Method and device for rapid evaluation of oil and gas exploration potential in basin edge area

Abstract

This invention relates to a rapid evaluation method for oil and gas exploration potential in basin margin areas, comprising the following steps: determining the development of source rocks in the study area and identifying source rock reflection characteristics revealed by surrounding drilled wells based on seismic identification parameters of the source rocks; determining source conditions based on source rock development and features of depressions and faults; and identifying potential zones based on both source and migration conditions. This invention addresses the shortcomings of traditional methods for evaluating the exploration potential of oil and gas basin margin areas with few or no wells.

Description

Technical Field

[0001] This invention relates to the field of oil and gas extraction technology, specifically to a method and apparatus for rapid evaluation of oil and gas exploration potential in basin margin areas. Background Technology

[0002] Currently, the traditional method for evaluating the oil and gas exploration potential in areas with few or no wells at the basin margins follows classical petroleum geology theory. This involves analyzing each petroleum geological condition of the study area, including source rocks, reservoir rocks, caprocks, traps, migration, and preservation. Drilling is then deployed only after all these conditions are met, revealing the oil and gas content and exploration potential of the basin margins. Existing methods emphasize the completeness of all petroleum geological conditions in hydrocarbon accumulation. They analyze the source rocks, reservoir rocks, caprocks, traps, migration, and preservation conditions of the study area, evaluating the exploration potential only when all conditions are met, including deploying wells to reveal the oil and gas content. The implementation cycle from research to drilling typically ranges from several months to several years.

[0003] However, while traditional methods have a certain degree of systematicity, they also have two shortcomings: First, they cannot be used in specific emergency situations where there is an urgent need to quickly assess the exploration potential of basin margins within a short period of time (e.g., within a month or even a few days); second, the labor and drilling costs required by traditional methods are relatively high. Summary of the Invention

[0004] To address the aforementioned problems, the present invention aims to provide a method and apparatus for rapid evaluation of oil and gas exploration potential in basin margin areas, thereby overcoming the shortcomings of traditional methods in evaluating the exploration potential of oil and gas-bearing basin margin areas with few or no wells.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] The rapid evaluation method for oil and gas exploration potential in basin margin areas as described in this invention includes the following steps:

[0007] Based on the seismic identification parameters of source rocks and combined with the reflection characteristics of source rocks revealed by surrounding wells, the development of source rocks in the study area is judged, and the source conditions are determined.

[0008] Based on the development of source rocks and the characteristics of depressions and faults, the conditions for hydrocarbon migration are determined.

[0009] Potential zones are identified based on hydrocarbon source and migration conditions.

[0010] The aforementioned rapid evaluation method for oil and gas exploration potential in basin margin areas, preferably, involves determining hydrocarbon source conditions as follows:

[0011] By analyzing the dominant frequency, continuity, and maximum thickness of the source rock seismic identification parameters, it can be determined whether the block has the conditions for a source rock.

[0012] The aforementioned rapid evaluation method for oil and gas exploration potential in basin margin areas preferably involves determining oil and gas migration conditions based on the development of source rocks and the characteristics of depressions, troughs, and faults. Specifically:

[0013] Within the distribution range of source rocks, it is determined that conditions for oil and gas migration are present;

[0014] If a site is not located within the distribution range of source rocks, but is situated on a slope zone, and is not separated from source rocks by depressions or reverse faults, it is considered to have the conditions for oil and gas migration.

[0015] If a site is not located within the distribution range of source rocks, but is situated on a slope zone and is separated from the source rocks by depressions or reverse faults, it is considered to lack the conditions for oil and gas migration.

[0016] The aforementioned rapid evaluation method for oil and gas exploration potential in basin margin areas preferably involves determining potential zones based on hydrocarbon source and migration conditions, specifically as follows:

[0017] By matching and logically judging the hydrocarbon source conditions and migration conditions, if the results show that the block has hydrocarbon source conditions, it is directly evaluated as a potential area; if it does not have hydrocarbon source conditions, but the oil and gas generated by source rocks in other regions can migrate to this area to form reservoirs, it has oil and gas migration conditions, and is evaluated as a potential area; if the results show that the block does not have hydrocarbon source conditions or migration conditions, it is evaluated as a no-potential area.

