of the application is a lamp shadow group of the earthquake denier system, and the lamp shadow group is divided into four lamps (Z) from top to bottom according to lithology and biological characteristics₂d⁴) Lamp and lamp assemblyIII (Z)₂d³) Lamp two (Z)₂d²) And lamp one (Z)₂d¹) Four lithologic segments. Wherein the important hydrocarbon source rocks of earthquake denier of Szechwan basin of algae cloud of lamp shadow are mainly distributed in the lamp IV (Z)₂d⁴) And lamp two (Z)₂d²) And the section, the burial depth exceeds 5000m, all the hydrocarbon source rocks reach a high-over mature thermal evolution stage, the thickness is 300 m-1350 m, and the hydrocarbon source rocks are widely distributed in the Sichuan basin.

Referring to the attached drawings 1 to 7, the invention provides a method for evaluating the residual hydrocarbon content of a marine high-over-mature hydrocarbon source rock, wherein a conceptual model for hydrocarbon expulsion of the high-over-mature hydrocarbon source rock is established and is shown in fig. 2, and the method comprises the following steps: and S100, establishing a hydrocarbon generation potential evolution section and a hydrocarbon source rock hydrogen index evolution section of the over-mature hydrocarbon source rock. According to parameters obtained by pyrolysis experiments of the cloud rock source rock of the algae of the seismic denier system of the Sichuan basin, calculating to obtain a hydrocarbon potential index () Hydrogen index (f)) Equivalent environmental reflectance。

In a marine stratum lacking vitrinite, establishing a hydrocarbon-generating potential evolution section map and a hydrocarbon source rock hydrogen index evolution section map (figure 3) of a over-mature hydrocarbon source rock based on a hydrocarbon-generating potential index, a hydrogen index and an equivalent environment plastid reflectivity; the hydrocarbon-producing potential evolution section diagram of the hydrocarbon source rock is a relational diagram of the hydrocarbon-producing potential index changing along with the equivalent environment plastid reflectivity; the hydrocarbon source rock hydrogen index evolution section diagram is a relation diagram of hydrogen index changing with equivalent environment plastid reflectivity.

Further, the air conditioner is provided with a fan,(ii) a Wherein the content of the first and second substances,the maximum pyrolysis peak temperature of the pyrolysis experiment of the hydrocarbon source rock;in the unit of (a) is,the unit of (A) is [ deg. ] C.

And S200, determining hydrocarbon discharge critical conditions of the hydrocarbon source rock of the cloud rock of the algae of over maturity in the seismic denier system of the Sichuan basin, and inverting the original hydrocarbon generation potential of the hydrocarbon source rock. Firstly, through the chip analysis and geological analysis under the mirror, the lamp shade group of the Sichuan basin has three-stage inclusion formation, the first-stage inclusion is formed in dolomite crystal grains, the homogeneous temperature distribution diagram (figure 4) of the fluid inclusion is obtained through the lamp shade group inclusion experimental analysis, the homogeneous temperature peak temperature of the first-stage inclusion is determined to be between 120 ℃ and 130 ℃, and for quantitative characterization, the intermediate value of 125 ℃ (the final main peak value) is taken to represent that a large amount of hydrocarbon discharge of the hydrocarbon source rock starts at the paleoid geothermal temperature. Combining the typical well-grinding stream 8-well deposition and burial history and the thermal evolution history chart (figure 5) of the Sichuan basin, and inverting the hydrocarbon discharge critical maturity of the nephrite hydrocarbon source rock of the alga Hippocampus KelvinOn the graph, the minimum temperature of 125 ℃ isotherm of the lamp shadow groupNamely the critical maturity of hydrocarbon discharge of cloud rock of algae of lampshadesWhich is0.92% of the total amount of the algae-nephrite in the seismic denier system of the Sichuan basinInitial large amount of hydrocarbon expulsion from 0.92% of the source rock, i.e. critical maturity for expulsion of hydrocarbons: () Correspond to=0.92%。

Acquiring hydrocarbon potential index envelope curve according to hydrocarbon potential evolution profile of high over-mature hydrocarbon source rock；+53.48。

Acquiring the original hydrocarbon generation potential of the hydrocarbon source rock according to the envelope curve of the hydrocarbon generation potential index of the high over-mature hydrocarbon source rock and the hydrocarbon discharge critical maturity(ii) a Specifically, fitting a mathematical relation between an envelope curve of the hydrocarbon generation potential index and the thermal evolution degree, wherein the hydrocarbon generation potential corresponding to the hydrocarbon discharge critical maturity position on the hydrocarbon source rock hydrocarbon discharge evolution section is the original hydrocarbon generation potential of the hydrocarbon source rock, and calculating the original hydrocarbon generation potential of the algae cloud rock in the seismic denier system of the Sichuan basin, namely the original hydrocarbon generation potential of the algae cloud rock756 mg HC/g TOC。

Further, hydrocarbon generation critical conditions of the seismic denier system of the Sichuan basin higher than that of the hydrocarbon source rock of the cloud rock of the mature algae are inverted.

