A two-way self-regulating chemical flooding method and system for enhancing oil recovery

Abstract

The present invention relates to a two-way self-regulating chemical flooding method and system for improving oil recovery, comprising: determining the average particle size of dispersed phase droplets during the stable seepage of an oil-in-water emulsion according to the average permeability of the reservoir; determining the injection concentration of an emulsifier matching the target reservoir according to the seepage velocity of the reservoir; under the condition of ensuring the constant injection concentration of the emulsifier, determining the optimal polymer injection concentration matching the injection concentration of the emulsifier through core flooding experiments with the maximum equivalent ton of incremental oil production as the target; determining the total injection amount of the emulsifier and the total injection amount of the polymer for the implementation well group unit; and optimizing the injection allocation amounts of the emulsifier and the polymer for each individual well by invoking a chemical flooding reservoir numerical simulator with the maximum cumulative recovery degree as the target and the total injection amounts of the emulsifier and the polymer as the constraint conditions. The present invention simultaneously reduces the viscosity of the oil phase and increases the viscosity of the water phase, effectively improving the crude oil development effect.

Description

Technical Field

[0001] The present invention relates to a two-way self-regulating chemical flooding method and system for enhancing oil recovery, belonging to the technical field of oil and gas field development. Background Art

[0002] In China, the resources of high-viscosity oil reservoirs are abundant, with a geological reserve of about 1.3 billion tons. At present, such oil reservoirs are mainly developed by water flooding and steam stimulation. Due to the high viscosity of crude oil and a water-oil viscosity ratio less than 0.005, severe viscous fingering occurs, the sweep efficiency is lower than 55%, and the recovery factor is less than 20%. Existing chemical flooding technologies such as polymer flooding can, to a certain extent, enhance the oil recovery of conventional heavy oil reservoirs by increasing the viscosity of the aqueous phase and reducing the water-oil viscosity ratio. However, due to the limited increase in the viscosity of the aqueous phase and the synchronous increase in the seepage resistance, the existing chemical flooding technologies at home and abroad are only applicable to oil reservoirs with an underground crude oil viscosity less than 100 mPa·s, and it is difficult to effectively exploit high-viscosity oil reservoirs with an underground crude oil viscosity of 100 mPa·s - 2000 mPa·s. Thermal oil recovery methods such as steam stimulation can reduce the viscosity of the oil phase by injecting high-temperature fluids to heat the formation and improve the water-oil mobility ratio, thereby increasing the oil recovery of high-viscosity oil reservoirs. However, steam heating consumes a large amount of energy, has a high economic cost, and emits a large amount of carbon dioxide, resulting in great environmental pressure. Therefore, it is urgent to create a new chemical composite cold production flooding method for high-viscosity oil reservoirs to significantly improve the recovery factor.

[0003] Field practice shows that after the emulsifier is injected into the oil reservoir, it can emulsify high-viscosity heavy oil into a water-in-oil emulsion with a lower viscosity, playing a role in reducing the viscosity of the oil phase and promoting flow; the polymer solution can effectively increase the viscosity of the aqueous phase, inhibit water channeling, and expand the swept range. Summary of the Invention

[0004] In view of the deficiencies of the prior art, the present invention proposes a two-way self-regulating chemical flooding method for enhancing oil recovery. By synergistically using the dual functions of the emulsifier to reduce the viscosity of the oil phase and the polymer to increase the viscosity of the aqueous phase, the present invention proposes a new chemical flooding method for two-way adjustment of the water-oil viscosity ratio, and gives a determination method for the droplet size of the dispersed phase of the emulsion, the injection concentrations of the emulsifier and the polymer, and the chemical agent injection volume per well that match the target oil reservoir, which helps to implement the two-way self-regulating chemical flooding method in the field to improve the water-oil mobility ratio of the oil field and enhance the oil recovery of high-viscosity oil reservoirs, and can provide an important supporting role for ensuring China's energy security.

[0005] The present invention also proposes a two-way self-regulating chemical flooding system for enhancing oil recovery.

[0006] Term Explanation:

[0007] Core flooding experiment simulates the actual underground crude oil production under laboratory conditions. In this experimental method, a displacement fluid such as a chemical agent solution is injected into the inlet end of a natural core stored in a holder through an injection pump, and the crude oil previously saturated in the core is displaced to be produced from the outlet end. Real-time data such as injection pressure, oil production, and water production during the oil displacement process are recorded through a pressure monitoring and fluid collection device. The main experimental processes include core vacuuming and water saturation, permeability testing, oil saturation, pre-water flooding, chemical agent injection, and subsequent water flooding, etc.

