A reef carbonate reservoir well arrangement method, device and storage medium

Abstract

This invention discloses a well placement method, equipment, and storage medium for bioherm-type carbonate reservoirs. The well placement method includes the following steps: S1. Obtaining the amplitude spectrum data of the reservoir to be well placed; S2. Classifying the bioherm type and reservoir category, and determining the connectivity of the reservoir; S3. Determining the optimal well placement area and optimal well placement pattern based on the determined bioherm type, reservoir category, and reservoir connectivity; S4. Performing economic calculations on the wells to be placed within the optimal well placement area, establishing an economic model, and determining the optimal well spacing d. i And the optimal number of oil and gas wells N i This method, tailored to the characteristics of bioherm-type carbonate reservoirs, classifies them into different types, distribution ranges, and connectivity, providing a reliable reference for well placement. It designs optimal well placement areas and patterns, effectively improving well development efficiency. An economic model is established through economic accounting to optimize well spacing and the number of oil and gas wells, thereby increasing reservoir development utilization and economic benefits.

Description

Technical Field

[0001] This invention relates to the field of carbonate reservoir development technology, and in particular to a well placement method, equipment and storage medium for bioherm-type carbonate reservoirs. Background Technology

[0002] Bioherm reservoirs, also known as reef block reservoirs, occupy an important position in carbonate oil and gas fields due to their excellent reservoir properties. Their oil and gas resources have always been a valuable asset attracting global attention. In recent years, with the continuous development of oil and gas exploration technology, carbonate bioherm reservoirs have attracted particular attention due to their enormous reserves.

[0003] Bioherm reservoirs are concealed oil and gas reservoirs that are difficult to explore, especially marine bioherm reservoirs, which generally have high porosity and permeability, while continental oil and gas reservoirs have lower permeability. Carbonate reservoirs exhibit strong heterogeneity, and bioherm reservoirs show significant heterogeneity with a lack of connectivity between reservoirs. Existing technologies have made some progress in well placement for development based on the reservoir characteristics of carbonate rocks. However, due to the strong heterogeneity, poor connectivity, low porosity, and low permeability of continental bioherm reservoirs, well placement and development of bioherm reservoirs are still lacking. Furthermore, given the limited investment cost per well, how to effectively develop and utilize these reservoirs to obtain greater economic benefits is an urgent problem to be solved. Summary of the Invention

[0004] The purpose of this invention is to overcome the problem that existing well placement methods lack research on bioherm-type carbonate reservoirs, resulting in poor well placement targeting and low development economic benefits. This invention provides a well placement method, equipment, and storage medium for bioherm-type carbonate reservoirs.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0006] A well placement method for bioherm-type carbonate reservoirs includes the following steps:

[0007] S1. Perform spectral frequency decomposition on the three-dimensional seismic data volume of the reservoir to be placed in the well to obtain the amplitude spectrum data volume of the reservoir to be placed in the well;

[0008] S2. Classification of bioherms: Bioherms with a length-to-width ratio ≥ 3 and a paleogeographic location on the edge of the platform are called platform margin reefs; Bioherms with a length-to-width ratio < 3 and a paleogeographic location on the interior of the platform are called platform interior reefs.

[0009] Reservoir classification: Reservoirs with reef porosity ≥10% and reef fracture porosity ≥1% are classified as good reservoirs; reservoirs with 10% > reef porosity ≥5% and 1% > reef fracture porosity ≥0.5% are classified as relatively good reservoirs; reservoirs with 5% > reef porosity and 0.5% > reef fracture porosity are classified as poor reservoirs.

[0010] Determining reservoir connectivity: If the dominant frequency of seismic data is in the range of 5–10 Hz and the reservoir amplitude spectrum value is greater than 0, the reservoir is connected; if the dominant frequency of seismic data is in the range of 5–10 Hz and the reservoir amplitude spectrum value is less than 0, the reservoir is not connected.

