Triangle phase diagram based reservoir performance adjustment method for high water cut stage

Abstract

The application provides a high water cut stage reservoir variable flow line regulation method based on a triangular phase diagram, which comprises the following steps: step 1, evaluating the dispersion degree of remaining oil; step 2, using the result of logarithmic processing of the instantaneous liquid passing multiple to represent the hydrodynamic strength; step 3, calculating the dominant potential abundance as a representation index of reservoir potential; and step 4, classifying the reservoir flow line parameters through a density peak value algorithm to establish a flow line adjustment technology partition. The high water cut stage reservoir variable flow line regulation method based on the triangular phase diagram is simple, quick and effective, easy to use and popularize, and can better guide the remaining oil tapping work in the high water cut development stage of the reservoir, and plays an important economic benefit in improving the recovery efficiency and improving the development effect of the old oilfield.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil production engineering in oil and gas, in particular to a high water cut reservoir flow line adjustment method based on triangular phase diagram. BACKGROUND

[0002] Oil and gas are important strategic resources for the country, and are the lifeline of the national economic development. With the expansion of oil and gas exploration, efficient development of high water cut reservoirs has become one of the main fields of enhanced oil recovery in China's major oilfields.

[0003] At present, the reconstruction of flow lines in high water cut reservoirs has become a popular research content. For this research, domestic and foreign scholars have done some research work. Hou Yupeng divides the adjustment of reservoir flow lines into well pattern adjustment, layer adjustment, production system adjustment, etc. On this basis, he designs a flow line reconstruction scheme for the actual block in Chengdong East District, and achieves good results. Yao Zheng proposes adjustment methods such as shutting down high water cut wells and their corresponding injection wells, changing layers and drilling new wells for existing wells, converting production wells to injection wells, rotating injection, layer adjustment, etc. on the basis of numerical simulation research in Weizhou A oilfield. Feng Qihong considers the strength of the reservoir flow line as the main indicator of well pattern optimization, and optimizes the development effect of the reservoir. Jiang Ruzhong et al. form an evaluation system for reservoir flow lines through bp neural network, and propose corresponding variable flow line control methods. However, the essence of the flow line reconstruction proposed by the current research is still based on production system adjustment, and no quantitative reconstruction method is proposed from the essence of variable flow line control.

[0004] In the Chinese patent application with application number CN201110078072.4, a three-dimensional flow line control method for improving recovery in water drive reservoirs is involved, which is characterized by: the method is to identify the development direction of the dominant flow channel plane and the vertical development layer, and to quantitatively calculate the production parameters; to establish a three-dimensional geological model containing the characteristics of the dominant flow channel, to establish an oil reservoir numerical simulation model, and to accurately determine the remaining oil distribution characteristics under the current heterogeneous conditions through oil reservoir numerical simulation; to perform well pattern adjustment and water plugging profile control optimization design; and to determine whether layering injection is needed according to the vertical water well water absorption characteristics and the oil well liquid production characteristics based on the oil reservoir numerical simulation results. However, this patent mainly proposes well pattern optimization measures for the development status of the dominant flow channel, and does not establish an effective variable flow line chart from different aspects of flow field research to guide the implementation of variable flow line adjustment measures.

[0005] In the Chinese patent application with the application number CN201510420093.8, a method for improving recovery efficiency by partition control in fault block reservoirs in ultra-high water cut stage is disclosed. The method comprises: step 1, analyzing the structural and geological characteristics and well pattern evolution characteristics of the research area; step 2, conducting reasonable partition research through complex remaining oil characteristics and influencing factor research, and developing a partition scheme for complex fault block reservoirs in ultra-high water cut stage by analyzing the differences in plane water drive effect and influencing factors of typical fault block reservoirs; and step 3, using numerical simulation or reservoir engineering methods to determine the development contradictions in each partition and optimize the partition control technology policy, and designing the partition injection-production control scheme. However, the patent considers the structural and geological characteristics, fault edge description, fault combination description, reservoir heterogeneity and oil-water distribution characteristics, but fails to identify the key factors for adjusting the flow lines.

