A method, system, device and medium for identifying an oil and gas vertical migration path

Abstract

The present application belongs to the technical field of oil and gas geological exploration, and discloses an oil and gas vertical migration path identification method, system, device and medium, comprising: establishing a fault plane model based on three-dimensional seismic data to determine the fault ridge position; restoring the structural evolution process of the profile of at least three different directions passing through the same point at the target period based on the balanced profile method, and solving the principal stress direction according to the compression rate of each direction; decomposing the extrusion stress into a stress component acting vertically on the fault plane according to the principal stress direction, calculating the stress component at different positions of the fault plane, and obtaining the stress transport capacity distribution on the fault plane; spatially coupling the fault ridge position and the stress transport capacity distribution to determine the superimposed position of the fault ridge and the strong stress transport capacity, and obtaining the vertical dominant migration path of the fault. The technical scheme of the present application can accurately and finely depict the vertical dominant migration path of the fault.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas geological exploration technology, and in particular relates to a method, system, equipment and medium for identifying vertical migration paths of oil and gas. Background Technology

[0002] Source faults are important channels connecting source rocks and shallow traps, playing a key role in controlling the vertical migration and accumulation of oil and gas. Existing research suggests that: (1) mudstone smearing is an important factor controlling fault sealing, and the shale smearing ratio (SGR) can reflect the fault sealing capacity well. The higher the SGR value, the stronger the fault sealing capacity. (2) As the main channel for vertical migration of oil and gas, the activity rate and activity time of source faults determine their transport capacity. Generally, the greater the activity rate and activity time of faults, the stronger their vertical migration capacity. (3) The fault plane is uneven, and the convex ridge is the dominant channel for vertical transport. Oil and gas converge from the concave to the convex and migrate upward along the fault ridge.

[0003] Existing studies mostly focus on evaluating the overall conductivity of faults or analyzing single controlling factors, which do not adequately characterize the spatial differences in conductivity on fault planes. They also fail to take into account key dynamic conditions such as stress, making it difficult to achieve a detailed characterization of the conductivity and dominant vertical migration paths at any location on the fault plane. Furthermore, they lack quantitative analysis of the synergistic relationship between the geometric morphology and stress state of the fault plane, making it difficult to effectively characterize the dominant migration paths of oil and gas on the fault plane. Summary of the Invention

[0004] The purpose of this invention is to provide a method, system, device, and medium for identifying vertical migration paths of oil and gas, which effectively combines fault ridges and stress to achieve a precise characterization of the transport capacity and dominant vertical migration paths at any location on the fault plane, thereby solving the problems existing in the prior art.

[0005] In a first aspect, to achieve the above objective, the present invention provides a method for identifying vertical migration paths of oil and gas, comprising:

[0006] S1: Establish a fault plane model based on three-dimensional seismic data, and determine the location of the fault ridge according to the range of upward protrusion of the fault plane on the fault plane model;

[0007] S2: Based on the equilibrium profile method, reconstruct the structural evolution process of at least three profiles in different directions passing through the same point during the target period, calculate the compressibility in each direction, and solve the principal stress direction based on the compressibility in each direction.

[0008] S3: Based on the principal stress direction, the compressive stress is decomposed into stress components that act perpendicularly on the fault plane, and the stress components at different locations on the fault plane are calculated to obtain the stress conduction capacity distribution on the fault plane.

[0009] S4: Spatially couple the location of the fault ridge with the distribution of stress conduction capacity to determine the overlapping location of the fault ridge and the location with strong stress conduction capacity, and obtain the vertically dominant migration path of the fault.

[0010] Optionally, step S1, the construction process of the interruption-level model, specifically includes:

[0011] Based on 3D seismic profile data, the fault is interpreted in detail, and fault interpretation lines are picked on different survey lines. Spatial interpolation and fitting are performed on the fault interpretation lines on different survey lines to establish the fault plane model.

[0012] Optionally, in step S2, there are three cross-sections in different directions, two of which are orthogonal and the third direction is oblique to the first two directions.

