Method and system for determining polymer flooding injection speed range in loose sandstone reservoir and readable medium

Abstract

The invention relates to a method and system for determining a polymer flooding injection speed range in a loose sandstone oil reservoir and a readable medium. The method comprises the steps that basic physical property parameters and polymer solution physical property parameters of the known loose sandstone oil reservoir are collected; obtaining an optimal polymer flooding injection speed range through the loose sandstone reservoir polymer flooding numerical simulation model; changing the basic physical property parameters and the polymer solution physical property parameters to obtain optimal polymer flooding injection speed ranges corresponding to the different loose sandstone reservoir basic physical property parameters and the polymer solution parameters, and generating a relation model of the basic physical property parameters and the polymer solution physical property parameters and the optimal polymer flooding injection speed ranges; and inputting the basic physical property parameters of the to-be-measured loose sandstone reservoir and the physical property parameters of the polymer solution into the relation model to obtain the optimal polymer flooding injection speed range of the to-be-measured loose sandstone reservoir. The operation is simple, the principle is clear, and guidance can be provided for researching the multi-stage phase change rule of hydrates in pores with different pore diameters.

Description

Technical Field

[0001] The invention relates to a method, a system and a readable medium for determining a polymer flooding injection velocity range in a loose sandstone reservoir, and belongs to the technical field of polymer flooding. Background Art

[0002] Polymer flooding is a measure to increase oil production by injecting polymers into the formation. On a macro level, it mainly relies on increasing the viscosity of the displacement fluid and reducing the mobility ratio of the displacement fluid to the displaced fluid, thereby expanding the swept volume; on a micro level, due to its inherent viscoelasticity, the polymer stretches the oil film or oil droplets during the flow process, increasing the carrying capacity and improving the microscopic oil washing efficiency.

[0003] The main oil fields in Bohai Bay are mainly loose sandstones. The cementation degree of this type of oil reservoir is poor, and particle blockage is prone to occur during the polymer flooding development process, resulting in a decrease in injection and production capacity. Due to many restrictive conditions for offshore oil field development, the cost of new facilities is high, and the injection and production pressure provided by existing facilities is limited. Therefore, in the current situation where it is difficult to increase the power of injection and production pumps, how to adjust the injection and production system to improve the injection and production capacity of oil field polymer flooding and increase the injection and production fluid volume during the life cycle of the platform has become an urgent problem to be solved in offshore loose sandstone reservoirs. Summary of the invention

[0004] In view of the above problems, the purpose of the present invention is to provide a method, system and readable medium for determining the injection rate range of polymer flooding in loose sandstone reservoirs, which are simple to operate and have clear principles, and can provide guidance for studying the multi-level phase change laws of hydrates in pores with different pore sizes.

[0005] To achieve the above-mentioned purpose, the present invention proposes the following technical scheme: a method for determining the injection rate range of polymer flooding in a loose sandstone reservoir, comprising the following steps: collecting basic physical property parameters and physical property parameters of a known loose sandstone reservoir; obtaining an optimal polymer flooding injection rate range through a loose sandstone reservoir polymer flooding numerical simulation model; changing the basic physical property parameters and physical property parameters of the polymer solution to obtain an optimal polymer flooding injection rate range corresponding to different basic physical property parameters and polymer solution parameters of loose sandstone reservoirs, and generating a relationship model between the basic physical property parameters and the physical property parameters of the polymer solution and the optimal polymer flooding injection rate range; inputting the basic physical property parameters and the physical property parameters of the polymer solution to be tested into the relationship model to obtain the optimal polymer flooding injection rate range of the loose sandstone reservoir to be tested.

[0006] Furthermore, the basic physical property parameters include porosity, permeability, initial temperature, initial pressure, residual resistance coefficient, water content during injection, number of grids and grid size; the physical property parameters of the polymer solution include solution viscosity, polymer slug and injection speed.

[0007] Furthermore, the relationship model is constructed using a machine learning method.

[0008] Furthermore, the machine learning methods include linear regression, logistic regression, support vector machine, decision tree, neural grid, K-means clustering and hierarchical clustering.

[0009] Furthermore, the optimal polymer flooding injection rate range is obtained through the loose sandstone reservoir polymer flooding numerical simulation model: when the loose sandstone reservoir is water-driven to a threshold value, a larger polymer flooding injection rate range is input into the loose sandstone reservoir polymer flooding numerical simulation model, and the liquid production index reduction and the degree of recovery within a preset range are calculated. A plot is drawn with basic physical properties and polymer solution physical properties as the horizontal axis and the liquid production index reduction and the degree of recovery as the vertical axis. The liquid production index reduction limit and the degree of recovery limit are used as standards to determine the optimal polymer flooding injection rate range from the larger polymer flooding injection rate range.