[0006] In the Chinese patent application with the application number CN201611093557.X, a method for improving CO2 storage capacity and oil recovery efficiency is disclosed. The method comprises: obtaining a pressure level versus oil displacement efficiency curve based on a long-thin tube oil displacement experiment; determining a target area pressure safety limit using a CO2 oil displacement and sealing target area caprock and fault stability evaluation method; optimizing a reasonable pressure maintenance level using a reservoir numerical simulation method; achieving CO2 vertical balanced displacement based on reservoir parameters, production parameters and process methods; achieving CO2 plane balanced displacement by using variable well spacing, differential reservoir modification based on target area reservoir heterogeneity and remaining reserve abundance distribution; and adjusting the injection-production flow line by optimizing injection methods, injection speed, injection-production control and foam plugging. However, the patent does not provide specific adjustment schemes and guidance for water drive reservoirs based on the optimization of CO2 oil displacement injection-production parameters.

[0007] Therefore, we invented a new method for adjusting flow lines in high water cut stage reservoirs based on triangular phase diagrams, which solves the above technical problems. SUMMARY

[0008] The purpose of the present application is to provide a method for adjusting flow lines in high water cut stage reservoirs based on triangular phase diagrams, which is simple to operate, fast and effective, easy to promote and use, and can better guide the remaining oil potential tapping work in high water cut stage reservoirs.

[0009] The object of the present application can be achieved by the following technical measures: a triangular phase diagram-based reservoir flow line adjustment method in a high water cut stage, comprising: step 1, evaluating the dispersion degree of remaining oil; step 2, using the logarithmic processed result of instantaneous liquid passing multiple to represent the hydrodynamic strength; step 3, calculating the dominant potential abundance as a representation index of reservoir potential; and step 4, classifying the reservoir flow line parameters by the density peak value algorithm, and establishing a flow line adjustment technology partition.

[0010] The object of the present application can also be achieved by the following technical measures:

[0011] In step 1, the dispersion degree of remaining oil is evaluated by selecting three indexes of average patch area, patch density and average shape index.

[0012] In step 1, the smaller the average patch area, the smaller the single-block remaining oil recoverable reserves, and the higher the dispersion degree of remaining oil; the greater the patch density, the more the number of remaining oil patches, and the higher the dispersion degree of remaining oil; the greater the average shape index, the more complex the shape of remaining oil patch, and the higher the dispersion degree of remaining oil.

[0013] In step 1, according to the results of reservoir numerical simulation, the continuous oil phase, i.e. the remaining oil patch, is identified by using the 8-neighborhood boundary tracking algorithm and labeled; the area and perimeter of the labeled patch are obtained by the regionprops function; and the matrix of remaining oil patch attributes at different time steps is obtained, so that the dispersion degree of remaining oil at different time steps can be calculated by the entropy weight method.

[0014] In step 2, the calculation formula of fluid flow in reservoir numerical simulation is:

[0015]

[0016] In the formula, flow is the grid flow size, m 3 / d; FLOIL I+ is the oil flow of the I+ direction grid, m 3 / d; FLOIL J+ is the oil flow of the J+ direction grid, m 3 / d; FLOIL K+ is the oil flow of the K+ direction grid, m 3 / d; FLOWAT I+ is the water flow of the I+ direction grid, m 3 / d; FLOWAT J+ is the water flow of the J+ direction grid, m 3 / d; FLOWAT K+ is the water flow of the K+ direction grid, m 3 / d;

[0017] The formula for calculating hydrodynamic intensity is:

[0018]

[0019] HS represents hydrodynamic intensity, and PRORV represents pore volume.

[0020] In step 2, the oil and water flow rates in the I, J, and K directions of each grid are extracted from the numerical simulation to calculate the grid flow rate of each grid; the pore volume of each grid is extracted to calculate the hydrodynamic intensity field distribution of each grid. The hydrodynamic intensity is an instantaneous quantity that represents the fluid flow situation at the current moment.

[0021] In step 3, the formula for calculating the abundance potential of dominance is:

[0022]

[0023] in:

[0024] In the formula, J O3 For superior reserves abundance, 10 4 t / km 2 h is the reservoir thickness, in meters. Porosity; S o Oil saturation; S or Residual oil saturation; ρ o Crude oil density, g / cm³ 3 B o α is the crude oil volume factor; α is the dominant potential abundance factor; K is the reservoir permeability, 10 -3 μm 2 ;K max The maximum permeability within the reservoir, 10 -3 μm 2 ;K ro K represents the relative permeability of the oil phase. rw The relative permeability of the aqueous phase; μ o Crude oil viscosity, mPa·s; μ w Let be the viscosity of water, in mPa·s.

