Method and device for determining productivity after water plugging in a vertical well

Abstract

The application discloses a method and device for determining the productivity of a straight well after water plugging, and the method comprises the following steps: obtaining basic data of a target oil well before water plugging; drawing an IPR curve of the target oil well according to the basic data; determining the reduction ratio of reservoir pore permeability after water plugging according to the basic data; correcting the IPR curve according to the reduction ratio of reservoir pore permeability to obtain an IPR curve after water plugging; and predicting the productivity after water plugging according to the IPR curve after water plugging. According to the method, the inflow performance of the oil well after water plugging can be quickly and accurately determined, the amount of plugging agent is optimized, and the oil well recovery rate is improved.

Description

Technical Field

[0001] This invention relates to the field of gas field development, and in particular to a method and apparatus for determining production capacity after water shut-off of a vertical well. Background Technology

[0002] Water channeling frequently occurs during oil well production, causing a gradual increase in water content. Water shut-off has become a production enhancement measure throughout the entire oil well production lifecycle. Water shut-off increases water production by injecting plugging agents into the reservoir to reduce reservoir permeability. Essentially, it blocks the pores and channels (narrow sections of the pore passages through which fluid flows) of the reservoir, thereby reducing reservoir permeability and altering the well's inflow dynamics. Currently, there is no theoretically effective method for determining the production dynamics before and after water shut-off in oil wells. This is due to the different plugging mechanisms and types of plugging agents used, as well as the complexity of actual plugging and reservoir physicochemical properties. However, calculating the IPR (Inflow Performance Relationship) curve after water shut-off is crucial for predicting water shut-off and selecting the appropriate plugging agent dosage. Therefore, understanding the relationship between bottomhole flowing pressure and production after water shut-off, i.e., production capacity prediction, is of great importance. How to quickly and effectively determine the well's inflow dynamics at a specific plugging agent dosage is one of the urgent problems to be solved in actual production.

[0003] Currently, the main method for determining the inflow dynamics after water shut-off is through numerical simulation. Based on experimental data, the permeability reduction value of the shut-off area is artificially changed to simulate the oil well production process. This method can only provide a preliminary estimate of the changes in reservoir permeability, and numerical simulation methods require a high degree of accuracy in reservoir data and oil well production data, often resulting in simulation results that differ significantly from reality. Summary of the Invention

[0004] This invention provides a method and apparatus for determining the production capacity after water shut-off in a vertical well, so as to quickly and accurately determine the inflow dynamics of the oil well after water shut-off, thereby optimizing the amount of plugging agent and improving the oil well recovery rate.

[0005] Therefore, the present invention provides the following technical solution:

[0006] This invention provides a method for determining the production capacity after water shut-off in a vertical well, the method comprising:

[0007] Before shutting off water from the target oil well, the basic data includes: calculation parameters, physical properties of formation crude oil and formation water, bottom hole flow pressure, saturation pressure and deep reservoir pressure;

[0008] The IPR curve of the target oil well is plotted based on the aforementioned basic data;

[0009] The percentage reduction in reservoir pore permeability after water shut-off is determined based on the aforementioned basic data.

[0010] The IPR curve is corrected based on the reduction ratio of reservoir pore permeability to obtain the IPR curve after water shut-off.

[0011] The production capacity after water plugging is predicted based on the IPR curve after water plugging.

[0012] Optionally, the target oil well includes an oil well with stable production output and wellhead pressure over a certain period of time.

[0013] Optionally, the calculation parameters include any one or more of the following: wellhead temperature, daily gas production and daily water production, downhole tubing conditions, and reservoir pore size data.

[0014] Optionally, plotting the IPR curve of the target oil well based on the basic data includes:

[0015] The liquid recovery index and critical production rate are determined based on the aforementioned basic data;

[0016] Calculate the bottom hole flow pressure at each production rate based on the fluid production index and the critical production rate, and plot the IPR curve of the target oil well based on the calculation results.

[0017] Optionally, determining the percentage reduction in reservoir pore permeability after water shut-off based on the basic data includes:

[0018] The sweep radius of the plugging agent is determined based on the amount of plugging agent used;

[0019] The cross-sectional area of ​​a single capillary bundle is calculated based on the average reservoir pore radius and the number of capillary bundles in the capillary bundle model.