[0011] S3. Based on the bioherm type, reservoir category, and reservoir connectivity determined in S2, determine the optimal well placement area and optimal well placement pattern. The optimal well placement area for the platform margin reef is located within a good or relatively good reservoir with connectivity in the plane; the optimal well placement area for the platform inner reef is located within a connected reservoir and within a good or relatively good reservoir; the optimal well placement pattern includes a single-branch unidirectional pattern, or a double-branch bidirectional pattern, or a multi-branch multidirectional pattern.

[0012] S4. Perform economic calculations on the well placement within the optimal well placement area, establish an economic model, and determine the optimal well spacing d. i And the optimal number of oil and gas wells N i .

[0013] This invention provides a well placement method for bioherm-type carbonate reservoirs. Addressing the characteristics of bioherm-type carbonate reservoirs, such as strong heterogeneity, poor connectivity, low porosity, and low permeability, this method uses 3D seismic data analysis to classify them into different types, distribution ranges, and connectivity, providing a reliable reference for well placement, reducing blind exploration, and improving exploration efficiency. Based on the reservoir characteristics of different reef types, this method designs optimal well placement areas and patterns, effectively improving well placement and development efficiency. Through economic accounting, an economic model is established to determine the relationship between net present value and the number and spacing of wells, thereby determining the optimal well scale within the optimal well placement area, rationally optimizing well spacing and the number of oil and gas wells, minimizing overall drilling costs, maximizing economic benefits, and effectively improving reservoir development and utilization rates and economic efficiency.

[0014] Optionally, S1 can also determine the connectivity of the reservoir of the well to be deployed by obtaining pressure measurement data from adjacent wells: reservoirs with the same pressure decrease trend during the production process are connected.

[0015] By acquiring pressure measurement data from adjacent wells, the connectivity of the reservoir to be drilled can be determined. The dynamic pressure data from adjacent wells can directly reflect the fluid migration in the reservoir, making the connectivity assessment more accurate and reliable. Seismic data has limited analytical resolution and depth range, while pressure data from adjacent wells can expand the stratigraphic range for connectivity assessment. Based on the pressure transmission situation, it is possible to better design combined development of interconnected layers and improve the development degree of complex reservoirs. During production, pressure data can be used to monitor reservoir dynamic changes in real time, allowing for timely adjustments to the development plan and avoiding drilling into unconnected interlayers, thus reducing drilling risks.

[0016] Optionally, S1 can also determine the connectivity of the reservoir of the well to be deployed by acquiring dynamic monitoring data of adjacent wells: the inter-well reservoir connectivity where the tracer is effective in dynamic monitoring.

[0017] By acquiring dynamic monitoring data from adjacent wells, the connectivity of the reservoir to be injected can be determined. Tracer testing allows direct observation of fluid flow paths, making connectivity assessment more accurate. Cross-layer tracer testing can also determine the vertical connectivity between different reservoirs. Based on tracer flow patterns, injection well placement can be optimized to improve development efficiency. Tracer testing is beneficial for assessing the degree of unobstructed flow and fluid mobility within a local area.

[0018] Optionally, the optimal well placement area of ​​the platform margin reef described in S3 is located within a good or relatively good reservoir layer that is connected in the plane, and is distributed in a strip shape along the reef body.

[0019] Further optimization of the best well placement areas on the platform reefs allows for priority development of areas with good connectivity and favorable reservoir properties, increasing oil and gas production per well. Well placement along the reef's strike can control or reduce the adverse effects of water on oil and gas production, extending the stable production period. Continuous strip-shaped well placement allows for sharing a single oil production network system, reducing the number of development wells required. Arranging wells along the reef's strike utilizes topographical features, facilitating the movement of drilling rigs and other equipment.