[0010] Furthermore, the threshold value of water flooding development of the loose sandstone reservoir is that the water content of the loose sandstone reservoir reaches 60-95%.

[0011] Furthermore, the larger polymer flooding injection rate ranges from 0.0 to 0.1 PV / a, with an interval of 0.02 PV / a.

[0012] Furthermore, the standard determines the development speed of polymer flooding based on a decrease in the liquid production index of 15%-30%.

[0013] The present invention also discloses a system for determining a polymer flooding injection rate range in a loose sandstone reservoir, comprising: a data acquisition module, used for acquiring basic physical property parameters and polymer solution physical property parameters of a known loose sandstone reservoir; an optimal injection rate calculation module, used for obtaining an optimal polymer flooding injection rate range through a loose sandstone reservoir polymer flooding numerical simulation model; a relationship model construction module, used for changing the basic physical property parameters and polymer solution physical property parameters to obtain an optimal polymer flooding injection rate range corresponding to different loose sandstone reservoir basic physical property parameters and polymer solution parameters, and generating a relationship model between the basic physical property parameters and polymer solution physical property parameters and the optimal polymer flooding injection rate range; and a result output module, used for inputting the basic physical property parameters and polymer solution physical property parameters of the loose sandstone reservoir to be tested into the relationship model to obtain the optimal polymer flooding injection rate range of the loose sandstone reservoir to be tested.

[0014] The present invention also discloses a computer-readable storage medium having a computer program stored thereon. The computer program is executed by a processor to implement any of the above methods for determining a polymer flooding injection rate range in a loose sandstone reservoir.

[0015] The technical solution of the present invention has at least the following technical effects or advantages: the present invention adopts a machine learning method to construct a training model of a reasonable injection rate range, basic physical property parameters of loose sandstone reservoirs and polymer solution parameters, inputs the physical property parameters and polymer solution physical property parameters of any loose sandstone reservoir, and realizes rapid prediction of the reasonable injection rate range through the training model. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a curve diagram for determining the initial injection speed in one embodiment of the present invention;

[0017] Figure 2 This is a curve diagram for determining the injection rate of 6.25×6.25×1.4 in one embodiment of the present invention. DETAILED DESCRIPTION

[0018] In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention is described in detail through specific embodiments. However, it should be understood that the provision of specific embodiments is only for a better understanding of the present invention, and they should not be understood as limitations of the present invention. In the description of the present invention, it should be understood that the terms used are only for the purpose of description and cannot be understood as indicating or implying relative importance.

[0019] In view of the problems in the prior art that it is difficult to increase the power of the injection and production pump, the injection and production system cannot be effectively adjusted to improve the injection and production capacity of the polymer drive in the oil field, and the amount of injection and production fluid within the life cycle of the platform, the present invention proposes a method, system and readable medium for determining the injection rate range of polymer drive in a loose sandstone reservoir, and constructs a training model of a reasonable injection rate range, basic physical properties of loose sandstone reservoirs and polymer solution parameters through machine learning, and uses a machine learning method to construct a training model of a reasonable injection rate range, basic physical properties of loose sandstone reservoirs and polymer solution parameters, so as to achieve rapid prediction of a reasonable injection rate range. The present invention uses the reduction limit of the degree of production and the liquid production index as the standard, and uses a machine learning method to construct a training model of a reasonable injection rate range, basic physical properties of loose sandstone reservoirs and polymer solution parameters. The scheme of the present invention is described in detail below through embodiments in conjunction with the accompanying drawings.

[0020] Embodiment 1

[0021] This embodiment discloses a method for determining a polymer flooding injection rate range in a loose sandstone reservoir, comprising the following steps:

[0022] S1 collects the basic physical property parameters of known loose sandstone reservoirs and the physical property parameters of polymer solutions.

[0023] The basic physical property parameters of known loose sandstone reservoirs and the physical property parameters of polymer solutions were collected, as shown in Table 1. The basic physical property parameters include porosity, permeability, initial temperature, initial pressure, residual resistance coefficient, water content during injection, number of grids and grid size; the physical property parameters of polymer solutions include solution viscosity, polymer slug and injection rate.

[0024] Table 1 Main parameter values ​​of vertical well development reservoir model

[0025]

[0026] S2 obtains the optimal polymer flooding injection rate range through a numerical simulation model of polymer flooding in unconsolidated sandstone reservoirs.