[0013] Optionally, the solution process for the principal stress directions in step S2 is as follows:

[0014] The compressibility ratio is calculated based on the compression amount in each direction of the profile, and then substituted into the stress-strain equation:

[0015]

[0016] Solve for the strain components and the principal stress directions by simultaneously solving the stress-strain equations:

[0017]

[0018] In the formula, α is the true azimuth of the selected profile extension direction relative to geographic north; when deflected counterclockwise from true north, α takes a positive value, and when deflected clockwise, it takes a negative value. Let α be the compressibility in the direction α; , , These represent the strain components evolving along the cross-sections in three directions. The principal stress direction This represents the arctangent function.

[0019] Optionally, in step S3, the compressive stress is decomposed into a first component σ' along the horizontal direction perpendicular to the fault strike, and then the first component σ' is decomposed along the direction perpendicular to the fault plane to obtain a second component σ'' acting perpendicularly to the fault plane.

[0020] Optionally, the calculation process of the first component σ' and the second component σ'' in step S3 is as follows:

[0021]

[0022]

[0023] In the formula, The angle between the fault dip and the compressive stress direction. σ is the fault dip angle, and σ is the compressive stress.

[0024] Optionally, step S4 specifically includes: adjusting the stress conduction capacity distribution and the position of the fault ridge to a uniform size, and coupling the horizontal and vertical coordinates in the drawing software to determine the fault ridge and the position of strong stress conduction capacity, thereby obtaining the vertically dominant migration path of the fault.

[0025] Secondly, to achieve the above objectives, the present invention provides a vertical migration path identification system for oil and gas, comprising:

[0026] The first processing module is used to establish a fault plane model based on three-dimensional seismic data and determine the location of the fault ridge based on the range of upward protrusion of the fault plane on the fault plane model.

[0027] The second processing module is used to reconstruct the structural evolution process of at least three different directions of the same point during the target period according to the equilibrium profile method, calculate the compression ratio in each direction, and solve the principal stress direction based on the compression ratio in each direction.

[0028] The third processing module is used to decompose the compressive stress into stress components that act perpendicularly on the fault plane according to the principal stress direction, calculate the stress components at different locations on the fault plane, and obtain the stress conduction capacity distribution on the fault plane.

[0029] The fourth processing module is used to spatially couple the location of the fault ridge with the distribution of stress conduction capacity, determine the overlapping location of the fault ridge and the location with strong stress conduction capacity, and obtain the vertical dominant migration path of the fault.

[0030] Thirdly, to achieve the above objectives, the present invention provides an electronic device, including a memory and a processor, wherein the memory is used to store a computer program, and the processor runs the computer program to enable the electronic device to execute the oil and gas vertical migration path identification method described in the first aspect.

[0031] Fourthly, to achieve the above objectives, the present invention provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements a method for identifying vertical migration paths of oil and gas as described in the first aspect.

[0032] The technical effects of this invention are as follows:

[0033] This invention provides a method for characterizing fault conduction and dominant migration paths based on structural ridge-stress coupling, which effectively combines fault ridges and stress to achieve a fine characterization of the conduction capacity and dominant vertical migration paths at any location on the fault plane. Attached Figure Description

[0034] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. 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.

[0035] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0036] Figure 1 This is a schematic diagram of stress decomposition in an embodiment of the present invention;

[0037] Figure 2 This is a cross-sectional ridge distribution diagram of the Zaxi Fault in Embodiment 2 of the present invention;

[0038] Figure 3 N2 in Embodiment 2 of the present invention 2 Distribution of the transport capacity of the Zaxi Fault during a certain period;

[0039] Figure 4 N2 in Embodiment 2 of the present invention 2 A schematic diagram of the vertical dominant migration path of the Zaxi Fault during that period;

[0040] Figure 5 This is a cross-sectional ridge distribution diagram of fault XIII in Embodiment 3 of the present invention;

[0041] Figure 6 N2 in Embodiment 3 of the present invention 1 Distribution map of the conduction capacity of the XIII fault during the period;

[0042] Figure 7 N2 in Embodiment 3 of the present invention 1 A schematic diagram of the vertical dominant migration path of the XIII fault during the period;

[0043] Figure 8 This is a flowchart illustrating the implementation of an embodiment of the present invention. Detailed Implementation

[0044] Various exemplary embodiments of the present invention will now be described in detail. This detailed description should not be considered as a limitation of the present invention, but rather as a more detailed description of certain aspects, features, and embodiments of the present invention.