[0020] Calculate the remaining cross-sectional area of ​​the single capillary bundle after it is blocked, based on the sweep radius of the plugging agent and the cross-sectional area of ​​the single capillary bundle.

[0021] The percentage reduction in reservoir pore permeability after water shut-off is calculated based on the cross-sectional area of ​​a single capillary bundle and the remaining cross-sectional area after plugging.

[0022] Optionally, the step of correcting the IPR curve based on the reduction ratio of reservoir pore permeability to obtain the IPR curve after water shut-off includes:

[0023] Calculate the fluid production index and well production after water shut-off based on the reservoir porosity reduction ratio and the fluid production index.

[0024] The IPR curve is corrected based on the fluid production index and well production after water shut-off to obtain the IPR curve after water shut-off.

[0025] The present invention also provides a device for determining the production capacity after water shut-off in a vertical well, the device comprising:

[0026] The data acquisition module is used to acquire basic data of the target oil well before water shut-off. The basic data includes: calculation parameters, physical property parameters related to formation crude oil and formation water, saturation pressure and reservoir pressure.

[0027] The IPR curve generation module is used to draw the IPR curve of the target oil well based on the basic data.

[0028] The permeability determination module is used to determine the percentage reduction in reservoir pore permeability after water shut-off based on the aforementioned basic data.

[0029] The curve correction module is used to correct the IPR curve according to the reduction ratio of the reservoir pore permeability to obtain the IPR curve after water shut-off.

[0030] The prediction module is used to predict the production capacity after water plugging based on the IPR curve after water plugging.

[0031] Optionally, the IPR curve generation module includes:

[0032] The first calculation unit determines the liquid recovery index and critical production rate based on the basic data, and calculates the flow pressure at each production rate based on the liquid recovery index and the critical production rate.

[0033] The curve plotting unit is used to plot the IPR curve of the target oil well based on the calculation results.

[0034] Optionally, the penetration rate determination module includes:

[0035] The plugging agent spillover area determination unit is used to determine the spillover radius of the plugging agent based on the amount of plugging agent used;

[0036] The second calculation unit is used to calculate the cross-sectional area of ​​a single capillary bundle based on the average reservoir pore radius and the number of capillary bundles in the capillary bundle model; to calculate the remaining cross-sectional area of ​​a single capillary bundle after plugging based on the sweep radius of the plugging agent and the cross-sectional area of ​​the single capillary bundle; and to calculate the percentage reduction in reservoir pore permeability after water plugging based on the cross-sectional area of ​​the single capillary bundle and the remaining cross-sectional area after plugging.

[0037] Optionally, the curve correction module includes:

[0038] The third calculation unit is used to calculate the fluid production index and oil well production after water shut-off based on the reservoir porosity reduction ratio and the fluid production index.

[0039] The correction unit is used to correct the IPR curve based on the fluid production index and oil well production after water shut-off, so as to obtain the IPR curve after water shut-off.

[0040] The present invention also provides a computer-readable storage medium having a computer program stored thereon, wherein the computer program, when executed by a processor, performs the steps of the method for determining the production capacity after water shut-off of a vertical well.

[0041] The method and apparatus for determining the production capacity of a vertical well after water shut-off provided in this invention generate an IPR curve based on the production status of the oil well before water shut-off. Then, based on the amount of plugging agent used and combined with reservoir static data, the reduction ratio of reservoir pore permeability after water shut-off, i.e., the degree of reduction in the production index, is calculated. By correcting the IPR curve before water shut-off, the inflow dynamics of the oil well after water shut-off are determined, i.e., the IPR curve after water shut-off. The production capacity after water shut-off is predicted based on the IPR curve after water shut-off. Using this invention, the inflow dynamics of the oil well after water shut-off can be determined quickly and accurately, thereby optimizing the amount of plugging agent used and improving the oil well recovery rate. Attached Figure Description

[0042] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the embodiments will be briefly described below. Obviously, the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any creative effort.

[0043] Figure 1 This is a flowchart of a method for determining the production capacity after water shut-off in a vertical well, provided in an embodiment of the present invention.

[0044] Figure 2 These are schematic diagrams showing the shapes of IPR curves under several different reservoir drive types.

