Method for evaluating oil and gas reservoir fullness of deep depression zone turbidite

Abstract

The application provides a method for evaluating fullness of a deep and low turbidite oil and gas reservoir, and the method comprises the following steps: S1, calculating displacement pressure difference according to test data; S2, obtaining turbidite trap closure height h according to three-dimensional seismic data; S3, judging the possibility of turbidite reservoir formation during oil and gas reservoir formation; and S4, determining turbidite trap oil and gas fullness. The method provides an effective way for evaluating turbidite reservoir formation conditions in a shale oil development area and lays a foundation for effective exploration of turbidite in the shale oil development area.

Description

Technical Field

[0001] This invention relates to the fields of structural geology and petroleum geology, and in particular to a method for evaluating the fullness of turbidite oil and gas reservoirs in deep depressions. Background Technology

[0002] In recent years, with the increasing level of exploration, the difficulty of exploration has gradually increased, and the exploration of turbidite oil and gas reservoirs has become a key exploration area and target in mature exploration areas. Currently, most research on turbidites focuses on analyzing the sedimentary facies types, distribution characteristics, reservoir characteristics, and influencing factors of turbidite fans. Furthermore, the evaluation of factors controlling the fullness of turbidite oil and gas reservoirs mainly focuses on sand body burial depth and sand body properties, neglecting the influence of the surrounding rocks' displacement pressure conditions on turbidite reservoir formation, particularly in turbidites developed in deep-depression shale oil-bearing areas and surrounded by mudstone and shale layers. Therefore, accurately analyzing and understanding turbidite reservoir formation in shale oil-bearing areas can serve as a prerequisite for the aforementioned research methods and is of great significance for turbidite oil and gas exploration. Summary of the Invention

[0003] In view of the above problems, the present invention is proposed to provide a method for evaluating the fullness of turbidite oil and gas reservoirs in deep depressions, in order to overcome or at least partially solve the above problems.

[0004] According to one aspect of the present invention, a method for evaluating the fullness of turbidite oil and gas reservoirs in deep depressions is provided, the evaluation method comprising:

[0005] Step S1: Calculate the displacement pressure difference based on the test data;

[0006] Step S2: Obtain the closure height h of the turbidite spheroid based on 3D seismic data;

[0007] Step S3: Determine the likelihood of hydrocarbon accumulation in turbidite deposits during the hydrocarbon accumulation period;

[0008] Step S4: Determine the hydrocarbon filling degree of the turbidite trap.

[0009] Optionally, step S1: calculating the displacement pressure difference based on test data specifically includes:

[0010] Based on the test data, the displacement pressure P1 of mudstone and the displacement pressure P2 of turbidite were obtained, and the displacement pressure difference P was calculated. 差 .

[0011] Optionally, the displacement pressure difference P 差 =P1-P2.

[0012] Optionally, step S2: obtaining the closure height h of the turbidite spheroid based on three-dimensional seismic data specifically includes:

[0013] A plan view of turbidite structures in shale oil development zones was obtained based on 3D seismic data.

[0014] The closure height h of the turbidite spheroid is obtained from the structural plan.

[0015] Optionally, step S3: determining the likelihood of hydrocarbon accumulation in turbidite deposits specifically includes:

[0016] By comparing the displacement pressure difference, we can determine the possibility of hydrocarbon accumulation in turbidites during the hydrocarbon accumulation period.

[0017] Optionally, the comparison of displacement pressure differences to determine the likelihood of turbidite accumulation during the hydrocarbon accumulation period specifically includes:

[0018] When P1-P2≤0, turbidites cannot form reservoirs;

[0019] When P1-P2>0, turbidites can form reservoirs, but their filling height is affected by the trap closure height h.

[0020] Optionally, step S4: determining the hydrocarbon saturation of the turbidite trap specifically includes:

[0021] The hydrocarbon filling degree of the turbidite trap is determined based on the relationship between the displacement pressure difference and the closure height h of the turbidite trap.