[0025] In step 4, reservoir streamline parameters are classified using the density peak algorithm, streamline adjustment technology zones are established, and six types of control modes are determined: streamlining, stream establishment, stream replenishment, stream stabilization, stream uniformity, and stream control. Specific implementation is carried out in the control zones.

[0026] This invention presents a streamline control method for high water-cut reservoirs based on triangular phasors. Starting from indicators such as remaining oil dispersion, hydrodynamic intensity, and abundance of dominant potential, it uses a density peak clustering algorithm to perform cluster analysis on different seepage characteristic regions of the reservoir, establishing a streamline adjustment base classification map. Six streamline reconstruction and management strategies are proposed: "vegetated flow line," "replenished flow line," "uniform flow line," "stabilized flow line," and "controlled flow line." This guides the work of tapping remaining oil potential and improving oil recovery in high water-cut reservoirs from a streamline perspective. The method involved in this invention can conveniently, accurately, quickly, and effectively quantitatively identify different seepage characteristic regions of the reservoir and propose management strategies such as "vegetated flow line," "uniform flow line," "replenished flow line," "stabilized flow line," and "controlled flow line" based on the triangular phasor diagram. This has played a significant economic role in improving the recovery rate and development effect of old oilfields. Attached Figure Description

[0027] Figure 1 This is a classification diagram of variable streamline adjustment technology in a specific embodiment of the present invention;

[0028] Figure 2 This is a flowchart of a specific embodiment of the method for regulating the flow lines of a high-water-cut reservoir based on a triangular phase diagram according to the present invention. Detailed Implementation

[0029] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0030] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments of the present invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, and / or combinations thereof.

[0031] like Figure 2 As shown, Figure 2 This is a flowchart of the method for regulating the flow lines of a high-water-cut reservoir based on a triangular phase diagram, as described in this invention.

[0032] Step 101. Residual oil dispersity index implementation: Based on the achievements of landscape, combined with the characteristics of the planar distribution of residual oil, three indexes of mean patch size (MPS), patch density (PD) and mean shape index (MSI) are selected to evaluate the dispersity of residual oil. The smaller the mean patch size, the smaller the single block of residual oil recoverable reserves, and the higher the dispersity of residual oil. The greater the patch density, the more the number of residual oil patches, and the higher the dispersity of residual oil. The greater the mean shape index, the more complex the shape of residual oil patch, and the higher the dispersity of residual oil.

[0033] The oil reservoir numerical simulation result file is extracted, and the continuous oil phase, i.e. residual oil patch, is identified by using 8-neighborhood boundary tracking algorithm, and is labeled. The area, perimeter and other properties of the labeled patch are obtained by using regionprops function. The matrix of residual oil patch properties at different time steps is obtained, and the dispersity of residual oil at different time steps can be calculated by using entropy weight method.

[0034] Step 102. Hydrodynamic strength index implementation: The logarithmic processed result of instantaneous liquid passing multiple is used to represent the hydrodynamic strength.

[0035] The calculation formula of fluid flow in oil reservoir numerical simulation is as follows:

[0036]

[0037] In the formula, flow is the size of grid flow, m 3 / d; FLOOIL I+ is the oil flow of I+ direction grid, m 3 / d; FLOOIL J+ is the oil flow of J+ direction grid, m 3 / d; FLOOIL K+ is the oil flow of K+ direction grid, m 3 / d; FLOWAT I+ is the water flow of I+ direction grid, m 3 / d; FLOWAT J+ is the water flow of J+ direction grid, m 3 / d; FLOWAT K+ is the water flow of K+ direction grid, m 3 / d;

[0038] The calculation formula of hydrodynamic strength is as follows:

[0039]

[0040] The oil and water flow in I, J, K direction of each grid is simulated by extraction of numerical value, the grid flow size of each grid is calculated, the pore volume of each grid is extracted, so that the water dynamics strength field distribution of each grid can be calculated, the water dynamics strength is instantaneous quantity, which shows the current fluid flow condition.

