Method for quantitatively evaluating vertical oil and gas transmission capacity of fractured basin fracture

Abstract

The invention relates to the technical field of oil and gas exploration, in particular to a method for quantitatively evaluating the vertical oil and gas transmission capacity of fractured basin fractures, and aims to calculate channel source fracture transmission capacity quantitative evaluation parameters by identifying the distribution condition of effective channel source fractures in a fractured basin containing oil and gas. And performing quantitative evaluation on the vertical conduction capability of the trench source fracture by combining the fracture activity rate, the inclination angle, the fracture zone area, the effective fracture-hydrocarbon contact area, the section positive pressure, the effective hydrocarbon supply amount of the hydrocarbon source rock and the oil gas discovery condition. According to the method, multi-factor comprehensive geological evaluation is considered, data acquisition is convenient, the applicability is wide, the reliability is high, and reliable theoretical support can be provided for favorable zone optimization in fractured basin oil-gas exploration.

Description

Technical Field

[0001] This invention relates to the technical field of oil and gas exploration, and more specifically, to a method for quantitatively evaluating the vertical oil and gas transport capacity of faults in rift basins. Background Technology

[0002] For a long time, assessing the vertical transport capacity of faults for hydrocarbons has been a crucial aspect of hydrocarbon basin research, especially for continental rift basins. Quantitatively characterizing the opening and closing of fault-conducting hydrocarbon channels is of significant guiding importance in hydrocarbon exploration within rift basins. Currently, various research methods have been published for assessing the transport capacity of faults in rift basins, primarily focusing on quantitatively evaluating the migration capacity of transport systems based on factors such as fault normal pressure, fault dip angle, fault activity rate during hydrocarbon accumulation, and migration distance.

[0003] Existing technology discloses a quantitative research method for efficient hydrocarbon migration and accumulation based on a dynamic fault-sand transport system, including: fine characterization of the transport system; establishment of the evolution process of deep transporters and the macroscopic transport framework during key periods; and quantitative evaluation of the transport capacity of multiple transport media. However, because this method mainly considers activity rate, fault normal pressure, dip angle, and fault ridge development for quantitative evaluation of the fault and fracture transport system, and does not incorporate the multifaceted characteristics of the internal structure of the fault zone into the evaluation indicators, the reliability of the evaluation results needs further improvement.

[0004] Existing technologies disclose methods and systems for evaluating the transport capacity of static oil-source fractures during the reservoir formation period. They provide a method for evaluating the transport capacity of fractures for oil and gas based on the distribution characteristics of the width of induced fracture zones in the upper and lower plates of the migration fracture. The width of the induced fracture zones in the upper and lower plates of the fracture is calculated based on the resistivity and porosity logging parameters of wells drilling through the fracture surface and fitted with the fracture offset to quantitatively evaluate the transport efficiency. However, since most wells avoid drilling on fractures as much as possible for construction safety, the applicability of this method is limited.

[0005] Existing technologies disclose quantitative identification methods for oil and gas migration in sand transport systems and provide quantitative calculation methods based on fracture internal resistance and migration force. This method uses the buoyancy caused by the density difference between oil, gas and water and the source-storage pressure difference for coupled calculation. It has high accuracy when the source fracture of the migration channel and the sand body form a reverse shielding combination. However, there are uncertainties when evaluating the forward sand-fault combination, which limits the reliability of quantitative evaluation.

[0006] Therefore, existing methods for evaluating the fault conduction capacity of rift basins do not comprehensively consider the evaluation parameters for vertical fault conduction of hydrocarbons, and their applicability and reliability are limited. Summary of the Invention

[0007] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for quantitatively evaluating the vertical oil and gas transport capacity of faults in rift basins, which is convenient to obtain data, has wide applicability, and high reliability.

