Phase-controlled reserve chemical flooding wave and coefficient calculation method

Abstract

The invention relates to a phase control reserve chemical flooding wave and coefficient calculation method. The method comprises the following steps: (1) establishing a high-precision three-dimensional porosity and permeability model; and (2) calculating the chemical flooding conformance coefficient of the phase-controlled reserves. According to the method, the calculation precision of the chemical flooding conformance coefficient of the phase-controlled reserves can be improved, so that an accurate basis is provided for chemical flooding reservoir engineering scheme design, numerical simulation precision, tracking adjustment and post-evaluation of scheme implementation effects. Compared with traditional chemical flooding sweep coefficient calculation, the method is more scientific, clearer in concept, more quantitative in index and more accurate and reliable in chemical flooding sweep coefficient calculation result, and has great significance in guiding oil field production and development data.

Description

Technical Field

[0001] The present invention relates to the technical field of quantifying spatial sweep coefficient of phase-controlled reserve chemical flooding based on three-dimensional geological model, and in particular to a method for improving the calculation accuracy of spatial sweep coefficient of phase-controlled reserve chemical flooding of three types of oil layers. Background Art

[0002] The spatial sweep coefficient of chemical flooding of phase-controlled reserves refers to the sweep degree of chemical agents in the oil layer, which is the ratio of the volume of oil layers washed by chemical agents to the total volume of oil layers. It directly affects the development effect of chemical flooding and is of great significance to the design of chemical flooding reservoir engineering schemes, numerical simulation accuracy, tracking and adjustment, and post-implementation effect evaluation of schemes. At present, the commonly used method in oil fields is to calculate the ratio of the connected volume of sand bodies of phase-controlled reserves to the total volume of well group controlled reserves, without considering the inaccessible pores of chemical flooding and the quality of connectivity between injection and production units, resulting in the calculation results of the sweep coefficient of phase-controlled reserves chemical flooding of the technology being too large, which directly affects the results of chemical flooding reservoir engineering scheme design, numerical simulation, tracking and adjustment, and post-implementation effect evaluation of schemes. Summary of the invention

[0003] In order to solve the problems existing in the background technology, the present invention provides a method for calculating the sweep coefficient of chemical flooding of phase-controlled reserves. This application is based on water wells and considers the influence of chemical flooding microscopic accessible pores, interlayer heterogeneity and phase change to determine the calculation method of the sweep coefficient of chemical flooding of phase-controlled reserves.