[0022] Optionally, determining the hydrocarbon filling degree of the turbidite sac based on the relationship between the displacement pressure difference and the closure height h of the turbidite sac specifically includes:

[0023] When P1-P2≤ρgh, the turbidite trap cannot be filled.

[0024] When P1-P2>ρgh, the turbidite trap can be filled.

[0025] This invention also provides a system for determining the reservoir formation conditions of turbidite in deep-depression shale oil development areas, applying the aforementioned method for evaluating the fullness of turbidite oil and gas reservoirs in deep-depression zones. The system includes:

[0026] The displacement pressure difference calculation module is used to calculate the displacement pressure difference based on test data.

[0027] The turbidite spheroid closure height acquisition module is used to obtain the turbidite spheroid closure height h based on 3D seismic data.

[0028] The module for judging the formation of hydrocarbon reservoirs in turbidites during hydrocarbon accumulation periods is used to determine the likelihood of hydrocarbon accumulation in turbidites during hydrocarbon accumulation periods.

[0029] The module for determining the hydrocarbon filling degree of turbidite sacs is used to determine the hydrocarbon filling degree of turbidite sacs.

[0030] Optionally, the turbidite spheroid closure height acquisition module includes:

[0031] The module for obtaining turbidite structural plan maps of shale oil development areas is used to obtain turbidite structural plan maps of shale oil development areas based on 3D seismic data.

[0032] The turbidite spheroid closure height acquisition module is used to obtain the turbidite spheroid closure height h based on the structural plan.

[0033] This invention provides a method for evaluating the filling degree of turbidite oil and gas reservoirs in deep depressions. The method includes: step S1: calculating the displacement pressure difference based on test data; step S2: obtaining the closure height h of the turbidite trap based on 3D seismic data; step S3: determining the probability of turbidite reservoir formation during the hydrocarbon accumulation period; and step S4: determining the hydrocarbon filling degree of the turbidite trap. This provides an effective approach for further evaluating the hydrocarbon accumulation conditions of turbidite in shale oil development areas and lays the foundation for effective exploration of turbidite in shale oil development areas.

[0034] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and in order to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Attached Figure Description

[0035] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0036] Figure 1 A flowchart illustrating a specific embodiment of a method for evaluating the fullness of turbidite oil and gas reservoirs in deep depressions, provided by an embodiment of the present invention;

[0037] Figure 2 This is a contour map of turbidite structures in the shale oil development area of ​​the Boxing Depression, according to one embodiment of the present invention.

[0038] Figure 3 This is a schematic diagram illustrating the relationship between the target displacement pressure difference and hydrocarbon accumulation in an example of the present invention;

[0039] Figure 4 This is a schematic diagram illustrating the relationship between the target displacement pressure difference and the degree of filling in an example of the present invention. Detailed Implementation

[0040] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0041] The terms "comprising" and "having," and any variations thereof, in the specification, embodiments, claims, and drawings of this invention are intended to cover non-exclusive inclusion, such as including a series of steps or units.

[0042] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0043] The present invention provides a method for determining the hydrocarbon accumulation conditions of turbidite in deep-depression shale oil development areas, comprising the following steps: obtaining the displacement pressure P1 of mudstone and shale and the displacement pressure P2 of turbidite based on test data, and calculating the displacement pressure difference Pdifference; obtaining a structural plan view of turbidite in the shale oil development area based on three-dimensional seismic data, and obtaining the closure height h of turbidite traps based on the structural map; comparing the displacement pressure difference to determine the possibility of hydrocarbon accumulation in turbidite during the hydrocarbon accumulation period; and determining the hydrocarbon filling degree of the turbidite traps based on the relationship between the displacement pressure difference and the closure height h of the turbidite traps.