[0008] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows: A method for quantitatively evaluating the vertical hydrocarbon transport capacity of faults in a rift basin is provided, comprising the following steps: S1: Identification of effective trench-source fractures; S2: Calculation of quantitative evaluation parameters for the transport capacity of source faults; including fault activity rate, dip angle, fracture zone area, effective fault-hydrocarbon contact area, cross-sectional normal pressure, and effective hydrocarbon supply from source rocks. S3: Determination of the relationship between quantitative evaluation parameters of channel source fracture conduction capacity and oil column height; S4: Quantitative evaluation of the vertical transport capacity of the channel source fracture.

[0009] This invention provides a method for quantitatively evaluating the vertical hydrocarbon transport capacity of faults in rift basins. By identifying the distribution of effective source faults in hydrocarbon-bearing rift basins, and comprehensively considering the coupling relationship between fault activity rate, dip angle, fracture zone area, effective fault-hydrocarbon contact area, fault surface normal pressure, effective hydrocarbon supply from source rocks, and hydrocarbon discovery, the vertical transport capacity of source faults is quantitatively evaluated. This invention considers a multi-factor comprehensive geological evaluation, offers convenient data acquisition, has wide applicability, and high reliability, providing reliable theoretical support for the selection of favorable zones in hydrocarbon exploration in rift basins.

[0010] Preferably, in step S1, the method for identifying effective source fractures is as follows: a fracture framework is established by combining the interpretation of three-dimensional seismic data and variance slices, the development strata of source rocks are determined by the existing drilling data, and source fractures that break the underlying source rocks are identified and numbered.

[0011] Preferably, the paleodisplacement of a fault is characterized by the thickness difference between two sedimentary strata from the same geological period. The ages of the top and bottom of the strata are investigated, and the vertical displacement of each fault source on the seismic profile is measured to calculate the paleodisplacement. The activity rate of each fault source is then calculated. ; In the formula, Indicates the rate of fracture activity; Indicates the thickness of the fractured descending disk; Indicates the thickness of the fractured rising plate; Indicates the age of the bottom surface of the stratum; Indicates the age of the top surface of the stratum.

[0012] Preferably, the degree of opening of the source rock fracture transport channel is affected by the magnitude of the normal pressure on the top surface of the source rock. The greater the normal pressure, the more difficult it is for oil and gas to be vertically transported through the source rock strata. In step S2, the normal pressure is calculated: ; In the formula, Indicates the normal force at the cross section; This indicates the depth of the source fault buried at the top surface of the hydrocarbon source rock strata; Indicates the density of the overlying rock strata; Indicates the density of water in the overlying strata; This indicates the dip angle of the source fault at the top surface of the source rock strata.

[0013] Preferably, the effective fault-hydrocarbon contact area determines the scale of vertical oil and gas transported by the source fault, and the vertical transport capacity of oil and gas increases with the increase of the fault-hydrocarbon contact area; the effective fault-hydrocarbon contact area is calculated based on the length of the source fault inserted into the underlying source rock strata and the width of the fault extension in the source rock strata: ; In the formula, Indicates the effective contact area between the hydrocarbon and the cut-off point; Indicates the vertical length of the fracture insertion into the source rock strata; This indicates the width of the fracture extension within the source rock strata.

[0014] Preferably, the active fault interior has a multi-element structure, and the vertical transport capacity of oil and gas increases with the increase of the fracture zone area inside the fault. The width of the internal fracture zone is calculated by using the normal distribution law of the fault variance. The larger the variance value, the more discontinuous the strata, indicating a more developed geological structure within the fracture zone of the fault. The area of ​​the fracture zone of the fault is then calculated. ; In the formula, Indicates the area of ​​the fracture zone; Indicates the width of the fracture zone inside the gully source fracture (calculated with a variance value between 0.6 and 1); This indicates the length of the plane extending from the source of the fracture.

[0015] Preferably, based on the structural morphology of the top surface of the source rock strata and the theory of hydrocarbon migration troughs, combined with the distribution of source faults in the E-sub-depression of the depression, the hydrocarbon supply range of the drilled area is delineated and the area is defined, and the effective hydrocarbon supply of the source rock is calculated: ; In the formula, Indicates the effective hydrocarbon supply from the source rock; Indicates the hydrocarbon supply range of the source rock; Indicates the thickness of the source rock; This indicates the hydrocarbon expulsion rate from the source rock.