[0008] The technical solution of the present invention is as follows:

[0009] A two-way self-regulating chemical flooding method for improving oil recovery includes the following steps:

[0010] (1) Determine the average particle size of the dispersed-phase droplets during the stable seepage of the oil-in-water emulsion;

[0011] According to the average permeability of the reservoir, based on the matching relationship model between the average particle size of the dispersed-phase droplets of the oil-in-water emulsion and the average permeability of the reservoir during its stable seepage, calculate the average particle size of the dispersed-phase droplets of the emulsion that matches the target reservoir;

[0012] (2) Determine the injection concentration of the emulsifier;

[0013] According to the average particle size of the dispersed-phase droplets during the stable seepage of the oil-in-water emulsion obtained in step (1), and the reservoir seepage velocity determined according to the field implementation conditions, based on the regression relationship model among the average particle size of the dispersed-phase droplets, the reservoir seepage velocity, and the injection concentration of the emulsifier, calculate the injection concentration of the emulsifier that matches the target reservoir;

[0014] (3) Determine the injection concentration of the polymer;

[0015] Under the condition of keeping the injection concentration of the emulsifier unchanged, adjust the polymer injection concentration, conduct several groups of core flooding experiments, count the injection volumes of the emulsifier and polymer solution and the cumulative oil production in each group of core flooding experiments, calculate the equivalent tons of polymer incremental oil production, and the polymer injection concentration used in the core flooding experiment with the maximum equivalent tons of polymer incremental oil production is the optimal polymer injection concentration that matches the emulsifier injection concentration.

[0016] (4) Determine the total injection amounts of the emulsifier and polymer for the well group unit;

[0017] According to the pore volume of the well group unit and the given injection pore volume multiple, based on the injection concentration of the emulsifier obtained in step (2) and the injection concentration of the polymer obtained in step (3), calculate the total injection amount of the emulsifier and the total injection amount of the polymer required for the well group unit;

[0018] (5) Optimize the injection allocation amounts of the emulsifier and polymer for each individual well;

[0019] Taking the maximum cumulative production degree as the goal, with the total injection volume of emulsifier and polymer in the well group unit determined in step (4) as the constraint condition, and the injection volume of emulsifier and polymer in each single well as the adjustable variables, call the chemical flooding reservoir numerical simulator to simulate and calculate different combinations of adjustable variables, and count the cumulative production degree of each plan. The adjustable variables corresponding to the maximum value are the optimal values of the injection volume of emulsifier and polymer in each single well.

[0020] Preferably according to the present invention, in step (1), the calculation formula for the average particle size of the dispersed phase droplets of the emulsion matching the target reservoir is shown in formula (I):

[0021] d = exp((k - 0.1583) / 2.3194) (I)

[0022] In formula (I), k is the average permeability of the reservoir, μm 2 ; d is the average particle size of the dispersed phase droplets of the emulsion matching the target reservoir, μm; exp() is the exponential function.

[0023] Preferably according to the present invention, in step (2), the calculation formula for the injection concentration of the emulsifier matching the target reservoir is shown in formula (II):

[0024] w m = 4.15exp(0.06d + 6.63v 2 - 4.58v) (II)

[0025] In formula (II), w m is the injection concentration of the emulsifier matching the target reservoir, kg / m 3 ; d is the average particle size of the dispersed phase droplets of the emulsion matching the target reservoir, μm; v is the seepage velocity of the reservoir, cm / min; exp() is the exponential function.

[0026] Preferably according to the present invention, in step (3), the calculation formula for the equivalent tons of polymer incremental oil production is shown in formula (III):

[0027]

[0028] In formula (III), E t is the equivalent tons of polymer incremental oil production, m 3 / t; Q o is the cumulative chemical flooding oil production, 10 -6 m 3 ; Q oi is the cumulative water flooding oil production, 10 -6 m 3 ; w p is the polymer injection concentration, kg / m3 ; V p is the injection volume of the polymer solution, 10 -6 m 3 ; w m is the injection concentration of the emulsifier, kg / m 3 ; V m is the injection volume of the emulsifier solution, 10 -6 m 3 ; P p is the price of the polymer dry powder, yuan / t; P m is the price of the emulsifier dry powder, yuan / t.

