Method for calculating comprehensive seepage capacity of injection-production well group of sandstone reservoir
By dividing the well group sedimentary units in the target study area, establishing a planar series model and performing weighted rolling thickness, the problem of inaccurate calculation of the well group seepage capacity in the existing technology was solved, and a more accurate seepage capacity assessment and improved polymer displacement effect were achieved.
Patent Information
- Application Number
- CN202410323353.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-21
- Publication Date
- 2025-09-23
AI Technical Summary
In the prior art, the permeability of the injection and production wells in a well group is calculated by taking a thickness-weighted average method. However, the result cannot reflect the permeability of the well group and has poor application reliability.
By determining the target study area and well group, dividing the sedimentary units, establishing a plane series model, combining Darcy's law, calculating the seepage capacity of the well group, and performing weighted rolling thickness to obtain the comprehensive seepage capacity of the well group.
The calculation results are more consistent with the actual reservoir development, the parameters are easy to obtain, the calculation is convenient and fast, and the polymer displacement effect and benefit are improved.
Smart Images
Figure CN120684185A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of oil reservoir engineering, and in particular to a method for calculating the comprehensive seepage capacity of an injection-production well group in a sandstone oil reservoir. Background Art
[0002] Currently, to truly reflect the comprehensive seepage capacity of injection and production well groups in heterogeneous sandstone reservoirs, achieve optimal matching of polymer flooding system parameters with the reservoir, and improve the displacement efficiency and benefits of the polymer system, existing technologies use a thickness-weighted average method to calculate the permeability of injection and production wells within a well group. However, this method only calculates the average permeability of the well group and does not consider the connectivity of the reservoirs between injection and production wells. The calculated results cannot reflect the seepage capacity of the well group, and the reliability of subsequent applications is poor. Therefore, to address these shortcomings, a method for calculating the comprehensive seepage capacity of injection and production well groups in sandstone reservoirs is proposed. Summary of the Invention
[0003] (1) Technical issues to be resolved
[0004] The present invention provides a method for calculating the comprehensive seepage capacity of an injection-production well group in a sandstone oil reservoir, so as to overcome the defects of the existing method of calculating the permeability of the injection-production wells in the well group by taking the thickness-weighted average method, the calculation result cannot reflect the seepage capacity of the well group, and the reliability of subsequent application is poor.
[0005] (2) Technical solution
[0006] To solve the above problems, the present invention provides a method for calculating the comprehensive seepage capacity of an injection-production well group in a sandstone oil reservoir, comprising:
[0007] Step S1: determine the target study area, select a target well group within the target study area, and determine the target layer interval corresponding to the target well group;
[0008] Step S2: Divide the target layer into different sedimentary units according to the different permeability oil layers of the target well group determined in step S1, and establish a plane series model of the corresponding sedimentary units;
[0009] Step S3: Obtain the basic data and logging information of the target well group determined in step S1, and establish a comprehensive seepage capacity calculation model in combination with the plane series model and Darcy's law obtained in step S2;
[0010] Step S4: Calculating the seepage capacity of the target well group determined in step S1 using the comprehensive seepage capacity calculation model obtained in step S3;
[0011] Step S5: performing thickness weighting on the seepage capacity calculation result obtained in step S4 to obtain the comprehensive seepage capacity of the target well group determined in step S1.
[0012] Preferably, in step S1, the target well group is a preset well pattern, and the types of preset well patterns include one injection and four production five-point area well pattern, one injection and three production four-point area well pattern or one injection and eight production reverse nine-point area well pattern.
[0013] Preferably, in step S2, the types of the plane series models include a sudden change plane series model of sand bodies between injection and production wells and a gradual change plane series model of sand bodies between injection and production wells.
[0014] Preferably, the calculation formula of the sudden change plane series model of the sand body between the injection and production wells is:
[0015]
[0016] Where: K xi — Plane seepage capacity of well group i, μm 2 ;K wi —Permeability of layer i in the injection well, μm 2 ;h wi —Effective thickness of layer i corresponding to the injection well, m; —Average effective thickness of the oil producing well in layer i, m; —Weighted average permeability of layer i corresponding to the oil well, μm 2 ; —weighted average permeability of layer i corresponding to the injection well, μm 2 .