[0016] Preferably, in step S3, the fracture activity rate, effective fracture-hydrocarbon contact area, fracture zone area, effective hydrocarbon supply from source rock and the oil and gas level are positively correlated, while the cross-sectional positive pressure is negatively correlated with the oil and gas level.

[0017] Preferably, in step S4, based on the fracture correlation analysis in step S3, an evaluation formula for the vertical hydrocarbon transport capacity of fractures in a rift basin is established: ; In the formula, Indicator of vertical oil and gas transport capacity of fractures; Indicates the effective hydrocarbon supply from the source rock; Indicates the effective contact area between the hydrocarbon and the cut-off point; Indicates the area of ​​the fracture zone; Indicates the normal force at the cross section; This indicates the rate of fracture activity.

[0018] Preferably, the source fractures in each well area are identified, and the vertical oil and gas transport capacity index of multiple fractures is calculated and weighted, and the correlation with the discovered oil columns is statistically analyzed.

[0019] Compared with the prior art, the beneficial effects of this invention are as follows: This invention considers a comprehensive geological evaluation of multiple factors, and the data is easy to obtain, widely applicable, and highly reliable. It can provide reliable theoretical support for the selection of favorable zones in oil and gas exploration in rift basins. Attached Figure Description

[0020] Figure 1 This is a flowchart of a method for quantitatively evaluating the vertical hydrocarbon transport capacity of faults in a rift basin, as described in an embodiment of the present invention. Figure 2 This is a schematic diagram of effective trench source fracture identification in Embodiment 3 of the present invention; Figure 3 This is a slice of the fracture isochronous variance volume in Embodiment 3 of the present invention; Figure 4 Effective channel-source fracture in Embodiment 3 of the present invention The variance distribution plot; Figure 5 This is a diagram showing the hydrocarbon supply range of the source rock in the hydrocarbon source layer in Embodiment 3 of the present invention; Figure 6 This is a graph showing the fitting relationship between oil column height and vertical transport index in Embodiment 3 of the present invention. Detailed Implementation

[0021] The present invention will be further described below with reference to specific embodiments.

[0022] Example 1 A method for quantitatively evaluating the vertical hydrocarbon transport capacity of faults in rift basins, such as... Figure 1 As shown, it includes the following steps: S1: Identification of effective trench-source fractures; S2: Calculation of quantitative evaluation parameters for the transport capacity of source faults; including fault activity rate, dip angle, fracture zone area, effective fault-hydrocarbon contact area, cross-sectional normal pressure, and effective hydrocarbon supply from source rocks. S3: Determination of the relationship between quantitative evaluation parameters of channel source fracture conduction capacity and oil column height; S4: Quantitative evaluation of the vertical transport capacity of the channel source fracture.

[0023] The aforementioned method for quantitatively evaluating the vertical hydrocarbon transport capacity of faults in rift basins identifies the distribution of effective source faults within hydrocarbon-bearing rift basins and comprehensively evaluates the vertical transport capacity of source faults by considering the coupling relationship between fault activity rate, dip angle, fracture zone area, effective fault-hydrocarbon contact area, fault normal pressure, effective hydrocarbon supply from source rocks, and hydrocarbon discovery. This embodiment considers a multi-factor comprehensive geological evaluation, with convenient data acquisition, wide applicability, and high reliability, providing reliable theoretical support for the selection of favorable zones in hydrocarbon exploration in rift basins.

[0024] In step S1, the method for identifying effective source fractures is as follows: A fracture framework is established by combining 3D seismic data interpretation and variance slices; the source rock development strata are determined using existing drilling data; and source fractures that break the underlying source rocks are identified and numbered. Specifically, fractures whose activity can break the source rocks and connect the discovered hydrocarbon accumulation strata are considered effective source fractures.