[0029] According to the preference of the present invention, in step (4), the calculation formula for the total injection amount of the emulsifier required for the well group unit is shown in formula (IV):

[0030]

[0031] In formula (IV), m m is the total injection amount of the emulsifier, kg; α is the injection pore volume multiple of the two-way self-regulating chemical flooding, PV; is the pore volume of the well group unit, m 3 ; w m is the emulsifier injection concentration obtained in step (2), kg / m 3 .

[0032] According to the preference of the present invention, in step (4), the calculation formula for the total injection amount of the polymer required for the well group unit is shown in formula (V):

[0033]

[0034] In formula (V), m p is the total injection amount of the polymer, kg; w p is the injection concentration of the polymer obtained in step (3), kg / m 3 .

[0035] A two-way self-regulating chemical flooding system for enhancing oil recovery, comprising:

[0036] An average particle size calculation module for the emulsion dispersed phase droplets, configured to: calculate the average particle size of the dispersed phase droplets during the stable seepage of the oil-in-water emulsion;

[0037] An emulsifier injection concentration calculation module, configured to: calculate the injection concentration of the emulsifier;

[0038] A polymer injection concentration calculation module, configured to: calculate the injection concentration of the polymer;

[0039] The total injection volume calculation module for emulsifier and polymer in the well group unit is configured to calculate the total injection volume of emulsifier and polymer in the well group unit;

[0040] The injection volume optimization module for emulsifier and polymer in each single well is configured to optimize the injection volume of emulsifier and polymer in each single well.

[0041] The beneficial effects of the present invention are as follows:

[0042] 1. By calculating the average particle size of the dispersed phase droplets of the oil-in-water emulsion that matches the target reservoir, it is possible to ensure the viscosity reduction effect of heavy oil emulsification while avoiding the destructive plugging of pore throat structures by the dispersed phase droplets due to the Jamin effect, effectively improving the oil recovery rate.

[0043] 2. By successively calculating the injection concentration of the emulsifier required to obtain the target dispersed phase droplet size and the matching polymer injection concentration, it is possible to maximize the two-way synergistic effect of the emulsifier reducing the oil phase viscosity and the polymer increasing the water phase viscosity, significantly reducing the oil-water viscosity ratio and improving the oil recovery rate.

[0044] 3. By calculating the total injection volume of emulsifier and polymer in the well group unit and optimizing the differential injection volume of emulsifier and polymer in each single well with this as a constraint condition, it is possible to improve the utilization rate of chemical agents as much as possible without increasing the total injection volume, maximizing the economic and technical development effect of the reservoir. Description of the Drawings

[0045] Figure 1 It is a schematic diagram of the correlation between the equivalent ton of polymer-increased oil production and the polymer injection concentration;

[0046] Figure 2 It is a schematic diagram of the well location distribution in the well group unit;

[0047] Figure 3 It is a curve graph of the change in oil recovery rate. Detailed Embodiments

[0048] The present invention will be further limited below in conjunction with the drawings of the specification and embodiments, but not limited thereto.

[0049] Embodiment 1

[0050] A two-way self-regulating chemical flooding method for improving oil recovery includes the following steps:

[0051] (1) Calculate the average particle size of the dispersed phase droplets during the stable seepage of the oil-in-water emulsion;

[0052] According to the average permeability of the reservoir obtained from core tests in the oil field, the average permeability of a well group unit in a certain oil reservoir in China is 1.85μm 2, based on the matching relationship model between the average particle size of the dispersed phase droplets in the water-in-oil emulsion and the average permeability of the reservoir during stable seepage, calculate the average particle size of the dispersed phase droplets in the emulsion that matches the target reservoir;

[0053] The calculation formula for the average particle size of the dispersed phase droplets in the emulsion that matches the target reservoir is shown in Equation (I):

[0054] d = exp((k - 0.1583) / 2.3194) (I)

[0055] In Equation (I), k is the average permeability of the reservoir, μm 2 ; d is the average particle size of the dispersed phase droplets in the emulsion that matches the target reservoir, μm; exp() is the exponential function.

[0056] According to Equation (I), the average particle size of the dispersed phase droplets in the emulsion that matches the permeability of this well group unit is calculated to be 2.08 μm.