[0017] Preferably, the calculation formula of the plane series model of the gradual change of sand body between injection and production wells is:
[0018]
[0019] Where: K xi — Plane seepage capacity of well group i, μm 2 ;K wi —Permeability of layer i in the injection well, μm 2 ;h wi —Effective thickness of layer i corresponding to the injection well, m; —Average effective thickness of the oil producing well in layer i, m; —Weighted average permeability of layer i corresponding to the oil well, μm 2 ; —weighted average permeability of layer i corresponding to the injection well, μm 2 .
[0020] Preferably, in step S3, the basic data of the target well group includes the permeability, connectivity and thickness of the connected layer of the injection and production wells in the target well group; the well logging information of the target well group includes the effective thickness and permeability interpretation information of the target layer.
[0021] Preferably, in step S4, the comprehensive seepage capacity calculation model includes a sudden change comprehensive seepage capacity calculation model of sand bodies between injection and production wells and a gradual change comprehensive seepage capacity calculation model of sand bodies between injection and production wells.
[0022] Preferably, the calculation formula of the calculation model of the sudden-type comprehensive seepage capacity of the sand body between the injection and production wells is:
[0023]
[0024] Where: K is the comprehensive seepage capacity of the well group, μm 2 ;k wij —Permeability of the layer connecting the injection well j and the well i in the well group, μm 2 ;h wij —Thickness of the connection between the jth layer of the injection well and the i-th well in the well group, m; k oij —Permeability of the jth layer of the i-th oil well in the well group, μm 2 ;h oij —Thickness of the connection between the jth layer of the i-th oil well in the well group and the injection well, m; f j —Ratio of the number of connected directions in the jth layer, %; n—Number of connected directions in the i-th layer of the injection well; m—Number of layers with different permeability in the injection well.
[0025] Preferably, the calculation formula of the calculation model of the gradual change comprehensive seepage capacity of the sand body between the injection and production wells is:
[0026]
[0027] Where: K is the comprehensive seepage capacity of the well group, μm 2 ;k wij —Permeability of the layer connecting the injection well j and the well i in the well group, μm 2 ;h wij —Thickness of the connection between the jth layer of the injection well and the i-th well in the well group, m; k oij —Permeability of the jth layer of the i-th oil well in the well group, μm 2 ;h oij —Thickness of the connection between the jth layer of the i-th oil well in the well group and the injection well, m; f j —Ratio of the number of connected directions in the jth layer, %; n—Number of connected directions in the i-th layer of the injection well; m—Number of layers with different permeability in the injection well.
[0028] Preferably, in step S5, the calculation formula for the flattened thickness is:
[0029] H=((h1+h2+…+h n-1 +h n ) / n+h0) / 2
[0030] Among them, H is the flattening thickness of the target well group; h1 is the effective thickness of the oil layer of oil well No. 1, h2 is the effective thickness of the oil layer of oil well No. 2, and so on. n-1 is the effective thickness of the oil layer of oil well n-1, h n is the effective thickness of the oil layer of oil well No. n; h0 is the effective thickness of the oil layer of the water injection well; n is the number of oil wells.
[0031] (3) Beneficial effects
[0032] The method for calculating the comprehensive seepage capacity of an injection-production well group in a sandstone reservoir provided by the present invention selects a target well group according to a determined target study area, establishes a comprehensive seepage capacity calculation model, takes comprehensive calculation parameters into consideration, is simple to obtain, and the calculation results are consistent with the actual development of the reservoir, and the calculation is convenient and fast. BRIEF DESCRIPTION OF THE DRAWINGS
[0033] Figure 1 This is a flow chart of a method for calculating the comprehensive seepage capacity of an injection-production well group in a sandstone oil reservoir according to an embodiment of the present invention;
[0034] Figure 2 This is the model of uniform permeability variation of oil layer thickness according to the embodiment of the present invention;
[0035] Figure 3 This is the sudden change model of oil layer thickness and permeability according to the embodiment of the present invention;
[0036] Figure 4 This is a model in which both the thickness and permeability of the gradual oil layer change in an embodiment of the present invention. DETAILED DESCRIPTION
[0037] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.
