Method and apparatus for determining parameters of polymer solution in oil displacement agent

Abstract

The application provides a method and device for determining parameters of polymer solution in oil displacement agent, the method comprises the following steps: obtaining an actual temperature of an oil field, which is a first preset temperature; determining values of each coefficient in a preset relationship between the concentration of polymer solution, the salinity of the oil field and the viscosity of the polymer solution under the condition of the first preset temperature and the first preset molecular weight according to the input of at least two groups of experimental data; determining the viscosity of the polymer solution when the salinity of the oil field is the first preset salinity and the polymer solution is at different concentrations according to the preset relationship and the values of each coefficient; and determining the viscosity range of the polymer solution and the corresponding polymer concentration range when the salinity of the oil field is the first preset salinity according to the preset viscosity requirement.

Description

Technical Field

[0001] This application belongs to the field of oil and gas extraction technology, and specifically relates to a method and apparatus for determining the parameters of a polymer solution in an oil displacement agent. Background Technology

[0002] After an oil field is discovered through exploration, waterflooding (secondary oil recovery) is often carried out after the natural energy extraction (primary oil recovery). In the middle and late stages of oil field development, that is, the end of secondary oil recovery, the development of medium and high permeability reservoirs often faces the problem of "double high", namely high water cut and high recovery rate. At this stage, the general waterflooding adjustment measures are often less and less effective, and the cost of oil field development is getting higher and higher. It is necessary to change the development method and enter the tertiary oil recovery stage.

[0003] Chemical flooding is a common tertiary oil recovery technology. Its application principle is to simultaneously expand the swept volume and improve the oil washing efficiency, so as to reduce the residual oil in the reservoir to the greatest extent possible. There are many methods to expand the swept volume, the most important of which is to inject polymers. Therefore, when designing a chemical flooding scheme for tertiary oil recovery, it is necessary to specifically design the concentration and molecular weight parameters of the polymer solution.

[0004] The polymers used in chemical flooding generally refer to high molecular weight polyacrylamide, hereinafter referred to as polymers. When dissolved in water, the polymer forms a continuous aqueous solution with a viscosity higher than that of water. Because the aqueous solution has a higher viscosity than water, it alters the water-oil mobility ratio, changing and expanding the water flow channel, and increasing the reservoir injection sweep range.

[0005] Related technologies propose a method for obtaining target oil layers and determining whether they are homogeneous. If the target oil layer is homogeneous, the molecular weight and concentration range of injectable polymers in the target oil layer are determined based on its permeability. The maximum polymer molecular weight and its corresponding concentration are used as the molecular weight of the polymer used for oil displacement and the concentration of the polymer solution. If the target oil layer is heterogeneous, it is divided into multiple homogeneous sub-layers. The molecular weight and concentration range of injectable polymers in each sub-layer are determined based on its permeability. The corresponding enhanced oil recovery value is obtained based on the injectable polymer molecular weight and its corresponding concentration in each sub-layer. The molecular weight of the polymer used for oil displacement in the target oil layer and the concentration of the polymer solution for oil displacement in each sub-layer are then obtained based on the enhanced oil recovery value corresponding to each polymer molecular weight in each sub-layer. When using this method to determine polymer parameters, core physical simulation experiments must be conducted to obtain the injectable polymer molecular weight and concentration range for cores with different permeabilities, and a relationship diagram between the injectable polymer molecular weight and concentration and permeability must be plotted. Furthermore, all constants in the calculation formula require extensive physical model experiments to obtain, making it difficult to quickly determine the concentration and molecular weight technical parameters of the polymer solution required in the scheme.

[0006] Therefore, inventing a method that can automatically determine the minimum concentration of polymer solution based on reservoir conditions in order to reduce residual oil in the reservoir has become an urgent problem to be solved. Summary of the Invention

[0007] The present invention aims to solve or improve at least one of the above-mentioned technical problems.

[0008] The first aspect of the present invention provides a method for determining the parameters of a polymer solution in an oil displacement agent.

[0009] The second aspect of the present invention provides a device for determining the parameters of a polymer solution in an oil displacement agent.