Obtaining a hydrogen index envelope curve according to the hydrogen index evolution profile of the cloud rock hydrocarbon source rock of the algae of the seismic denier system of the Sichuan basin，+(ii) a According to obtainingThe original hydrocarbon-generating potential of the algae nephrite of the seismic denier system of the Sichuan basin and the hydrogen index envelope curve are obtained to obtain the hydrocarbon-generating critical condition of the hydrocarbon source rock(i.e., the equivalent environmental plastid reflectivity at the intersection of the hydrogen index envelope and the original hydrocarbon-producing potential of the source rock), in this example,。

step S400, building a model of the hydrocarbon residue of the hydrocarbon source rock with high over-maturity (in the embodiment, building a model of the hydrocarbon residue of the cloud rock of the Alternaria porphyra with high over-maturity, fig. 6) based on the evolution profile of the hydrocarbon potential of the hydrocarbon source rock with high over-maturity, the evolution profile of the hydrogen index of the hydrocarbon source rock, the hydrocarbon exclusion critical condition, the original hydrocarbon potential of the hydrocarbon source rock, the hydrocarbon critical condition of the hydrocarbon source rock with high over-maturity and MATLAB software, and identifying the model of the hydrocarbon residue of the hydrocarbon source rock with high over-maturity in the model、、、And. On the model, the hydrocarbon generation potential and the hydrogen index of the hydrocarbon source rock are reduced along with the increase of the thermal maturity.

And S500, determining that the hydrocarbon generation rate, the hydrocarbon discharge rate and the residual hydrocarbon rate of the seismic denier system of the Sichuan basin are higher than that of the cloud rock hydrocarbon source rock of the over-mature algae. Calculating hydrocarbon generation rate of hydrocarbon source rock based on high over-mature hydrocarbon source rock hydrocarbon generation and discharge residual hydrocarbon modelHydrocarbon-expelling rate of hydrocarbon source rockAnd residual hydrocarbon fraction of source rock。

。

=。

=。

Step S600, determining the residual hydrocarbon strength and the residual hydrocarbon amount of the hydrocarbon source rock of the cloud rock of the algae of the seismic denier system of the Sichuan basin. According to the hydrocarbon discharge rate, the organic matter abundance and the thickness and density integral of the hydrocarbon source rock corresponding to different thermal evolution stages, the residual hydrocarbon strength of the hydrocarbon source rock at different thermal evolution stages is obtainedObtaining the total amount of residual hydrocarbon in each geological period based on the intensity of the residual hydrocarbon。

Wherein the content of the first and second substances,h is the thickness of the source rock;is the density of the source rock;the distribution area of the hydrocarbon source rock;is the original total organic carbon content of the source rock.

。

。

。

Further, referring to FIG. 7, FIG. 7 is a graph of the intensity of the residual hydrocarbons in the Dowanella yunnanensis source rock of the Szechwan basinUp toTotal amount of residual hydrocarbons in algae cloud rock source rock of Szechwan basin seismic denier systemIs composed ofOil equivalent. The shale gas favorable exploration target area is located in an area with the highest residual hydrocarbon strength.

The above embodiments are only used for illustrating the present invention, and the implementation steps of the method and the like can be changed, and all equivalent changes and modifications based on the technical scheme of the present invention should not be excluded from the protection scope of the present invention.

While the invention has been described with reference to a preferred embodiment, various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention, and particularly, features shown in the various embodiments may be combined in any suitable manner without departing from the scope of the invention. It is intended that the invention not be limited to the particular embodiments disclosed, but that the invention will include all embodiments falling within the scope of the appended claims.

In the description of the present invention, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like, which indicate directions or positional relationships, are based on the directions or positional relationships shown in the drawings, which are for convenience of description only, and do not indicate or imply that the devices or elements must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

Furthermore, it should be noted that, in the description of the present invention, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

The terms "comprises," "comprising," or any other similar term are intended to cover a non-exclusive inclusion, such that a process, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, article, or apparatus.

So far, the technical solutions of the present invention have been described in connection with the preferred embodiments shown in the drawings, but it is easily understood by those skilled in the art that the scope of the present invention is obviously not limited to these specific embodiments. Equivalent changes or substitutions of related technical features can be made by those skilled in the art without departing from the principle of the invention, and the technical scheme after the changes or substitutions can fall into the protection scope of the invention.