Optimization design method for forward plugging and reverse driving water plugging based on flow field regulation and control

Abstract

The invention provides a positive plugging and reverse flooding water plugging optimization design method based on flow field regulation and control, and relates to the technical field of oilfield development. The method comprises the steps that positive plugging and reverse flooding expansion numerical simulation is conducted, and a positive plugging and reverse flooding sample database is established; establishing a flow field grading and classifying standard based on the positive plugging and back flooding sample database; determining a flow field grading and classifying condition according to the flow field grading and classifying standard; quantitative characterization of flow field regulation and control of a single system; quantitative characterization of flow field regulation and control of the combined system; establishing a flow field regulation and control prediction model of the water plugging system; verifying the accuracy of the flow field regulation and control prediction model of the water plugging system; a water storage system is preferably selected; and preferably selecting injection parameters based on the optimal selection result of the water storage system. According to the method, flow field evaluation and regulation are integrated, so that the purpose of improving the recovery efficiency is achieved, and important support is provided for water plugging system design, positive plugging and reverse flooding effect evaluation and injection process parameter optimization under different oil reservoir conditions.

Description

Technical Field

[0001] The invention relates to the technical field of oilfield development, and in particular to a positive plugging and reverse drive water plugging optimization design method based on flow field regulation. Background Art

[0002] Water-injected reservoirs will enter a high or extra-high water-cut period in the later stages of development, and generally encounter problems such as bottom water coning, poor water injection effects, and reduced recovery. In addition, long-term water injection production has made the contradictions in reservoir development increasingly prominent, the heterogeneity of the reservoir has increased, the flow field has been fixed for a long time, and the efficiency of injected water has decreased, which ultimately leads to a decrease in reservoir recovery. Therefore, how to quantitatively characterize the flow field and form an effective flow field control optimization method is crucial for the development of high-water-cut reservoirs.

[0003] Currently, existing flow field control technologies are mainly concentrated on well network adjustment and production measure adjustment.

[0004] Well pattern adjustment is mainly carried out through numerical simulation methods, such as transferring production wells and adding new wells to adjust the flow field. This is costly and does not achieve the purpose of optimization from the essence of flow field regulation.

[0005] The production measures are mainly adjusted to inject water plugging system to plug the dominant channel and expand the affected area to achieve the purpose of flow field regulation. This development method is more efficient and low-cost. In addition, most of the current injection methods are general injection, with a single regulation strategy, lack of pertinence and flexibility, and cannot adapt to the characteristics and changes of complex reservoirs.

[0006] Therefore, there is an urgent need for an optimization design method for positive plugging and back-drive water plugging based on flow field regulation to solve the above technical problems. Summary of the invention

[0007] The purpose of the present invention is to provide a positive plugging and back-drive water plugging optimization design method based on flow field regulation. The method establishes flow field quantitative characterization indicators and a grading and classification method, quantitatively characterizes the flow field of different water plugging systems, completes model verification and prediction, optimizes the water plugging system, and optimizes the supporting injection process parameters, forming an integrated flow field evaluation and regulation, thereby achieving the purpose of improving the recovery rate.

[0008] The various technical effects that can be produced by the preferred technical solutions among the various technical solutions provided by the present invention are described in detail below.

[0009] To achieve the above object, the present invention provides the following technical solutions:

[0010] The present invention provides a method for optimizing the design of water plugging by positive plugging and reverse drive based on flow field regulation, comprising:

[0011] Expand the numerical simulation of positive plugging and reverse drive and establish a sample database of positive plugging and reverse drive;

[0012] Based on the positive plugging and back-drive sample database, a flow field classification standard is established;

[0013] Determining the flow field classification status according to the flow field classification standard;

[0014] Quantitative characterization of flow field regulation in a single system;

[0015] Quantitative characterization of flow field regulation in combined systems;

[0016] Establish a flow field control prediction model for water plugging system;

[0017] Verify the accuracy of the flow field control prediction model of the water plugging system;

[0018] Optimize water storage system;

[0019] Based on the optimization results of the water storage system, the injection parameters are optimized.

[0020] Preferably, the positive plugging and reverse drive expansion numerical simulation and establishment of a positive plugging and reverse drive sample database include:

[0021] Obtain target reservoir characteristic data and establish positive plugging and reverse drive mechanism model;

[0022] Through the positive plugging and reverse drive mechanism model, numerical simulations of different parameter combination schemes are carried out to establish a positive plugging and reverse drive sample database.