[0010] The third aspect of the present invention provides a device for determining the parameters of a polymer solution in an oil displacement agent.

[0011] The fourth aspect of the present invention provides a readable storage medium.

[0012] The first aspect of this invention is to provide a method for determining parameters of a polymer solution in an oil displacement agent, comprising the following steps: obtaining the actual temperature of the oil field, denoted as a first preset temperature; determining, based on input of at least two sets of experimental data, the values ​​of each coefficient in a preset relationship between the concentration of the polymer solution, the salinity of the oil field, and the viscosity of the polymer solution under the conditions of the first preset temperature and a first preset molecular weight; the preset relationship is: f(x,y)=a+bx+cy+dx 2 +exy+gy2+hx 2 y + mxy² + ny³; where f(x,y) is the viscosity of the polymer solution, x is the salinity of the oil field, y is the concentration of the polymer solution, and a, b, c, d, e, g, h, m, and n are all coefficients; based on the preset relationship and the values ​​of each coefficient, the viscosity of the polymer solution at different concentrations is determined when the salinity of the oil field is the first preset salinity; based on the preset viscosity requirements, the viscosity range of the polymer solution and its corresponding polymer concentration range are determined when the salinity of the oil field is the first preset salinity.

[0013] The method for determining the parameters of the polymer solution in the oil displacement agent provided by this invention can determine the concentration range and viscosity range of the polymer solution according to different reservoir conditions, so that the staff can quickly prepare the polymer solution and thus improve the extraction efficiency.

[0014] In the above technical solution, the step of determining the first preset salinity in the oil field based on the preset relationship and the values ​​of each coefficient, and determining the viscosity of the polymer solution at different concentrations, includes: calculating the viscosity of the polymer solution when the salinity in the oil field is the first preset salinity and the polymer solution is at a first concentration, based on the preset relationship and the values ​​of each coefficient; wherein, the first concentration can take different values ​​to calculate the viscosity of the polymer solution under different conditions, so as to obtain multiple viscosity values.

[0015] In this technical solution, once the salinity of the oil field is known, only the viscosity and concentration of the polymer solution are unknown in the entire preset formula. Based on the preset viscosity requirement, that is, the minimum viscosity is limited, the viscosity range of the polymer solution can be determined, and the concentration range of the polymer solution can be calculated.

[0016] In the above technical solution, the first concentration is at least 10 values.

[0017] In this technical solution, the first concentration is limited to at least 10 values ​​to ensure the accuracy of the calculation.

[0018] In the above technical solution, the first concentration is greater than or equal to 500 mg / L and less than or equal to 5000 mg / L.

[0019] Furthermore, the first preset temperature is greater than or equal to 30℃ and less than or equal to 90℃, which can ensure the oil displacement effect of the oil displacement agent and avoid the problem of poor oil displacement effect due to excessively high temperature.

[0020] Furthermore, the first preset molecular weight is greater than or equal to 19 million and less than or equal to 25 million, which can avoid the problem that high molecular weight polymers are expensive and low molecular weight polymers have poor thickening effect.

[0021] Furthermore, the first preset mineralization is greater than or equal to 500 mg / L and less than or equal to 5000 mg / L, which is more suitable for the North China Oilfield.

[0022] In these technical solutions, by limiting the temperature, molecular weight, mineralization, and concentration range, the accuracy of the determined concentration and viscosity ranges can be ensured.

[0023] In the above technical solution, the preset viscosity requirement includes a polymer viscosity greater than 2.98 mPa·s.

[0024] In these technical solutions, the viscosity of the polymer is limited to be greater than 2.98 mPa·s (the viscosity of water is 2.98 mPa·s). This ensures that the viscosity of the polymer is greater than that of water, thus determining the minimum viscosity of the polymer, and consequently, the viscosity range and concentration range of the polymer.