[0004] The technical solution provided by the present invention is: a method for calculating the chemical flooding sweep coefficient of a well group controlled reserves, comprising the following steps: Step (1): Establish a high-precision three-dimensional porosity and permeability model: ① According to the current logging sampling interval, the porosity and permeability logging interpretation model is reconstructed to complete the fine secondary interpretation of logging parameters, thereby effectively characterizing the heterogeneity within the single well layer; ② In the Petrel software platform, based on the fault results of seismic interpretation and combined with the adjustment of fault boundary control lines, a fault model that conforms to the actual spatial form is established. The layer results of seismic interpretation are used as trend constraints to establish the oil layer group-level framework layer. Using the well point stratification data and the "thickness constraint" method, a sedimentary unit-level layer model with reasonable contact relationship between strata and structural characteristics in line with geological laws is established. Through the detailed verification and adjustment of the contact relationship between the fault model and the layer model, a sedimentary unit-level structural framework with reasonable contact relationship between faults and layers is established. Considering the contact relationship between each sedimentary unit, the "equal thickness subdivision" technology is used from bottom to top to further subdivide each vertical sedimentary unit and establish a three-dimensional fine structural geological model. ③ Using the secondary interpretation results of the logging parameters of a single well, a single well LOG file (containing three columns of depth, porosity and permeability) is prepared according to the logging sampling interval of 0.125m. The single well data file is loaded into the corresponding single well folder of the structural geological model work area, and the porosity and permeability data of the single well are discretized. The porosity and permeability data are collected from the single well folder to the corresponding grid, so that different depths of the grid at the well point location are given different porosity and permeability values; ④Use the phase point file (including three columns of horizontal coordinate, vertical coordinate and phase value) of each sedimentary unit derived from the existing fine reservoir description work area to load it into the structural geological model work area, use the nearest point value method to perform interpolation operation, complete the digitization of the sedimentary phase data points of each sedimentary unit, apply the grid direct assignment method, sample the digitized sedimentary phase data of each unit into the grid, and finally establish a three-dimensional sedimentary phase model; ⑤ Taking the sedimentary facies model as the trend constraint condition, taking the porosity and permeability collected in the grid as the basic data source, applying the random function interpolation theory, through the variogram analysis, using the sequential Gaussian interpolation method, finally establish a high-precision phase-controlled porosity and permeability three-dimensional physical property parameter geological model; Step (2), calculation of chemical flooding sweep coefficient of phase-controlled reserves: ① Based on the three-dimensional fine structural geological model, the Geometrical Modeling module is applied in the Petrel software platform to establish a grid volume model (Cell volume). The attribute calculator is used to multiply the established grid volume model with the porosity geological model to obtain the total pore volume model at the sedimentary unit level. Based on the total pore volume model, the total pore volume of each sedimentary unit in the block is calculated; ② According to the permeability limit that is difficult for the chemical agent to reach determined by the indoor experiment, the part of the total pore volume model that is below the permeability limit is removed by the filter function using the attribute calculator to obtain the macroscopic accessible pore volume model. According to the chemical agent microscopic pore volume correction coefficient data under different permeability core conditions determined by the indoor experiment, the relationship between permeability and chemical agent microscopic pore volume correction coefficient is fitted. In the Geometrical Modeling module, a new constant geometric model is established. The attribute calculator is used to calculate the constant geometric model with the fitted permeability and chemical agent microscopic pore volume correction coefficient relationship to obtain the affected pore volume correction coefficient model of each sedimentary unit. The attribute calculator is used to multiply the affected pore volume correction coefficient model with the porosity to obtain the porosity correction model. The attribute calculator is used again to multiply the porosity correction model with the grid volume model (Cell volume) to obtain the affected pore volume model that does not consider the layer combination and plane phase change. ③ On the existing sedimentary facies belt map of the sub-sedimentary units, the well group is divided according to the block well pattern, the sand body combination mode between different injection and production units in each sedimentary unit well group is counted, the sand body phase change type and connectivity type between different injection and production units are determined, and the control area of ​​each injection and production unit is delineated according to the well pattern. The affected pore volume model without considering the stratum combination and plane phase change established in the above step ② is cut into the affected pore volume model without considering the stratum combination and plane phase change at the injection and production unit level according to the control area of ​​each injection and production unit; ④ According to the phase change type of each deposition unit between each injection and production unit determined in step ③ above, the chemical agent macro-wave and pore volume correction coefficients of different phase change types are determined in combination with indoor experiments, and the chemical agent macro-wave and pore volume correction coefficients of each deposition unit between the injection and production units are statistically calculated. The Geometrical Modeling module is used to establish a constant geometric model for each injection and production unit. The constant geometric model is assigned to each deposition unit according to the statistical chemical agent macro-wave and pore volume correction coefficients of the sub-deposition units, so as to obtain the chemical agent macro-wave and pore volume correction coefficient model for each injection and production unit; ⑤ Apply the property calculator to multiply the accessible pore volume model of chemical flooding without considering phase change at the injection-production unit level by the chemical agent macroscopic affected pore volume correction coefficient model at the injection-production unit level, that is, to obtain the accessible pore volume model of each sedimentary unit considering phase change at the injection-production unit level; based on the accessible pore volume model of each injection-production unit considering phase change, merge the accessible pore volume models of each sedimentary unit considering phase change in all injection-production units in the well group, that is, to obtain the chemical flooding accessible pore volume model of each sedimentary unit considering phase change in the well group; merge the accessible pore volume models of each sedimentary unit considering phase change in all well groups, that is, to obtain the chemical flooding accessible pore volume model of each sedimentary unit considering phase change in the block; ⑥ Using the attribute calculator, the river channel, main body and a type of sandstone in the sedimentary facies are calculated as effective sandstone, and the remaining facies are invalid sandstone. A net-to-gross ratio model is established, and the injection-production unit-level porosity model and the net-to-gross ratio model are used to calculate the facies-controlled reserve model of each sedimentary unit; ⑦ Apply the attribute calculator to divide the merged chemical flooding accessible pore volume model of each sedimentary unit considering phase change with the total pore volume model of each sedimentary unit, that is, to obtain the chemical flooding sweep coefficient of the phase-controlled reserves of each sedimentary unit in the block. At the same time, the phase-controlled reserve model is filtered and sorted with the chemical flooding sweep coefficient model, and the area with sweep coefficient equal to 0 is screened out to obtain the phase-controlled reserves accessible by chemical flooding.