[0027] like Figure 1 As shown, when the loose sandstone reservoir is water-driven to the threshold value, in this embodiment, the threshold value of the loose sandstone reservoir water-driven development is that the loose sandstone reservoir water content reaches 60-95%. In this embodiment, when the loose sandstone reservoir is water-driven to 60% water content, the polymer drive is switched to development. Since the method in this embodiment is to select a smaller optimal polymer drive injection rate range from a larger polymer drive injection rate range, the method is specifically as follows: input the larger polymer drive injection rate range into the loose sandstone reservoir polymer drive numerical simulation model, calculate the liquid production index drop and the recovery degree within the preset range, draw a graph with the basic physical property parameters and the polymer solution physical property parameters as the horizontal axis, and the liquid production index drop and the recovery degree as the vertical axis, and determine the optimal polymer drive injection rate range from the larger polymer drive injection rate range with the liquid production index drop limit and the recovery degree limit as the standard.

[0028] In this embodiment, the larger polymer flooding injection rate range is 0.0-0.1 PV / a, with an interval of 0.02 PV / a. The preset range is 25 years in this embodiment, but it can be determined according to actual needs. The standard determines the development rate of polymer flooding with a 15%-30% drop in the production index. In this embodiment, the optimal polymer flooding injection rate range is 0.022-0.06 PV·a based on a 15% drop in the production index. -1 .

[0029] S3 changes the basic physical property parameters and the physical property parameters of the polymer solution to obtain the optimal polymer flooding injection rate range corresponding to the basic physical property parameters and the polymer solution parameters of different loose sandstone reservoirs, and generates a relationship model between the basic physical property parameters, the physical property parameters of the polymer solution and the optimal polymer flooding injection rate range.

[0030] like Figure 2As shown, the relationship model is constructed using a machine learning method. Machine learning methods include linear regression, logistic regression, support vector machine, decision tree, neural grid, K-means clustering and hierarchical clustering. In this embodiment, the neural grid method is used to construct a relationship model between the optimal polymer flooding injection velocity range and the basic physical property parameters of the loose sandstone reservoir and the polymer solution parameters. The grid size of the loose sandstone reservoir is changed to 6.25×6.25×1.4, and the reasonable injection velocity range is determined by training the model to be 0.022-0.072PV·a -1 .

[0031] S4 inputs the basic physical property parameters of the unconsolidated sandstone reservoir to be tested and the physical property parameters of the polymer solution into the relationship model to obtain the optimal polymer flooding injection rate range of the unconsolidated sandstone reservoir to be tested.

[0032] Embodiment 2

[0033] Based on the same inventive concept, this embodiment discloses a system for determining a polymer flooding injection rate range in a loose sandstone reservoir, comprising:

[0034] A data acquisition module, used to collect basic physical property parameters of known loose sandstone reservoirs and physical property parameters of polymer solutions;

[0035] The optimal injection rate calculation module is used to obtain the optimal polymer flooding injection rate range through the loose sandstone reservoir polymer flooding numerical simulation model;

[0036] A relationship model building module is used to change the basic physical property parameters and the polymer solution physical property parameters, obtain the optimal polymer flooding injection rate range corresponding to the basic physical property parameters and the polymer solution parameters of different loose sandstone reservoirs, and generate a relationship model between the basic physical property parameters, the polymer solution physical property parameters and the optimal polymer flooding injection rate range;

[0037] The result output module is used to input the basic physical property parameters of the loose sandstone reservoir to be tested and the physical property parameters of the polymer solution into the relationship model to obtain the optimal polymer flooding injection rate range of the loose sandstone reservoir to be tested.

[0038] Embodiment 3

[0039] Based on the same inventive concept, this embodiment discloses a computer-readable storage medium having a computer program stored thereon. The computer program is executed by a processor to implement any of the above methods for determining a polymer flooding injection rate range in a loose sandstone reservoir.

[0040] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Therefore, the present invention may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment combining software and hardware. Moreover, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0041] The present invention is described with reference to flowcharts and / or block diagrams of methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or block in the flowchart and / or block diagram, as well as the combination of processes and / or blocks in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the processes in the flowchart and / or block diagram. Figure 1 A process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0042] These computer program instructions may also be stored in a computer-readable memory capable of directing a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 A process or multiple processes and / or boxes Figure 1 A function specified in one or more boxes.

[0043] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing instructions for implementing the process. Figure 1 A process or multiple processes and / or boxes Figure 1 The steps for the functions specified in one or more boxes.