[0044] Example 1

[0045] In a specific embodiment 1 of the present invention, the method for determining the hydrocarbon accumulation conditions of turbidite in a deep-depression shale oil development zone includes the following steps:

[0046] Step 1: Based on the test data, obtain the displacement pressure P1 of mudstone and shale and the displacement pressure P2 of turbidite, and calculate the displacement pressure difference P. 差 ;

[0047] Step 2: Obtain the structural plan of turbidite in the shale oil development area based on 3D seismic data, and obtain the closure height h of the turbidite trap based on the structural plan;

[0048] Step 3: Compare the displacement pressure difference to determine the possibility of hydrocarbon accumulation in turbidites during the hydrocarbon accumulation period;

[0049] Step 4: Determine the hydrocarbon filling degree of the turbidite trap based on the relationship between the displacement pressure difference and the closure height h of the turbidite trap.

[0050] Example 2

[0051] In a specific embodiment 2 of the present invention, such as Figure 1 As shown, Figure 1 This is a flowchart of a method for determining the reservoir formation conditions of turbidite in deep-depression shale oil development zones, according to the present invention.

[0052] Methods for determining the reservoir formation conditions of turbidite deposits in deep-deep shale oil development areas include:

[0053] In step 1, the displacement pressure P1 of mudstone and the displacement pressure P2 of turbidite are obtained based on the test data, and the displacement pressure difference P is calculated. 差 =P1-P2.

[0054] In step 2, a structural plan view of turbidite in the shale oil development area is obtained based on three-dimensional seismic data, and the closure height h of the turbidite trap is obtained based on the structural map.

[0055] like Figure 3 As shown, in step 3, the displacement pressure difference is compared to determine the possibility of turbidite reservoir formation during the hydrocarbon accumulation period. When P1-P2≤0, turbidite cannot form a reservoir; when P1-P2>0, turbidite can form a reservoir, but its charging height is affected by the trap closure height h.

[0056] like Figure 4 As shown, in step 4, the hydrocarbon filling degree of the turbidite trap is determined based on the relationship between the displacement pressure difference and the closure height h of the turbidite trap. Specifically, when P1-P2≤ρgh, the turbidite trap cannot be filled; when P1-P2>ρgh, the turbidite trap can be filled.

[0057] Example 3

[0058] In a specific embodiment 3 of the present invention, the method for determining the reservoir formation conditions of turbidite in deep-depression shale oil development zones includes:

[0059] In step 1, as Figure 2 As shown, the displacement pressure P1 of mudstone and shale and the displacement pressure P2 of five turbidite sandstone bodies were obtained based on the test data and are listed in the table below:

[0060] Table 1. Displacement pressure data of shale and different turbidite sand bodies.

[0061]

[0062] In step 2, a structural plan view of turbidite in the shale oil development area is obtained based on 3D seismic data, and the closure height h of the turbidite traps is obtained based on the structural map and listed in the following table:

[0063] Table 2. Closure Height of Traps in Different Turbidite Sandbodies

[0064]

[0065] In step 3, the displacement pressure differences of different turbidite sand bodies were compared to determine the probability of hydrocarbon accumulation during the hydrocarbon accumulation period, as shown in the table below:

[0066] Table 3. Closure Height of Traps in Different Turbidite Sandbodies

[0067]

[0068] In step 4, based on the turbidite sand bodies selected in step 3 that are capable of hydrocarbon accumulation, the hydrocarbon filling degree of the turbidite traps is determined according to the relationship between the displacement pressure difference and the closure height h of the turbidite traps, and is listed in the following table:

[0069] Table 4. Closure Height of Traps in Different Turbidite Sandbodies

[0070]

[0071] Beneficial effects: The method for determining the reservoir formation conditions of turbidites in deep-depression shale oil development areas provides an effective approach for further evaluating the reservoir formation conditions of turbidites in shale oil development areas, and lays the foundation for effective exploration of turbidites in shale oil development areas.