[0005] In the fourth step of the above step (1), a three-dimensional sedimentary facies model is established: the sedimentary facies data points are derived according to the sedimentary units using the existing fine reservoir description work area, including three columns of data: abscissa, ordinate and phase value. The sedimentary facies data points of each sedimentary unit are added to the three-dimensional fine structural model work area. The sedimentary facies data points of each sedimentary unit are digitized according to the nearest point value method. The digitized sedimentary facies data of each unit are sampled into the grid by the grid assignment method, and finally a three-dimensional sedimentary facies model is established. Then, a porosity geological model and a permeability geological model are established: the 0.125 Based on the encrypted interpretation results of the reservoir physical property parameters of 0.125 m, the porosity and permeability data of all single wells in the study area are split according to the physical property parameter sampling interval of 0.125 m, and a LOG physical property parameter file is formed for each single well; the split single well physical property parameter file is loaded into the 3D model, and the single well physical property parameter file is sampled into the grid framework through data discretization processing, and then based on the random function interpolation theory, the random simulation technology controlled by the sedimentary phase model is adopted, and through the variation function analysis, the sequential Gaussian interpolation method is applied to generate a 3D physical property parameter geological model of porosity and permeability.

[0006] In the above step (2), in steps ③-⑦, the sand body combination patterns between different injection and production units in each sedimentary unit well group are counted, and the affected pore volume model without considering the stratum combination and plane phase change is cut into the affected pore volume model at the injection and production unit level according to the controlled area of ​​each injection and production unit; the chemical flooding accessible pore volume model without considering the phase change at the injection and production unit level is multiplied by the chemical agent macroscopic affected pore volume correction coefficient model at the injection and production unit level, that is, the accessible pore volume model considering the phase change at the injection and production unit level is obtained, and the chemical flooding accessible pore volume model considering the phase change at the injection and production unit level is divided by the total pore volume model to obtain the chemical flooding affected coefficient model of the phase-controlled reserves of each injection and production unit. By combining the chemical flooding affected coefficient model at the injection and production unit level, the overall chemical flooding affected coefficient of the phase-controlled reserves can be obtained.

[0007] The beneficial effects of the present invention are as follows: the present method can improve the calculation accuracy of chemical flooding sweep coefficient of phase-controlled reserves, thereby providing an accurate basis for the design of chemical flooding reservoir engineering schemes, numerical simulation accuracy, tracking adjustment and post-scheme implementation effect evaluation. Compared with the traditional chemical flooding sweep coefficient calculation, the method is more scientific, the concept is clearer, the index is more quantitative, and the calculation result of chemical flooding sweep coefficient is more accurate and reliable, which is of great significance for guiding oilfield production and development. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 It is a three-dimensional fine structural geological model map; Figure 2 It is a three-dimensional sedimentary facies model diagram; Figure 3 It is a high-precision porosity geological model map; Figure 4 It is a high-precision permeability geological model map; Figure 5 The total pore volume model is shown in the figure; Figure 6 It is a model diagram of macroscopically accessible pore volume; Figure 7 This is the relationship between the sweepable pore volume correction factor and permeability. Figure 8 It is a model diagram of the correction factor of the accessible pore volume for each sedimentary unit; Fig. 9 is the modified accessible porosity model map; Fig.10 is the model diagram of accessible pore volume for chemical flooding (phase change is not considered); Fig.11 It is the experimental determination diagram of the macro wave and pore volume correction coefficient of the phase change chemical agent between the injection and production units; Fig.12 It is the distribution diagram of the phase change types of reserves controlled by the well group. DETAILED DESCRIPTION

[0009] The following is a method for calculating the sweep coefficient of phase-controlled reserve chemical flooding, but it is worth noting that the method is not limited to these embodiments. In the detailed description of the method below, some specific details are described in detail. However, for the parts that are not described in detail, those skilled in the art can also fully understand.

[0010] This application takes the calculation of chemical flooding sweep coefficient of phase-controlled reserves as the research object, and clarifies the method to improve the calculation accuracy of chemical flooding sweep coefficient of phase-controlled reserves from three aspects: the establishment of fine geological model, the determination of microscopic accessible pore correction coefficient and phase change pore volume correction coefficient.