[0025] In the above technical solution, the method for determining the parameters of the polymer solution in the oil displacement agent further includes: based on the minimum concentration in the verification experiment and the actual minimum viscosity obtained through the verification experiment, determining the theoretical minimum viscosity corresponding to the minimum concentration through a preset relationship and the values ​​of each coefficient, comparing the actual minimum viscosity with the theoretical minimum viscosity, and issuing an early warning if the actual minimum viscosity is less than the theoretical minimum viscosity; wherein, the minimum concentration is the smallest concentration among all concentrations in the determined polymer concentration range.

[0026] In this technical solution, verification experiments can be conducted to determine whether the calculated concentration and viscosity ranges match the actual values. If they do not match, an alarm will be issued in a timely manner, allowing users to take appropriate corrective measures promptly.

[0027] A second aspect of the present invention provides a parameter determination device for a polymer solution in an oil displacement agent, comprising: an acquisition unit for acquiring the actual temperature of an oil field, denoted as a first preset temperature; and a processing unit for determining, based on input of at least two sets of experimental data, the values ​​of various coefficients in a preset relationship between the concentration of the polymer solution, the salinity of the oil field, and the viscosity of the polymer solution under the conditions of the first preset temperature and a first preset molecular weight; the preset relationship is:

[0028] f(x,y)=a+bx+cy+dx 2 +exy+gy2+hx 2 y + mxy² + ny³;

[0029] Where f(x,y) is the viscosity of the polymer solution, x is the salinity of the oil field, y is the concentration of the polymer solution, and a, b, c, d, e, g, h, m, and n are coefficients. The unit is also used to determine the viscosity of the polymer solution at different concentrations when the salinity of the oil field is the first preset salinity, based on the preset relationship and the values ​​of each coefficient. The unit is also used to determine the viscosity range of the polymer solution and its corresponding polymer concentration range when the salinity of the oil field is the first preset salinity, based on the preset viscosity requirements.

[0030] A third aspect of the present invention provides a device for determining the parameters of a polymer solution in an oil displacement agent, comprising a storage device and a processor. The storage device stores a computer program or instructions, and the processor executes the program or instructions to implement the method for determining the parameters of a polymer solution in an oil displacement agent as provided in any of the technical solutions of the first aspect of this application.

[0031] The fourth aspect of the present invention provides a readable storage medium storing a program or instructions, wherein when a processor executes the program or instructions, it implements the method for determining parameters of a polymer solution in an oil displacement agent as provided in any of the technical solutions of the first aspect of the present application.

[0032] Additional aspects and advantages of the invention will become apparent in the following description or may be learned by practice of the invention. Attached Figure Description

[0033] Figure 1 A flowchart illustrating the method for determining parameters of the polymer solution in the oil displacement agent provided in an embodiment of the present invention is shown.

[0034] Figure 2 A flowchart illustrating a method for determining parameters of a polymer solution in an oil displacement agent according to another embodiment of the present invention is shown.

[0035] Figure 3 The diagram shows the concentration-mineralization-viscosity curves at 30°C during the process of determining the parameters of the polymer solution in the oil displacement agent provided in the embodiments of the present invention.

[0036] Figure 4 The diagram shows the concentration-mineralization-viscosity curves at 50°C during the process of determining the parameters of the polymer solution in the oil displacement agent provided in the embodiments of the present invention.

[0037] Figure 5 The diagram shows the concentration-mineralization-viscosity curves at 70°C during the process of determining the parameters of the polymer solution in the oil displacement agent provided in the embodiments of the present invention.

[0038] Figure 6 The diagram shows the concentration-mineralization-viscosity curves at 90°C during the process of determining the parameters of the polymer solution in the oil displacement agent provided in the embodiments of the present invention.

[0039] Figure 7 A block diagram of a device for determining parameters of a polymer solution in an oil displacement agent provided in an embodiment of the present invention is shown.

[0040] Figure 8 A block diagram of a device for determining parameters of a polymer solution in an oil displacement agent provided in an embodiment of the present invention is shown.