[0041] Step 103. Advantage potential abundance index is realized: when the reservoir enters the high water cut development period, the conventional method for characterizing the remaining potential is to calculate the remaining oil reserve abundance or the remaining oil recoverable reserve abundance. The calculation formula of the remaining oil recoverable reserve abundance is:

[0042]

[0043] The calculation formula of the remaining oil recoverable reserve abundance is:

[0044]

[0045] In the formula, J O1 is the remaining oil reserve abundance, 10 4 t / km 2 ; J O1 is the remaining oil recoverable reserve abundance, 10 4 t / km 2 ; h is the reservoir thickness, m; is the porosity; S o is the oil saturation; S or is the residual oil saturation; p o is the oil density, g / cm 3 ; B o is the oil volume factor.

[0046] The reserve abundance reflects the remaining oil enrichment on the block plane to a certain extent, but ignores the flow capacity of the remaining oil. The factors affecting the flow capacity include the absolute permeability of the reservoir, the relative permeability of the oil-water two-phase and the viscosity of the oil-water two-phase. Based on the above factors, the advantage potential abundance calculation formula is proposed:

[0047]

[0048] Among them:

[0049] In the formula, J O3 is the advantage reserve abundance, 10 4 t / km 2 ; a is the advantage potential abundance coefficient; K is the reservoir permeability, 10 -3 μm 2 ; K max is the maximum permeability in the reservoir, 10 -3 μm 2 ; Kro Ko is the relative permeability of the oil phase; K rw Kw is the relative permeability of the water phase; μ o μo is the viscosity of the crude oil, mPa.S; μ w μw is the viscosity of water, mPa.S.

[0050] The advantage potential abundance characterizes the potential abundance of a region with good physical properties in the reservoir, which can eliminate the remaining oil in the low permeability region, make the adjustment region more clear, and has more pertinence when implementing the remaining oil potential tapping measures than the remaining recoverable reserves abundance. The law can better reflect the relationship between the reservoir physical properties and the remaining oil, and therefore, the advantage potential abundance is selected as the characterization index of the reservoir potential.

[0051] Step 104. Variable flow line region division: the density peak value algorithm is used to classify the reservoir flow line parameters, the flow line adjustment technology partition is established, six types of adjustment and control modes, i.e., “plant flow line”, “build flow line”, “supplement flow line”, “stable flow line”, “uniform flow line” and “control flow line”, are determined respectively, and specific implementation is performed on the adjustment and control partition.

[0052] In the specific embodiment 1 of the application, the variable flow line adjustment and control method for the high water cut stage reservoir based on the triangular phase diagram comprises the following steps:

[0053] Step 1. Realization of the remaining oil dispersion degree index: referring to the related research results of landscape, combined with the characteristics of the plane distribution of the remaining oil, three indexes, i.e., the average patch area (MPS), the patch density (PD) and the average shape index (MSI) are selected to evaluate and study the dispersion degree of the remaining oil. The smaller the average patch area, the smaller the single block recoverable reserves of the remaining oil, and the higher the dispersion degree of the remaining oil. The greater the patch density, the more the number of the remaining oil patches, and the higher the dispersion degree of the remaining oil. The greater the average shape index, the more complex the patch shape of the remaining oil, and the higher the dispersion degree of the remaining oil.

[0054] The reservoir numerical simulation result file is extracted, the continuous oil phase, i.e., the remaining oil patch is identified by using the 8-neighborhood boundary tracking algorithm, and is labeled. The area, perimeter and other properties of the labeled patch are obtained by using the regionprops function. The matrix composed of the properties of the remaining oil patches at different time steps is obtained, and the dispersion degree of the remaining oil at different time steps can be calculated by using the entropy weight method.

[0055] Step 2. Realization of the hydrodynamic strength index: the result of the logarithmic processing of the instantaneous liquid passing multiple is used to characterize the hydrodynamic strength.