[0011] The specific process is as follows: (1) Establish a high-precision three-dimensional porosity and permeability model: Table 1 Comparison of the original porosity and permeability interpretation results and the infill interpretation results ① According to the current logging sampling interval, the porosity and permeability logging interpretation model is reconstructed to complete the fine secondary interpretation of the logging parameters in the study area. According to the encrypted interpretation of the reservoir physical property parameters at the logging sampling interval, the intra-layer heterogeneity can be finely characterized, providing a reliable basis for the fine calculation of the control degree of chemical flooding; ② Establish a new work area, load the well head, well layer (top), breakpoints of logging interpretation, fault files (sticks format) of seismic interpretation and horizon files of seismic tracing, use seismic interpretation horizon data as constraints, and establish digital layers through convergence method interpolation calculation according to the well layer (top) file; activate the fault module (Faultmodeling), use the faults (sticks) of seismic interpretation to directly convert them into preliminary fault models, apply the breakpoint constraints of logging interpretation, correct the trend and shape of the preliminary fault model, and finally establish a digital fault model with accurate position and reasonable shape; define a new geological model and determine the simulation boundary, carry out Pillar griding, establish a spatial grid geological body and a gridded fault model; use the make horizon to complete the gridding of the digitized layers, consider the contact relationship between different sedimentary units, use the "equal thickness subdivision" method to subdivide the thickness of the vertical sedimentary units, and then characterize the longitudinal heterogeneity within the layer, and establish a three-dimensional fine structural model containing fault and structural information. At the same time, the "four inspections" of the structural model, including consistency inspection between layers and stratification points, contact relationship inspection between layers and faults, cross-grid inspection of upper and lower layers, and grid negative volume inspection, are carried out to complete the quality control of the three-dimensional fine structural model; the three-dimensional fine structural model is as follows; Figure 1 shown.

[0012] ③ From the existing fine reservoir description work area (generally GPTmap), the gridded sedimentary facies data points (including three columns of horizontal coordinates, vertical coordinates and phase values) of each sedimentary unit are respectively exported, and the sedimentary facies data points of each sedimentary unit are imported and loaded into the structural geological model work area. According to the closest point value (Closest) method, the digitization of the sedimentary facies data points of each sedimentary unit is completed. Under the conditions of the Facies modeling module, the grid direct assignment method (Assign values) is applied to sample the digitized sedimentary facies data of each sedimentary unit into the grid, and finally a three-dimensional sedimentary facies model is established; the three-dimensional sedimentary facies model is as follows: Figure 2 As shown; ④ Using the physical property parameter encryption interpretation results of 0.125m logging sampling interval, the porosity and permeability attribute data of all single wells in the study area are split, and each single well forms a separate physical property parameter log file; the splitting results of the single well physical property parameter data are shown in Table 2.

[0013] Table 2 The results of physical property parameter data splitting of G229-S345 well (physical property parameter log file)

[0014] ⑤ Load the single well physical property parameter log file into the wellhead file, apply the Scale up well logs module, sample the single well physical property parameters into the grid framework, and then apply the Petrophysical modeling module, adopt the random simulation technology constrained by sedimentary phase trend, and use the sequential Gaussian interpolation method through variogram analysis (Data analysis) to establish a high-precision three-dimensional porosity (Ф) and permeability (stl) geological model; the porosity (Ф) geological model is as follows Figure 3 As shown, the permeability (stl) geological model is as follows Figure 4 shown.

[0015] (2) Calculation of chemical flooding sweep coefficient for phase-controlled reserves: ① Based on the established spatial grid geological body, apply the Geometrical Modeling module, select the Cellvolume method, establish the grid volume model (Bulk volume), use the Property calculator (Property calculator), multiply the grid volume model (Bulk volume) and the porosity model (Ф), select the template as Porevolume, and obtain the total pore volume model; the total pore volume model is as follows Figure 5 As shown; ② According to the experimentally determined limit of the pores with a permeability less than 20 mD that are difficult for the chemical agent to reach, the pores with a permeability less than 20 mD in the total pore volume model are filtered out using the property calculator to obtain a macroscopically accessible pore volume model; the macroscopically accessible pore volume model is as follows: Figure 6 As shown; ③ Based on the chemical agent microscopic wave and pore volume correction coefficient data under different permeability core conditions measured by indoor experiments, the relationship between permeability and chemical agent microscopic wave and pore volume correction coefficient is fitted: microscopic wave and pore volume correction coefficient = 0.2304ln (permeability) - 0.5589; the relationship curve between the permeability correction coefficient and the permeability is shown in Figure 7 As shown; ④ Use the Property calculator to establish the accessible pore volume correction coefficient model. The accessible pore volume correction coefficient model = 0.2304ln (permeability model) - 0.5589; the accessible pore volume correction coefficient model for each sedimentary unit is as follows: Figure 8 As shown; ⑤Use the property calculator to establish a modified accessible porosity model. The modified accessible porosity model is equal to the product of the accessible pore volume correction coefficient model and the porosity model. The modified accessible porosity model is as follows: Fig. 9 As shown; ⑥ Using the property calculator, establish an accessible pore volume model without considering phase change. The accessible pore volume model without considering phase change is equal to the product of the macroscopic accessible pore volume model and the modified accessible porosity model; the chemical flooding accessible pore volume model (without considering phase change) is as follows: Fig.10 shown.