[0025] In step S3, the fracture activity rate, effective fracture-hydrocarbon contact area, fracture zone area, effective hydrocarbon supply from source rock and the oil and gas level are positively correlated, while the positive pressure of the fracture surface is negatively correlated with the oil and gas level.

[0026] In step S4, based on the correlation analysis in step S3, an evaluation formula for the vertical hydrocarbon transport capacity of faults in a rift basin is established: ; In the formula, Indicator of vertical oil and gas transport capacity of fractures; Indicates the effective hydrocarbon supply from the source rock; Indicates the effective contact area between the hydrocarbon and the cut-off point; Indicates the area of ​​the fracture zone; Indicates the normal force at the cross section; This indicates the rate of fracture activity.

[0027] We analyzed the source fractures in each well area, calculated and weighted the vertical oil and gas transport capacity index of multiple fractures, and statistically analyzed its correlation with the discovered oil columns.

[0028] Example 2 This embodiment is similar to Embodiment 1, except that the specific calculation method for the quantitative evaluation parameters of the channel source fracture conduction capacity in step S2 is different.

[0029] Paleoelevation of faults is characterized by the thickness difference between two sedimentary strata from the same geological period. The ages of the top and bottom of the strata are investigated, and the vertical displacement of each fault source in the seismic profile is measured to calculate the paleoelevation. The activity rate of each fault source is then calculated. ; In the formula, Indicates the rate of fracture activity; Indicates the thickness of the fractured descending disk; Indicates the thickness of the fractured rising plate; Indicates the age of the bottom surface of the stratum; Indicates the age of the top surface of the stratum.

[0030] The degree of opening of the source rock fault-conducting oil and gas channel is affected by the magnitude of the normal pressure on the top surface of the source rock. The greater the normal pressure, the more difficult it is for oil and gas to penetrate the source rock strata vertically for transport. In step S2, the normal pressure is calculated: ; In the formula, Indicates the normal force at the cross section; This indicates the depth of the source fault buried at the top surface of the hydrocarbon source rock strata; Indicates the density of the overlying rock strata; Indicates the density of water in the overlying strata; This indicates the dip angle of the source fault at the top surface of the source rock strata.

[0031] The effective fault-hydrocarbon contact area determines the scale of vertical oil and gas transported by source faults, and the vertical transport capacity increases with the increase of the fault-hydrocarbon contact area. The effective fault-hydrocarbon contact area is calculated based on the length of the source fault's insertion into the underlying source rock strata and the width of the fault's extension in the source rock strata. ; In the formula, Indicates the effective contact area between the hydrocarbon and the cut-off point; Indicates the vertical length of the fracture insertion into the source rock strata; This indicates the width of the fracture extension within the source rock strata.

[0032] The active faults contain a multi-element structure, and the vertical transport capacity of oil and gas increases with the increase of the fracture zone area within the fault source. The width of the internal fracture zone is calculated by using the normal distribution of the variance values ​​of the fault source. A larger variance value indicates more discontinuous strata and a more developed geological structure within the fracture zone. Well sections encountering fracture zones exhibit low resistivity, low acoustic signature, and high porosity, with variance values ​​ranging from 0.6 to 1. The area of ​​the fracture zone within the fault source is then calculated. ; In the formula, Indicates the area of ​​the fracture zone; Indicates the width of the fracture zone inside the gully source fracture (calculated with a variance value between 0.6 and 1); This indicates the length of the plane extending from the source of the fracture.

[0033] Based on the structural morphology of the top surface of the source rock strata and the theory of hydrocarbon migration troughs, combined with the distribution of source faults in the E-sub-depression of the depression, the hydrocarbon supply range of the drilled area is delineated and its area is defined, and the effective hydrocarbon supply of the source rock is calculated: ; In the formula, Indicates the effective hydrocarbon supply from the source rock; Indicates the hydrocarbon supply range of the source rock; Indicates the thickness of the source rock; This indicates the hydrocarbon expulsion rate from the source rock.

