Deep adjustment and plugging well optimization selection method

Abstract

This invention discloses a method for optimizing the selection of deep plugging wells, comprising: acquiring production dynamic data of all oil and water wells in a target block or formation; calculating plugging decision factors using the production dynamic data; calculating the water drive non-uniformity coefficient of the well group; calculating the injection-production non-uniformity coefficient; and allocating the amount of plugging agent used in the oil and water wells. This invention utilizes production dynamic data for the optimized selection of deep plugging wells, solving the well selection decision problem during the allocation of plugging agents between oil and water wells. It provides guidance for the selection of oil and water wells during deep plugging operations in ultra-high water-cut reservoirs. The required data is readily available, and the method is simple and practical, playing a significant role in reducing costs and improving efficiency in the development of ultra-high water-cut reservoirs.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas field development technology, specifically a method for optimizing the selection of deep wells for plugging and regulating. Background Technology

[0002] After decades of water injection development, major onshore oilfields in eastern my country have generally entered the stage of ultra-high water-cut development. A large amount of crude oil remains underground in ultra-high water-cut reservoirs, indicating significant potential for further improving water-drive recovery. Achieving efficient development of ultra-high water-cut reservoirs is of strategic importance for the steady development of China's oil and gas industry and for ensuring national energy security. Deep plugging technology has a significant effect on increasing oil production, reducing water content, and improving development in ultra-high water-cut reservoirs. It can effectively utilize low-permeability areas with high remaining oil saturation, thereby improving reservoir recovery. However, the high cost and large quantities of plugging agents commonly used in these technologies urgently need to be addressed.

[0003] Existing research indicates that, under optimal total plugging agent usage within a well group, rationally distributing the plugging agent between oil and water wells results in better plugging performance for both oil and water wells compared to plugging solely from water or oil wells. Therefore, simultaneously implementing profile control and water shut-off operations on oil and water wells to seal extreme water-washed zones plays a positive role in further improving the development of ultra-high water-cut reservoirs and achieving cost reduction and efficiency improvement in oilfield development. Optimizing the selection of drilling wells is a problem that urgently needs to be solved in field applications.

[0004] Chinese patent document CN103244087B discloses a method for selecting wells for profile control and water shut-off in low-permeability reservoirs. This method calculates decision factors reflecting plugging agent injection characteristics and intra-layer, inter-layer, and planar heterogeneity to establish profile control and water shut-off decision factors, thereby optimizing the selection of profile control and water shut-off wells. This method addresses the problems of poor applicability and predictive ability of the PI decision method in low-permeability oilfields, unstable decision factor calculation, and inability to reflect reservoir heterogeneity, thus achieving scientific well selection for profile control and water shut-off wells in low-permeability reservoirs. However, it cannot solve the problem of optimizing the selection of construction wells when oil and water wells are operated simultaneously.

[0005] Chinese patent document CN106894800B discloses a method for profile control and well selection decision-making applicable to offshore heavy oil reservoirs. This method, based on classifying single-factor indicators in profile control and well selection decision-making according to their attributes, calculates the comprehensive evaluation index value of the water injection well to be evaluated and the average value of the comprehensive evaluation index of the water injection wells in the block. By comparing the two, it determines whether the water injection well to be evaluated needs profile control measures. This method uses the analytic hierarchy process (AHP) to calculate the weights of each component, eliminating the influence of human factors and making the profile control and well selection decision-making method more scientific and reasonable. However, it can only optimize the selection of profile control wells and cannot solve the problem of optimizing the selection of construction wells when oil and water wells are operated simultaneously.

[0006] Overall, there is currently a lack of research on the optimal selection method for construction wells when oil and water wells are operated simultaneously within a well group, which cannot effectively guide mine construction. Summary of the Invention

[0007] In view of the above problems, the present invention is proposed to provide an optimized selection method for deep well plugging and sealing to overcome or at least partially solve the above problems.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] A method for optimizing the selection of deep plugging wells, the method comprising the following steps:

[0010] S1. Obtain the production dynamic data of all oil and water wells in the target block or formation;

[0011] S2. Calculate congestion control decision factors using production dynamic data;

[0012] S3. Calculate the water drive non-uniformity coefficient of the well group;

[0013] S4. Calculate the injection-production non-uniformity coefficient;

[0014] S5. Allocate the amount of plugging agent used in oil and water wells.