[0016] ⑦ The study area is a five-point area well network. The Gao 229-Xie 345 well group is selected. Taking the Gao 33 sedimentary unit as an example, the phase-controlled reserve chemical flooding sweep coefficient of a single well group and a single sedimentary unit is obtained. The accessible pore volume (without considering phase change) of the four injection and production units of the Gao 33 sedimentary unit of the Gao 229-Xie 345 well group is read from the chemical flooding accessible pore volume model (without considering phase change). The volume is 23717m 3 、32586m 3 、27386m 3 、23725m 3 The accessible pore volume of chemical flooding without considering phase change is 107414m 3 The sand body combination modes of the high 33 sedimentary units among the four injection and production units of the typical well group are non-main body and non-main body combination, non-main body and river channel combination, non-main body and non-main body combination, and non-main body and non-main body combination. The experimentally determined chemical agent macroscopic wave correction coefficient of the non-main body and non-main body combination between the injection and production units is 0.68, and the chemical agent macroscopic wave correction coefficient of the non-main body and river channel combination is 0.863. In this way, the chemical agent macroscopic wave correction coefficients of the four injection and production units are 0.68, 0.863, 0.68 and 0.68 respectively. The accessible pore volume (without considering phase change) read by each injection and production unit is multiplied by the corresponding chemical agent macroscopic wave correction coefficient, and the accessible pore volume of the high 33 sedimentary unit considering phase change in each direction is 16128m 3 、28122m 3 、18622m 3 、16133m 3 The accessible pore volume of the high 33 sedimentary units considering phase change in the four injection and production units of phase-controlled reserves is accumulated, and the accessible pore volume of the chemical flooding considering phase change in the well group single layer is 79005m 3 The experimental determination diagram of the macroscopic wave and pore volume correction coefficient of the above-mentioned phase change chemical agent between the injection and production units is as follows: Fig.11 shown.

[0017] ⑧Use the attribute calculator to calculate the river channel, main body and a type of sandstone in the sedimentary facies as effective sandstone, and the other facies as invalid sandstone, establish the net-to-gross ratio model of the Gao 229-Xie 345 well group, and use the porosity model and net-to-gross ratio model of the Gao 229-Xie 345 well group to calculate the phase-controlled reserve model of the Gao 229-Xie 345 well group. The phase-controlled reserves of the Gao 229-Xie 345 well group are read as 58,000 tons, and the phase-controlled reserves of the Gao 229-Xie 345 well group in the Gao 33 sedimentary unit are 5,000 tons; ⑨ The total pore volume of the 33rd sedimentary unit in the well group is read from the total pore volume model as 167627m 3 The accessible pore volume of the Gao 33 sedimentary unit of the Gao 229-Xie 345 well group is 79005m 3 Divided by the total pore volume of the 33 sedimentary units in the well group, it is 167627m 3 , that is, the chemical flooding sweep coefficient of the Gao 33 sedimentary unit of the well group controlled reserves is 0.4713. At the same time, the phase-controlled reserve model uses the chemical flooding sweep coefficient model for filtering and sorting, and the area with a sweep coefficient of 0 is screened out, and the phase-controlled reserves that can be swept by chemical flooding in the Gao 33 sedimentary unit are 19,000 tons; the phase change type distribution diagram of the phase-controlled reserves is shown in Fig.12 shown.

[0018] This application is highly concise and targeted, and the operation method is simple and efficient, which can guide the calculation of chemical flooding sweep coefficient of phase-controlled reserves.

