A volatile oil reservoir imbibition oil recovery method, device, equipment and storage medium

Abstract

The embodiment of the application provides a volatile oil reservoir imbibition oil production method, device, equipment and storage medium, the method comprises the following steps: obtaining experimental parameters for conducting imbibition experiments; using the experimental parameters to conduct multiple first dynamic imbibition experiments on the experimental core to determine the optimal displacement speed; using the experimental parameters to conduct multiple static imbibition experiments on the experimental core to obtain multiple static imbibition recovery curves; using the experimental parameters to conduct multiple second dynamic imbibition experiments on the experimental core to obtain multiple second dynamic imbibition recovery curves; using the multiple static imbibition recoveries and the multiple second dynamic imbibition recoveries to draw a comprehensive imbibition recovery curve; using the inflection point of the comprehensive imbibition recovery curve to determine the optimal imbibition pressure; and using the optimal displacement speed and the optimal imbibition pressure to conduct imbibition oil production. The embodiment of the application comprehensively considers the influence of static imbibition and dynamic imbibition, determines the optimal displacement speed and the optimal imbibition pressure of the core, and reduces the exploitation cost of the volatile oil reservoir.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oilfield development, and particularly relates to a volatile oil reservoir imbibition oil production method, device, equipment and storage medium. BACKGROUND

[0002] Carbonate rock oil and gas reservoirs are important oil and gas reservoirs that are currently concentratedly developed in the world, and their recoverable reserves account for more than half of the world's remaining recoverable reserves of oil and gas reservoirs, and are important fields for future oil and gas reserves and production increase. With the deepening of exploration and development of carbonate rock reservoirs, a kind of reservoir fluid with high shrinkage characteristics is found. This kind of fluid exists in liquid form under reservoir conditions, and its composition and thermodynamic properties are between ordinary black oil and condensate gas. This kind of reservoir is called volatile oil reservoir.

[0003] The volatile oil reservoir is different from the conventional oil reservoir, and has the characteristics of high volume coefficient, high oil compression coefficient, high original dissolved gas oil ratio, high saturation pressure, high shrinkage rate, and low formation oil viscosity and density. Therefore, the conventional oil reservoir production method is not suitable for the volatile oil reservoir. SUMMARY

[0004] Therefore, the purpose of the present application is to provide a volatile oil reservoir imbibition oil production method, device, equipment and storage medium, which comprehensively considers the influence of static imbibition and dynamic imbibition, determines the optimal displacement speed and optimal imbibition pressure of the core, reduces the production cost of the volatile oil reservoir, and provides guidance for improving the oil recovery in the actual mine. The specific technical scheme is as follows:

[0005] In a first aspect, the present application provides a volatile oil reservoir imbibition oil production method, which comprises:

[0006] Obtaining experimental parameters for imbibition experiments, the experimental parameters including related parameters corresponding to experimental cores and related coefficients corresponding to an oil environment to be produced;

[0007] Performing a plurality of first dynamic imbibition experiments on the experimental cores by using the experimental parameters to determine an optimal displacement speed, different first dynamic imbibition experiments corresponding to different displacement speeds;

[0008] Performing a plurality of static imbibition experiments on the experimental cores by using the experimental parameters to obtain a plurality of static imbibition recovery curves, different static imbibition experiments corresponding to different imbibition pressures;

[0009] Performing a plurality of second dynamic imbibition experiments on the experimental cores by using the experimental parameters to obtain a plurality of second dynamic imbibition recovery curves, different second dynamic imbibition experiments corresponding to different imbibition pressures, and different second dynamic imbibition experiments corresponding to the optimal displacement speed;

[0010] The comprehensive imbibition recovery rate curve is drawn by using a plurality of static imbibition recovery rates and a plurality of second dynamic imbibition recovery rates, the plurality of static imbibition recovery rates are obtained from the plurality of static imbibition recovery rate curves, different static imbibition recovery rates correspond to different static imbibition recovery rate curves, and the plurality of second dynamic imbibition recovery rates are obtained from the plurality of second dynamic imbibition recovery rate curves, different second dynamic imbibition recovery rates correspond to different second dynamic imbibition recovery rate curves;

[0011] The optimal imbibition pressure is determined by using an inflection point of the comprehensive imbibition recovery rate curve.

[0012] The imbibition oil recovery is performed by using the optimal displacement speed and the optimal imbibition pressure.