[0038] Figure 1 FIG. 1 is a flow chart of a method for calculating the comprehensive seepage capacity of an injection-production well group in a sandstone oil reservoir according to an embodiment of the present invention. Figure 1 As shown, the present invention provides a method for calculating the comprehensive seepage capacity of an injection-production well group in a sandstone oil reservoir, which specifically includes:
[0039] Step S1: determine the target study area, select a target well group within the target study area, and determine the target layer interval corresponding to the target well group;
[0040] Step S2: Divide the target layer into different sedimentary units according to the different permeability oil layers of the target well group determined in step S1, and establish a plane series model of the corresponding sedimentary units;
[0041] Step S3: Obtain the basic data and logging information of the target well group determined in step S1, and establish a comprehensive seepage capacity calculation model in combination with the plane series model and Darcy's law obtained in step S2;
[0042] Step S4: Calculating the seepage capacity of the target well group determined in step S1 using the comprehensive seepage capacity calculation model obtained in step S3;
[0043] Step S5: performing thickness weighting on the seepage capacity calculation result obtained in step S4 to obtain the comprehensive seepage capacity of the target well group determined in step S1.
[0044] In this calculation method, in step S1, the target well group is a preset well network. The well group is selected according to the designed well network and is not limited to a certain well network. The types of preset well networks include one injection and four production five-point method area well network, one injection and three production four-point method well network or one injection and eight production reverse nine-point area well network.
[0045] In practical applications, in step S2, the types of plane series models include a plane series model with a sudden change of sand bodies between injection and production wells and a plane series model with a gradual change of sand bodies between injection and production wells.
[0046] In this calculation method, in step S3, the basic data of the target well group includes the permeability, connectivity and thickness of the connected layer of the injection and production wells in the target well group; the well logging information of the target well group includes the effective thickness and permeability interpretation information of the target layer.
[0047] In this calculation method, in step S4, the comprehensive seepage capacity calculation model includes a sudden change comprehensive seepage capacity calculation model of the sand body between the injection and production wells and a gradual change comprehensive seepage capacity calculation model of the sand body between the injection and production wells.
[0048] Specifically, the average permeability formula of the small layer is derived based on the plane series model, and the arithmetic average of its thickness and the weighted average of its permeability are used to obtain the comprehensive seepage capacity of a well group.
[0049] Figure 2 The model of uniform permeability variation of oil layer thickness in the embodiment of the present invention is as follows: Figure 2 As shown in the figure, assuming that the change in K occurs at half the well spacing, and the thickness h and width d remain unchanged, according to Darcy's law, the calculation formula for the liquid production Q is:
[0050]
[0051] The consumption pressure difference △P1 and △P2 of the injected liquid volume can be expressed as:
[0052]
[0053] Deduced from the above formula, we can get:
[0054]
[0055] Where: △P1 and △P2 are the pressure differences between sections A and B, MPa; Q is the liquid volume, m 3 / d; h is the effective thickness, m; d is the model width, m; L is the injection-production well spacing, m; μ fluid viscosity, mPa.s; K1, K2-A, B section permeability, μm 2 .
[0056] Figure 3 This is the sudden change model of oil layer thickness and permeability in the embodiment of the present invention, as shown in FIG. Figure 3 As shown, assuming that the width d remains constant and the thickness h suddenly changes at half the well spacing, we can obtain:
[0057]
[0058] In the formula: h1, h2 are the thickness of oil layer in sections A and B respectively, in m.
[0059] Figure 4 This is a model in which both the thickness and permeability of the gradual-change oil layer change, as shown in the example of the present invention. Figure 4 As shown, the thickness of the oil layer is gradual, and the average thickness of the oil layer in the K1 section is:
[0060]
[0061] Among them, the average thickness of the oil layer with permeability K2 is:
[0062]
[0063] By deducing the above three formulas, we can get:
[0064]
[0065] From this, we know that for the calculation of the comprehensive seepage capacity of a single injection and multiple production well, the thickness of a certain layer of all oil production wells is calculated by arithmetic average, and the seepage capacity is calculated by weighted average method:
[0066]
[0067] The calculation formula of the sudden change plane series model of sand bodies between injection and production wells is:
[0068]
[0069] Where: K xi— Plane seepage capacity of well group i, μm 2 ;K wi —Permeability of layer i in the injection well, μm 2 ;h wi —Effective thickness of layer i corresponding to the injection well, m; —Average effective thickness of the oil producing well in layer i, m; —Weighted average permeability of layer i corresponding to the oil well, μm 2 ; —weighted average permeability of layer i corresponding to the injection well, μm 2 .