[0056] The calculation formula of the fluid flow in the reservoir numerical simulation is as follows:

[0057]

[0058] In the formula, flow is the grid flow size, m 3 / d; FLOOIL I+ Oil flow rate of I+ direction grid, m 3 / d; FLOOIL J+ Oil flow rate of J+ direction grid, m 3 / d; FLOOIL K+ Oil flow rate of K+ direction grid, m 3 / d; FLOWAT I+ Water flow rate of I+ direction grid, m 3 / d; FLOWAT J+ Water flow rate of J+ direction grid, m 3 / d; FLOWAT K+ Water flow rate of K+ direction grid, m 3 / d;

[0059] The formula for calculating the hydrodynamic strength is:

[0060]

[0061] By extracting the numerical simulation of oil and water flow rate of each grid in I, J, K direction, the grid flow rate of each grid is calculated; the pore volume of each grid is extracted, so that the distribution of hydrodynamic strength field of each grid can be calculated. Hydrodynamic strength is instantaneous quantity, which represents the current fluid flow situation.

[0062] Step 3. Realize the advantage potential abundance index: when the reservoir enters the high water cut development period, the conventional method to characterize the remaining potential is to calculate the remaining oil reserves abundance or the remaining oil recoverable reserves abundance. The formula for calculating the remaining oil recoverable reserves abundance is:

[0063]

[0064] The formula for calculating the remaining oil recoverable reserves abundance is:

[0065]

[0066] In the formula, J O1 is the remaining oil reserves abundance, 10 4 t / km 2 ; J O1 is the remaining oil recoverable reserves abundance, 10 4 t / km 2 ; h is the reservoir thickness, m; is the porosity; S o is the oil saturation; S or is the residual oil saturation; p o is the oil density, g / cm 3 ; B o is the oil volume factor.

[0067] Reserve abundance reflects the remaining oil enrichment on the block to some extent, but ignores the flow capacity of the remaining oil. Factors affecting flow capacity include absolute permeability of the reservoir, relative permeability of oil and water, and viscosity of oil and water. Based on the above factors, the dominant potential abundance calculation formula is proposed:

[0068]

[0069] Wherein:

[0070] In the formula, J O3 is the dominant reserve abundance, 10 4 t / km 2 ; alpha is the dominant potential abundance coefficient; K is the reservoir permeability, 10 -3 mu 2 m; K max is the maximum permeability in the reservoir, 10 -3 mu 2 m; K ro is the oil phase relative permeability; K rw is the water phase relative permeability; mu o is the oil viscosity, mPa.S; mu w is the viscosity of water, mPa.S.

[0071] The dominant potential abundance represents the potential abundance of the area with good reservoir properties, which can eliminate the remaining oil in low permeability areas, make the adjustment area more clear, and be more targeted in implementing remaining oil potential tapping measures than the remaining recoverable reserve abundance. Such rules can better reflect the relationship between reservoir properties and remaining oil, so the dominant potential abundance is selected as the characterization index of reservoir potential.

[0072] Step 4. Variable flow line area division: the density peak value algorithm is used to classify the reservoir flow line parameters, and the Figure 1 variable flow line adjustment technology is established to determine six types of adjustment and control modes, i.e. "plant flow line", "build flow line", "supplement flow line", "stable flow line", "uniform flow line" and "control flow line".

[0073] In the specific embodiment 2 of the application, the variable flow line adjustment and control method for high water cut reservoirs based on triangular phase diagram includes the following steps:

[0074] Step 1: Remaining oil dispersion index implementation method

[0075] In this study, the results of landscape science are used for reference, combined with the characteristics of the distribution of remaining oil on the plane, three indexes, i.e. mean patch size (MPS), patch density (PD) and mean shape index (MSI), are selected to evaluate the dispersion degree of remaining oil, and the specific description of each parameter is shown in Table 1.

[0076] Table 1 Characterization of Residual Oil Dispersion Index

[0077]

[0078] In the table, A represents the total area of ​​remaining oil; N represents the number of remaining patches; and E represents the total perimeter of the remaining oil patches.

[0079] As shown in Table 1, the smaller the average patch area, the smaller the recoverable reserves of a single patch, and the higher the residual oil dispersion; the greater the patch density, the more residual oil patches there are, and the higher the residual oil dispersion; the greater the average shape index, the more complex the shape of the residual oil plate, and the higher the residual oil dispersion.