[0034] Example 3 This embodiment is similar to Embodiment 2, except that this embodiment takes a fault in a rift basin as an example.

[0035] By combining the interpretation of 3D seismic data with variance slicing to establish a fault framework, and using existing well data to determine the hydrocarbon source rock development strata, such as... Figure 2 As shown, the effective trench-source fractures in the E-sub-depression were identified and numbered as follows: , , ... .

[0036] Calculate the activity rate of each fault source: ; In the formula, Indicates the rate of fracture activity; Indicates the thickness of the fractured descending disk; Indicates the thickness of the fractured rising plate; Indicates the age of the bottom surface of the stratum; Indicates the age of the top surface of the stratum.

[0037] Calculate the normal force of the cross section: ; In the formula, Indicates the normal force at the cross section; This indicates the depth of the source fault buried at the top surface of the hydrocarbon source rock strata; Indicates the density of the overlying rock strata; Indicates the density of water in the overlying strata; This indicates the dip angle of the source fault at the top surface of the source rock strata.

[0038] Calculate the effective contact area between the hydrocarbon and the cut-off point: ; In the formula, Indicates the effective contact area between the hydrocarbon and the cut-off point; Indicates the vertical length of the fracture insertion into the source rock strata; This indicates the width of the fracture extension within the source rock strata.

[0039] The interior of active faults exhibits a multi-layered structure, and the vertical transport capacity of hydrocarbons increases with the increase of the fracture zone area within the fault's source region. By using the normal distribution of the variance values ​​of the source faults to inversely calculate the width of the internal fracture zone, a larger variance value indicates greater stratigraphic discontinuity and a more developed geological structure within the fracture zone. For example... Figure 3 , Figure 4 As shown, the area of ​​the fracture zone of the gully-source fracture is calculated based on the width of the fracture zone inside the gully-source fracture and the horizontal extension length of the gully-source fracture: ; In the formula, Indicates the area of ​​the fracture zone; Indicates the width of the fracture zone inside the gully source fracture (calculated with a variance value between 0.6 and 1); This indicates the length of the plane extending from the source of the fracture.

[0040] Based on the structural morphology of the top surface of the source rock strata and the theory of hydrocarbon migration troughs, combined with the distribution of source faults in the E-sub-depression of the depression, the hydrocarbon supply range of the drilled area is delineated and its area is defined, such as... Figure 5 As shown, the effective hydrocarbon supply from the source rock is calculated: ; In the formula, Indicates the effective hydrocarbon supply from the source rock; Indicates the hydrocarbon supply range of the source rock; Indicates the thickness of the source rock; This indicates the hydrocarbon expulsion rate from the source rock.

[0041] The correlation between the oil and gas discoveries in drilled reservoir sand bodies and the characteristics of trench-source fault activity and hydrocarbon supply is shown in Table 1: Table 1. Statistics on the characteristics of trench-source fracture activity, hydrocarbon supply, and oil column height in the drilled area of ​​the E-sub-depression.

[0042] Table 1 shows that the fault activity rate, effective fault-hydrocarbon contact area, fracture zone area, effective hydrocarbon supply from source rocks, and hydrocarbon-bearing height are positively correlated, while the positive pressure on the fault surface is negatively correlated with hydrocarbon-bearing height.

[0043] Based on the correlation analysis between fracture parameters and hydrocarbon supply in the above steps, an evaluation formula for the vertical hydrocarbon transport capacity of fractures in rift basins is established: ; In the formula, Indicator of vertical oil and gas transport capacity of fractures; Indicates the effective hydrocarbon supply from the source rock; Indicates the effective contact area between the hydrocarbon and the cut-off point; Indicates the area of ​​the fracture zone; Indicates the normal force at the cross section; This indicates the rate of fracture activity.