[0045] Figure 3 This is a schematic diagram of the IPR curve of an oil well in an embodiment of the present invention;

[0046] Figure 4 This is a schematic diagram of the IPR curves of an oil well before and after water plugging in an embodiment of the present invention;

[0047] Figure 5 This is a schematic diagram of a device for determining the production capacity after water plugging in a vertical well, provided in an embodiment of the present invention. Detailed Implementation

[0048] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0049] To address the problem of determining the inflow dynamics after water shut-off using existing numerical simulation methods, this invention provides a method and apparatus for determining the production capacity of a vertical well after water shut-off. Based on the production status and plugging agent dosage of the oil well before water shut-off, combined with reservoir static data, the degree of reduction in reservoir pore radius is calculated, the degree of reduction in the well's production index is judged, and the inflow dynamics of the oil well after water shut-off are determined.

[0050] like Figure 1 The diagram shown is a flowchart of a method for determining the production capacity after water shut-off in a vertical well, provided by the present invention, which includes the following steps:

[0051] Step 101: Obtain basic data of the target oil well. The basic data includes, but is not limited to: calculation parameters, formation crude oil and formation water related physical properties (such as tortuosity, reservoir thickness, control reserve radius, porosity, etc.), bottom hole flow pressure, saturation pressure and deep reservoir pressure, etc.

[0052] The target oil wells include those with stable production output and wellhead pressure over a certain period (e.g., 30 days). The basic data represents the production status of the oil wells before water shut-off.

[0053] The calculation parameters may include, but are not limited to, any one or more of the following: wellhead temperature, daily production, downhole tubing conditions, reservoir pore size data, etc.

[0054] Step 102: Plot the IPR curve of the target oil well based on the basic data.

[0055] The IPR (Inflow Performance Relationship) curve represents the relationship between well production q and bottomhole flowing pressure p. wf The IPR curve reflects the reservoir's ability to supply oil to the well. Using the IPR curve, the optimal operating mode for the well can be determined, and well dynamics can be analyzed.

[0056] The shape of the IPR curve is usually related to the reservoir drive type, such as Figure 2 As shown, schematic diagrams illustrating the shapes of IPR curves under several different reservoir drive types are presented. Wherein, P... b P represents the saturation pressure. r p represents the deep reservoir pressure.wf q represents the bottom hole flow pressure, and q represents the oil well production.

[0057] in:

[0058] Well A is a water-drive well, satisfying the following condition: P r >p wf >P b ;

[0059] Well B's drive type is between water drive and dissolved gas drive, satisfying the following condition: P r >P b >p wf ;

[0060] Well C is driven by dissolved gas and meets the following conditions: P r <P b .

[0061] The calculation methods for IPR (Intake Reservoir Precipitation) typically include reservoir numerical simulation and semi-empirical methods. Among them, reservoir numerical simulation is complex and time-consuming, while semi-empirical methods are simple and easy to use, but have certain errors.

[0062] It should be noted that, in the embodiments of the present invention, the oil well production q refers to the oil well fluid production, that is, the oil-water mixture volume.

[0063] In this embodiment of the invention, the oil well production rate q and the bottom hole flowing pressure p can be calculated in the following manner. wf The relationship is then used to generate the corresponding IPR curve:

[0064] First, the fluid production index and critical production rate are determined based on the basic data; then, the flowing pressure at each production rate is calculated based on the fluid production index and critical production rate; finally, the IPR curve of the target oil well is plotted based on the calculation results.

[0065] The calculation process described above will be explained in detail below.

[0066] (1) Calculation of the liquid recovery index:

[0067] The fluid production index J refers to the oil well production per unit production pressure difference. It is a comprehensive indicator that reflects the relationship between oil reservoir properties, thickness, fluid parameters, completion conditions, and drainage area and production.

[0068] Assume the bottom-hole flow pressure at a certain test point is p wf(test) The corresponding oil well production is q. t(test) The deep reservoir pressure is The saturation pressure is p b The liquid collection index J is calculated as follows:

[0069] When p wf(test) ≥pb hour,

[0070] When p wf(test) <p b hour,

[0071] in, f w Indicates moisture content.

[0072] If the basic data provides the oil and water production q at a specific test point... oil and q water However, since the well production rate at this test point is not given, the well production rate q at this test point can be calculated using the following formula. (test) :

[0073] q (test) =f w q water +(1-f w )q oil (3)

[0074] (2) Calculation of critical output:

[0075] The critical production rate refers to the maximum production rate of an oil well before the bottom water cone enters the wellbore during the production process. Exceeding this value will cause the oil well to reach water, affecting production efficiency.