[0041] in, Figures 7 to 8 The correspondence between component names and their designations is as follows:

[0042] 1. Parameter determination device for polymer solution in oil displacement agent, 12. Acquisition unit, 14. Determination unit, 16. Storage, 18. Processor. Detailed Implementation

[0043] To better understand the above aspects, features, and advantages of the embodiments of the present invention, the embodiments of the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0044] Many specific details are set forth in the following description in order to provide a full understanding of the embodiments of the present invention. However, the embodiments of the present invention may also be implemented in other ways different from those described herein. Therefore, the protection provided by the embodiments of the present invention is not limited to the specific embodiments disclosed below.

[0045] like Figure 1 As shown, a first aspect of the present invention provides a method for determining the parameters of a polymer solution in an oil displacement agent, comprising the following steps:

[0046] S102: Obtain the actual temperature of the oilfield and record it as the first preset temperature;

[0047] S104: Based on the input of at least two sets of experimental data, determine the values ​​of each coefficient in the preset relationship between the concentration of the polymer solution, the salinity of the oil field, and the viscosity of the polymer solution under the conditions of a first preset temperature and a first preset molecular weight; the preset relationship is:

[0048] f(x,y)=a+bx+cy+dx 2 +exy+gy2+hx 2 y + mxy² + ny³; where f(x,y) is the viscosity of the polymer solution, x is the salinity of the oil field, y is the concentration of the polymer solution, and a, b, c, d, e, g, h, m, and n are all coefficients.

[0049] S108: Determine the first preset salinity in the oil field based on the preset relationship and the values ​​of each coefficient, and determine the viscosity of the polymer solution at different concentrations.

[0050] S110: Based on the preset viscosity requirements, determine the viscosity range of the polymer solution and the corresponding polymer concentration range when the salinity of the oil field is the first preset salinity.

[0051] The method for determining parameters of the polymer solution in the oil displacement agent provided by this invention first obtains the actual temperature of the oilfield, denoted as the first preset temperature. Then, the user can conduct a small number of indoor evaluation experiments. Based on the input of experimental data, the values ​​of each coefficient in the preset relationship formula between the concentration of the polymer solution, the salinity of the oilfield, and the viscosity of the polymer solution under the conditions of the first preset temperature and the first preset molecular weight can be determined. The preset relationship formula is:

[0052] f(x,y)=a+bx+cy+dx 2 +exy+gy2+hx 2 y + mxy² + ny³; where f(x,y) is the viscosity of the polymer solution, x is the salinity of the oil field, y is the concentration of the polymer solution, and a, b, c, d, e, g, h, m, and n are all coefficients.

[0053] In other words, under the conditions of a first preset temperature and a first preset molecular weight, the user can conduct at least two sets of indoor evaluation experiments. Then, the data on the polymer solution concentration, oilfield salinity, and polymer solution viscosity from each set of experiments are transmitted to the system. This allows the system to determine the specific relationship between the polymer solution concentration, oilfield salinity, and polymer solution viscosity. After determining this relationship, the system can determine the viscosity of the polymer solution at different concentrations when the oilfield salinity is at the first preset salinity. Furthermore, based on the preset viscosity requirements, the system can determine the viscosity range of the polymer solution and the corresponding polymer concentration range when the oilfield salinity is at the first preset salinity. For example, if the oilfield temperature is 30℃ and the required polymer molecular weight is 25 million, then a small number of experiments can determine the relationship f(x,y)=a+bx+cy+dx. 2 +exy+gy2+hx 2 In y+mxy2+ny3, a=-1.691, b=0.02018, c=0.001047, d=-3.939×10 -6 e = -2.47 × 10 -5 g = 4.784 × 10 -5 h = 5.445 × 10 -9 m = -7.75 × 10 -9 n = 6.4 × 10 -10At this point, by substituting a, b, c, d, e, g, h, m, and n, we can obtain the specific relationship between the viscosity of the polymer solution, the salinity of the oil field, and the concentration of the polymer solution. Knowing any two parameters allows us to determine the third parameter. For example, when the salinity of the oil field x = 2000 mg / L and the concentration of the polymer solution y = 200 mg / L, the viscosity of the polymer solution can be immediately calculated as 18.90 mPa·s; when the salinity of the oil field x = 2000 mg / L and the concentration of the polymer solution y = 500 mg / L, the viscosity of the polymer solution can be immediately calculated as 17.79 mPa·s; and when the salinity of the oil field x = 2000 mg / L and the concentration of the polymer solution y = 800 mg / L, the viscosity of the polymer solution can be immediately calculated as 22.68 mPa·s. This allows us to determine the viscosity range of the polymer solution within a certain concentration range. Alternatively, when the salinity of the oil field is x = 500 mg / L and the concentration of the polymer solution is y = 2000 mg / L, the viscosity of the polymer solution can be immediately calculated as 116.67 mPa·s; when the salinity of the oil field is x = 2000 mg / L and the concentration of the polymer solution is y = 2000 mg / L, the viscosity of the polymer solution can be immediately calculated as 56.63 mPa·s; when the salinity of the oil field is x = 5000 mg / L and the concentration of the polymer solution is y = 2000 mg / L, the viscosity of the polymer solution can be immediately calculated as 36.49 mPa·s, thus determining the range of polymer solution viscosity within a certain salinity range of the oil field. In other words, during oilfield extraction, the viscosity requirement can be set to a polymer viscosity greater than 2.98 mPa·s, where the viscosity of water is 2.98 mPa·s. By limiting the polymer viscosity to greater than 2.98 mPa·s, it can be ensured that the polymer viscosity is greater than that of water, thereby improving oil production efficiency. Once the range of polymer viscosity is known, since the oilfield temperature, polymer molecular weight, and oilfield salinity are all constant values, the range of polymer concentration can be determined based on the range of polymer viscosity.