Claims

1. A method for calculating the sweep coefficient of phase-controlled reserve chemical flooding, comprising the following steps: (1) Establish a high-precision three-dimensional porosity and permeability model: According to the current logging sampling interval, the porosity and permeability logging interpretation model is reconstructed to complete the fine secondary interpretation of logging parameters, thereby effectively characterizing the heterogeneity within a single well layer; In the Petrel software platform, based on the fault results of seismic interpretation and combined with the adjustment of fault boundary control lines, a fault model that conforms to the actual spatial form is established. The layer results of seismic interpretation are used as trend constraints to establish the oil layer group-level framework layer. Using the well point stratification data and the "thickness constraint" method, a sedimentary unit-level layer model with reasonable contact relationship between strata and structural characteristics in line with geological laws is established. Through the detailed verification and adjustment of the contact relationship between the fault model and the layer model, a sedimentary unit-level structural framework with reasonable contact relationship between faults and layers is established. Considering the contact relationship between each sedimentary unit, the "equal thickness subdivision" technology is used from top to bottom to further subdivide each vertical sedimentary unit and establish a three-dimensional fine structural geological model. Using the secondary interpretation results of the logging parameters of a single well, a single well LOG file is created according to the logging sampling interval of 0.125m, which contains three columns: depth, porosity and permeability. The single well data file is loaded into the corresponding single well folder of the structural geological model work area, and the porosity and permeability data of the single well are discretized. The porosity and permeability data are collected from the single well folder to the corresponding grid, so that different depths of the grid at the well point location are given different porosity and permeability values; The phase point file of each sedimentary unit derived from the existing fine reservoir description work area, which contains three columns of horizontal coordinate, vertical coordinate and phase value, is loaded into the structural geological model work area. The nearest point value method is used for interpolation operation to complete the digitization of the sedimentary phase data points of each sedimentary unit. The grid direct assignment method is used to sample the digitized sedimentary phase data of each unit into the grid, and finally a three-dimensional sedimentary phase model is established. Taking the sedimentary facies model as the trend constraint condition, the collected grid porosity and permeability as the basic data source, applying the random function interpolation theory, through the variogram analysis, using the sequential Gaussian interpolation method, finally establish a high-precision phase-controlled porosity and permeability three-dimensional physical property parameter geological model; (2) Calculation of chemical flooding sweep coefficient for phase-controlled reserves: ① Based on the three-dimensional fine structural geological model, the Geometrical Modeling module is applied in the Petrel software platform to establish a grid volume model Cell volume. The attribute calculator is used to multiply the established grid volume model with the porosity geological model to obtain the total pore volume model at the sedimentary unit level. Based on the total pore volume model, the total pore volume of each sedimentary unit in the block is calculated; ② According to the permeability limit that is difficult for the chemical agent to reach determined by the indoor experiment, the part of the total pore volume model that is below the permeability limit is removed by the filter function using the attribute calculator to obtain the macroscopic accessible pore volume model; according to the microscopic pore volume correction coefficient data of the chemical agent under the core conditions of different permeabilities determined by the indoor experiment, the relationship between the permeability and the microscopic pore volume correction coefficient of the chemical agent is fitted, and in the Geometrical Modeling module, a new constant geometric model is established, and the attribute calculator is used to calculate the constant geometric model with the fitted permeability and the microscopic pore volume correction coefficient of the chemical agent to obtain the affected pore volume correction coefficient model of each sedimentary unit, and the attribute calculator is used to multiply the affected pore volume correction coefficient model with the porosity to obtain the porosity correction model; the attribute calculator is used again to multiply the porosity correction model with the grid volume model Cell volume to obtain the affected pore volume model that does not consider the layer combination and plane phase change; ③ On the existing sedimentary facies belt map of the sub-sedimentary units, the well group is divided according to the block well pattern, the sand body combination mode between different injection and production units in each sedimentary unit well group is counted, the sand body phase change type and connectivity type between different injection and production units are determined, and the control area of ​​each injection and production unit is delineated according to the well pattern. The affected pore volume model without considering the stratum combination and plane phase change established in the above step ② is cut into the affected pore volume model without considering the stratum combination and plane phase change at the injection and production unit level according to the control area of ​​each injection and production unit; ④ According to the phase change type of each deposition unit between each injection and production unit determined in step ③ above, the chemical agent macro-wave and pore volume correction coefficients of different phase change types are determined in combination with indoor experiments, and the chemical agent macro-wave and pore volume correction coefficients of each deposition unit between the injection and production units are statistically calculated. The Geometrical Modeling module is used to establish a constant geometric model for each injection and production unit. The constant geometric model is assigned to each deposition unit according to the statistical chemical agent macro-wave and pore volume correction coefficients of the sub-deposition units, so as to obtain the chemical agent macro-wave and pore volume correction coefficient model for each injection and production unit; ⑤ Apply the property calculator to multiply the accessible pore volume model of chemical flooding without considering phase change at the injection-production unit level by the chemical agent macroscopic affected pore volume correction coefficient model at the injection-production unit level, that is, to obtain the accessible pore volume model of each sedimentary unit considering phase change at the injection-production unit level; based on the accessible pore volume model of each injection-production unit considering phase change, merge the accessible pore volume models of each sedimentary unit considering phase change in all injection-production units in the well group, that is, to obtain the chemical flooding accessible pore volume model of each sedimentary unit considering phase change in the well group; merge the accessible pore volume models of each sedimentary unit considering phase change in all well groups, that is, to obtain the chemical flooding accessible pore volume model of each sedimentary unit considering phase change in the block; ⑥ Using the attribute calculator, the river channel, main body and a type of sandstone in the sedimentary facies are calculated as effective sandstone, and the remaining facies are invalid sandstone. A net-to-gross ratio model is established, and the injection-production unit-level porosity model and the net-to-gross ratio model are used to calculate the facies-controlled reserve model of each sedimentary unit; ⑦ Using the attribute calculator, divide the merged chemical flooding accessible pore volume model of each sedimentary unit considering phase change by the total pore volume model of each sedimentary unit to obtain the chemical flooding sweep coefficient of the phase-controlled reserves of each sedimentary unit in the block; at the same time, the phase-controlled reserve model is filtered and sorted using the chemical flooding sweep coefficient model to screen out the areas with sweep coefficient equal to 0, so as to obtain the phase-controlled reserves accessible by chemical flooding.