[0076] In this embodiment of the invention, the critical yield is calculated as follows:

[0077]

[0078] Maximum oil production:

[0079] Maximum output:

[0080] Where, q l The variable representing the corresponding oil well production q can be viewed as the oil well production under different operating conditions.

[0081] (3) Calculate the production rate q for each type of oil well based on the fluid recovery index and critical production rate. l Bottom-hole flow pressure p wf The specific calculation formula is as follows:

[0082] If q omax l ≤q lmax ,but:

[0083]

[0084] If q b ​l ≤q omax ,but:

[0085]

[0086] If 0 l ≤q b ,but:

[0087]

[0088] Based on the above calculations, the output q for each type of product is obtained. l Bottom-hole flow pressure p wf The IPR curve is then plotted based on the calculation results. This IPR curve is the IPR curve of the oil well before water shut-off.

[0089] Step 103: Determine the percentage reduction in reservoir pore permeability after water shut-off based on the aforementioned basic data.

[0090] Specifically, the sweep radius of the plugging agent can be determined based on the amount of plugging agent Q. The sweep radius can be determined based on the production of the plugging agent Q in the formation, and the calculation formula is as follows:

[0091]

[0092] Where, r 波及 r is the radius of influence. ω The radius of the wellbore is represented by h, and the thickness of the oil layer is h. This refers to reservoir porosity.

[0093] Then, based on the number of capillary bundles in the capillary bundle model, the reduction ratio of reservoir pore permeability after water shut-off is calculated.

[0094] The capillary bundle model is an ideal model for characterizing porous media (such as rocks), simplifying rock pores into a structure composed of parallel capillary bundles of equal diameter. The capillary bundle model is primarily used to describe fluid flow behavior in porous media, and is particularly important in oil and gas reservoir evaluation and development. By simplifying the pore structure, this model helps researchers understand and predict the transport characteristics of fluids in porous media, such as capillary pressure, porosity, and permeability.

[0095] The capillary bundle model refers to the capillary bundle model corresponding to the target oil well. The construction method of the capillary bundle model can adopt existing related technologies, and this embodiment of the invention does not limit it.

[0096] The specific calculation process for the reduction in reservoir porosity permeability is as follows:

[0097] Based on the average reservoir pore radius r and the number of capillary bundles n in the capillary bundle model, calculate the cross-sectional area A of a single capillary bundle.​​b A b =πr 2 ;

[0098] Based on the sweep radius of the plugging agent and the cross-sectional area A of the single capillary bundle. b Calculate the remaining cross-sectional area A after a single capillary bundle becomes blocked. a A a =A b -Qρ / nr 波及 ρ represents the plugging efficiency. The plugging efficiency refers to the percentage of plugging agent effectively applied to the reservoir relative to the total amount of plugging agent.

[0099] Based on the cross-sectional area A of a single capillary bundle b and the remaining cross-sectional area A after blockage a Calculate the percentage decrease in reservoir pore permeability N after water shut-off, i.e., N = A a / A b .

[0100] The Kozeny-Carman equation is a classic equation used to describe the permeability of fluids in porous media. It is a simple mathematical model that can be used to predict the permeability of fluids in porous media.

[0101] In this embodiment of the invention, according to the Kozeny-Carman equation, the reservoir pore permeability k can be expressed as:

[0102]

[0103] in, denoted as reservoir porosity, and r as the mean reservoir pore radius.

[0104] Based on the above formula, the permeability k′ after plugging agent injection can be obtained as:

[0105]

[0106] Where r′ is the average reservoir pore radius after plugging agent injection.

[0107] Considering the limited volume of reservoir plugging agent injection, its impact on reservoir porosity is minimal. Assuming the reservoir porosity remains constant, the following equation holds:

[0108]

[0109] Therefore, based on the above equation, the reduction ratio of reservoir pore permeability after water shut-off can be calculated, i.e.: The value of .

[0110] The degree of impact on oil well production can be determined by the percentage decrease in reservoir pore permeability after water shut-off.

[0111] Step 104: Correct the IPR curve according to the reduction ratio of reservoir pore permeability to obtain the IPR curve after water shut-off.

[0112] Specifically, the IPR curve can be calculated based on the reduction ratio of reservoir pore permeability and the production index after water shut-off, and then the IPR curve can be corrected based on the production index and production index after water shut-off to obtain the IPR curve after water shut-off.