[0023] Preferably, the flow field classification standard is established based on the positive plugging and back-drive sample database, including:

[0024] Based on the positive plugging and back-drive sample database, typical sections are selected, the quantitative characterization indexes and calculation methods of the flow field are determined, and the flow field classification standard is established.

[0025] Preferably, the establishment of flow field classification standards includes:

[0026] The quantitative characterization indexes of the flow field are standardized to [0, 1] and weights are assigned respectively;

[0027] The comprehensive index is: 1-the actual value obtained after assigning weights;

[0028] Among them, the quantitative characterization indicators of flow field include: surface flux, permeability, oil saturation, and pressure gradient.

[0029] Preferably, determining the flow field classification status according to the flow field classification standard includes:

[0030] According to the flow field classification standard, the flow field quantitative characterization index is calculated, and the flow field classification is performed on all positive plugging and back-drive sample databases to determine the flow field classification status, wherein:

[0031] The grading includes at least five levels in sequence from best to worst.

[0032] Preferably, the single system flow field regulation quantitative characterization and the combined system flow field regulation quantitative characterization both include:

[0033] Analyze the variation of flow field parameters under different systems, different concentrations, and different reservoir conditions;

[0034] The index when the water content reaches 95% is compared with the index when the water content reaches 95% again after the plugging agent is injected, and the plugging agent effect is quantitatively characterized.

[0035] Preferably, the establishment of a water plugging system flow field control prediction model includes:

[0036] Establish an extended numerical simulation model under different permeability extremes, different injection rates, different water plugging systems, different well types, and different injection volumes, and calculate the comprehensive flow field indicators before and after the injection of the water plugging system;

[0037] Establishing a water plugging system flow field control sample database based on the statistical flow field comprehensive indicators before and after injection into the water plugging system;

[0038] Establish a flow field control prediction model for the water plugging system.

[0039] Preferably, the verification of the accuracy of the water plugging system flow field control prediction model includes verifying the oil wells that have been implemented on site and inverting the oil wells that have not been implemented on site, wherein:

[0040] The verification has been carried out on oil wells, including:

[0041] Based on the parameters of the wells that have been implemented on site, the flow field parameters are integrated to calculate the quantitative characterization indicators of the flow field after implementation;

[0042] Use the water plugging system flow field control prediction model to predict the quantitative characterization indicators of the flow field after implementation;

[0043] Compare the predicted value with the actual calculated value to verify the accuracy of the flow field control prediction model of the water plugging system;

[0044] The inversion site has no oil wells implemented, including:

[0045] Establishment of numerical simulation inversion model for unimplemented oil wells;

[0046] Fitting is performed with oil production and water production rate as evaluation targets to accurately invert the flow field of the oil well;

[0047] Calculate the quantitative characterization indicators of the flow field before implementation, and classify the flow field.

[0048] Preferably, the preferred water plugging system comprises:

[0049] The flow field control prediction model of the water plugging system is used to predict the quantitative characterization indicators of the flow field under different water plugging systems and different combinations. The changing trends of the indicators before and after control are compared to optimize the water plugging system.

[0050] Preferably, the optimization of injection parameters based on the optimization result of the water storage system includes:

[0051] Based on the optimization results of the water plugging system, the matching injection process parameters are optimized according to the target pressure field characteristics.

[0052] The present invention provides a positive plugging and backwashing water plugging optimization design method based on flow field regulation. The method can introduce the relationship between flow field classification standards and quantitative characterization on the basis of fully considering the complexity of reservoir geology and the diversity of water plugging systems, and establish a flow field regulation prediction model for water plugging systems, so as to formulate a reasonable positive plugging and backwashing water plugging system design and injection parameter optimization plan, which provides important support for the design of water plugging systems and the evaluation of positive plugging and backwashing effects under different reservoir conditions and the targeted optimization of injection process parameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0054] Figure 1 It is a flow chart of the water plugging optimization design method of the present invention based on flow field regulation and control by positive plugging and reverse drive;

[0055] Figure 2 A geological concept model diagram used in an embodiment of the present invention;

[0056] Figure 3 A typical cross-sectional view used in one embodiment of the present invention;

[0057] Figure 4 This is a diagram showing the evaluation effect of the water plugging system of the B31 well injection scheme adopted in the present invention;

[0058] Figure 5 This is a diagram showing the change in water content before and after the production measures of Well B31 adopted in the present invention;

[0059] Figure 6This is a diagram showing the oil production rate change of the B31 well before and after the production measures adopted by the present invention;

[0060] Figure 7 This is the water plugging evaluation diagram of the A43H1 well injection scheme adopted in the present invention. DETAILED DESCRIPTION

[0061] To make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be described in detail below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by ordinary technicians in this field without creative work belong to the scope of protection of the present invention.