[0057] (2) Determine the injection concentration of the emulsifier;

[0058] Based on the average particle size of the dispersed phase droplets during the stable seepage of the water-in-oil emulsion obtained in step (1), and the average seepage velocity of the reservoir obtained from the interpretation of the field tracer test, based on the regression relationship model among the average particle size of the dispersed phase droplets, the reservoir seepage velocity, and the injection concentration of the emulsifier, calculate the injection concentration w of the emulsifier that matches the target reservoir m ; The calculation formula for the injection concentration of the emulsifier that matches the target reservoir is shown in Equation (II):

[0059] w m = 4.15exp(0.06d + 6.63v 2 - 4.58v) (II)

[0060] In Equation (II), w m is the injection concentration of the emulsifier that matches the target reservoir, kg / m 3 ; d is the average particle size of the dispersed phase droplets in the emulsion that matches the target reservoir, μm; v is the reservoir seepage velocity, cm / min; exp() is the exponential function.

[0061] In this example, the seepage velocity is 0.1 cm / min. According to Equation (II), the injection concentration of the emulsifier is calculated to be 3.18 kg / m 3 .

[0062] Adjust the polymer injection concentration, conduct several groups of core flooding experiments, count the injection volumes of the emulsifier and polymer solution and the cumulative oil production in each group of core flooding experiments, calculate the equivalent tons of polymer incremental oil production. The polymer injection concentration used in the core flooding experiment with the maximum equivalent tons of polymer incremental oil production is the optimal polymer injection concentration matching the emulsifier injection concentration.

[0063] (3) Obtain the injection concentration of the polymer;

[0064] Under the condition that the injection concentration of the emulsifier remains unchanged at 3.18 kg / m 3 , use a core model to conduct 5 groups of emulsifier and polymer solution flooding experiments respectively. The polymer injection concentrations are 0.5 kg / m 3 , 1.0 kg / m 3 , 1.5 kg / m 3 , 2.0 kg / m 3 , 2.5 kg / m 3 respectively. Count the cumulative oil production in each group of core flooding experiments, calculate the equivalent tons of polymer incremental oil production, draw the relationship curve between the equivalent tons of polymer incremental oil production and the polymer injection concentration, and regress the non-linear relationship model. Optimize and solve to obtain the polymer injection concentration with the maximum equivalent tons of polymer incremental oil production. This concentration is the optimal polymer injection concentration matching the emulsifier injection concentration.

[0065] The calculation formula for the equivalent tons of polymer incremental oil production is shown in Equation (III):

[0066]

[0067] In Equation (III), E t is the equivalent tons of polymer incremental oil production, m 3 / t; Q o is the cumulative oil production of chemical flooding, 10 -6 m 3 ; Q oi is the cumulative oil production of water flooding, 10 -6 m 3 ; w p is the polymer injection concentration, kg / m 3 ; V p is the injection volume of the polymer solution, 10 -6 m 3 ; w m is the emulsifier injection concentration, kg / m 3 ; V m is the injection volume of the emulsifier solution, 10 -6 m 3 ; P p is the price of polymer dry powder, yuan / t; P m is the price of emulsifier dry powder, yuan / t.

[0068] In the core flooding experiment of this embodiment, the injection volume of the emulsifier solution is 185×10 -6 m 3 ; the injection volume of the polymer solution is 185×10 -6 m 3 ; the price of the emulsifier dry powder is 20,000 yuan / t, and the price of the polymer dry powder is 15,000 yuan / t. The statistical results of the oil production of 5 groups of core flooding experiments and the calculation results of the equivalent ton polymer incremental oil are shown in Table 1:

[0069] Table 1

[0070]

[0071] The correlation between the equivalent ton polymer incremental oil and the polymer injection concentration is as Figure 1 shown. The optimal polymer injection concentration obtained by optimization is 1.71 kg / m 3 .

[0072] (4) Obtain the total injection amounts of the emulsifier and the polymer for the well group unit;

[0073] The well location distribution of the well group unit is as Figure 2 shown. According to the pore volume of the well group unit obtained from the field test and the injection pore volume multiple given by the two-way self-regulating chemical flooding in the field implementation, based on the injection concentration of the emulsifier obtained in step (2) and the injection concentration of the polymer obtained in step (3), calculate the total injection amount of the emulsifier and the total injection amount of the polymer required for the well group unit; the calculation formula for the total injection amount of the polymer required for the well group unit is shown in formula (V):

[0074]

[0075] In formula (V), m p is the total injection amount of the polymer, kg; w p is the injection concentration of the polymer obtained in step (3), kg / m 3 .

[0076] The calculation formula for the total injection amount of the emulsifier required for the well group unit is shown in formula (IV):

[0077]

[0078] In formula (IV), m m is the total injection amount of the emulsifier, kg; α is the injection pore volume multiple of the two-way self-regulating chemical flooding, PV; is the pore volume of the well group unit, m 3 ; w m is the injection concentration of the emulsifier obtained in step (2), kg / m 3 .