[0054] In the above embodiments, the first concentration has at least 10 values. By limiting the range of the first concentration, the accuracy of the calculation can be ensured.

[0055] In the above embodiments, the first concentration is greater than or equal to 500 mg / L and less than or equal to 5000 mg / L.

[0056] Furthermore, the first preset temperature is greater than or equal to 30℃ and less than or equal to 90℃, which can ensure the oil displacement effect of the oil displacement agent and avoid the problem of poor oil displacement effect due to excessively high temperature.

[0057] Furthermore, the first preset molecular weight is greater than or equal to 19 million and less than or equal to 25 million, which can avoid the problem that high molecular weight polymers are expensive and low molecular weight polymers have poor thickening effect.

[0058] Furthermore, the first preset mineralization is greater than or equal to 500 mg / L and less than or equal to 5000 mg / L, which is more suitable for the North China Oilfield.

[0059] In these embodiments, by defining temperature, molecular weight, mineralization, and concentration ranges, the accuracy of the determined concentration and viscosity ranges can be ensured.

[0060] In the above embodiments, the preset viscosity requirement includes a polymer viscosity greater than 2.98 mPa·s.

[0061] In this embodiment, the viscosity of the polymer is limited to be greater than 2.98 mPa·s (the viscosity of water is 2.98 mPa·s). This ensures that the viscosity of the polymer is greater than that of water, thus determining the minimum viscosity of the polymer, and consequently, the viscosity range and concentration range of the polymer.

[0062] In the above embodiments, the method for determining the parameters of the polymer solution in the oil displacement agent further includes: based on the minimum concentration in the verification experiment and the actual minimum viscosity obtained through the verification experiment, determining the theoretical minimum viscosity corresponding to the minimum concentration through a preset relationship and the values ​​of each coefficient, comparing the actual minimum viscosity with the theoretical minimum viscosity, and issuing an early warning if the actual minimum viscosity is less than the theoretical minimum viscosity; wherein, the minimum concentration is the smallest concentration among all concentrations in the determined polymer concentration range.

[0063] In this embodiment, a verification experiment can be conducted to determine whether the calculated concentration range and viscosity range match the actual values. If they do not match, an alarm will be issued in a timely manner, allowing the user to take appropriate corrective measures.