[0072] The above specific embodiments further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above are merely specific embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for evaluating the fullness of oil and gas reservoirs in deep depression turbidite zones, characterized in that, The evaluation methods include: Step S1: Calculate the displacement pressure difference based on the test data; Step S2: Obtain the closure height h of the turbidite spheroid based on 3D seismic data; Step S3: Determine the likelihood of hydrocarbon accumulation in turbidite deposits during the hydrocarbon accumulation period; Step S4: Determine the hydrocarbon filling degree of the turbidite trap.

2. The method for evaluating the filling degree of a deep-depression turbidite oil and gas reservoir according to claim 1, characterized in that, Step S1: Calculating the displacement pressure difference based on test data specifically includes: obtaining the displacement pressure P1 of mudstone and shale and the displacement pressure P2 of turbidite based on test data, and calculating the displacement pressure difference P. 差 .

3. The method for evaluating the filling degree of a deep-depression turbidite oil and gas reservoir according to claim 2, characterized in that, The displacement pressure difference P 差 =P1-P2.

4. The method for evaluating the filling degree of a deep-depression turbidite oil and gas reservoir according to claim 1, characterized in that, Step S2: Obtaining the closure height h of the turbidite spheroid based on 3D seismic data specifically includes: A plan view of turbidite structures in shale oil development zones was obtained based on 3D seismic data. The closure height h of the turbidite spheroid is obtained from the structural plan.

5. The method for evaluating the filling degree of a deep-depression turbidite oil and gas reservoir according to claim 1, characterized in that, Step S3, determining the likelihood of hydrocarbon accumulation in turbidite deposits, specifically includes: By comparing the displacement pressure difference, we can determine the possibility of hydrocarbon accumulation in turbidites during the hydrocarbon accumulation period.

6. The method for evaluating the filling degree of a deep-depression turbidite oil and gas reservoir according to claim 1, characterized in that, The comparison of displacement pressure differences to determine the likelihood of hydrocarbon accumulation in turbidite reservoirs specifically includes: When P1-P2≤0, turbidites cannot form reservoirs; When P1-P2>0, turbidites can form reservoirs, but their filling height is affected by the trap closure height h.

7. The method for evaluating the fullness of turbidite oil and gas reservoirs in deep depressions according to claim 1, characterized in that, Step S4: Determining the hydrocarbon saturation of the turbidite spheroid specifically includes: The hydrocarbon filling degree of the turbidite trap is determined based on the relationship between the displacement pressure difference and the closure height h of the turbidite trap.

8. The method for evaluating the fullness of turbidite oil and gas reservoirs in deep depressions according to claim 6, characterized in that, The determination of the hydrocarbon filling degree of the turbidite sac based on the relationship between the displacement pressure difference and the sac closure height h of the turbidite sac specifically includes: When P1-P2≤ρgh, the turbidite trap cannot be filled. When P1-P2>ρgh, the turbidite trap can be filled.

9. A system for determining the accumulation conditions of turbidite in deep-depression shale oil development areas, comprising the system for determining the accumulation conditions of turbidite in deep-depression shale oil development areas as described in any one of claims 1-8, characterized in that, The determining system includes: The displacement pressure difference calculation module is used to calculate the displacement pressure difference based on test data. The turbidite spheroid closure height acquisition module is used to obtain the turbidite spheroid closure height h based on 3D seismic data. The module for judging the formation of hydrocarbon reservoirs in turbidites during hydrocarbon accumulation periods is used to determine the likelihood of hydrocarbon accumulation in turbidites during hydrocarbon accumulation periods. The module for determining the hydrocarbon filling degree of turbidite sacs is used to determine the hydrocarbon filling degree of turbidite sacs.

10. The system for determining the reservoir formation conditions of turbidite in deep-depression shale oil development areas according to claim 9, characterized in that, The module for obtaining the closure height of the turbidite spheroid includes: The module for obtaining turbidite structural plan maps of shale oil development areas is used to obtain turbidite structural plan maps of shale oil development areas based on 3D seismic data. The turbidite spheroid closure height acquisition module is used to obtain the turbidite spheroid closure height h based on the structural plan.

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