[0015] Optionally, the production dynamic data in step S1 includes the development month of the production well and the corresponding monthly fluid production, and the water injection month of the water well and the corresponding monthly water injection volume.

[0016] Optionally, step S2 includes:

[0017] S21. Count the number of all water wells in the target block or stratum, divide the wells into injection-production well groups centered on the water wells, and distinguish each injection-production well group by w, where w = 1, 2, ..., N. w N w This indicates the number of water wells in the target block, which is also the number of injection-production well groups.

[0018] S22. For each injection-production well group w, count the number of production wells that have an injection-production correspondence with the central injection well, and distinguish each production well by i, where i = 1. This indicates the number of production wells in well group w that have an injection-production relationship with the central injection well;

[0019] S23. For each injection-production well group w, for each production well i that has an injection-production relationship with the central injection well of the well group, select the water injection volume data of the injection well and the liquid production data of the production well for the 12 months prior to the decision time, and calculate the plugging decision factor of production well i in the injection-production well group w according to formula (1).

[0020]

[0021] In formula (1), Q is the decision factor for regulating and plugging production well i in injection-production well group w; w (t) represents the water injection volume of injection well w in month t; DQ w (t)=Q w (t+1)-Q w (t), representing the difference in water injection volume between two consecutive months for injection well w, t = 1, 2, ..., 11; q i (t) represents the fluid production of production well i in month t; D q i (t)=q i (t+1)-q i (t) represents the difference in production volume of well i in two adjacent months, t = 1, 2, ..., 11.

[0022] Optionally, step S3 includes:

[0023] S31. For each injection-production well group w, calculate the water drive non-uniformity coefficient NC of the well group according to formula (2). w :

[0024]

[0025] In formula (2), NC w denoted as the water drive non-uniformity coefficient of well group w (injection-production well group); This indicates the number of production wells in well group w that have an injection-production relationship with the central injection well; This represents the normalized value of the plugging decision factor between production well i and injection well w in the injection-production well group centered on injection well w; Indicates the injection-production well group w The average value;

[0026] The larger the water drive non-uniformity coefficient of the injection-production well group, the more serious the non-uniform displacement of the well group, and the higher the necessity of deep plugging.

[0027] S32. Sort the calculated water drive non-uniformity coefficients of all injection-production well groups centered on injection wells in the target block.

[0028] S33. Compare each water drive non-uniformity coefficient with the average water drive non-uniformity coefficient of the target block, and select injection-production well groups with water drive non-uniformity coefficients higher than the average water drive non-uniformity coefficient of the target block for deep plugging construction.

[0029] Optionally, the water drive non-uniformity coefficient of the well group in step S3 can be calculated using the deep plugging construction well group.

[0030] Optionally, step S4 includes:

[0031] S41, with w n Distinguish the selected well groups for construction, w n =1,2,…,N wn N wn Indicates the number of selected well groups for construction in the target block;

[0032] S42. Selection and optimization of well groups for construction. n The central injection well has corresponding production wells with injection-production relationships. Each production well is distinguished by j, where j=1. Indicates w n The number of production wells with injection-production correspondence between well groups and injection wells is further optimized to select production wells to be constructed; w is calculated according to formula (3). n Injection-production non-uniformity coefficient for each production well in the well group that has an injection-production correspondence with the central injection well.

[0033]

[0034] In the formula, For w n The injection-production non-uniformity coefficient of production well j in the well group that has an injection-production correspondence with the central injection well; Indicates water injection well w n In the injection-production well group centered on the well, production well j and injection well w n The normalized values ​​of the decision factors for congestion control; Indicates injection and production well group w n middle The average value.

[0035] S43, w n The injection-production non-uniformity coefficients of each production well in the well group that has an injection-production correspondence with the central injection well are sorted from largest to smallest, and the production well with the largest injection-production non-uniformity coefficient is selected as the construction well.

[0036] Optionally, the injection-production non-uniformity coefficient in step S4 can be calculated using the production wells that need to be shut off within the deep well group.

[0037] Optionally, the principles for allocating the plugging agent in oil and water wells in step S5 include:

[0038] The total amount of plugging agent used in the well group is 40% of the pore volume in the extreme water-washed zone.