[0062] At present, the commonly used flow field research of water plugging systems is mostly based on numerical simulation, while the flow field characterization research combined with the distribution law of water plugging systems is far from sufficient, and the commonly used flow field characterization methods of water plugging systems are usually based on the identification and characterization of dominant channels in the reservoir, which is difficult to match the complexity of reservoir geology and the diversity of water plugging systems. The flexibility and operability of the research methods lag behind the field practice; in addition, the design of water plugging systems often only optimizes a single indicator, such as surface flux, water content, and degree of recovery, and cannot simultaneously consider the overall displacement status of the reservoir. There is a lack of water plugging system design methods that comprehensively consider the development characteristics of the reservoir, the classification of flow fields, and the differences in the effects of different water plugging systems.

[0063] Therefore, the present invention provides a method for optimizing the design of water plugging by positive plugging and reverse drive based on flow field regulation. The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0064] See also Figure 1 In one embodiment of the present invention, the process of the water plugging optimization design method based on flow field regulation mainly includes the following steps:

[0065] S201, numerical simulation of positive plugging and reverse drive expansion, establishment of positive plugging and reverse drive sample database, including:

[0066] S2011, obtain the characteristic data of the target reservoir and establish the positive plugging and reverse drive mechanism model;

[0067] S2012, through the positive plugging and reverse drive mechanism model, numerical simulations of different parameter combination schemes were carried out to establish a positive plugging and reverse drive sample database.

[0068] Specifically, this embodiment includes extracting reservoir characteristic data from an actual oil well model and establishing a positive plugging and reversing mechanism model. Considering bottom water as a driving type, factors such as the different adsorption amount, injection capacity and residual resistance coefficient of the water plugging system in different permeability regions, a mine-scale numerical simulation model is established, and the changes in the pressure field and saturation field are characterized. A positive plugging and reversing mechanism model for different well types and different permeability differences is established. Based on the principles of comprehensiveness, differentiation and combination diversity, numerical simulations of different parameter combination schemes are carried out to establish a positive plugging and reversing sample database.

[0069] S202: Based on the positive plugging and back-drive sample database, establish the flow field classification standard, including:

[0070] Based on the positive plugging and backdrive sample database, typical sections are selected, and the variation patterns of flow field parameters are statistically analyzed to determine the quantitative characterization indicators and calculation methods of the flow field. In combination with the actual situation on site, the flow field classification standard is established.

[0071] Among them, the flow field classification standards are established, including:

[0072] Within the range of horizontal wells / vertical wells, 1 / 2 of the well control range of the production well is selected as a typical section. With balanced displacement as the goal, the surface flux, permeability, oil saturation, and pressure gradient are screened and determined as the quantitative characterization indicators of the flow field. The quantitative characterization indicators of the flow field are standardized to [0,1], and weights are assigned respectively. The comprehensive index R of the flow field is calculated, and the comprehensive index is: 1-the actual value obtained after assigning weights.

[0073] Specifically, in this embodiment, based on different parameter combination schemes, the quantitative characterization indicators of flow field are screened and determined as surface flux (M), permeability (K), oil saturation (S o ), pressure gradient

[0074] Surface flux

[0075] Where: M represents the surface flux (m); Q represents the flow rate (m 3 ), A represents the cross-sectional area (㎡);

[0076] The flow rate and area of ​​each grid can be output by using relevant reservoir numerical simulation software, thus obtaining the grid surface flux;

[0077] Indicators such as permeability, oil saturation and pressure gradient can be output through relevant numerical simulation software;

[0078] All indicators are normalized:

[0079]

[0080] In the formula: y represents the value after standardization, and x represents the value before standardization;

[0081] Comprehensive dimensionless characterization indexes to quantitatively characterize the flow field: R = f(S o (i),▽p(i),K(i),M(i))

[0082] S203, determining the flow field classification status according to the flow field classification standard, including:

[0083] According to the flow field classification standard, the flow field quantitative characterization index is calculated, the flow field is classified and classified for all positive plugging and backdrive sample databases, and the flow field classification status is determined, wherein the classification includes at least five levels from good to bad.