[0018] The rapid evaluation device for oil and gas exploration potential in basin margin areas according to the present invention includes:

[0019] The first processing unit is used to determine the development of source rocks in the study area and the source conditions based on the seismic identification parameters of source rocks and the reflection characteristics of source rocks revealed by surrounding wells.

[0020] The second processing unit is used to determine the conditions for hydrocarbon migration based on the development of source rocks and the characteristics of depressions and faults.

[0021] The third processing unit is used to determine the potential area based on hydrocarbon source conditions and migration conditions.

[0022] The computer storage medium of the present invention stores a computer program thereon, which, when executed by a processor, implements the steps of the method for rapid evaluation of oil and gas exploration potential in basin marginal areas.

[0023] The computer device of the present invention includes a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the computer program, it implements the steps of the method for rapid evaluation of oil and gas exploration potential in the basin margin area.

[0024] The present invention has the following advantages due to the adoption of the above technical solutions:

[0025] Based on the research results of basic petroleum geological conditions and seismic data in the study area, this invention achieves the goal of efficiently evaluating the hydrocarbon accumulation potential in areas with few or no wells at the edge of the basin and making reasonable exploration deployments through the joint analysis of the two most critical hydrocarbon accumulation elements: "hydrocarbon source" and "migration". It is a simple and practical method.

[0026] This invention is easy to implement and requires little work. It can quickly evaluate the exploration potential of basin margin areas and provide a basis for subsequent exploration deployment. Attached Figure Description

[0027] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. In the drawings:

[0028] Figure 1 This is a flowchart illustrating the present invention;

[0029] Figure 2 This is a potential area evaluation result map based on the "hydrocarbon transport dual-control" model;

[0030] Figure 3 It involves using seismic data to determine the main hydrocarbon source rocks and the block's potential map in Block A;

[0031] Figure 4 It uses seismic data to determine the main source rocks of hydrocarbons in Block B and the block's potential map. Detailed Implementation

[0032] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0033] This invention provides a rapid evaluation method for oil and gas exploration potential in basin margin areas. Integrating principles of petroleum geology and seismic sedimentology, it analyzes two key hydrocarbon accumulation factors—the first controlling factor (hydrocarbon source conditions) and the second controlling factor (migration conditions)—and determines their configuration relationship to quickly evaluate the oil and gas exploration potential in basin margin areas. This invention is characterized by its timeliness and low cost, and can provide effective guidance for exploration deployment and decision-making.

[0034] like Figure 1 As shown, the rapid evaluation method for oil and gas exploration potential in basin margin areas provided by this invention includes the following steps:

[0035] Based on the seismic identification parameters of source rocks and combined with the reflection characteristics of source rocks revealed by surrounding wells, the development of source rocks in the study area is judged, and the source conditions are determined.

[0036] Based on the development of source rocks and the characteristics of depressions and faults, the conditions for hydrocarbon migration are determined.

[0037] Potential zones are identified based on hydrocarbon source and migration conditions.

[0038] In the above embodiments, preferably, determining the hydrocarbon source conditions specifically involves:

[0039] By analyzing the dominant frequency, continuity, and maximum thickness of the source rock seismic identification parameters, it can be determined whether the block has the conditions for a source rock.

[0040] In the above embodiments, preferably, the hydrocarbon migration conditions are determined based on the development of source rocks and the characteristics of depressions and faults, specifically as follows:

[0041] Within the distribution range of source rocks, it is determined that conditions for oil and gas migration are present;

[0042] If a site is not located within the distribution range of source rocks, but is situated on a slope zone, and is not separated from source rocks by depressions or reverse faults, it is considered to have the conditions for oil and gas migration.

[0043] If a site is not located within the distribution range of source rocks, but is situated on a slope zone and is separated from the source rocks by depressions or reverse faults, it is considered to lack the conditions for oil and gas migration.

[0044] In the above embodiments, preferably, the potential region is determined based on hydrocarbon source conditions and migration conditions, specifically as follows:

[0045] By matching and logically judging the hydrocarbon source conditions and migration conditions, if the results show that the block has hydrocarbon source conditions, it is directly evaluated as a potential area; if it does not have hydrocarbon source conditions, but the oil and gas generated by source rocks in other regions can migrate to this area to form reservoirs, it has oil and gas migration conditions, and is evaluated as a potential area; if the results show that the block does not have hydrocarbon source conditions or migration conditions, it is evaluated as a no-potential area.