[0020] Optionally, for the inner reef located in the optimal well placement area and with a reef length-to-width ratio less than 2, a single-direction well placement pattern is adopted, where one horizontal well is placed from the high part of the reef to the low part; for the inner reef located in the optimal well placement area and with a reef length-to-width ratio greater than or equal to 2, a double-branch bidirectional well placement pattern is adopted, where horizontal wells are placed from the high part of the reef along the reef's orientation to the low parts on both sides; for the platform margin reef located in the optimal well placement area and with the optimal well placement area extending in a strip, a multi-branch multidirectional well placement pattern is adopted, where horizontal wells are deployed from the high part to the low part along the reef and reservoir orientation, depending on the reef and reservoir orientation.

[0021] Designing targeted well placement patterns based on the morphological characteristics of different reefs can leverage their respective advantages. Appropriate well location selection can reduce the adverse effects of water on oil and gas production and increase single-well productivity. Placing wells from high to low locations can extend the stable production period. A reasonable extraction sequence can improve recovery rates and extend the lifespan of oil and gas fields. Optimizing well density and supporting facilities can reduce costs and improve economic efficiency.

[0022] Optionally, in S4, the fixed production area of ​​the optimal well placement zone is determined, and the control area S of a single well is fixed, by changing the number of oil and gas wells N. i And change the well spacing d i The economic model is established to obtain different numbers of oil and gas wells N. i Net Present Value (NPV) and Well Spacing (d) i The correspondence was established, and NPV~d was constructed. i Relationship curve diagram;

[0023] By varying the number N of oil and gas wells i Net Present Value (NPV) and Well Spacing (d) i The correspondence between these parameters was further obtained to determine the relationship between net present value (NPV) and the number of oil and gas wells (N). i The correspondence between NPV and N is plotted. i Relationship curve diagram;

[0024] According to NPV~d i Relationship curve and NPV~N i Relationship curve diagram to determine the optimal well spacing d i And the optimal number of oil and gas wells N i .

[0025] Establishing a net present value (NPV) economic model allows for the quantitative analysis of economic indicators under different well spacing and well number conditions. The relationship between economic indicators and well spacing and well number is directly clarified through correlation curves. Based on the calculation results of the economic model, the optimal well spacing and well number configuration can be determined to maximize economic benefits.

[0026] A well placement device for a bioherm-type carbonate reservoir includes at least one processor and a memory communicatively connected to the at least one processor; the memory stores instructions executable by the at least one processor, which are executed by the at least one processor to enable the at least one processor to perform the aforementioned well placement method for a bioherm-type carbonate reservoir.

[0027] A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described well placement method for a bioherm-type carbonate reservoir.

[0028] Compared with the prior art, the beneficial effects of the present invention are:

[0029] 1. This invention provides a well placement method for bioherm-type carbonate reservoirs. Addressing the characteristics of bioherm-type carbonate reservoirs, such as strong heterogeneity, poor connectivity, low porosity, and low permeability, this method uses 3D seismic data analysis to classify them into different types, distribution ranges, and connectivity, providing a reliable reference for well placement, reducing blind exploration, and improving exploration efficiency. Based on the reservoir characteristics of different reef types, this method designs optimal well placement areas and patterns, effectively improving well development efficiency. Through economic accounting, an economic model is established to determine the relationship between net present value and the number and spacing of wells, thereby determining the optimal well scale within the optimal well placement area, rationally optimizing well spacing and the number of oil and gas wells, minimizing overall drilling costs, maximizing economic benefits, and effectively improving reservoir development and utilization rates and economic efficiency.

[0030] 2. This method further optimizes the well placement area on the platform reef, prioritizing areas with good connectivity and reservoir properties to increase oil and gas production per well. Well placement along the reef's strike can control or reduce the adverse effects of water on oil and gas production, extending the stable production period. Continuous strip-shaped well placement allows for sharing a single oil production network system, reducing the number of development wells required. Well placement along the reef's strike also leverages topographical features, facilitating the movement of drilling rigs and other equipment.