[0084] In this embodiment, the flow field classification status is determined by calculating the weight value of each standardized index using the hierarchical analysis method to obtain the flow field comprehensive index.

[0085] The flow field of the actual heterogeneous reservoir is classified and the flow field classification standard is shown in Table 1:

[0086] Table 1 Classification of flow field in water plugging system

[0087] Grading good better medium generally Difference Oil saturation ＜0.05 0.05-0.1 0.1-0.2 0.2-0.8 >0.8 Pressure gradient ＜0.02 0.03-0.05 0.1-0.5 0.5-0.8 >0.8 Permeability 0.48 0.48 0.48 0.48 0.48 Surface flux ＜0.4 0.4-0.41 0.41-0.43 0.43-0.45 >0.45 Comprehensive indicators >0.85 0.70-0.85 0.50-0.70 0.30-0.50 0-0.3

[0088] S204, quantitative characterization of flow field regulation in a single system, including:

[0089] Carry out numerical simulation of positive plugging and backdrive expansion with different parameter combination schemes for a single system, analyze the change law of flow field parameters under different systems, different concentrations and different reservoir conditions, classify the flow field regulation of a single system according to the flow field classification standards, and establish a sample database of flow field regulation of a single system.

[0090] In this embodiment, the index when the water content reaches 95% is compared with the index when the water content reaches 95% again after the plugging agent is injected, so as to achieve the quantitative characterization of saturation, pressure and surface flux. And according to the flow field classification standard, the flow field regulation of a single system is classified and classified to judge the degree of closeness of the comprehensive index to 1. The closer the comprehensive index is to 1, the better the effect of the plugging agent.

[0091] Specifically, this embodiment takes a horizontal well heterogeneous reservoir as an example, and the parameters in the model are shown in Table 2. The geological concept model is shown in Table 2. Figure 2 shown.

[0092] Table 2 Reservoir and fluid parameters

[0093] Parameter name Numeric Reservoir size (m) 510×510×50 Reservoir temperature (℃) 65 Initial atmospheric pressure (MPa) 10 Formation porosity (%) 30 Initial oil saturation (%) 0.65 <![CDATA[Permeability (10 -3 μm 2 )]]> 2700:600:1500 Horizontal well length (m) 330 Crude oil viscosity (mPa·s) 180 <![CDATA[Production rate (m 3 / d)]]> 500

[0094] Horizontal production wells with a depth of 500m 3 / d production rate, and stop production when the water content reaches 95%. The production well is converted into an injection well and a gel water plugging system is injected. The plugging agent concentration is 30000ppm of functional microspheres + 30000ppm of functional monomers + 6000ppm of gel promoters. The injection rate is 200m 3 / d, the total injection water plugging system is 3000m 3 .

[0095] After the injection is completed, the injection well is converted into a production well and the injection well is continuously pumped at a rate of 500m 3 / d speed production;

[0096] The horizontal well and the halfway point of the bottom water are selected as typical sections, such as Figure 3 As shown, by comparing the water content at the moment when the water content reaches 95% twice before and after the injection of the gel system, the plugging agent effect is quantitatively characterized.

[0097] Table 3 Classification of flow fields before and after injection of water plugging system

[0098] Grading Value before injection into water plugging system After injection into the water plugging system Oil saturation 0.88 0.15 Pressure gradient 0.94 0.04 Permeability 0.48 0.31 Surface flux 0.46 0.47 Comprehensive indicators 0.31 0.71

[0099] As shown in Table 3, at 1 / 2 of the typical section, when the water content reached 95% before the injection of the plugging agent, the comprehensive index of the flow field was 0.31, and after the injection of the plugging agent, the comprehensive index of the flow field was 0.71; the plugging effect was good, the typical section was determined, and the rationality of the flow field classification was verified.

[0100] S205, quantitative characterization of flow field regulation of combined systems, including:

[0101] Carry out numerical simulation of positive plugging and backdrive expansion with different parameter combination schemes of combined system, analyze the change law of flow field parameters under different system combination methods, different injection speeds, different concentrations and different reservoir conditions, classify the flow field regulation of combined system according to the flow field classification standards, and establish a sample database of flow field regulation of combined system.