[0045] It should be understood that the terminology used in this invention is merely for describing particular embodiments and is not intended to limit the invention. Furthermore, with respect to numerical ranges in this invention, it should be understood that each intermediate value between the upper and lower limits of the range is also specifically disclosed. Every smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included in this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0046] The terms “include,” “including,” “have,” “contain,” etc., used in this article are all open-ended terms, meaning that they include but are not limited to.

[0047] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0048] Example 1

[0049] like Figure 1 , Figure 8 As shown, this embodiment provides a method for identifying vertical migration paths of oil and gas, including:

[0050] This embodiment provides a method for identifying vertical migration paths of oil and gas based on ridge-stress coupling, including establishing a fault model and determining the location of the fault ridge, restoring the direction of extrusive stress, determining the stress closure-conductivity of the fault surface, and coupling the fault ridge and extrusive stress to characterize the dominant migration path. The specific implementation process includes:

[0051] (1) Establishing a fault model and determining the location of the fault ridge: First, based on three-dimensional seismic profile data (which includes post-stack time-migrated amplitude volumes, layer data, and three-dimensional fault plane grids), the faults in the study area are finely interpreted. Fault interpretation lines are picked on different seismic lines to determine the spatial distribution characteristics of the faults. Then, spatial interpolation and fitting are performed on the fault interpretation lines on different seismic lines to establish a fault plane model. Finally, the location of the fault ridge is determined based on the extent of the upward protrusion of the fault plane on the fault plane model.

[0052] (2) Reconstructing the direction of compressive stress: Using the equilibrium profile method, the structural evolution process of three different directions (a pair of orthogonal directions and one oblique direction, with the direction angle represented by α) passing through the same point at a certain period is reconstructed. The compression amount on the three-direction profile is calculated, and the compression ratio in each direction is obtained based on the compression amount and the original length of the profile. Based on the compressibility in the three directions, substituting them into the following stress-strain equations, we obtain three equations:

[0053]

[0054] Solve the three equations simultaneously to find the unknown. , , Substitute into the following formula to solve for the direction of the first principal stress. :

[0055]

[0056] Where α is the true azimuth of the selected profile extension direction relative to geographic north (0° reference); α takes a positive value when deflected counterclockwise from true north and a negative value when deflected clockwise. The compression ratio in the specified direction (α); , , These represent the strain components evolving along the cross-sections in three directions. This is the direction of the first principal stress at that point. It is the arctangent function.

[0057] (3) Determine the stress sealing-conductivity of the cross section: Compressive stress in the direction (compressive stress is expressed in terms of direction) This indicates that the first principal stress is consistent within the fault plane range and does not need to be calculated. The magnitude (here, the relative magnitude of the fault's stress conduction capacity is evaluated by the stress direction relative to the fault strike and dip angle) is first decomposed along the horizontal direction and perpendicular to the strike to obtain the component of the compressive stress perpendicular to the strike. Then, decompose along the direction perpendicular to the fault plane to obtain the components perpendicular to the fault plane. The calculation formula is as follows.

[0058]

[0059]

[0060] in, The angle between the fault dip and the compressive stress direction. The fault dip angle, This refers to the component of the compressive stress perpendicular to the direction of the stress. The component of the regional compressive stress acting perpendicularly to the fault plane.

[0061] A smaller value indicates weaker stress containment and stronger conductivity at the fault plane. Calculations were performed at different locations on the fault plane. Obtain the compressive stress components on the fracture surface. Distribution, i.e., the distribution of stress conduction capacity.

[0062] (4) Depicting the dominant migration path of the coupled cross-section ridge-compression stress: Adjust the stress conduction capacity distribution map and the cross-section ridge distribution map to the same size in space according to the same scale. Then, complete the precise coupling of X and Y coordinates in CorelDraw drawing software. During coupling, the fault distribution positions of the two maps should be strictly consistent. The position where the stress conduction capacity is strong and the cross-section ridge distribution coincides is determined as the vertical dominant migration path of the fault.