[0079] In this example, the injection pore volume multiple of the two-way self-regulating chemical flooding is 0.4 PV; the pore volume of the well group unit is 1.22×10 6 m 3 ; the injection concentration of the emulsifier determined in step (3) is 3.18 kg / m 3 ; the injection concentration of the polymer determined in step (4) is 1.71 kg / m 3 , and according to the above formula, the total injection amounts of the emulsifier and the polymer required for the well group unit to implement the two-way self-regulating chemical flooding are calculated to be 1546 t and 831 t respectively.

[0080] (5) Optimize the injection amounts of the emulsifier and the polymer for each single well;

[0081] Taking the maximum cumulative production degree as the goal, taking the total injection amounts of the emulsifier and the polymer in the well group unit determined in step (4) as the constraint conditions, and taking the injection amounts of the emulsifier and the polymer for each single well as the adjustable variables, call the existing chemical flooding reservoir numerical simulator to perform simulation calculations on different combinations of adjustable variable schemes, and count the cumulative production degrees of each scheme. The adjustable variable corresponding to the maximum value is the optimal value of the injection amounts of the emulsifier and the polymer for each single well. The optimized injection amounts of the emulsifier and the polymer for each single well are shown in Table 2.

[0082] Table 2

[0083] Injection well name Polymer injection volume, t Emulsifier injection volume, t Total chemical injection volume, t I1 198.4 369.1 567.5 I2 210.5 391.7 602.2 I3 206.3 383.8 590.1 I4 215.8 401.4 617.2 Total 831 1546 2377

[0084] Based on the well group unit model of this example, numerical simulation calculations of the new two-way self-regulating chemical flooding and the existing polymer / surfactant binary composite flooding are carried out respectively. The injection parameters of the emulsifier and the polymer used in the two-way self-regulating chemical flooding are as described in steps (2) to (5). The polymer injection parameters in the binary composite flooding are the same as those of the polymer in the two-way self-regulating chemical flooding, and the surfactant injection parameters are the same as those of the emulsifier in the two-way self-regulating chemical flooding. The comparison curve of the oil recovery rates obtained by the two chemical flooding methods is as Figure 3 shown. It can be seen that the two-way self-regulating chemical flooding method proposed by the present invention can increase the oil recovery rate by 7.2%.

[0085] Example 2

[0086] A two-way self-regulating chemical flooding system for improving oil recovery, comprising:

[0087] An average particle size calculation module for the emulsion dispersed phase droplets, configured to: calculate the average particle size of the dispersed phase droplets during the stable seepage of the water-in-oil emulsion;

[0088] An emulsifier injection concentration calculation module, configured to: calculate the injection concentration of the emulsifier;

[0089] Polymer injection concentration calculation module, configured to: calculate the injection concentration of the polymer;

[0090] Total injection volume calculation module of emulsifier and polymer for well group unit, configured to: calculate the total injection volume of emulsifier and polymer for the well group unit;

[0091] Optimization module for injection allocation volume of emulsifier and polymer for each individual well, configured to: optimize the injection allocation volume of emulsifier and polymer for each individual well.