[0044] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit them. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the relevant field should understand that the specific implementation of the present invention can still be modified or replaced by equivalents, and any modification or equivalent replacement that does not deviate from the spirit and scope of the present invention should be included in the protection scope of the claims of the present invention. The above content is only a specific implementation of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can easily think of changes or replacements 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 shall be based on the protection scope of the claims.

Claims

1. A method for determining the injection rate range of polymer flooding in a loose sandstone reservoir, characterized in that: The following steps are involved: Collect basic physical property parameters of known loose sandstone reservoirs and physical property parameters of polymer solutions; The optimal polymer flooding injection rate range is obtained through the numerical simulation model of polymer flooding in unconsolidated sandstone reservoirs; Changing the basic physical property parameters and the physical property parameters of the polymer solution to obtain the optimal polymer flooding injection rate range corresponding to the basic physical property parameters and the polymer solution parameters of different loose sandstone reservoirs, and generating a relationship model between the basic physical property parameters, the physical property parameters of the polymer solution and the optimal polymer flooding injection rate range; The basic physical property parameters of the unconsolidated sandstone reservoir to be tested and the physical property parameters of the polymer solution are input into the relationship model to obtain the optimal polymer flooding injection rate range of the unconsolidated sandstone reservoir to be tested.

2. The method for determining the injection rate range of polymer flooding in unconsolidated sandstone reservoirs according to claim 1, characterized in that: The basic physical property parameters include porosity, permeability, initial temperature, initial pressure, residual resistance coefficient, water content during injection, number of grids and grid size; the physical property parameters of the polymer solution include solution viscosity, polymer slug and injection speed.

3. The method for determining the injection rate range of polymer flooding in a loose sandstone reservoir according to claim 1, characterized in that: The relationship model is constructed using a machine learning method.

4. The method for determining the injection rate range of polymer flooding in unconsolidated sandstone reservoirs according to claim 3, characterized in that: The machine learning methods include linear regression, logistic regression, support vector machine, decision tree, neural grid, K-means clustering and hierarchical clustering.

5. The method for determining the injection rate range of polymer flooding in unconsolidated sandstone reservoirs according to claim 1, characterized in that: The optimal polymer flooding injection rate range is obtained through the loose sandstone reservoir polymer flooding numerical simulation model: When the water flooding development of the loose sandstone reservoir reaches the threshold value, a larger polymer flooding injection rate range is input into the loose sandstone reservoir polymer flooding numerical simulation model, and the liquid production index reduction and the recovery degree within the preset range are calculated. A plot is drawn with the basic physical property parameters and the polymer solution physical property parameters as the horizontal axis and the liquid production index reduction and the recovery degree as the vertical axis. The liquid production index reduction limit and the recovery degree limit are used as standards to determine the optimal polymer flooding injection rate range from the larger polymer flooding injection rate range.

6. The method for determining the injection rate range of polymer flooding in unconsolidated sandstone reservoirs according to claim 5, characterized in that: The threshold value of water flooding development of the loose sandstone reservoir is that the water content of the loose sandstone reservoir reaches 60-95%.

7. The method for determining the injection rate range of polymer flooding in a loose sandstone reservoir according to claim 5, characterized in that: The larger polymer flooding injection rate ranges from 0.0 to 0.1 PV / a, with an interval of 0.02 PV / a.

8. The method for determining the injection rate range of polymer flooding in unconsolidated sandstone reservoirs according to claim 5, characterized in that: The standard determines the development speed of polymer flooding by taking a decrease in the liquid production index of 15%-30% as the limit.

9. A system for determining the injection rate range of polymer flooding in unconsolidated sandstone reservoirs, characterized in that: include: A data acquisition module, used to collect basic physical property parameters of known loose sandstone reservoirs and physical property parameters of polymer solutions; The optimal injection rate calculation module is used to obtain the optimal polymer flooding injection rate range through the loose sandstone reservoir polymer flooding numerical simulation model; A relationship model building module is used to change the basic physical property parameters and the polymer solution physical property parameters to obtain the optimal polymer flooding injection rate range corresponding to the basic physical property parameters and the polymer solution parameters of different loose sandstone reservoirs, and generate a relationship model between the basic physical property parameters, the polymer solution physical property parameters and the optimal polymer flooding injection rate range; The result output module is used to input the basic physical property parameters of the loose sandstone reservoir to be tested and the physical property parameters of the polymer solution into the relationship model to obtain the optimal polymer flooding injection rate range of the loose sandstone reservoir to be tested.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and the computer program is executed by a processor to implement the method for determining the injection rate range of polymer flooding in a loose sandstone reservoir as described in any one of claims 1 to 8.

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