[0046] It should be noted that this invention is based on the research results of basic petroleum geological conditions and seismic data of the study area. Through the joint analysis of the two most critical hydrocarbon-forming elements—"hydrocarbon source" and "migration"—it aims to efficiently evaluate the hydrocarbon accumulation potential in areas with few or no wells at the basin's edge and to rationally deploy exploration resources. Hydrocarbon source rocks are the material basis for the generation of oil and natural gas; their presence or absence directly determines the exploration potential of a depression or region, and is the primary control factor. Oil and gas migration determines whether oil and gas from this area or other areas can migrate to this area, and is the secondary control factor. Based on the determination of these two factors, the exploration potential of the study area can be quickly evaluated. If there is no exploration potential, drilling can be discontinued; if there is exploration potential, it is identified as a potential area, and drilling deployment can be carried out on favorable traps. This invention is characterized by its timeliness and low cost, and can provide effective guidance for exploration deployment and decision-making.

[0047] This invention first determines the primary controlling factor: hydrocarbon source conditions. The determination is based on the analogy of seismic reflection characteristics of source rocks revealed by existing well drilling within the basin, applied to the identification of major source rocks in the basin's marginal areas. The seismic reflection characteristics of source rocks consider three parameters: dominant frequency, continuity, and thickness of the seismic data. This invention defines the identification criteria for these three parameters as follows: dominant frequency F < 20Hz, continuity C > 6km, and maximum thickness T > 50m (see Table 1).

[0048] Table 1. Statistical data of seismic identification parameters for source rocks.

[0049]

[0050] The present invention further determines the migration conditions of the second major controlling factor. The determination is based on the analysis of the configuration relationship between the study area and the source rocks, which can be divided into three situations: (1) within the distribution range of the source rocks, it is determined that the conditions for oil and gas migration are met; (2) outside the distribution range of the source rocks, located in the slope zone, and without depressions or reverse faults between the source rocks, it is determined that the conditions for oil and gas migration are met; (3) outside the distribution range of the source rocks, located in the slope zone, and with depressions or reverse faults between the source rocks, it is determined that the conditions for oil and gas migration are not met (see Figure 2 ).

[0051] Finally, based on the analysis results of hydrocarbon source conditions and migration conditions, this invention uses a "binary control" approach to determine whether a block is a potential area. If the basin margin area (block) has developed source rocks and reaches the hydrocarbon generation threshold, then the block is directly evaluated as a potential area; if it does not have hydrocarbon source conditions, but hydrocarbons generated from source rocks in other areas can migrate to this area and form reservoirs, then it has hydrocarbon migration conditions (see...). Figure 2If the results show that the block has neither hydrocarbon source conditions nor migration conditions, it is evaluated as a potential area; if the results show that the block has neither hydrocarbon source conditions nor migration conditions, it is evaluated as a no-potential area. The evaluation results based on the "dual control of hydrocarbon migration" under different conditions are shown in Table 2.

[0052] Table 2. Analysis of Evaluation Results Based on "Dual Control of Hydrocarbon Transport" under Different Circumstances

[0053]

[0054] This invention also provides a device for rapid evaluation of oil and gas exploration potential in basin margin areas, comprising:

[0055] The first processing unit is used to determine the development of source rocks in the study area and the source conditions based on the seismic identification parameters of source rocks and the reflection characteristics of source rocks revealed by surrounding wells.

[0056] The second processing unit is used to determine the conditions for hydrocarbon migration based on the development of source rocks and the characteristics of depressions and faults.

[0057] The third processing unit is used to determine the potential area based on hydrocarbon source conditions and migration conditions.

[0058] The present invention also provides a computer storage medium storing a computer program thereon, which, when executed by a processor, implements the steps of the above-described method for rapid evaluation of oil and gas exploration potential in basin marginal areas.

[0059] The present invention also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the above-mentioned method for rapid evaluation of oil and gas exploration potential in basin marginal areas.

[0060] Example 1: Rapid evaluation of oil and gas exploration potential in Block A on the edge of a basin.

[0061] 1) Based on seismic data of the study area, combined with the regional geological background and information revealed by surrounding wells, an analysis of the development of source rocks was conducted. This analysis showed that the dominant frequency (F) was 11.5 Hz, the continuity (C) length was 12.5 km, and the maximum thickness (T) of the source rocks was 750 m, meeting the criteria for identifying source rocks. Therefore, it was concluded that source rocks are developed in the study area. Figure 3 (shaded area).