[0070] In addition, the calculation formula of the plane series model of the gradual change of sand body between injection and production wells is:
[0071]
[0072] Where: K xi — Plane seepage capacity of well group i, μm 2 ;K wi —Permeability of layer i in the injection well, μm 2 ;h wi —Effective thickness of layer i corresponding to the injection well, m; —Average effective thickness of the oil producing well in layer i, m; —Weighted average permeability of layer i corresponding to the oil well, μm 2 ; —weighted average permeability of layer i corresponding to the injection well, μm 2 .
[0073] In practical applications, given the same permeability on a plane, the fewer injection-production methods a group has, the smaller the drainage area and the lower its permeability. Therefore, it is necessary to incorporate the injection well connectivity ratio to calibrate the formula for the calculated permeability of the small layer plane.
[0074] K′xi=Kxifi
[0075] Where: f1—connectivity ratio of layer i, %; K xi —average permeability of the i-th layer, μm2; K′ xi —The corrected average permeability of the ith layer, μm2.
[0076]
[0077] Where: m is the number of small layers with different permeability in the injection well; h is the number of small layers with different permeability in the injection well; i —Thickness of the i-th layer, m.
[0078] The calculation formula of the sudden-type comprehensive seepage capacity calculation model between injection-production well groups is obtained by weighted average calculation formula of the sudden-type plane series model of sand bodies between injection-production wells:
[0079]
[0080] Where: K is the comprehensive seepage capacity of the well group, μm 2 ;k wij —Permeability of the layer connecting the injection well j and the well i in the well group, μm 2 ;h wij —Thickness of the connection between the jth layer of the injection well and the i-th well in the well group, m; k oij —Permeability of the jth layer of the i-th oil well in the well group, μm 2 ;h oij —Thickness of the connection between the jth layer of the i-th oil well in the well group and the injection well, m; f j —Ratio of the number of connected directions in the jth layer, %; n—Number of connected directions in the i-th layer of the injection well; m—Number of layers with different permeability in the injection well.
[0081] The calculation formula of the gradual change comprehensive seepage capacity calculation model between injection and production well groups is obtained by weighted average of the calculation formula of the gradual change plane series model of sand bodies between injection and production wells:
[0082]
[0083] Where: K is the comprehensive seepage capacity of the well group, μm 2 ;k wij —Permeability of the layer connecting the injection well j and the well i in the well group, μm 2 ;h wij —Thickness of the connection between the jth layer of the injection well and the i-th well in the well group, m; k oij —Permeability of the jth layer of the i-th oil well in the well group, μm 2 ;h oij —Thickness of the connection between the jth layer of the i-th oil well in the well group and the injection well, m; f j —Ratio of the number of connected directions in the jth layer, %; n—Number of connected directions in the i-th layer of the injection well; m—Number of layers with different permeability in the injection well.
[0084] In practical applications, in step S5, the calculation formula for the flattened thickness is:
[0085] H=((h1+h2+…+hn-1+hn) / n+h0) / 2
[0086] Among them, H is the flattening thickness of the target well group; h1 is the effective thickness of the oil layer of oil well No. 1, h2 is the effective thickness of the oil layer of oil well No. 2...hn-1 is the effective thickness of the oil layer of oil well No. n-1, hn is the effective thickness of the oil layer of oil well No. n; h0 is the effective thickness of the oil layer of the water injection well; n is the number of oil wells.
[0087] The present invention provides a method for calculating the comprehensive seepage capacity of an injection-production well group in a sandstone reservoir. The method selects a target well group based on a determined target study area and establishes a comprehensive seepage capacity calculation model. This method comprehensively considers calculation parameters, makes parameter acquisition simple, and provides calculation results that align with reservoir development practices. The calculation is quick and easy. The following describes the implementation of this method for calculating the comprehensive seepage capacity of an injection-production well group in a sandstone reservoir:
[0088] Step 1: Determine the target study area, select the target well group within the target study area, and determine the target layer interval corresponding to the target well group;
[0089] Step 2: Divide the target layer into different sedimentary units according to the different permeability oil layers of the target well group, and establish a plane series model of the corresponding sedimentary units;
[0090] Step 3: Obtain basic data and logging information of the target well group, and establish a comprehensive seepage capacity calculation model based on the plane series model and Darcy's law;
[0091] Step 4: Calculate the seepage capacity of the target well group using a comprehensive seepage capacity calculation model;
[0092] Step 5: Weight the calculated seepage capacity by flattening thickness to obtain the comprehensive seepage capacity of the target well group.