[0080] Using the results of reservoir numerical simulation, the result file is extracted, and the continuous oil phase, i.e., the remaining oil patches, is identified and labeled using the 8-neighborhood boundary tracking algorithm. The area, perimeter, and other attributes of the labeled patches are obtained using the regionprops function. A matrix composed of the attributes of the remaining oil patches at different time steps is obtained, and the remaining oil dispersion at different time steps can be calculated using the entropy weight method.

[0081] Step 2: Method for Implementing Hydrodynamic Intensity Field

[0082] The result after logarithmic transformation of the instantaneous liquid flow ratio is used to characterize the hydrodynamic intensity.

[0083] Formula for calculating fluid flow rate in reservoir numerical simulation:

[0084]

[0085] In the formula, flow is the grid flow rate, m 3 / d;FLOOIL I+ For the oil flow rate in the I+ direction grid, m 3 / d;FLOOIL J+ For the oil flow rate in the J+ direction grid, m 3 / d;FLOOIL K+ For the oil flow rate in the K+ direction grid, m 3 / d;FLOWAT I+ For the water flow rate in the I+ direction grid, m 3 / d;FLOWAT J+ For the water flow rate in the J+ direction grid, m 3 / d;FLOWAT K+ For the water flow rate in the K+ direction grid, m 3 / d;

[0086] The formula for calculating hydrodynamic intensity is:

[0087]

[0088] The oil and water flow in the I, J, K direction of each grid is simulated by extraction, and the grid flow size of each grid is calculated; the pore volume of each grid is extracted, so that the water dynamics strength field distribution of each grid can be calculated. The water dynamics strength is an instantaneous quantity, which represents the current fluid flow situation.

[0089] Step 3: Advantage potential abundance field implementation method

[0090] Advantage potential abundance calculation formula:

[0091]

[0092] Wherein:

[0093]

[0094] In the formula, J O3 is the advantage reserve abundance, 10 4 t / km 2 ; α is the advantage potential abundance coefficient; K is the reservoir permeability, 10 -3 μm 2 ; K max is the maximum permeability in the reservoir, 10 -3 μm 2 ; K ro is the oil phase relative permeability; K rw is the water phase relative permeability; μ o is the oil viscosity, mPa.S; μ w is the viscosity of water, mPa.S.

[0095] The advantage potential abundance represents the potential abundance of the area with good physical properties in the reservoir. It can remove the remaining oil in the low permeability area, make the adjustment area more clear, and has more pertinence in implementing the remaining oil potential tapping measures than the remaining recoverable reserve abundance. Such rules can better reflect the relationship between reservoir physical properties and remaining oil, so the advantage potential abundance is selected as the characterization index of reservoir potential.

[0096] Step 4: Density peak clustering algorithm determines the triangular phase diagram variable flow line regulation mode

[0097] The density peak algorithm can quickly determine the set of flow lines of the same class by classifying the reservoir flow line parameters. The specific steps of the density peak algorithm are as follows: (1) input the sample set to form the distance matrix between samples; (2) calculate the adjacent points, relative distance and local density of each sample point; (3) determine the clustering center and classify the non-clustering center; (4) assign the boundary points with noise to a clustering cluster associated with the core point.

[0098] In the specific embodiment 3 of the application, the reservoir flow lines are divided into six categories based on the density peak clustering algorithm, and a three-parameter triangular phase diagram is established to quantitatively regulate the reservoir flow lines, and a "building, planting, supplementing, uniforming, stabilizing and controlling" six-class flow line regulation mode for high water cut reservoirs is proposed.

[0099] (1) Building flow line regulation

[0100] In the area where the well pattern is imperfect, the flow line is established in a large area to perfect the layer system well pattern, and the building flow line work is carried out, and the main methods are as follows:

[0101] Layer system reorganization to build longitudinal layer system

[0102] Planar deployment of new wells to build well pattern

[0103] (2) Planting flow line regulation

[0104] In the area where the injection-production well pattern control degree is low and the displacement effect is poor, the method of perfecting the injection-production well pattern and subdividing the layer system is adopted, and the planting flow line work is carried out, and the main methods are as follows:

[0105] Edge expansion to perfect injection-production well pattern and plant flow line

[0106] Reconstruction of injection-production well pattern and flow line in fault block reservoir

[0107] Subdivision of layer system and planting flow line in multi-layer heterogeneous reservoir