[0064] like Figure 2 As shown, another embodiment of the present invention provides a method for determining the parameters of the polymer solution in the oil displacement agent. Compared to the previous embodiment, this method further includes a step of verifying and alarming the determined parameter range. Specifically, the method for determining the parameters of the polymer solution in the oil displacement agent in this embodiment includes the following steps:

[0065] S202: Obtain the actual temperature of the oilfield and record it as the first preset temperature;

[0066] S204: Based on the input of at least two sets of experimental data, determine the values ​​of each coefficient in the preset relationship between the concentration of the polymer solution, the salinity of the oil field, and the viscosity of the polymer solution under the conditions of a first preset temperature and a first preset molecular weight; the preset relationship is:

[0067] f(x,y)=a+bx+cy+dx 2 +exy+gy2+hx 2 y + mxy² + ny³; where f(x,y) is the viscosity of the polymer solution, x is the salinity of the oil field, y is the concentration of the polymer solution, and a, b, c, d, e, g, h, m, and n are all coefficients.

[0068] S206: Determine the first preset salinity in the oil field based on the preset relationship and the values ​​of each coefficient, and determine the viscosity of the polymer solution at different concentrations.

[0069] S208: Based on the preset viscosity requirements, determine the viscosity range of the polymer solution and the corresponding polymer concentration range when the salinity of the oil field is the first preset salinity.

[0070] S210: Based on the minimum concentration and the actual minimum viscosity obtained from the verification experiment, the theoretical minimum viscosity corresponding to the minimum concentration is determined by the preset relationship and the values ​​of each coefficient. The actual minimum viscosity is compared with the theoretical minimum viscosity. If the actual minimum viscosity is less than the theoretical minimum viscosity, an early warning is issued. The minimum concentration is the smallest concentration among all concentrations in the determined polymer concentration range.

[0071] In this embodiment, after determining the viscosity range of the polymer solution and its corresponding polymer concentration range, the user can conduct a verification experiment, that is, take the polymer solution with the lowest concentration for verification. This verification experiment will obtain the minimum viscosity of the polymer solution at the lowest concentration. Since the theoretical minimum viscosity is calculated based on the viscosity of water, during the verification experiment, it is only necessary to compare the actual minimum viscosity with the theoretical minimum viscosity. If the actual minimum viscosity is greater than the theoretical minimum viscosity (since the theoretical minimum viscosity is the minimum viscosity of water), it can be determined that the viscosity and concentration range determined by the system conforms to the standard. Conversely, if the actual minimum viscosity is less than the theoretical minimum viscosity, it means that the actual minimum viscosity of the polymer solution at the lowest concentration is less than the viscosity of water. Therefore, it can be determined that the viscosity and concentration range determined by the system does not conform to the standard, and an alarm will be issued immediately. This allows relevant personnel to take timely corrective measures.

[0072] The method of this invention can significantly reduce the number of experiments and the workload. Specifically, with current technology, determining polymer parameters requires at least 120 sets of experiments because multiple factors, including temperature, molecular weight, concentration, and oilfield salinity, affect viscosity. These experiments are: 2 for temperature, 3 for molecular weight, 10 for concentration, and 2 for oilfield salinity. This means at least 120 sets of experiments are needed to determine the optimal polymer solution parameters, requiring 2 people, 3 days, and costing 500 yuan per experiment. Measuring the initial viscosity alone costs 60,000 yuan. If aging evaluation is conducted, each sample needs 7 measurements, requiring 420,000 yuan in testing costs. However, the method of this invention allows for the pre-establishment of relationship curves between concentration, oilfield salinity, and concentration at different temperatures. Figure 3 , Figure 4 , Figure 5 and Figure 6 As shown, the corresponding concentration and oilfield salinity range can be directly obtained from the graph based on the viscosity requirements. To verify that the viscosity meets the requirements, only one temperature, one molecular weight, one concentration, and one oilfield salinity are needed during the experiment to ensure that the obtained viscosity meets the requirements. Of course, to improve the accuracy of the experiment, two temperatures, three concentrations, and two salinities can be selected. It is understandable that the extra temperatures, concentrations, and salinities can be used as auxiliary reference experiments to ensure the accuracy of the experiment and ensure that the viscosity meets the requirements. Therefore, in the actual experimental process, this application needs to calculate the actual... The number of tests is: 2 for temperature × 1 for molecular weight × 3 for concentration × 2 for oilfield salinity = 12 groups. This requires 1 person and 1 day to complete, with a cost of 500 yuan per test. The initial viscosity test alone costs 6,000 yuan. If aging evaluation is carried out, each sample group needs to be tested 7 times, requiring a testing cost of 42,000 yuan. Therefore, before this application was disclosed, experimental parameters were selected blindly during the experiment, which increased the number of experiments and the experimental cost. However, through the application of this invention, the number of experiments can be significantly reduced, the workload can be reduced, energy can be saved and consumption can be reduced, research time can be saved, and the requirements of low-carbon research can be met.