[0063] Example 2

[0064] like Figures 1-4 , Figure 8 As shown, this embodiment takes the Zaxi Fault in the southwest Qaidam Basin as an example. Figure 8 This is a flowchart of a method for identifying vertical migration paths of oil and gas based on "ridge-strain" coupling according to this embodiment. The method includes the following steps:

[0065] (1) Establishing a fault model and determining the location of the fault ridge: Based on the 3D seismic data of the southwest region of Qaidam Basin, the fault modeling function in Petrel software was used to perform spatial interpolation and fitting on the fault interpretation lines on different survey lines to establish a model of the Zhaxi Fault, generate a two-dimensional window for the fault's two-way travel time, and determine the location of the fault ridge based on the extent of the upward protrusion of the fault surface on the fault plane model (e.g., Figure 2 (As shown).

[0066] (2) Restoring the direction of compressive stress: using the equilibrium profile method to analyze the N2 stress during the critical period. 2 The tectonic stress direction during the period was reconstructed. Three profiles with azimuth angles α of 14°, 74°, and 104° from well Guozha 16 were selected to reconstruct the tectonic evolution process of the three profiles, and N2 was statistically calculated. 2 Compression and compressibility of stratigraphic profile length during the period The results are shown in Table 1.

[0067] Table 1 N2 2 Statistical table of compression amount and compression rate in different directions of stratigraphic profiles during different periods

[0068]

[0069] Based on the compressibility in the three directions, substituting them into the following stress-strain equations, we obtain three equations:

[0070]

[0071] Solve the three equations simultaneously to find the unknown. , , The values ​​are -0.014889, -0.005766, and 0.000689, respectively; substituting these values ​​into the following formula, the direction of the first principal stress can be solved. :

[0072]

[0073] Where α is the true azimuth of the selected profile extension direction relative to geographic north (0° reference); α takes a positive value when deflected counterclockwise from true north and a negative value when deflected clockwise. The compression ratio in the specified direction (α); , , These represent the strain components evolving along the cross-sections in three directions. This is the direction of the first principal stress at that point.

[0074] Calculate N2 using the method described above. 2 Direction of maximum principal stress during the period It is 2.16°.

[0075] (3) Determine the stress closure-conductivity of the cross section: the compressive stress First, decompose the stress along the horizontal and vertical directions to obtain the component of the compressive stress perpendicular to the direction. Then, decompose along the direction perpendicular to the fault plane to obtain the components perpendicular to the fault plane. The calculation formula is as follows:

[0076]

[0077]

[0078] in, The angle between the fault dip and the compressive stress direction. The fault dip angle, This refers to the component of the compressive stress perpendicular to the direction of the stress. The component of the regional compressive stress acting perpendicularly to the fault plane.

[0079] Calculate separately at different locations on the fault plane Obtain the compressive stress components on the fracture surface. Distribution, i.e., distribution of stress conduction capacity, results as follows Figure 3 As shown.

[0080] (4) Depicting the dominant migration path of faults by coupling the ridge-compression stress: The stress conduction capacity distribution and the ridge plane distribution are adjusted to a uniform size, and the X and Y coordinates are coupled in drawing software such as CorelDRAW to achieve a fine depiction of the vertical dominant migration path of the fault. The vertical dominant migration path of oil and gas in the Zaxi Fault is shown below. Figure 4 As indicated by the arrow.

[0081] To verify the effectiveness of the method, the hydrocarbon indication results of wells near faults were statistically analyzed. The results showed that wells along the vertically dominant migration path of hydrocarbons had a high degree of hydrocarbon indication during drilling, proving that the method has a good effect on characterizing the vertically dominant migration path of hydrocarbons.

[0082] Example 3

[0083] like Figure 1 , Figures 5-8 As shown, this embodiment takes the XIII fault as an example, and the specific implementation process includes:

[0084] (1) Establishing a fault model and determining the location of the fault ridge: Using the fault modeling function in Petrel software, a model of fault XIII is established. The location of the fault ridge is determined based on the upward protrusion of the fault plane on the fault plane model (e.g., Figure 5 (As shown).