[0108] (3) Supplementing flow line regulation

[0109] Depending on single well point adjustment to improve water injection, expand water drive control degree, increase flow line coverage degree and improve development effect (repair damaged flow line field), the main methods are as follows:

[0110] Restoring flow line: restoring flow line in damaged well area

[0111] Enhancing flow line: single well point injection and liquid lifting in well area

[0112] Changing flow line: injection well point update

[0113] (4) Uniform flow line regulation

[0114] For relatively perfect injection-production well pattern, relatively high water drive control degree and relatively good water drive development effect, in order to further improve the recovery efficiency, the overall work aiming at uniform flow line is carried out, and the main methods are as follows:

[0115] Profile control and flooding: improving water drive sweep volume

[0116] Sub-injection and fine sub-injection: improving oil layer producing degree

[0117] Pulse water injection: unstable displacement

[0118] (5) Stable flow line regulation

[0119] For the well pattern of injection and production, the water drive effect is better, the water drive front is uniform, and the overall water content is relatively low. The main work is to stabilize the flow line distribution, and the main methods are:

[0120] Maintain water quality and achieve stable and good water quality indicators

[0121] Maintain wellbore integrity and apply tubing liner to prevent secondary pollution of injected water

[0122] Maintain water absorption capacity and strengthen injection pressure difference stability

[0123] (6) Control flow line regulation

[0124] For the low-efficiency injection seepage area caused by long-term water injection, the dominant seepage channel is relatively obvious, and the water drive degree is relatively high. In order to further improve the recovery efficiency, the overall work is carried out for the purpose of controlling the flow line, and the main methods are:

[0125] Deep profile control: inhibit injection dominant channel

[0126] Plugging high permeability layer: reduce ineffective injection

[0127] Sub-injection and fine sub-injection: improve oil layer producing degree

[0128] With the help of numerical simulation results of oil reservoir, different parts of oil reservoirs that meet the characteristics of each region are treated to improve development effect and recovery efficiency.

[0129] Taking an actual block oil reservoir as an example, the numerical values of the dispersion degree of remaining oil, water dynamics strength and dominant potential abundance are determined through numerical simulation results, and the density peak clustering algorithm is used to establish a variable flow line regulation technology classification diagram, as shown in Figure 1 .

[0130] Quantitative division of oil reservoir "build flow line", "plant flow line", "supplement flow line", "uniform flow line", "stable flow line" and "control flow line" related characteristic areas, and take variable flow line regulation measures for different quantitative characteristic areas.

[0131] Finally, it should be noted that the above is only a preferred embodiment of the present application and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some technical features. Any modification, equivalent substitution, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

[0132] All technical features not described in the specification are known to the skilled person.