2. The method for calculating the chemical flooding sweep coefficient of the well group controlled reserves according to claim 1, characterized in that: In step (1), in step (4), a three-dimensional sedimentary facies model is established: the sedimentary facies data points are derived according to the sedimentary units using the existing fine reservoir description work area, including three columns of data: horizontal coordinate, vertical coordinate and phase value. The sedimentary facies data points of each sedimentary unit are added to the three-dimensional fine structural model work area. According to the method of nearest point value selection, the sedimentary facies data points of each sedimentary unit are digitized. Through the grid assignment method, the digitized sedimentary facies data of each unit are sampled into the grid, and finally a three-dimensional sedimentary facies model is established; then the porosity geological model and the permeability geological model are established: using the 0.125m The encrypted interpretation results of reservoir physical property parameters are used to split the porosity and permeability data of all single wells in the study area according to the physical property parameter sampling interval of 0.125m, and a LOG physical property parameter file is formed for each single well; the split single well physical property parameter file is loaded into the three-dimensional model, and the single well physical property parameter file is sampled into the grid framework through data discretization processing, and then based on the random function interpolation theory, the random simulation technology controlled by the sedimentary phase model is adopted, and through the variation function analysis, the sequential Gaussian interpolation method is applied to generate a three-dimensional physical property parameter geological model of porosity and permeability.

3. The method for calculating the chemical flooding sweep coefficient of the well group controlled reserves according to claim 1, characterized in that: In step (2), in steps ③ to ⑦, the sand body combination patterns between different injection and production units in each sedimentary unit well group are counted. According to the controlled area of ​​each injection and production unit, the affected pore volume model without considering the stratum combination and the plane phase change is cut into the affected pore volume model at the injection and production unit level; the chemical flooding accessible pore volume model without considering the phase change at the injection and production unit level is multiplied by the chemical agent macroscopic affected pore volume correction coefficient model at the injection and production unit level to obtain the injection and production unit level The accessible pore volume model considering the phase change is obtained, and the chemical flooding accessible pore volume model considering the phase change at the injection and production unit level is divided by the total pore volume model to obtain the chemical flooding sweep coefficient model of the phase-controlled reserves of each injection and production unit; by merging the chemical flooding sweep coefficient model at the injection and production unit level, the overall chemical flooding sweep coefficient of the phase-controlled reserves can be obtained.

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