[0031] 3. This method designs targeted well placement patterns based on the morphological characteristics of different reefs, leveraging their respective advantages. Appropriate well location selection can reduce the adverse effects of water on oil and gas production and increase single-well productivity. Placing wells from high to low locations can extend the stable production period. A reasonable extraction sequence can improve recovery rates and extend the lifespan of oil and gas fields. Optimizing well density and supporting facilities can reduce costs and improve economic efficiency.

[0032] 4. This method, by establishing a net present value economic model, can quantitatively analyze economic indicators under different well spacing and well number conditions. The relationship between economic indicators and well spacing and well number is directly clarified through the corresponding relationship curves. Based on the calculation results of the economic model, the optimal well spacing and well number configuration is optimized to maximize economic benefits. Attached Figure Description

[0033] Figure 1 This is a flowchart of the well placement method for bioherm-type carbonate reservoirs in Example 1;

[0034] Figure 2 NPV~d of Example 1 i Relationship diagram;

[0035] Figure 3 NPV~N of Example 1 i Relationship diagram. Detailed Implementation

[0036] The present invention will be further described in detail below with reference to experimental examples and specific embodiments. The present invention uses a bioherm carbonate rock in Sichuan Province as an example, but this should not be construed as limiting the scope of the present invention to the following embodiments. All technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0037] Example 1

[0038] like Figure 1 As shown, a well placement method for bioherm-type carbonate reservoirs includes the following steps:

[0039] S1. Obtain geological parameters and 3D seismic data of the reservoir in the area to be well-placed. Geological parameters include reef aspect ratio, reef paleogeographic location, reef porosity parameters, and reef fracture development parameters. These parameters can be obtained using data from existing production wells or through field measurements. Perform spectral decomposition on the 3D seismic data volume of the reservoir in the area to be well-placed to obtain the amplitude spectrum data volume of the reservoir.

[0040] S2. Classification of bioherms: Bioherms with a length-to-width ratio ≥ 3 and a paleogeographic location on the edge of the platform are called platform margin reefs; Bioherms with a length-to-width ratio < 3 and a paleogeographic location on the interior of the platform are called platform interior reefs.

[0041] Reservoir classification: Reservoirs with reef porosity ≥10% and reef fracture porosity ≥1% are classified as good reservoirs; reservoirs with 10% > reef porosity ≥5% and 1% > reef fracture porosity ≥0.5% are classified as relatively good reservoirs; reservoirs with 5% > reef porosity and 0.5% > reef fracture porosity are classified as poor reservoirs.

[0042] Determining reservoir connectivity: If the dominant frequency of seismic data is in the range of 5–10 Hz and the reservoir amplitude spectrum value is greater than 0, the reservoir is connected; if the dominant frequency of seismic data is in the range of 5–10 Hz and the reservoir amplitude spectrum value is less than 0, the reservoir is not connected. Alternatively, the connectivity of the reservoir in the well to be deployed can be determined by obtaining pressure measurement data from adjacent wells or dynamic monitoring data from adjacent wells: wells with the same pressure decreasing trend during production are connected; wells where tracers are effective during dynamic monitoring are connected.

[0043] In this embodiment, the bioherm type selected for the well placement area is a platform reef, and the reservoir type is good and relatively good reservoir, with connectivity between the reservoirs.

[0044] S3. Based on the bioherm type, reservoir category, and reservoir connectivity determined in S2, determine the optimal well placement area and optimal well placement pattern. The optimal well placement area for the platform margin reef is located within a good or relatively good reservoir with connectivity in the plane, and extends in a strip along the reef body direction. The optimal well placement area for the platform inner reef is located within a reservoir with connectivity, and is located within a good or relatively good reservoir. The optimal well placement pattern includes a single-well unidirectional pattern, i.e., a single well extends into the reservoir in only one direction; or a double-well bidirectional pattern, i.e., a single well extends into two different reservoirs in two directions; or a multi-well multidirectional pattern, i.e., a single well extends into multiple different reservoirs in multiple directions. Specifically, for the inner reefs located in the optimal well placement area and with a reef length-to-width ratio less than 2, a single-well, unidirectional well placement pattern is adopted, with one horizontal well placed from the high part of the reef to the low part; for the inner reefs located in the optimal well placement area and with a reef length-to-width ratio greater than or equal to 2, a double-well, bidirectional well placement pattern is adopted, with horizontal wells placed from the high part of the reef along the reef's orientation to the low parts on both sides; for the platform margin reefs located in the optimal well placement area and with the optimal well placement area extending in a strip shape, a multi-well, multidirectional well placement pattern is adopted, with horizontal wells deployed from the high part to the low part along the reef and reservoir orientation, based on the reef and reservoir orientation.