[0062] 2) The block has developed source rocks and has reached the hydrocarbon generation threshold (the hydrocarbon generation threshold in this area is 2800m). Figure 3 The corresponding time (2500ms) indicates that the region has hydrocarbon source conditions and can be directly identified as a potential area.

[0063] Example 2: Rapid evaluation of oil and gas exploration potential in Block B on the edge of a basin.

[0064] 1) Based on seismic data of the study area, combined with the regional geological background and information revealed by surrounding wells, an analysis of the development of source rocks was conducted. The results showed that the dominant frequency (F) was 26 Hz, the continuity (C) length was 0 km, and the maximum thickness (T) of the source rocks was 0 m, which does not meet the criteria for judging source rocks. Therefore, it was concluded that source rocks are not developed in the study area (see...). Figure 4 ).

[0065] 2) No source rocks are developed in the block, nor are source rocks developed in the depression adjacent to the block, and there is a reverse fault between the block and the depression. Therefore, it is determined that block B does not have the conditions for migration.

[0066] 3) Based on the hydrocarbon source conditions in step 1) and the migration conditions in step 2, determine the appropriate method. Figure 1 Based on the technical process and the situation assessment table in Table 2, it is concluded that Block B has no exploration potential and is therefore a no-potential area.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A rapid evaluation method for oil and gas exploration potential in basin marginal areas, characterized in that, Includes the following steps: Based on the seismic identification parameters of source rocks and combined with the reflection characteristics of source rocks revealed by surrounding wells, the development of source rocks in the study area is assessed, and the source conditions are determined. Specifically, the source conditions are determined as follows: By analyzing the dominant frequency, continuity, and maximum thickness of the source rock seismic identification parameters, it can be determined whether the block has the conditions for a source rock. Based on the development of source rocks and the characteristics of depressions and faults, the conditions for hydrocarbon migration are determined; specifically: Within the distribution range of source rocks, it is determined that conditions for oil and gas migration are present; If a site is not located within the distribution range of source rocks, but is situated on a slope zone, and is not separated from source rocks by depressions or reverse faults, it is considered to have the conditions for oil and gas migration. If a site is not within the distribution range of source rocks, is located on a slope zone, and is separated from source rocks by depressions or reverse faults, it is judged to lack the conditions for oil and gas migration. Potential zones are identified based on hydrocarbon source and migration conditions.

2. The rapid evaluation method for oil and gas exploration potential in basin margin areas according to claim 1, characterized in that, Based on hydrocarbon source and migration conditions, potential areas are identified, specifically as follows: By matching and logically judging the hydrocarbon source conditions and migration conditions, if the results show that the block has hydrocarbon source conditions, it is directly evaluated as a potential area; if it does not have hydrocarbon source conditions, but the oil and gas generated by source rocks in other regions can migrate to this area to form reservoirs, it has oil and gas migration conditions, and is evaluated as a potential area; if the results show that the block does not have hydrocarbon source conditions or migration conditions, it is evaluated as a no-potential area.

3. A rapid evaluation device for oil and gas exploration potential in basin marginal areas, characterized in that, include: The first processing unit is used to determine the development of source rocks in the study area based on seismic identification parameters of source rocks and the reflection characteristics of source rocks revealed by surrounding wells, and to determine the source conditions; the determination of source conditions specifically includes: By analyzing the dominant frequency, continuity, and maximum thickness of the source rock seismic identification parameters, it can be determined whether the block has the conditions for a source rock. The second processing unit is used to determine hydrocarbon migration conditions based on the development of source rocks and the characteristics of depressions and faults; specifically: Within the distribution range of source rocks, it is determined that conditions for oil and gas migration are present; If a site is not located within the distribution range of source rocks, but is situated on a slope zone, and is not separated from source rocks by depressions or reverse faults, it is considered to have the conditions for oil and gas migration. If a site is not within the distribution range of source rocks, is located on a slope zone, and is separated from source rocks by depressions or reverse faults, it is judged to lack the conditions for oil and gas migration. The third processing unit is used to determine the potential area based on hydrocarbon source conditions and migration conditions.

4. A computer storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the steps of the method for rapid evaluation of oil and gas exploration potential in basin margin areas as described in any one of claims 1-2.

5. A computer device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the steps of the rapid evaluation method for oil and gas exploration potential in basin marginal areas as described in any one of claims 1-2.

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