[0044] This depression has abundant drilled oil and gas shows, but the exploration results and oil and gas discoveries vary significantly across different well areas. Therefore, this study quantitatively evaluates the transport capacity of the transport system based on factors such as cross-sectional normal pressure, fault dip angle, fault activity rate during the reservoir formation period, and effective hydrocarbon supply from source rocks. Taking well areas A-1, A-3, and A-4 as examples, the study systematically analyzes the source faults in each well area. By calculating and weighting the vertical oil and gas transport capacity index of multiple faults, the correlation between the index and the discovered oil columns is statistically analyzed. Figure 6 As shown, it is believed that The fractured structure exhibits strong vertical conduction capability. When the strength is between 0.4 and 0.8, the vertical conduction capacity of the fracture is generally low. The vertical transport capacity of the fracture was poor. Subsequent drilling in the area, with well A-2, encountered an oil-bearing layer and a considerable oil column height, indicating that this method is quite accurate in predicting the vertical transport capacity of oil and gas along the fracture, providing strong support for oil and gas resource assessment and exploration in the area.

[0045] This invention provides a quantitative evaluation method for the vertical transport capacity of fractures, based on fracture activity rate, dip angle, fracture zone area, effective fracture-hydrocarbon contact area, cross-sectional normal pressure, and effective hydrocarbon supply from source rocks. This method offers advantages such as convenient data acquisition, wide applicability, and high reliability. Compared to the comprehensive evaluation method combining fluid anomaly pressure and fracture activity, it not only eliminates the need for extensive drilling data from mature exploration areas but also allows for calculation and analysis using seismic data volumes in low-exploration areas, demonstrating greater applicability. Compared to dynamic modeling and evaluation methods for fracture permeability, this invention utilizes oil column height for fitting and correction, resulting in weaker randomness in evaluation parameters and higher reliability. Compared to fracture rock mechanics methods, this invention is more efficient and economical, balancing cost control and timeliness optimization. This invention is simple to operate, widely applicable, and can rapidly conduct quantitative analysis of hydrocarbon migration in the initial exploration stage of oil and gas basins, providing guidance for the selection of favorable zones in oil and gas exploration.

[0046] In the specific implementation of the above embodiments, the technical features can be combined in any non-contradictory way. For the sake of brevity, not all possible combinations of the above technical features are described. However, as long as the combination of these technical features is not contradictory, it should be considered to be within the scope of this specification.

[0047] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A method for quantitatively evaluating the vertical hydrocarbon transport capacity of faults in a rift basin, characterized in that, Includes the following steps: S1: Identification of effective trench-source fractures; S2: Calculation of quantitative evaluation parameters for the transport capacity of source faults; including fault activity rate, dip angle, fracture zone area, effective fault-hydrocarbon contact area, cross-sectional normal pressure, and effective hydrocarbon supply from source rocks. S3: Determination of the relationship between quantitative evaluation parameters of channel source fracture conduction capacity and oil column height; S4: Quantitative evaluation of the vertical transport capacity of the channel source fracture.

2. The method for quantitatively evaluating the vertical hydrocarbon transport capacity of faults in a rift basin according to claim 1, characterized in that, In step S1, the method for identifying effective source fractures is as follows: a fracture framework is established by combining the interpretation of 3D seismic data and variance slices, the development strata of source rocks are determined by the existing drilling data, and source fractures that break the underlying source rocks are identified and numbered.

3. The method for quantitatively evaluating the vertical hydrocarbon transport capacity of faults in a rift basin according to claim 1, characterized in that, Paleoelevation of faults is characterized by the thickness difference between two sedimentary strata from the same geological period. The ages of the top and bottom of the strata are investigated, and the vertical displacement of each fault source in the seismic profile is measured to calculate the paleoelevation. The activity rate of each fault source is then calculated. ； In the formula, Indicates the rate of fracture activity; Indicates the thickness of the fractured descending disk; Indicates the thickness of the fractured rising plate; Indicates the age of the bottom surface of the stratum; Indicates the age of the top surface of the stratum.