[0113] The specific calculation process is as follows:

[0114] The liquid extraction index J′ after water shut-off is:

[0115] Where, q′ (test) The oil well production at a certain test point. For the deep reservoir pressure, p′ wf(test) This represents the bottom-hole flow pressure at the test point.

[0116] because Therefore, let p wf(test) =p′ wf(test) Then we get the following equation:

[0117]

[0118] Based on the above equation, the well production rate corresponding to different reservoir depth pressures can be recalculated. Based on the calculation results (i.e., p′... wf(test) ,q′ (test) The dynamic curve of oil well inflow after water shut-off measures can be obtained, that is, the IPR curve after water shut-off.

[0119] Step 105: Predict the production capacity after water blocking based on the IPR curve after water blocking.

[0120] Specifically, based on the IPR curve after water shut-off, the corresponding predicted oil production can be determined by determining different bottom hole flowing pressures.

[0121] It should be understood that, although Figure 1 The steps in the flowchart shown are displayed sequentially as indicated by the arrows; however, these steps are not necessarily executed in the order indicated by the arrows. Unless otherwise explicitly stated herein, there is no strict order in which these steps are executed, and they can be performed in other orders. Furthermore, Figure 1At least some of the steps in the process may include multiple steps or multiple stages. These steps or stages are not necessarily completed at the same time, but may be executed at different times. The execution order of these steps or stages is not necessarily sequential, but may be executed in turn or alternately with other steps or at least some of the steps or stages in other steps.

[0122] The following example further illustrates the process of determining the production capacity of a vertical well after water shut-off using the method of the present invention. The specific process is as follows:

[0123] Step 1: Collect basic data on the target oil well.

[0124] The target oil wells include those that have been producing normally for the past 30 days, with a stable production rate of 21.5 t / d and a bottom-hole calculated pressure of 1 MPa. The basic data for these wells include: an average reservoir porosity radius of 1 micrometer; a reservoir control radius of 100 m; a reservoir thickness of 10 m; a porosity of 17%; a tortuosity of 2.5; and a water cut of 93%.

[0125] The estimated amount of plugging agent used is 200m³. 3 Assuming the plugging efficiency is 70%.

[0126] Step 2: For the oil well before water shut-off, plot the IPR curve based on the most recent stable production data of the oil well.

[0127] Specifically, it can be determined based on IPR-related theories and technical methods. Through calculation, the IPR curve of well X is obtained as follows: Figure 3 As shown.

[0128] Step 3: Using the average reservoir pore radius r, based on the well control reserve radius R and porosity The tortuosity τ is used to calculate the number of capillary bundles n in the simplified capillary bundle model of the reservoir, and then the reduction ratio of reservoir porosity permeability under a certain amount of plugging agent Q′ is calculated.

[0129] The number of capillary bundles, n, is calculated as follows:

[0130] n = V 孔隙 / V 管束

[0131] Among them, V 孔隙 Represents reservoir pore volume.

[0132] V 管束 V represents the volume of a single tube bundle. 管束 =r 2 Rτ.

[0133] Calculations yielded n = 6.8 × 10 3 A channel.

[0134] The sweep radius of the plugging agent is calculated by using the amount of plugging agent Q′, and then the cross-sectional area A of a single capillary bundle is calculated based on the average reservoir pore radius r. b .

[0135] Calculate the remaining cross-sectional area A after a single capillary tube becomes blocked using Q′ and n. a .

[0136] The calculation results are as follows:

[0137] A b =3.14×10 -12 m 2 ;

[0138] A a =2.84×10 -12 m 2 ;

[0139] According to A b and A a Calculate the percentage decrease in reservoir porosity, i.e.:

[0140]

[0141] Step 4: Based on the reduction ratio of reservoir pore permeability, recalculate the IPR curve to obtain the IPR curve after water shut-off.

[0142] The specific calculation process is as follows:

[0143] The fluid recovery index after water plugging is:

[0144] Let p wf(test) =p′ wf(test) ,but

[0145] By recalculating the well production based on different bottomhole flow pressures, the IPR curve after water shut-off can be obtained, such as... Figure 4 As shown.