[0039] The amount of plugging agent used in production wells that require water shut-off should be allocated according to 10% of the total plugging agent usage for the well group.

[0040] The amount of plugging agent used in water injection wells is equal to the total amount of plugging agent used in the well group minus the amount of plugging agent used in production wells.

[0041] The method for setting the plugging agent in water injection wells is as follows: the amount of plugging agent used in the extreme water washing zone is designed to be 70% of the design amount of the plugging agent for the well; the amount used in the transition zone between the extreme water washing zone and the strong water flooding zone is designed to be 20% of the design amount of the plugging agent for the well; and the amount used in the strong water flooding zone is designed to be 10% of the design amount of the plugging agent for the well.

[0042] The method for setting the plugging agent in production wells is as follows: the amount of plugging agent used in the extreme water-washing zone is designed to be 50% of the designed amount of plugging agent for the well; the amount used in the transition zone between the extreme water-washing zone and the strong water-flooding zone is designed to be 30% of the designed amount of plugging agent for the well; and the amount used in the strong water-flooding zone is designed to be 20% of the designed amount of plugging agent for the well.

[0043] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are:

[0044] 1. The technical solution of this invention provides an optimized selection method for deep plugging wells based on the construction technology requirements of deep plugging operations in ultra-high water-cut oil reservoirs. It divides injection-production well groups around injection wells, defines and calculates the water drive non-uniformity coefficient of the well groups, and preferentially selects the construction well groups for deep plugging. Based on this, it defines and calculates the injection-production non-uniformity coefficient, preferentially selects the production wells requiring water plugging within the construction well groups, and provides the principle for allocating plugging agent dosages in oil and water wells.

[0045] 2. The technical solution of this invention combines the distribution characteristics and development characteristics of remaining oil in ultra-high water-cut reservoirs, and uses production dynamic data to optimize the selection of deep plugging wells. It can solve the well selection decision problem when distributing plugging agents between oil and water wells, and provide guidance for the selection of oil and water wells during deep plugging operations in ultra-high water-cut reservoirs. The required data is easy to obtain, simple and practical, and plays an important role in reducing costs and improving efficiency in the development of ultra-high water-cut reservoirs. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of a method for optimizing the selection of deep plugging wells, provided as an embodiment of this application. Detailed Implementation

[0047] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0048] Please see Figure 1 This embodiment provides a method for optimizing the selection of deep plugging wells, the method comprising the following steps:

[0049] S1. Obtain the production dynamic data of all oil and water wells in the target block or layer.

[0050] The production dynamic data in step S1 includes the development month of the production well and the corresponding monthly fluid production, the water injection month of the water well and the corresponding monthly water injection volume, which are exported from the oil and water well production dynamic data acquisition system.

[0051] S2. Calculate congestion control decision factors using production dynamic data.

[0052] Step S2 includes:

[0053] S21. Count the number of all water wells in the target block or stratum, divide the wells into injection-production well groups centered on the water wells, and distinguish each injection-production well group by w, where w = 1, 2, ..., N. w N w This indicates the number of water wells in the target block, which is also the number of injection-production well groups.

[0054] S22. For each injection-production well group w, count the number of production wells that have an injection-production correspondence with the central injection well, and distinguish each production well by i, where i = 1. This indicates the number of production wells in well group w that have an injection-production relationship with the central injection well;

[0055] The test area has 6 water injection wells and 16 corresponding oil wells, so there are 6 injection-production well groups. The specific oil wells corresponding to each injection-production well group are shown in columns 1-2 of Table 1.

[0056] S23. For each injection-production well group w, for each production well i that has an injection-production relationship with the central injection well of the well group, select the water injection volume data of the injection well and the liquid production data of the production well in the 12 months before the decision time, and calculate the plugging decision factor of production well i in the injection-production well group w according to formula (1).

[0057]

[0058] In formula (1), Q is the decision factor for regulating and plugging production well i in injection-production well group w; w (t) represents the water injection volume of injection well w in month t; DQ w (t)=Q w (t+1)-Q w (t), representing the difference in water injection volume between two consecutive months for injection well w, t = 1, 2, ..., 11; q i (t) represents the fluid production of production well i in month t; D q i (t)=q i (t+1)-q i (t) represents the difference in production volume of well i in two adjacent months, t = 1, 2, ..., 11.