[0102] In this embodiment, the index when the water content reaches 95% is compared with the index when the water content reaches 95% again after the plugging agent is injected, so as to achieve the quantitative characterization of saturation, pressure and surface flux. And according to the flow field classification standard, the flow field regulation of the combined system is classified and classified to judge the degree of closeness of the comprehensive index to 1. The closer the comprehensive index is to 1, the better the effect of the plugging agent.

[0103] Specifically, in this embodiment, the parameters in the model are shown in Table 2, and the geological concept model is shown in Table 2. Figure 2 shown.

[0104] Horizontal production wells with a depth of 500m 3 / d production rate, and stop production when the water content reaches 95%. The production well is converted into an injection well and the gel water plugging system is injected. The combined water plugging system: the gel system concentration is 30000ppm of functional microspheres + 30000ppm of functional monomers + 6000ppm of gel promoters, and the oil displacement system concentration is 2500ppm; the injection rate is 200m 3 / d, the total injection water plugging system is 3000m 3 .

[0105] After the injection is completed, the injection well is converted into a production well and the injection well is continuously pumped at a rate of 500m 3 / d speed production;

[0106] The horizontal well and the halfway point of the bottom water are selected as typical sections, such as Figure 3 As shown, the dotted line position is the horizontal well and the bottom water 1 / 2, and the water content at the moment when the water content reaches 95% twice before and after the injection of the combined water plugging system is compared to quantitatively characterize the plugging agent effect.

[0107] Table 4 Flow field classification before and after injection of water plugging system

[0108] Grading Value before injection into water plugging system After injection into the water plugging system Oil saturation 0.88 0.13 Pressure gradient 0.94 0.08 Permeability 0.48 0.35 Surface flux 0.46 0.48 Comprehensive indicators 0.31 0.74

[0109] As shown in Table 4, at 1 / 2 of the typical section, when the water content reached 95% before the injection of the plugging agent, the comprehensive index of the flow field was 0.31, and after the injection of the plugging agent, the comprehensive index of the flow field was 0.74; the plugging effect was good, the typical section was determined, and the rationality of the flow field classification was verified.

[0110] S206, establishing a flow field control prediction model for a water plugging system, including: counting all forward plugging and reverse drive expansion numerical simulation results, establishing a flow field control sample database for a water plugging system, and building a flow field control prediction model for a water plugging system.

[0111] Specifically include: S2061, establish an extended numerical simulation model under different permeability extremes, different injection speeds, different water plugging systems, different well types, and different injection volumes, and calculate the comprehensive flow field indicators before and after the injection of the water plugging system;

[0112] S2062, establishing a water plugging system flow field control sample database based on the statistical flow field comprehensive indicators before and after injection into the water plugging system;

[0113] S2063, establish a flow field control prediction model for the water plugging system.

[0114] Specifically, in this embodiment, different permeability ranges (4.5:1:2.5, 6.5:1:3.5, 8.5:1:4.5, 11.5:1:5.5) and different injection speeds (150, 200, 300 m 3 / d), different water plugging systems (gel system, particle system, oil displacing agent system, particle + oil displacing agent system, oil displacing agent + particle system, gel + oil displacing agent system, oil displacing agent + gel system), different well types (directional well, horizontal well); extended numerical simulation model under different injection volumes (0, 0.05, 0.1, 0.15, 0.2PV), statistical flow field comprehensive indicators before and after injection of the water plugging system, thereby establishing a sample database for flow field regulation of the water plugging system, and building a flow field regulation prediction model for the water plugging system.

[0115] S207, verifying the accuracy of the flow field control prediction model of the water plugging system, including verifying the oil wells that have been implemented on site and the oil wells that have not been implemented on site by inversion.

[0116] Among them, the verification site has implemented oil wells, including:

[0117] S2071, based on the water content, recovery degree and other parameters of the oil wells that have been implemented on site, and the flow field parameters such as reservoir permeability, pressure, saturation, etc., calculate the quantitative characterization index of the flow field after implementation;

[0118] S2072, using the water plugging system flow field control prediction model, predict the quantitative characterization index of the flow field after implementation;

[0119] S2073, compare the predicted value with the actual calculated value to verify the accuracy of the flow field control prediction model of the water plugging system.

[0120] Specifically, in this embodiment, based on the quantitative characterization and classification method of the flow field of the positive plugging and reverse drive water plugging system, the water plugging measures and verification of the B-31 well were carried out. By establishing a numerical inversion model, the effect of the water plugging system under different parameters was evaluated. The injection parameter design table is shown in Table 5, and the injection scheme water plugging system effect evaluation is shown in Table 5. Figure 4 shown.