[0045] In this embodiment, the optimal well placement area is a platform margin reef reservoir with good connectivity, and a multi-branch, multi-directional well placement mode is adopted.

[0046] S4. Perform economic calculations on the well placement within the optimal well placement area, establish an economic model, and determine the optimal well spacing d. i And the optimal number of oil and gas wells N i .

[0047] Specifically, within the optimal well placement zone, the control area S of a single well is fixed, and the number of oil and gas wells N is varied. i And change the well spacing d i The relationship is as follows:

[0048]

[0049] The specific data for this embodiment is shown in Table 1. An economic model is established to obtain different numbers of oil and gas wells N. i Net Present Value (NPV) and Well Spacing (d) i The correspondence, such as Figure 2 As shown, NPV~d is prepared. i Relationship curve diagram;

[0050] By varying the number N of oil and gas wells i Net Present Value (NPV) and Well Spacing (d) i The correspondence between these parameters was further obtained to determine the relationship between net present value (NPV) and the number of oil and gas wells (N). i The correspondence, such as Figure 3 As shown, plot NPV~Ni Relationship curve diagram;

[0051] Determine the fixed mining area of ​​the optimal well placement zone based on the NPV~d i Relationship curve and NPV~N i Relationship curves are used to determine the optimal well spacing d. i And the optimal number of oil and gas wells N i That is, the total area of ​​the well placement area remains constant, the control area S of a single well remains constant, and the number of oil and gas wells N remains constant. i With well spacing d i Inversely proportional, after establishing an economic model, the optimal well spacing and number are determined through the economic model to maximize profits.

[0052] Table 1. Well Spacing, Number of Oil and Gas Wells, and Net Present Value Data

[0053]

[0054] Example 2

[0055] The present invention also provides a well placement device for a bioherm-type carbonate reservoir, including at least one processor and a memory communicatively connected to the at least one processor; the memory stores instructions executable by the at least one processor, the instructions being executed by the at least one processor to enable the at least one processor to perform the well placement method for the bioherm-type carbonate reservoir provided in Example 1.

[0056] Example 3

[0057] The present invention also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the well placement method for bioherm-type carbonate reservoirs provided in Embodiment 1.

[0058] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. 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 present invention.

Claims

1. A well placement method for bioherm-type carbonate reservoirs, characterized in that, Includes the following steps: S1. Perform spectral frequency decomposition on the three-dimensional seismic data volume of the reservoir to be placed in the well to obtain the amplitude spectrum data volume of the reservoir to be placed in the well; S2. Classification of bioherms: Bioherms with a length-to-width ratio ≥ 3 and a paleogeographic location on the edge of the platform are called platform margin reefs; Bioherms with a length-to-width ratio < 3 and a paleogeographic location on the interior of the platform are called platform interior reefs. Reservoir classification: Reservoirs with reef porosity ≥10% and reef fracture porosity ≥1% are classified as good reservoirs; reservoirs with 10% > reef porosity ≥5% and 1% > reef fracture porosity ≥0.5% are classified as relatively good reservoirs; reservoirs with 5% > reef porosity and 0.5% > reef fracture porosity are classified as poor reservoirs. Determining reservoir connectivity: If the dominant frequency of seismic data is in the range of 5–10 Hz and the reservoir amplitude spectrum value is greater than 0, the reservoir is connected; if the dominant frequency of seismic data is in the range of 5–10 Hz and the reservoir amplitude spectrum value is less than 0, the reservoir is not connected. S3. Based on the bioherm type, reservoir category, and reservoir connectivity determined in S2, determine the optimal well placement area and optimal well placement pattern. The optimal well placement area for the platform margin reef is located within a good or relatively good reservoir with connectivity in the plane; the optimal well placement area for the platform inner reef is located within a connected reservoir and within a good or relatively good reservoir; the optimal well placement pattern includes a single-branch unidirectional pattern, or a double-branch bidirectional pattern, or a multi-branch multidirectional pattern. S4. Perform economic calculations on the well placement within the optimal well placement area, establish an economic model, and determine the optimal well spacing d. i And the optimal number of oil and gas wells N i .