[0073] like Figure 7 As shown, a second aspect of the present invention provides a parameter determination device for a polymer solution in an oil displacement agent, comprising: an acquisition unit 12 for acquiring the actual temperature of the oil field, denoted as a first preset temperature; and a processing unit for determining, based on input of at least two sets of experimental data, the values ​​of various coefficients in a preset relationship between the concentration of the polymer solution, the salinity of the oil field, and the viscosity of the polymer solution under the conditions of the first preset temperature and a first preset molecular weight; the preset relationship is:

[0074] f(x,y)=a+bx+cy+dx 2 +exy+gy2+hx2 y + mxy² + ny³;

[0075] Where f(x,y) is the viscosity of the polymer solution, x is the salinity of the oil field, y is the concentration of the polymer solution, and a, b, c, d, e, g, h, m, and n are all coefficients. The determining unit 14 is also used to determine the viscosity of the polymer solution when the salinity of the oil field is the first preset salinity, and the polymer solution is at different concentrations, based on the preset relationship and the values ​​of each coefficient. The determining unit 14 is also used to determine the viscosity range of the polymer solution and its corresponding polymer concentration range when the salinity of the oil field is the first preset salinity, based on the preset viscosity requirements.

[0076] like Figure 8 As shown, the third aspect of the present invention provides a parameter determination device 1 for a polymer solution in an oil displacement agent, including a storage device 1616 and a processor 1818. The storage device 1616 stores a computer program or instructions, and the processor 1818 executes the program or instructions to implement the parameter determination method for a polymer solution in an oil displacement agent as provided in any of the technical solutions of the first aspect of this application.

[0077] The fourth aspect of the present invention provides a readable storage medium storing a program or instructions, wherein when a processor 18 executes the program or instructions, it implements the method for determining parameters of a polymer solution in an oil displacement agent as provided in any of the technical solutions of the first aspect of the present application.

[0078] In embodiments of the present invention, the terms "first," "second," and "third" are used only for descriptive purposes and should not be construed as indicating or implying relative importance; the term "multiple" refers to two or more unless otherwise expressly defined. The terms "install," "connect," "link," and "fix" should be interpreted broadly. For example, "connect" can be a fixed connection, a detachable connection, or an integral connection; "link" can be a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in embodiments of the present invention according to the specific circumstances.

[0079] Furthermore, although the operations are described in a specific order, this should be understood as requiring that such operations be performed in a specific order or sequential order, or requiring that all illustrated operations be performed to achieve the desired result. In certain environments, multitasking and parallel processing may be advantageous. Similarly, although several specific implementation details are included in the above discussion, these should not be construed as limiting the scope of the invention. Certain features described in the context of individual embodiments may also be implemented in combination in a single implementation. Conversely, various features described in the context of a single implementation may also be implemented individually or in any suitable sub-combination in multiple implementations.

[0080] Although the subject matter has been described using language describing specific structural features and / or methodological logic, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are merely illustrative examples of implementing the claims.

[0081] The above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Those skilled in the art will recognize that various modifications and variations are possible with respect to the embodiments of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the embodiments of the present invention should be included within the protection scope of the embodiments of the present invention.