[0121] Table 5 Flow field evaluation table before and after injection of plugging agent

[0122]

[0123]

[0124] From Table 5 and Figure 4 It can be seen that by comparing the comprehensive indicators under each injection scheme, the dosage of surfactant remains unchanged. With the increase of the dosage of gel system, the comprehensive indicators are constantly improving. However, when the injection volume of the gel system is 900m3, the increase in the dosage slows down. Considering the comprehensive water plugging effect and economic evaluation, the best injection scheme is determined to be 150m3 of surfactant, 900m3 of gel system injection, and a comprehensive flow field index of 0.72.

[0125] Comparing the numerical inversion model data with the actual injection data on site, the water content changes before and after the production measures in Well B31 are as follows: Figure 5 As shown in Figure 2, the oil production rate of Well B31 before and after the production measures are as follows: Figure 6 shown.

[0126] It can be seen that the numerical inversion results are highly consistent with the actual injection results on site. After the measures were taken, the water cut in Well B-31 dropped to 80.1%, which verified the accuracy of the numerical inversion model and the effectiveness of the positive plugging and reverse drive water plugging system method, and has a good guiding role in field applications.

[0127] There are no wells implemented at the inversion site, including:

[0128] S2074, establishing a numerical simulation inversion model for unimplemented oil wells;

[0129] S2075, fitting with oil production and water production rate as evaluation targets, accurately inverting the oil well flow field;

[0130] S2076, calculating the quantitative characterization index of the flow field before implementation, and performing flow field classification.

[0131] In this embodiment, the water plugging system effect under different parameters is evaluated. The injection parameters of A43H1 well are shown in Table 6. The water plugging evaluation of the injection scheme of A43H1 well is shown in Table 6. Figure 7 shown.

[0132] Table 6A43H1 well injection parameter design table

[0133]

[0134]

[0135] From Table 6 and Figure 7 It can be seen that by comparing the comprehensive indicators under various injection schemes, as the amount of particle system increases, the comprehensive indicators are getting better and better. However, when the particle system injection amount is 215m 3 When the dosage is increased, the growth rate of the comprehensive index slows down. Considering the water plugging effect and economic evaluation, the best injection scheme is determined to be a particle system with a dosage of 215m 3 , the amount of oil displacement agent is 300m 3 .

[0136] S208, optimizing the water storage system, including: based on the flow field classification of the actual oil well, using the flow field control prediction model of the water plugging system to predict the quantitative characterization indicators of the flow field under different water plugging systems and different combinations, and combining parameters such as water content and recovery degree to optimize the water plugging system.

[0137] The specific method for determining the optimal water plugging system required on site is: the water plugging system flow field control prediction model obtains the flow field quantitative indicators of different water plugging systems, compares the indicator change trends before and after the control, and optimizes the water plugging system.

[0138] S209, based on the water storage system optimization result, optimize the injection parameters. Including:

[0139] Based on the optimization results of the water plugging system and the target pressure field characteristics, the supporting injection process parameters are optimized through physical and digital simulations, and finally the optimal design of water plugging and backflow drive based on flow field regulation is formed to guide field application.

[0140] In this embodiment, the optimization results of the injection process parameters of the water plugging system are reflected in that, taking the combined system, particle system + oil displacement agent, as an example, when the concentration of the plugging agent system remains unchanged, as the amount of oil displacement agent increases, the comprehensive evaluation index of the flow field increases, but the increase gradually decreases; considering the comprehensive water plugging effect and economic evaluation, the reasonable amount of particle system and oil displacement agent is 215m 3 and 300m 3 ; and completed the verification of field data.

[0141] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for optimizing the design of water plugging by positive plugging and reverse drive based on flow field regulation, characterized in that: include: Expand the numerical simulation of positive plugging and reverse drive and establish a sample database of positive plugging and reverse drive; Based on the positive plugging and back-drive sample database, a flow field classification standard is established; Determining the flow field classification status according to the flow field classification standard; Quantitative characterization of flow field regulation in a single system; Quantitative characterization of flow field regulation in combined systems; Establish a flow field control prediction model for water plugging system; Verify the accuracy of the flow field control prediction model of the water plugging system; Optimize water storage system; Based on the optimization results of the water storage system, the injection parameters are optimized.