[0146] The method for determining the production capacity of a vertical well after water shut-off provided in this invention generates an IPR curve before water shut-off based on the actual production situation of the oil well. It then determines the reduction ratio of reservoir porosity permeability after water shut-off based on the oil well's basic data. By correcting the IPR curve before water shut-off, an IPR curve after water shut-off is obtained with a certain amount of plugging agent. Based on this IPR curve, the oil well production capacity after water shut-off can be predicted. This method is simple and efficient.

[0147] Accordingly, the present invention also provides a device for determining the production capacity after water shut-off in a vertical well, such as... Figure 5 The diagram shown is a structural schematic of the device.

[0148] The vertical well water shut-off production capacity determination device 500 includes the following modules:

[0149] Data acquisition module 501 is used to acquire basic data of the target oil well before water shut-off. The basic data includes: calculation parameters, physical property parameters related to formation crude oil and formation water, saturation pressure and reservoir pressure.

[0150] IPR curve generation module 502 is used to draw the IPR curve of the target oil well based on the basic data;

[0151] The permeability determination module 503 is used to determine the percentage reduction in reservoir pore permeability after water shut-off based on the basic data.

[0152] The curve correction module 504 is used to correct the IPR curve according to the reduction ratio of the reservoir pore permeability to obtain the IPR curve after water shut-off.

[0153] The prediction module 505 is used to predict the production capacity after water blocking based on the IPR curve after water blocking.

[0154] One non-limiting embodiment of the IPR curve generation module 502 may include the following units:

[0155] The first calculation unit determines the liquid recovery index and critical production rate based on the basic data, and calculates the flow pressure at each production rate based on the liquid recovery index and the critical production rate.

[0156] The curve plotting unit is used to plot the IPR curve of the target oil well based on the calculation results.

[0157] One non-limiting embodiment of the penetration rate determination module 503 may include the following units:

[0158] The plugging agent spillover area determination unit is used to determine the spillover radius of the plugging agent based on the amount of plugging agent used;

[0159] The second calculation unit is used to calculate the cross-sectional area A of a single capillary bundle based on the average reservoir pore radius and the number of capillary bundles in the capillary bundle model. b Based on the sweep radius of the plugging agent and the cross-sectional area of ​​the single capillary bundle, calculate the remaining cross-sectional area A after the single capillary bundle is blocked. a Based on the cross-sectional area A of a single capillary bundle b and the remaining cross-sectional area A after blockage a The percentage decrease in reservoir pore permeability after water shut-off was calculated.

[0160] One non-limiting embodiment of the curve correction module 504 may include the following units:

[0161] The third calculation unit is used to calculate the fluid production index and oil well production after water shut-off based on the reservoir porosity reduction ratio and the fluid production index.

[0162] The correction unit is used to correct the IPR curve based on the fluid production index and oil well production after water shut-off, so as to obtain the IPR curve after water shut-off.

[0163] The specific implementation methods of the above modules and units can be referred to the description in the previous embodiment of the method for determining the production capacity after water shut-off of vertical wells in this invention, and will not be repeated here.

[0164] Those skilled in the art will understand that all or part of the processes in the methods of the above embodiments can be implemented by a computer program instructing related hardware. The computer program can be stored in a non-volatile computer-readable storage medium, and when executed, it can include the processes of the embodiments of the methods described above. Any references to memory, storage, databases, or other media used in the embodiments provided by this invention can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory, or optical storage, etc. Volatile memory can include random access memory (RAM) or external cache memory. By way of illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM), etc.

[0165] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0166] The embodiments of the present invention have been described in detail above. Specific implementation methods have been used to illustrate the present invention. The descriptions of the embodiments above are only for the purpose of helping to understand the methods and systems of the present invention, and are merely some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention, and the content of this specification should not be construed as a limitation of the present invention. Therefore, any modifications, equivalent substitutions, improvements, etc., 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 method for determining the production capacity after water shut-off in a vertical well, characterized in that, The method includes: Before shutting off water from the target oil well, the basic data includes: calculation parameters, physical properties of formation crude oil and formation water, bottom hole flow pressure, saturation pressure and deep reservoir pressure; The IPR curve of the target oil well is plotted based on the aforementioned basic data; The percentage reduction in reservoir pore permeability after water shut-off is determined based on the aforementioned basic data. The IPR curve is corrected based on the reduction ratio of reservoir pore permeability to obtain the IPR curve after water shut-off. The production capacity after water plugging is predicted based on the IPR curve after water plugging.