4. The method for quantitatively evaluating the vertical hydrocarbon transport capacity of faults in a rift basin according to claim 1, characterized in that, The degree of opening of the source rock fault transport channel for oil and gas is affected by the magnitude of the normal pressure on the top surface of the source rock. The greater the normal pressure, the more difficult it is for oil and gas to be vertically transported through the source rock strata. In step S2, the normal pressure is calculated: ； In the formula, Indicates the normal force at the cross section; This indicates the depth of the source fault buried at the top surface of the hydrocarbon source rock strata; Indicates the density of the overlying rock strata; Indicates the density of water in the overlying strata; This indicates the dip angle of the source fault at the top surface of the source rock strata.

5. The method for quantitatively evaluating the vertical hydrocarbon transport capacity of faults in a rift basin according to claim 1, characterized in that, The effective fault-hydrocarbon contact area determines the scale of vertical oil and gas transported by source faults, and the vertical transport capacity increases with the increase of the fault-hydrocarbon contact area. The effective fault-hydrocarbon contact area is calculated based on the length of the source fault's insertion into the underlying source rock strata and the width of the fault's extension in the source rock strata. ； In the formula, Indicates the effective contact area between the hydrocarbon and the cut-off point; Indicates the vertical length of the fracture insertion into the source rock strata; This indicates the width of the fracture extension within the source rock strata.

6. The method for quantitatively evaluating the vertical hydrocarbon transport capacity of faults in a rift basin according to claim 1, characterized in that, The interior of active faults exhibits a multi-layered structure, and the vertical transport capacity of hydrocarbons increases with the increase of the fracture zone area within the fault headstock. The width of the internal fracture zone is calculated by using the normal distribution of the fault headstock variance. A larger variance indicates greater stratigraphic discontinuity, representing a more developed geological structure within the fracture zone. The area of ​​the fracture zone within the fault headstock is then calculated. ； In the formula, Indicates the area of ​​the fracture zone; Indicates the width of the fracture zone inside the gully source fracture (calculated with a variance value between 0.6 and 1); This indicates the length of the plane extending from the source of the fracture.

7. The method for quantitatively evaluating the vertical hydrocarbon transport capacity of faults in a rift basin according to claim 1, characterized in that, Based on the structural morphology of the top surface of the source rock strata and the theory of hydrocarbon migration troughs, combined with the distribution of source faults in the E-sub-depression of the depression, the hydrocarbon supply range of the drilled area is delineated and its area is defined, and the effective hydrocarbon supply of the source rock is calculated: ； In the formula, Indicates the effective hydrocarbon supply from the source rock; Indicates the hydrocarbon supply range of the source rock; Indicates the thickness of the source rock; This indicates the hydrocarbon expulsion rate from the source rock.

8. The method for quantitatively evaluating the vertical hydrocarbon transport capacity of faults in a rift basin according to claim 1, characterized in that, In step S3, the fracture activity rate, effective fracture-hydrocarbon contact area, fracture zone area, effective hydrocarbon supply from source rock and the oil and gas level are positively correlated, while the positive pressure of the fracture surface is negatively correlated with the oil and gas level.

9. The method for quantitatively evaluating the vertical hydrocarbon transport capacity of faults in a rift basin according to claim 8, characterized in that, In step S4, based on the fracture correlation analysis in step S3, an evaluation formula for the vertical hydrocarbon transport capacity of fractures in a rift basin is established: ； In the formula, Indicator of vertical oil and gas transport capacity of fractures; Indicates the effective hydrocarbon supply from the source rock; Indicates the effective contact area between the hydrocarbon and the cut-off point; Indicates the area of ​​the fracture zone; Indicates the normal force at the cross section; This indicates the rate of fracture activity.

10. The method for quantitatively evaluating the vertical hydrocarbon transport capacity of faults in a rift basin according to claim 9, characterized in that, We analyzed the source fractures in each well area, calculated and weighted the vertical oil and gas transport capacity index of multiple fractures, and statistically analyzed its correlation with the discovered oil columns.

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