[0093] In this embodiment, a planar series combination model of different permeability oil layers of injection and production wells is first established. Combining different combination models, according to Darcy's law, and taking into account the permeability, connectivity, and thickness of the connected layers of the injection and production wells within the well group, a calculation formula for the comprehensive seepage capacity of different permeability layers is derived. Secondly, the calculation results of the comprehensive seepage capacity of different permeability layers on the plane are weighted by flattening the thickness to obtain the comprehensive seepage capacity of the well group.
[0094] In practical application, a five-point well group in Lamadian Oilfield is taken as an example, with one injection well and four production wells. The target layer is divided into four sedimentary units. The permeability of the injection well is 0.678μm. 2 The permeability of oil well 1 is 0.661μm 2 The permeability of oil well 2 is 0.487μm 2 The permeability of oil well 3 is 0.501μm 2 The permeability of oil well 4 is 0.396μm 2The permeability of a certain well or the arithmetic average permeability of five wells can represent the comprehensive seepage capacity of the well group. In order to truly reflect the comprehensive seepage capacity of the well group, the well group is divided into four sections according to the sedimentary units. The sand body between the injection and production wells conforms to the mutation model, and the mutation model is selected to calculate the seepage capacity of each unit; the sand body between the injection and production wells conforms to the gradual change model, and the gradual change model is selected to calculate the seepage capacity of each unit. Then, the four units are flattened and weighted, and the comprehensive seepage capacity of the well group is obtained to be 0.514μm 2 .
[0095] This embodiment matched the injection parameters of more than 400 well groups. After implementation, the proportion of oil layer utilization thickness was nearly 90%, which was nearly 10 percentage points higher than the wells that used the permeability of the injection wells in the well group for injection parameter matching. The water content of more than 400 effective oil wells decreased by 15 percentage points, which was nearly 2 percentage points more than the water content reduction of the original matching method. The cumulative oil production increased by nearly 100,000 tons, and the profit was nearly 50,000 yuan.
[0096] The present invention provides a method for calculating the comprehensive seepage capacity of a sandstone reservoir injection and production well group. The calculation parameters involved are well logging interpretation results data. The method comprehensively considers the effective thickness of oil layers with different permeabilities in all injection and production wells in the well group, the extension distance of oil layers with different permeabilities between the injection and production wells, and the connectivity relationship. The parameters are comprehensively considered and the calculation method is simple.
[0097] The above embodiments are only used to illustrate the present invention, and are not intended to limit the present invention. Ordinary technicians in the relevant technical field may make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions also fall within the scope of the present invention, and the scope of patent protection of the present invention should be defined by the claims.
Claims
1. A method for calculating the comprehensive seepage capacity of an injection-production well group in a sandstone oil reservoir, characterized in that: include: Step S1: determine the target study area, select a target well group within the target study area, and determine the target layer interval corresponding to the target well group; Step S2: Divide the target layer into different sedimentary units according to the different permeability oil layers of the target well group determined in step S1, and establish a plane series model of the corresponding sedimentary units; Step S3: Obtain the basic data and logging information of the target well group determined in step S1, and establish a comprehensive seepage capacity calculation model in combination with the plane series model and Darcy's law obtained in step S2; Step S4: Calculating the seepage capacity of the target well group determined in step S1 using the comprehensive seepage capacity calculation model obtained in step S3; Step S5: performing thickness weighting on the seepage capacity calculation result obtained in step S4 to obtain the comprehensive seepage capacity of the target well group determined in step S1.
2. The method for calculating the comprehensive seepage capacity of an injection-production well group in a sandstone oil reservoir according to claim 1, characterized in that: In step S1, the target well group is a preset well pattern, and the types of preset well patterns include one injection and four production five-point area well pattern, one injection and three production four-point area well pattern, or one injection and eight production reverse nine-point area well pattern.
3. The method for calculating the comprehensive seepage capacity of an injection-production well group in a sandstone oil reservoir according to claim 1, characterized in that: In step S2, the types of the plane series models include a sudden change plane series model of sand bodies between injection and production wells and a gradual change plane series model of sand bodies between injection and production wells.