[0059] The decision factor for adjusting and blocking each production well i in each injection-production well group w is calculated according to formula (1), as shown in column 3 of Table 1.

[0060] Table 1: Optimal Results of Deep Plugging Well Groups in the Target Block in the Examples

[0061]

[0062]

[0063]

[0064] S3. Calculate the water drive non-uniformity coefficient of the well group. The water drive non-uniformity coefficient of the well group is calculated using the deep plugging construction well group.

[0065] Step S3 includes:

[0066] S31. For each injection-production well group w, calculate the water drive non-uniformity coefficient NC of the well group according to formula (2). w :

[0067]

[0068] In formula (2), NC w denoted as the water drive non-uniformity coefficient of well group w (injection-production well group); This indicates the number of production wells in well group w that have an injection-production relationship with the central injection well; This represents the normalized value of the plugging decision factor between production well i and injection well w in the injection-production well group centered on injection well w; Indicates the injection-production well group w The average value.

[0069] In the formula, In calculation On this basis, Calculate according to the following formula:

[0070] The larger the water drive non-uniformity coefficient of the injection-production well group, the more serious the non-uniform displacement of the well group, and the higher the necessity of deep plugging.

[0071] S32. Sort the calculated water drive non-uniformity coefficients of all injection-production well groups centered on injection wells in the target block; the larger the water drive non-uniformity coefficient, the higher the priority of deep plugging construction within the economic cost allowable range.

[0072] S33. Compare each water drive non-uniformity coefficient with the average water drive non-uniformity coefficient of the target block, and select injection-production well groups with water drive non-uniformity coefficients higher than the average water drive non-uniformity coefficient of the target block for deep plugging construction.

[0073] The water drive non-uniformity coefficient for each injection-production well group was calculated according to formula (2), as shown in column 4 of Table 1. The average value of the six water drive non-uniformity coefficients was 0.4077. Based on the selection principle of construction well groups, well groups w_3 and w_5 were selected as the construction well groups for deep plugging.

[0074] S4. Calculate the injection-production non-uniformity coefficient; the injection-production non-uniformity coefficient in step S4 is calculated using the production wells that need to be shut off within the deep well group for plugging and adjusting operations.

[0075] Step S4 includes:

[0076] S41. Based on the optimized selection results of deep well group selection for plugging and repair operations, with w n Distinguish the selected well groups for construction, w n =1,2,…,N wn N wn Indicates the number of selected well groups for construction in the target block;

[0077] S42. Selection and optimization of well groups for construction. n The central injection well has corresponding production wells with injection-production relationships. Each production well is distinguished by j, where j=1. Indicates w n The number of production wells with injection-production correspondence between well groups and injection wells is further optimized to select production wells to be constructed; w is calculated according to formula (3). n The injection-production non-uniformity coefficient of each production well in the well group that has an injection-production correspondence with the central injection well;

[0078]

[0079] In the formula, For w n The injection-production non-uniformity coefficient of production well j in the well group that has an injection-production correspondence with the central injection well; Indicates water injection well w n In the injection-production well group centered on the well, production well j and injection well w n The normalized values ​​of the decision factors for congestion control; Indicates injection and production well group w n middle The average value.

[0080] In the formula, In calculation On this basis,

[0081] S43, w n The injection-production non-uniformity coefficients of each production well in the well group that has an injection-production correspondence with the central injection well are sorted from largest to smallest, and the production well with the largest injection-production non-uniformity coefficient is selected as the construction well.

[0082] In this embodiment, two well groups need to undergo deep plugging construction, namely w_3 and w_5, which include oil wells i_6, i_7, i_8, i_11, i_12, i_13, i_14, and i_15, respectively. The injection-production non-uniformity coefficient within the deep plugging well group is calculated according to equation (3), as shown in Table 2.

[0083] Table 2: Non-uniformity coefficient of injection and production in deep plugging well groups

[0084]

[0085]

[0086] According to the selection principle of production wells that need to be shut off, i_8 is preferred as the construction production well in the w_3 deep plugging and adjustment well group, and i_12 is preferred as the construction production well in the w_5 deep plugging and adjustment well group.