Claims

1. A method for high water cut reservoirs flow line regulation based on triangular phase diagram, characterized in that, The triangular phase diagram-based high water cut stage reservoir flow line adjustment method comprises: Step 1, evaluating the dispersion degree of remaining oil; Step 2, using the logarithmic processed result of the instantaneous liquid displacement multiple to represent the hydrodynamic strength; Step 3, calculating the dominant potential abundance as a representation index of reservoir potential; Step 4, classifying the reservoir flow line parameters by the density peak value algorithm to establish a flow line adjustment technology partition; the reservoir flow line parameters refer to the remaining oil dispersion degree, hydrodynamic strength and dominant potential abundance parameters; In step 1, three indexes of average patch area, patch density and average shape index are selected to evaluate and study the dispersion degree of remaining oil; According to the numerical simulation result of the reservoir, the continuous oil phase, i.e. the remaining oil patch, is identified by using the 8-neighbor boundary tracking algorithm and is labeled; the area and perimeter of the labeled patch are obtained by using the regionprops function; a matrix of the remaining oil patch attributes at different time steps is obtained, i.e. the remaining oil dispersion degree at different time steps is calculated by using the entropy weight method; In step 2, the fluid flow is calculated in the numerical simulation of the reservoir according to the following formula: where flow is the grid flow size, m 3 FLOOIL I+ is the oil flow for the I+ direction grid, m 3 FLOOIL J+ is the oil flow for the J+ direction grid, m 3 FLOOIL K+ is the oil flow for the K+ direction grid, m 3 FLOWAT I+ is the water flow for the I+ direction grid, m 3 FLOWAT J+ is the water flow for the J+ direction grid, m 3 FLOWAT K+ is the water flow for the K+ direction grid, m 3 / The hydrodynamic strength calculation formula is: HS is the hydrodynamic strength; PRORV is the pore volume; The oil and water flow in the I, J, K directions of each grid in the numerical simulation is extracted to calculate the grid flow size of each grid; the pore volume of each grid is extracted to calculate the hydrodynamic strength field distribution of each grid; the hydrodynamic strength is instantaneous and represents the current fluid flow condition; In step 3, the dominant potential abundance calculation formula is: wherein: wherein J O3 is the dominant reserves abundance, 10 4 t / km 2 ; h is the reservoir thickness, m; is the porosity; S o is the oil saturation; S or is the residual oil saturation; p o is the crude oil density, g / cm 3 ; B o is the crude oil volume factor; a is the dominant potential abundance coefficient; K is the reservoir permeability, 10 -3 μm 2 ; K max is the maximum permeability within the reservoir, 10 -3 μm 2 ; K ro is the oil phase relative permeability; K rw is the water phase relative permeability; m o is the crude oil viscosity, mPa.S; m w is the water viscosity, mPa.S; In step 4, the reservoir flow line parameters are classified by the density peak value algorithm to establish a flow line adjustment technology partition, six types of adjustment modes, i.e. planting flow line, building flow line, supplementing flow line, stable flow line, uniform flow line and controlling flow line, are determined, and specific implementation is carried out on the adjustment partition; The six types of adjustment modes are as follows: (1) Building flow line adjustment In the area with imperfect well pattern, the flow line is built in a large area to improve the well pattern of the layer system, and the building flow line work is carried out, and the methods are as follows: Layer system reorganization to build vertical layer system Plane deployment of new well to build well pattern; (2) Planting flow line adjustment In the area with low control degree of injection-production well pattern and poor displacement effect, the method of improving injection-production well pattern and subdividing layer system is adopted to carry out planting flow line work, and the methods are as follows: Edge expansion to improve injection-production well pattern and plant flow line Rebuilding injection-production well pattern and planting flow line in fault block reservoir Subdividing layer system to plant flow line in multi-layer heterogeneous reservoir; (3) Supplementing flow line adjustment Depending on single well point adjustment, the water injection is improved, the water drive control degree is expanded, the flow line coverage degree is increased, the development effect is improved, and the damaged flow line field is repaired, and the methods are as follows: Restoring flow line: restoring flow line in damaged well area Enhancing flow line: increasing injection and increasing liquid production in single well point of well area Changing flow line: updating injection well point; (4) Uniform flow line adjustment For the reservoir with high perfection degree of injection-production well pattern, high water drive control degree and good water drive development effect, in order to further improve the recovery ratio, the overall work aiming at uniform flow line is carried out, and the methods are as follows: Profile control and flooding: improving water drive sweep volume Separate injection and subdivided injection: improving oil layer producing degree Pulse water injection: unstable displacement; (5) Stable flow line adjustment For the injection-production well pattern with high perfection, good water drive effect, uniform water drive front advance and low overall water cut, stable streamline distribution measures are taken, including: Maintaining water quality to meet the standards and achieve stable and good water quality indicators Maintaining wellbore integrity and applying tubing liner to prevent secondary pollution of injected water Maintaining water absorption capacity and strengthening injection pressure difference stability (6) Controlling flow lines For low-efficiency injection seepage zones caused by long-term water injection, the dominant seepage channel is obvious, and the water drive degree is high. In order to further improve the recovery efficiency, overall work is carried out to control the flow line, including: Deep profile control: inhibit injection dominant channel Sealing high permeability layer: reduce ineffective injection Sub-injection and fine sub-injection: improve oil layer producing degree.

2. The triangular phase diagram based reservoir performance regulation method of claim 1, wherein, In step 1, the smaller the average patch area, the smaller the single patch remaining oil recoverable reserves, and the higher the remaining oil dispersion degree; the greater the patch density, the more the number of remaining oil patches, and the higher the remaining oil dispersion degree; the greater the average shape index, the more complex the shape of the remaining oil patch, and the higher the remaining oil dispersion degree.

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