[0085] (2) Restoring the direction of compressive stress: using the equilibrium profile method to analyze the N2 stress during the critical period. 1 The tectonic stress direction during the period was reconstructed. Three profiles with azimuth angles α of 14°, 74°, and 104° from well Guozha 16 were selected to reconstruct the tectonic evolution process of the three profiles, and N2 was statistically calculated. 1 Compression and compressibility of stratigraphic profile length during the period The results are shown in Table 2.

[0086] Table 2 N2 1 Statistical table of compression amount and compression rate in different directions of stratigraphic profiles during different periods

[0087]

[0088] Based on the compressibility in the three directions, substituting them into the stress-strain equation, we obtain three equations:

[0089]

[0090] Solve the three equations simultaneously to find the unknown. , , The values ​​are -0.060348, -0.036050, and 0.005880, respectively; substituting these values ​​into the following formula, the direction of the first principal stress can be solved. :

[0091]

[0092] Find N2 1 Direction of maximum principal stress during the period It is 6.81°.

[0093] (3) Determine the stress closure-conductivity of the cross section: the compressive stress Decomposing the stress along both the horizontal and vertical directions yields the component of the compressive stress perpendicular to the direction of the stress. Then, decompose along the direction perpendicular to the fault plane to obtain the components perpendicular to the fault plane. The calculation formula is as follows:

[0094]

[0095]

[0096] Calculate separately at different locations on the fault plane Obtain the compressive stress components on the fracture surface. Distribution, i.e., distribution of stress conduction capacity, results as follows Figure 6 As shown.

[0097] (4) Depicting the dominant migration path of faults by coupling the ridge-compression stress: The stress conduction capacity distribution is coupled with the plane distribution of the ridge in the fault section using drawing software such as CorelDRAW, and the X and Y coordinates are coupled to achieve a fine depiction of the vertical dominant migration path of the fault. The vertical dominant migration path of oil and gas in fault XIII is shown in the figure. Figure 7 As indicated by the arrows. Statistical analysis of oil and gas shows in wells near the fault shows that wells along the dominant vertical migration path have a high degree of oil and gas indication. The eastern side of this fault, where the fault ridge overlaps with a highly conductive area, has not yet been drilled; this location can be used as a prediction zone for future favorable areas.

[0098] Example 4

[0099] This embodiment provides a system for identifying vertical migration paths of oil and gas, including:

[0100] The first processing module is used to establish a fault plane model based on three-dimensional seismic data and determine the location of the fault ridge based on the range of upward protrusion of the fault plane on the fault plane model.

[0101] The second processing module is used to reconstruct the structural evolution process of at least three different directions of the same point during the target period according to the equilibrium profile method, calculate the compression ratio in each direction, and solve the principal stress direction based on the compression ratio in each direction.

[0102] The third processing module is used to decompose the compressive stress into stress components that act perpendicularly on the fault plane according to the principal stress direction, calculate the stress components at different locations on the fault plane, and obtain the stress conduction capacity distribution on the fault plane.

[0103] The fourth processing module is used to spatially couple the location of the fault ridge with the distribution of stress conduction capacity, determine the overlapping location of the fault ridge and the location with strong stress conduction capacity, and obtain the vertical dominant migration path of the fault.

[0104] In practice, this embodiment also provides an electronic device, including a memory and a processor, wherein the memory is used to store a computer program, and the processor runs the computer program to enable the electronic device to perform the oil and gas vertical migration path identification method described in the first aspect.

[0105] In practice, this embodiment also provides a computer-readable storage medium storing a computer program that, when executed by a processor, implements a method for identifying vertical migration paths of oil and gas as described in the first aspect.