[0087] S5. Allocate the amount of plugging agent used in oil and water wells.

[0088] The principles for allocating the plugging agent in oil and water wells in step S5 include:

[0089] The total amount of plugging agent used in the well group is 40% of the pore volume in the extreme water-washed zone.

[0090] The amount of plugging agent used in production wells that require water shut-off should be allocated according to 10% of the total plugging agent usage for the well group.

[0091] The amount of plugging agent used in water injection wells is equal to the total amount of plugging agent used in the well group minus the amount of plugging agent used in production wells.

[0092] The method for setting the plugging agent in water injection wells is as follows: the amount of plugging agent used in the extreme water washing zone is designed to be 70% of the design amount of the plugging agent for the well; the amount used in the transition zone between the extreme water washing zone and the strong water flooding zone is designed to be 20% of the design amount of the plugging agent for the well; and the amount used in the strong water flooding zone is designed to be 10% of the design amount of the plugging agent for the well.

[0093] The method for setting the plugging agent in production wells is as follows: the amount of plugging agent used in the extreme water-washing zone is designed to be 50% of the designed amount of plugging agent for the well; the amount used in the transition zone between the extreme water-washing zone and the strong water-flooding zone is designed to be 30% of the designed amount of plugging agent for the well; and the amount used in the strong water-flooding zone is designed to be 20% of the designed amount of plugging agent for the well.

[0094] This embodiment provides an optimized selection method for deep plugging wells based on the construction technology requirements of deep plugging operations in ultra-high water-cut oil reservoirs. It divides injection-production well groups around injection wells, defines and calculates the water drive non-uniformity coefficient of these groups, and optimizes the selection of deep plugging well groups. Furthermore, it defines and calculates the injection-production non-uniformity coefficient, optimizes the production wells requiring plugging within the selected well groups, and provides principles for allocating plugging agent dosages between oil and water wells.

[0095] This embodiment combines the characteristics of remaining oil distribution and development in ultra-high water-cut reservoirs, and uses dynamic production data to optimize the selection of deep plugging wells. It can solve the well selection decision problem when distributing plugging agents between oil and water wells, and provide guidance for the selection of oil and water wells during deep plugging operations in ultra-high water-cut reservoirs. The required data is easy to obtain, simple and practical, and plays an important role in reducing costs and improving efficiency in the development of ultra-high water-cut reservoirs.

[0096] The above description, in conjunction with specific preferred embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, various simple deductions or substitutions can be made without departing from the concept of the present invention, and all such modifications and substitutions should be considered within the scope of protection of the present invention.

Claims

1. A method for optimizing the selection of deep plugging wells, characterized in that, The method includes the following steps: S1. Obtain the production dynamic data of all oil and water wells in the target block or formation; S2. Calculate congestion control decision factors using production dynamic data; S3. Calculate the water drive non-uniformity coefficient of the well group; S4. Calculate the injection-production non-uniformity coefficient; S5. Allocate the amount of plugging agent used in oil and water wells.

2. The method for optimizing the selection of deep plugging wells as described in claim 1, characterized in that, The production dynamic data in step S1 includes the development month of the production well and the corresponding monthly fluid production, and the water injection month of the water well and the corresponding monthly water injection volume.

3. The method for optimizing the selection of deep plugging wells as described in claim 1, characterized in that, Step S2 includes: S21, count all the water well numbers of the target block or horizon, divide the injection-production well group with the water well as the center, and distinguish each injection-production well group by w, w=1, 2, …, N w , N w represents the water well number of the target block, that is, the number of the divided injection-production well groups; S22, for each injection-production well group w, count the number of production wells having injection-production correspondence with the central injection well, distinguish each production well by i, i = 1, 2, …, N o w , N o w represents the number of production wells in injection-production well group w having injection-production correspondence with the central injection well; S23. For each injection-production well group w, for each production well i that has an injection-production relationship with the central injection well of the well group, select the water injection volume data of the injection well and the liquid production data of the production well for the 12 months prior to the decision time, and calculate the plugging decision factor of production well i in the injection-production well group w according to formula (1). In formula (1), Q is the decision factor for regulating and plugging production well i in injection-production well group w; w (t) represents the water injection volume of injection well w in month t; DQ w (t)=Q w (t+1)-Q w (t), representing the difference in water injection volume between two consecutive months for injection well w, t = 1, 2, ..., 11; q i (t) represents the fluid production of production well i in month t; D q i (t)=q i (t+1)-q i (t) represents the difference in production volume of well i in two adjacent months, t = 1, 2, ..., 11.