2. The method for determining the production capacity after water shut-off in a vertical well according to claim 1, characterized in that, The target oil wells include those with stable production output and wellhead pressure over a certain period of time.

3. The method for determining the production capacity after water shut-off in a vertical well according to claim 1, characterized in that, The calculation parameters include any one or more of the following: wellhead temperature, daily gas production and daily water production, downhole tubing conditions, and reservoir pore size data.

4. The method for determining the production capacity after water shut-off in a vertical well according to claim 3, characterized in that, The step of plotting the IPR curve of the target oil well based on the basic data includes: The liquid recovery index and critical production rate are determined based on the aforementioned basic data; Calculate the bottom hole flow pressure at each production rate based on the fluid production index and the critical production rate, and plot the IPR curve of the target oil well based on the calculation results.

5. The method for determining the production capacity after water shut-off in a vertical well according to claim 1, characterized in that, The determination of the reduction percentage of reservoir pore permeability after water shut-off based on the aforementioned basic data includes: The sweep radius of the plugging agent is determined based on the amount of plugging agent used; The cross-sectional area of ​​a single capillary bundle is calculated based on the average reservoir pore radius and the number of capillary bundles in the capillary bundle model. Calculate the remaining cross-sectional area of ​​the single capillary bundle after it is blocked, based on the sweep radius of the plugging agent and the cross-sectional area of ​​the single capillary bundle. The percentage reduction in reservoir pore permeability after water shut-off is calculated based on the cross-sectional area of ​​a single capillary bundle and the remaining cross-sectional area after plugging.

6. The method for determining the production capacity after water shut-off in a vertical well according to claim 4, characterized in that, The step of correcting the IPR curve based on the reduction ratio of reservoir pore permeability to obtain the IPR curve after water shut-off includes: Calculate the fluid production index and well production after water shut-off based on the reservoir porosity reduction ratio and the fluid production index. The IPR curve is corrected based on the fluid production index and well production after water shut-off to obtain the IPR curve after water shut-off.

7. A device for determining the production capacity after water shut-off in a vertical well, characterized in that, The device includes: The data acquisition module is used to acquire basic data of the target oil well before water shut-off. The basic data includes: calculation parameters, physical property parameters related to formation crude oil and formation water, saturation pressure and reservoir pressure. The IPR curve generation module is used to draw the IPR curve of the target oil well based on the basic data. The permeability determination module is used to determine the percentage reduction in reservoir pore permeability after water shut-off based on the aforementioned basic data. The curve correction module is used to correct the IPR curve according to the reduction ratio of the reservoir pore permeability to obtain the IPR curve after water shut-off. The prediction module is used to predict the production capacity after water plugging based on the IPR curve after water plugging.

8. The device for determining the production capacity after water shut-off in a vertical well according to claim 7, characterized in that, The IPR curve generation module includes: The first calculation unit determines the liquid recovery index and critical production rate based on the basic data, and calculates the flow pressure at each production rate based on the liquid recovery index and the critical production rate. The curve plotting unit is used to plot the IPR curve of the target oil well based on the calculation results.

9. The device for determining the production capacity after water shut-off in a vertical well according to claim 7, characterized in that, The penetration rate determination module includes: The plugging agent spillover area determination unit is used to determine the spillover radius of the plugging agent based on the amount of plugging agent used; The second calculation unit is used to calculate the cross-sectional area of ​​a single capillary bundle based on the average reservoir pore radius and the number of capillary bundles in the capillary bundle model; to calculate the remaining cross-sectional area of ​​a single capillary bundle after plugging based on the sweep radius of the plugging agent and the cross-sectional area of ​​the single capillary bundle; and to calculate the percentage reduction in reservoir pore permeability after water plugging based on the cross-sectional area of ​​the single capillary bundle and the remaining cross-sectional area after plugging.

10. The device for determining the production capacity after water shut-off in a vertical well according to claim 8, characterized in that, The curve correction module includes: The third calculation unit is used to calculate the fluid production index and oil well production after water shut-off based on the reservoir porosity reduction ratio and the fluid production index. The correction unit is used to correct the IPR curve based on the fluid production index and well production after water shut-off, so as to obtain the IPR curve after water shut-off.

11. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is run by the processor, it executes the steps of the method for determining the production capacity after water shut-off of a vertical well as described in any one of claims 1 to 6.

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