Claims

1. A method for determining parameters of a polymer solution in an oil displacement agent, characterized in that, Includes the following steps: The actual temperature of the oilfield is obtained and recorded as the first preset temperature; Based on the input of at least two sets of experimental data, determine the values ​​of each coefficient in the preset relationship between the concentration of the polymer solution, the salinity of the oil field, and the viscosity of the polymer solution under the conditions of the first preset temperature and the first preset molecular weight. The preset relation is: f(x,y)=a+bx+cy+dx²+exy+gy²+hx²y+mxy²+ny³; Where f(x,y) is the viscosity of the polymer solution, x is the salinity of the oil field, y is the concentration of the polymer solution, and a, b, c, d, e, g, h, m, and n are all coefficients. The first preset salinity is determined based on the preset relationship and the values ​​of each coefficient, and the viscosity of the polymer solution is determined at different concentrations of the polymer solution. Based on the preset viscosity requirements, the viscosity range of the polymer solution and the corresponding polymer concentration range are determined when the salinity of the oil field is the first preset salinity.

2. The determination method according to claim 1, characterized in that, The step of determining the first preset salinity of the oilfield based on the preset relationship and the values ​​of each coefficient, and determining the viscosity of the polymer solution at different concentrations, includes: The viscosity of the polymer solution is calculated based on the preset relationship and the values ​​of each coefficient when the salinity of the oil field is the first preset salinity and the polymer solution is the first concentration. The first concentration can take different values ​​to calculate the viscosity of the polymer solution under different conditions, so as to obtain multiple viscosity values.

3. The determination method according to claim 2, characterized in that, The first concentration has a value of at least 10.

4. The determination method according to claim 2, characterized in that, The first concentration is greater than or equal to 500 mg / L and less than or equal to 5000 mg / L.

5. The determination method according to any one of claims 1 to 4, characterized in that, The first preset temperature is greater than or equal to 30°C and less than or equal to 90°C; The first preset molecular weight is greater than or equal to 19 million and less than or equal to 25 million; The first preset mineralization is greater than or equal to 500 mg / L and less than or equal to 5000 mg / L.

6. The determining method according to any one of claims 1 to 4, characterized in that, Also includes: The preset viscosity requirement includes a polymer viscosity greater than 2.98 mPa•s.

7. The determining method according to any one of claims 1 to 4, characterized in that, Also includes: Based on the minimum concentration and the actual minimum viscosity obtained through the verification experiment, the theoretical minimum viscosity corresponding to the minimum concentration is determined by the preset relationship and the values ​​of each coefficient. The actual minimum viscosity is compared with the theoretical minimum viscosity. If the actual minimum viscosity is less than the theoretical minimum viscosity, an early warning is issued. Wherein, the minimum concentration is the smallest among all concentrations that determine the polymer concentration range.

8. A device for determining parameters of a polymer solution in an oil displacement agent, characterized in that, include: The acquisition unit is used to acquire the actual temperature of the oilfield, which is denoted as the first preset temperature. The determining unit is used to determine the values ​​of each coefficient in the preset relationship between the concentration of the polymer solution, the salinity of the oil field and the viscosity of the polymer solution under the conditions of the first preset temperature and the first preset molecular weight, based on the input of at least two sets of experimental data. The preset relation is: f(x,y)=a+bx+cy+dx²+exy+gy²+hx²y+mxy²+ny³; Where f(x,y) is the viscosity of the polymer solution, x is the salinity of the oil field, y is the concentration of the polymer solution, and a, b, c, d, e, g, h, m, and n are all coefficients. The determining unit is also used to determine the viscosity of the polymer solution at different concentrations when the mineralization degree of the oil field is the first preset mineralization degree, based on the preset relationship and the values ​​of each coefficient. The determining unit is further configured to determine, based on a preset viscosity requirement, the viscosity range of the polymer solution and its corresponding polymer concentration range when the salinity of the oil field is a first preset salinity.

9. A device for determining parameters of a polymer solution in an oil displacement agent, characterized in that, include: A storage device and a processor, wherein the storage device stores a computer program or instructions, and the processor executes the program or instructions to implement the determination method as described in any one of claims 1 to 7.

10. A readable storage medium, characterized in that, The readable storage medium stores a program or instructions, which, when executed by a processor, implement the determination method as described in any one of claims 1 to 7.

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