Claims

1. A two-way self-regulating chemical flooding method for improving oil recovery rate, characterized in that, it includes the following steps: (1) Obtain the average particle size of the dispersed-phase droplets during the stable seepage of the oil-in-water emulsion; According to the average permeability of the reservoir, based on the matching relationship model between the average particle size of the dispersed-phase droplets of the oil-in-water emulsion and the average permeability of the reservoir during its stable seepage, calculate the average particle size of the dispersed-phase droplets of the emulsion that matches the target reservoir; (2) Obtain the injection concentration of the emulsifier; According to the average particle size of the dispersed-phase droplets during the stable seepage of the oil-in-water emulsion obtained in step (1), and the seepage velocity of the reservoir determined according to the field implementation conditions, based on the regression relationship model among the average particle size of the dispersed-phase droplets, the seepage velocity of the reservoir, and the injection concentration of the emulsifier, calculate the injection concentration of the emulsifier that matches the target reservoir; (3) Obtain the injection concentration of the polymer; Under the condition of ensuring that the injection concentration of the emulsifier remains unchanged, adjust the injection concentration of the polymer, conduct several groups of core flooding experiments, count the injection volumes of the emulsifier and the polymer solution and the cumulative oil production in each group of core flooding experiments, calculate the equivalent tons of polymer incremental oil production, and the polymer injection concentration used in the core flooding experiment with the maximum equivalent tons of polymer incremental oil production is the optimal polymer injection concentration that matches the injection concentration of the emulsifier; (4) Obtain the total injection amounts of the emulsifier and the polymer for the well group unit; According to the pore volume of the well group unit and the given injection pore volume multiple, based on the injection concentration of the emulsifier obtained in step (2) and the injection concentration of the polymer obtained in step (3), calculate the total injection amount of the emulsifier and the total injection amount of the polymer required for the well group unit; (5) Optimize the injection allocation amounts of the emulsifier and the polymer for each individual well; Taking the maximum cumulative recovery degree as the goal, taking the total injection amounts of the emulsifier and the polymer for the well group unit determined in step (4) as the constraint conditions, taking the injection allocation amounts of the emulsifier and the polymer for each individual well as adjustable variables, call the chemical flooding reservoir numerical simulator to perform simulation calculations on different combinations of adjustable variable schemes, and count the cumulative recovery degrees of each scheme, and the adjustable variable corresponding to the maximum value is the optimal value of the injection allocation amounts of the emulsifier and the polymer for each individual well; In step (1), the calculation formula for the average particle size of the dispersed-phase droplets of the emulsion that matches the target reservoir is shown in formula (I): d = exp((k - 0.1583) / 2.3194) (I) In formula (I), k is the average reservoir permeability, μm 2 ; d is the average particle size of the dispersed phase droplets of the emulsion matched with the target reservoir, μm; exp() is the exponential function; In step (2), the calculation formula for the injection concentration of the emulsifier that matches the target reservoir is shown in formula (II): w m = 4.15exp(0.06d + 6.63v 2 - 4.58v)(II) In formula (II), w m is the injection concentration of the emulsifier matching the target reservoir, kg / m 3 ; d is the average particle size of the dispersed phase droplets of the emulsion matching the target reservoir, μm; v is the seepage velocity of the reservoir, cm / min; exp() is the exponential function.

2. The two-way self-regulating chemical flooding method for improving oil recovery rate according to claim 1, characterized in that, in step (3), the calculation formula for the equivalent tons of polymer incremental oil production is shown in formula (III): In formula (III), E t is the equivalent ton of incremental oil production, m 3 / t; Q o is the cumulative oil production of chemical flooding, 10 -6 m 3 ; Q oi is the cumulative oil production of water flooding, 10 -6 m 3 ; w p is the polymer injection concentration, kg / m 3 ; V p is the polymer solution injection volume, 10 -6 m 3 ; w m is the injection concentration of the emulsifier, kg / m 3 ; V m is the injection volume of the emulsifier solution, 10 -6 m 3 ; P p is the price of polymer dry powder, yuan / t; P m is the price of emulsifier dry powder, yuan / t.

3. The two-way self-regulating chemical flooding method for improving oil recovery rate according to claim 1, characterized in that, in step (4), the calculation formula for the total injection amount of the emulsifier required for the well group unit is shown in formula (IV): In formula (IV), m m is the total injection amount of the emulsifier, in kg; α is the injection pore volume multiple of the two-way self-regulating chemical flooding, in PV; is the pore volume of the well group unit, in m 3 ; w m is the emulsifier injection concentration obtained in step (2), in kg / m 3 .

4. The two-way self-regulating chemical flooding method for improving oil recovery rate according to claim 3, characterized in that, in step (4), the calculation formula for the total injection amount of the polymer required for the well group unit is shown in formula (V): In formula (V), m p is the total polymer injection amount, kg; w p is the injection concentration of the polymer obtained in step (3), kg / m 3 .

5. A two-way self-regulating chemical flooding system for enhancing oil recovery, which is used to implement a two-way self-regulating chemical flooding method for enhancing oil recovery according to any one of claims 1-4. It is characterized in that it includes: An average particle size calculation module for emulsion dispersed phase droplets, configured to calculate the average particle size of the dispersed phase droplets during the stable percolation of the oil-in-water emulsion; An emulsifier injection concentration calculation module, configured to calculate the injection concentration of the emulsifier; A polymer injection concentration calculation module, configured to calculate the injection concentration of the polymer; A total injection amount calculation module for emulsifier and polymer in the well group unit, configured to calculate the total injection amount of the emulsifier and polymer in the well group unit; An injection allocation optimization module for emulsifier and polymer in each individual well, configured to optimize the injection allocation of the emulsifier and polymer in each individual well.

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