[0106] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A method for identifying vertical migration paths of oil and gas, characterized in that, include: S1: Establish a fault plane model based on three-dimensional seismic data, and determine the location of the fault ridge according to the range of upward protrusion of the fault plane on the fault plane model; S2: Based on the equilibrium profile method, reconstruct the structural evolution process of at least three profiles in different directions passing through the same point during the target period, calculate the compressibility in each direction, and solve the principal stress direction based on the compressibility in each direction. S3: Based on the principal stress direction, the compressive stress is decomposed into stress components that act perpendicularly on the fault plane, and the stress components at different locations on the fault plane are calculated to obtain the stress conduction capacity distribution on the fault plane. S4: Spatially couple the location of the fault ridge with the distribution of stress conduction capacity to determine the overlapping location of the fault ridge and the location with strong stress conduction capacity, and obtain the vertically dominant migration path of the fault.

2. The method for identifying vertical migration paths of oil and gas according to claim 1, characterized in that, Step S1, the construction process of the interruption level model, is as follows: Based on 3D seismic profile data, the fault is interpreted in detail, and fault interpretation lines are picked on different survey lines. Spatial interpolation and fitting are performed on the fault interpretation lines on different survey lines to establish the fault plane model.

3. The method for identifying vertical migration paths of oil and gas according to claim 1, characterized in that, In step S2, there are three cross-sections in different directions, two of which are orthogonal and the third is oblique to the first two.

4. The method for identifying vertical migration paths of oil and gas according to claim 1, characterized in that, The solution process for the principal stress directions in step S2 is as follows: The compressibility ratio is calculated based on the compression amount in each direction of the profile, and then substituted into the stress-strain equation: Solve for the strain components and the principal stress directions by simultaneously solving the stress-strain equations: In the formula, α is the true azimuth of the selected profile extension direction relative to geographic true north; The deflection is positive when it is counterclockwise from due north and negative when it is clockwise. Let α be the compressibility in the direction α; , , These represent the strain components evolving along the cross-sections in three directions. The principal stress direction It is the arctangent function.

5. The method for identifying vertical migration paths of oil and gas according to claim 1, characterized in that, In step S3, the compressive stress is decomposed into a first component σ' along the horizontal direction perpendicular to the fault strike, and then the first component σ' is decomposed along the direction perpendicular to the fault plane to obtain a second component σ'' acting perpendicularly to the fault plane.

6. The method for identifying vertical migration paths of oil and gas according to claim 5, characterized in that, The calculation process of the first component σ' and the second component σ'' in step S3 is as follows: In the formula, The angle between the fault dip and the compressive stress direction. σ is the fault dip angle, and σ is the compressive stress.

7. The method for identifying vertical migration paths of oil and gas according to claim 1, characterized in that, Step S4 specifically includes: adjusting the stress conduction capacity distribution and the position of the fault ridge to a uniform size, and coupling the horizontal and vertical coordinates in the drawing software to determine the fault ridge and the position of strong stress conduction capacity, thereby obtaining the vertical dominant migration path of the fault.

8. A system for identifying vertical migration paths of oil and gas, characterized in that, include: The first processing module is used to establish a fault plane model based on three-dimensional seismic data and determine the location of the fault ridge based on the range of upward protrusion of the fault plane on the fault plane model. The second processing module is used to reconstruct the structural evolution process of at least three different directions of the same point during the target period according to the equilibrium profile method, calculate the compression ratio in each direction, and solve the principal stress direction based on the compression ratio in each direction. The third processing module is used to decompose the compressive stress into stress components that act perpendicularly on the fault plane according to the principal stress direction, calculate the stress components at different locations on the fault plane, and obtain the stress conduction capacity distribution on the fault plane. The fourth processing module is used to spatially couple the location of the fault ridge with the distribution of stress conduction capacity, determine the overlapping location of the fault ridge and the location with strong stress conduction capacity, and obtain the vertical dominant migration path of the fault.

9. An electronic device, characterized in that, The device includes a memory and a processor, wherein the memory stores a computer program and the processor runs the computer program to enable the electronic device to perform a method for identifying vertical migration paths of oil and gas according to any one of claims 1-7.

10. A computer-readable storage medium, characterized in that, It stores a computer program, which, when executed by a processor, implements a method for identifying vertical migration paths of oil and gas as described in any one of claims 1-7.

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