4. The method for optimizing the selection of deep plugging wells as described in claim 1, characterized in that, Step S3 includes: S31. For each injection-production well group w, calculate the water drive non-uniformity coefficient NC of the well group according to formula (2). w : In formula (2), NC w N is the water drive non-uniformity coefficient of injection-production well group w; o w This indicates the number of production wells in well group w that have an injection-production relationship with the central injection well; This represents the normalized value of the plugging decision factor between production well i and injection well w in the injection-production well group centered on injection well w; Indicates the injection-production well group w The average value; The larger the water drive non-uniformity coefficient of the injection-production well group, the more serious the non-uniform displacement of the well group, and the higher the necessity of deep plugging. S32. Sort the calculated water drive non-uniformity coefficients of all injection-production well groups centered on injection wells in the target block. S33. Compare each water drive non-uniformity coefficient with the average water drive non-uniformity coefficient of the target block, and select injection-production well groups with water drive non-uniformity coefficients higher than the average water drive non-uniformity coefficient of the target block for deep plugging construction.

5. The method for optimizing the selection of deep plugging wells as described in claim 1, characterized in that, In step S3, the water drive non-uniformity coefficient of the well group is calculated using the deep plugging construction well group.

6. The method for optimizing the selection of deep plugging wells as described in claim 1, characterized in that, Step S4 includes: S41, with w n Distinguish the selected well groups for construction, w n =1,2,…,N wn N wn Indicates the number of selected well groups for construction in the target block; S42. Selection and optimization of well groups for construction. n The central injection well has corresponding production wells with injection-production relationships. Each production well is distinguished by j, where j = 1, 2, ..., N. o wn N o wn Indicates w n The number of production wells with injection-production correspondence between well groups and injection wells is further optimized to select production wells to be constructed; w is calculated according to formula (3). n Injection-production non-uniformity coefficient for each production well in the well group that has an injection-production correspondence with the central injection well. In the formula, For w n The injection-production non-uniformity coefficient of production well j in the well group that has an injection-production correspondence with the central injection well; Indicates water injection well w n In the injection-production well group centered on the well, production well j and injection well w n The normalized values ​​of the decision factors for congestion control; Indicates injection and production well group w n middle The average value. S43, w n The injection-production non-uniformity coefficients of each production well in the well group that has an injection-production correspondence with the central injection well are sorted from largest to smallest, and the production well with the largest injection-production non-uniformity coefficient is selected as the construction well.

7. The method for optimizing the selection of deep plugging wells as described in claim 1, characterized in that, In step S4, the injection-production non-uniformity coefficient is calculated using the water-blocking production wells within the deep well group.

8. The method for optimizing the selection of deep plugging wells as described in claim 1, characterized in that, The principles for allocating the plugging agent in oil and water wells in step S5 include: The total amount of plugging agent used in the well group is 40% of the pore volume in the extreme water-washed zone. The amount of plugging agent used in production wells that require water shut-off should be allocated according to 10% of the total plugging agent usage for the well group. The amount of plugging agent used in water injection wells is equal to the total amount of plugging agent used in the well group minus the amount of plugging agent used in production wells. The method for setting the plugging agent in water injection wells is as follows: the amount of plugging agent used in the extreme water washing zone is designed to be 70% of the design amount of the plugging agent for the well; the amount used in the transition zone between the extreme water washing zone and the strong water flooding zone is designed to be 20% of the design amount of the plugging agent for the well; and the amount used in the strong water flooding zone is designed to be 10% of the design amount of the plugging agent for the well. The method for setting the plugging agent in production wells is as follows: the amount of plugging agent used in the extreme water-washing zone is designed to be 50% of the designed amount of plugging agent for the well; the amount used in the transition zone between the extreme water-washing zone and the strong water-flooding zone is designed to be 30% of the designed amount of plugging agent for the well; and the amount used in the strong water-flooding zone is designed to be 20% of the designed amount of plugging agent for the well.

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