4. The method for calculating the comprehensive seepage capacity of an injection-production well group in a sandstone oil reservoir according to claim 3, characterized in that: The calculation formula of the sudden change plane series model of sand bodies between injection and production wells is: Where: K xi — Plane seepage capacity of well group i, μm 2 ;K wi —Permeability of layer i in the injection well, μm 2 ; h wi —Effective thickness of layer i corresponding to the injection well, m; —Average effective thickness of the oil producing well in layer i, m; —Weighted average permeability of layer i corresponding to the oil well, μm 2 ; —weighted average permeability of layer i corresponding to the injection well, μm 2 .
5. The method for calculating the comprehensive seepage capacity of an injection-production well group in a sandstone oil reservoir according to claim 3, characterized in that: The calculation formula of the plane series model of the gradual change of sand body between injection and production wells is: Where: K xi — Plane seepage capacity of well group i, μm 2 ;K wi —Permeability of layer i in the injection well, μm 2 ; h wi —Effective thickness of layer i corresponding to the injection well, m; —Average effective thickness of the oil producing well in layer i, m; —Weighted average permeability of layer i corresponding to the oil well, μm 2 ; —weighted average permeability of layer i corresponding to the injection well, μm 2 .
6. The method for calculating the comprehensive seepage capacity of an injection-production well group in a sandstone oil reservoir according to claim 1, characterized in that: In step S3, the basic data of the target well group includes the permeability, connectivity and thickness of the connected layer of the injection and production wells in the target well group; the well logging information of the target well group includes the effective thickness and permeability interpretation information of the target layer.
7. The method for calculating the comprehensive seepage capacity of an injection-production well group in a sandstone oil reservoir according to claim 1, characterized in that: In step S4, the comprehensive seepage capacity calculation model includes a sudden change comprehensive seepage capacity calculation model of the sand body between the injection and production wells and a gradual change comprehensive seepage capacity calculation model of the sand body between the injection and production wells.
8. The method for calculating the comprehensive seepage capacity of an injection-production well group in a sandstone oil reservoir according to claim 7, characterized in that: The calculation formula of the calculation model of the sudden-type comprehensive seepage capacity of the sand body between the injection and production wells is: Where: K is the comprehensive seepage capacity of the well group, μm 2 ;k wij —Permeability of the layer connecting the injection well j and the well i in the well group, μm 2 ; h wij —Thickness of the connection between the jth layer of the injection well and the i-th well in the well group, m; k oij —Permeability of the jth layer of the i-th oil well in the well group, μm 2 ; h oij —Thickness of the connection between the jth layer of the i-th oil well in the well group and the injection well, m; f j —Ratio of the number of connected directions in the jth layer, %; n—Number of connected directions in the i-th layer of the injection well; m—Number of layers with different permeability in the injection well.
9. The method for calculating the comprehensive seepage capacity of an injection-production well group in a sandstone oil reservoir according to claim 7, characterized in that: The calculation formula of the calculation model of the gradual change comprehensive seepage capacity of the sand body between the injection and production wells is: Where: K is the comprehensive seepage capacity of the well group, μm 2 ;k wij —Permeability of the layer connecting the injection well j and the well i in the well group, μm 2 ; h wij —Thickness of the connection between the jth layer of the injection well and the i-th well in the well group, m; k oij —Permeability of the jth layer of the i-th oil well in the well group, μm 2 ; h oij —Thickness of the connection between the jth layer of the i-th oil well in the well group and the injection well, m; f j —Ratio of the number of connected directions in the jth layer, %; n—Number of connected directions in the i-th layer of the injection well; m—Number of layers with different permeability in the injection well.
10. The method for calculating the comprehensive seepage capacity of an injection-production well group in a sandstone oil reservoir according to claim 1, characterized in that: In step S5, the calculation formula for the flattened thickness is: H=((h1+h2+…+h n-1 +h n ) / n+h0) / 2 Among them, H is the flattening thickness of the target well group; h1 is the effective thickness of the oil layer of oil well No. 1, h2 is the effective thickness of the oil layer of oil well No. 2, and so on. n-1 is the effective thickness of the oil layer of oil well n-1, h n is the effective thickness of the oil layer of oil well No. n; h0 is the effective thickness of the oil layer of the water injection well; n is the number of oil wells.