2. The method for optimizing the design of water plugging by positive plugging and reverse drive based on flow field regulation according to claim 1 is characterized in that: The positive plugging and reverse drive expansion numerical simulation and the establishment of a positive plugging and reverse drive sample database include: Obtain target reservoir characteristic data and establish positive plugging and reverse drive mechanism model; Through the positive plugging and reverse drive mechanism model, numerical simulations of different parameter combination schemes are carried out to establish a positive plugging and reverse drive sample database.

3. The method for optimizing the design of water plugging by positive plugging and reverse drive based on flow field regulation according to claim 2 is characterized in that: The flow field classification standard is established based on the positive plugging and back-drive sample database, including: Based on the positive plugging and back-drive sample database, typical sections are selected, the quantitative characterization indexes and calculation methods of the flow field are determined, and the flow field classification standard is established.

4. The method for optimizing the design of water plugging by positive plugging and reverse drive based on flow field regulation according to claim 3 is characterized in that: The establishment of the flow field classification standard includes: The quantitative characterization indexes of the flow field are standardized to [0, 1] and weights are assigned respectively; The comprehensive index is: 1-the actual value obtained after assigning weights; Among them, the quantitative characterization indicators of flow field include: surface flux, permeability, oil saturation, and pressure gradient.

5. The method for optimizing the design of water plugging by positive plugging and reverse drive based on flow field regulation according to claim 4 is characterized in that: Determining the flow field classification status according to the flow field classification standard includes: According to the flow field classification standard, the flow field quantitative characterization index is calculated, and the flow field classification is performed on all positive plugging and back-drive sample databases to determine the flow field classification status, wherein: The grading includes at least five levels in sequence from best to worst.

6. The method for optimizing the design of water plugging by positive plugging and reverse drive based on flow field regulation according to claim 5 is characterized in that: The quantitative characterization of flow field regulation of the single system and the quantitative characterization of flow field regulation of the combined system both include: Analyze the variation of flow field parameters under different systems, different concentrations, and different reservoir conditions; The index when the water content reaches 95% is compared with the index when the water content reaches 95% again after the plugging agent is injected, and the plugging agent effect is quantitatively characterized.

7. A method for optimizing the design of water plugging by reverse drive based on flow field regulation according to any one of claims 1 to 6, characterized in that: The establishment of a water plugging system flow field control prediction model comprises: Establish an extended numerical simulation model under different permeability extremes, different injection rates, different water plugging systems, different well types, and different injection volumes, and calculate the comprehensive flow field indicators before and after the injection of the water plugging system; Establishing a water plugging system flow field control sample database based on the statistical flow field comprehensive indicators before and after injection into the water plugging system; Establish a flow field control prediction model for the water plugging system.

8. The method for optimizing the design of water plugging by positive plugging and reverse drive based on flow field regulation according to claim 7 is characterized in that: The verification of the accuracy of the flow field control prediction model of the water plugging system includes verifying the oil wells that have been implemented on site and the oil wells that have not been implemented on site, wherein: The verification has been carried out on oil wells, including: Based on the parameters of the wells that have been implemented on site, the flow field parameters are integrated to calculate the quantitative characterization indicators of the flow field after implementation; Use the water plugging system flow field control prediction model to predict the quantitative characterization indicators of the flow field after implementation; Compare the predicted value with the actual calculated value to verify the accuracy of the flow field control prediction model of the water plugging system; The inversion site does not implement oil wells, including: Establishment of numerical simulation inversion model for unimplemented oil wells; Fitting is performed with oil production and water production rate as evaluation targets to accurately invert the flow field of the oil well; Calculate the quantitative characterization indicators of the flow field before implementation, and classify the flow field.

9. The method for optimizing the design of water plugging by positive plugging and reverse drive based on flow field regulation according to claim 8 is characterized in that: The preferred water plugging system comprises: The flow field control prediction model of the water plugging system is used to predict the quantitative characterization indicators of the flow field under different water plugging systems and different combinations. The changing trends of the indicators before and after control are compared to optimize the water plugging system.

10. The method for optimizing the design of water plugging by positive plugging and reverse drive based on flow field regulation according to claim 9, characterized in that: The preferred injection parameters based on the water storage system optimization result include: Based on the optimization results of the water plugging system, the matching injection process parameters are optimized according to the target pressure field characteristics.

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