2. The well placement method for a bioherm-type carbonate reservoir according to claim 1, characterized in that, S1 can also determine the connectivity of the reservoir of the well to be deployed by obtaining pressure measurement data from adjacent wells: reservoirs with the same pressure drop trend during the production process are connected.

3. The well placement method for a bioherm-type carbonate reservoir according to claim 1, characterized in that, S1 can also determine the connectivity of the reservoir of the well to be placed by acquiring dynamic monitoring data of adjacent wells: the inter-well reservoir connectivity where the tracer is effective in dynamic monitoring.

4. The well placement method for a bioherm-type carbonate reservoir according to claim 1, characterized in that, The optimal well placement area of ​​the platform reef described in S3 is located within a good or relatively good reservoir layer that is connected in the plane, and is distributed in a strip shape along the reef body.

5. The well placement method for a bioherm-type carbonate reservoir according to claim 1, characterized in that, For the inner reefs located in the optimal well placement area and with a reef length-to-width ratio less than 2, a single-well, unidirectional well placement pattern is adopted, with one horizontal well placed from the high part of the reef to the low part. For the inner reefs located in the optimal well placement area and with a reef length-to-width ratio greater than or equal to 2, a double-well, bidirectional well placement pattern is adopted, with horizontal wells placed from the high part of the reef along the reef's orientation to the low parts on both sides. For the platform margin reefs located in the optimal well placement area and with the optimal well placement area extending in a strip, a multi-well, multidirectional well placement pattern is adopted, with horizontal wells deployed from the high part to the low part along the reef and reservoir orientation, based on the reef and reservoir orientation.

6. The well placement method for a bioherm-type carbonate reservoir according to claim 1, characterized in that, S4 determines the fixed production area of ​​the optimal well placement zone and the fixed control area S of a single well, by changing the number of oil and gas wells N. i And change the well spacing d i The economic model is established to obtain different numbers of oil and gas wells N. i Net Present Value (NPV) and Well Spacing (d) i The correspondence was established, and NPV~d was constructed. i Relationship curve; through different numbers of oil and gas wells N i Net Present Value (NPV) and Well Spacing (d) i The correspondence between these parameters was further obtained to determine the relationship between net present value (NPV) and the number of oil and gas wells (N). i The correspondence between NPV and N is plotted. i Relationship curve diagram; based on NPV~d i Relationship curve and NPV~N i Relationship curve diagram to determine the optimal well spacing d i And the optimal number of oil and gas wells N i .

7. A well placement device for bioherm-type carbonate reservoirs, characterized in that, It includes at least one processor and a memory communicatively connected to the at least one processor; the memory stores instructions executable by the at least one processor, which, when executed by the at least one processor, enable the at least one processor to perform a well placement method for a bioherm-type carbonate reservoir as described in any one of claims 1 to 6.

8. A computer-readable storage medium having a computer program stored thereon, characterized in that, When executed by a processor, the computer program implements the steps of a well placement method for a bioherm-type carbonate reservoir as described in any one of claims 1 to 6.

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