[0013] In a possible implementation, the performing a plurality of first dynamic imbibition experiments on the experimental core by using the experimental parameters to determine the optimal displacement speed comprises:

[0014] The plurality of first dynamic imbibition recovery rate curves are obtained by performing the plurality of first dynamic imbibition experiments on the experimental core by using the experimental parameters.

[0015] The optimal displacement speed is determined by using inflection points of the plurality of first dynamic imbibition recovery rate curves.

[0016] In a possible implementation, the determining the optimal displacement speed by using the inflection points of the plurality of first dynamic imbibition recovery rate curves comprises:

[0017] An optimal first dynamic imbibition recovery rate curve is determined, an inflection point of the optimal first dynamic imbibition recovery rate curve corresponds to a first dynamic imbibition recovery rate that is higher than a first dynamic imbibition recovery rate corresponding to an inflection point of another first dynamic imbibition recovery rate curve, the another first dynamic imbibition recovery rate curve being a first dynamic imbibition recovery rate curve other than the optimal first dynamic imbibition recovery rate curve in the plurality of first dynamic imbibition recovery rate curves.

[0018] The optimal first dynamic imbibition recovery rate curve corresponds to the optimal displacement speed.

[0019] In a possible implementation, the determining the correlation coefficient corresponding to the oil recovery environment comprises:

[0020] The effective porosity of a pre-experimental core, the water saturation of the pre-experimental core, a formation factor corresponding to the oil recovery environment, and a core resistance increase rate corresponding to the oil recovery environment are obtained.

[0021] The lithology first coefficient corresponding to the oil recovery environment and the cementation coefficient corresponding to the oil recovery environment are obtained by fitting the formation factor and the effective porosity of the pre-experimental core by using a power function.

[0022] The lithology second coefficient corresponding to the oil environment to be exploited and the saturation index corresponding to the oil environment to be exploited are obtained by fitting the core resistance increase rate and the pre-experiment core water saturation curve by a power function.

[0023] In a possible implementation, the drawing of the comprehensive imbibition recovery ratio curve by using the multiple static imbibition recovery ratios and the multiple second dynamic imbibition recovery ratios comprises:

[0024] The static imbibition recovery ratio and the second dynamic imbibition recovery ratio corresponding to the same imbibition pressure are weighted and summed to obtain multiple comprehensive imbibition recovery ratios.

[0025] The comprehensive imbibition recovery ratio curve is drawn based on the multiple comprehensive imbibition recovery ratios.

[0026] In a second aspect, the present application further provides a volatile oil reservoir imbibition oil extraction device, the device comprising:

[0027] An acquisition module is configured to acquire experimental parameters for an imbibition experiment, the experimental parameters comprising relevant parameters corresponding to an experimental core and relevant coefficients corresponding to an oil environment to be exploited;

[0028] A speed determination module is configured to perform multiple first dynamic imbibition experiments on the experimental core by using the experimental parameters to determine an optimal displacement speed, wherein the displacement speeds corresponding to different first dynamic imbibition experiments are different.

[0029] A static experiment module is configured to perform multiple static imbibition experiments on the experimental core by using the experimental parameters to obtain multiple static imbibition recovery ratio curves, wherein the imbibition pressures corresponding to different static imbibition experiments are different.

[0030] A dynamic experiment module is configured to perform multiple second dynamic imbibition experiments on the experimental core by using the experimental parameters to obtain multiple second dynamic imbibition recovery ratio curves, wherein the imbibition pressures corresponding to different second dynamic imbibition experiments are different, and the displacement speeds corresponding to different second dynamic imbibition experiments are the optimal displacement speed.

[0031] A drawing module is configured to draw a comprehensive imbibition recovery ratio curve by using multiple static imbibition recovery ratios and multiple second dynamic imbibition recovery ratios, wherein the multiple static imbibition recovery ratios are obtained from the multiple static imbibition recovery ratio curves, the static imbibition recovery ratio curves corresponding to different static imbibition recovery ratios are different, the multiple second dynamic imbibition recovery ratios are obtained from the multiple second dynamic imbibition recovery ratio curves, and the second dynamic imbibition recovery ratio curves corresponding to different second dynamic imbibition recovery ratios are different.

[0032] The pressure determining module is configured to determine an optimal imbibition pressure by using an inflection point of the comprehensive imbibition recovery curve.

[0033] The oil production module is configured to perform imbibition oil production by using the optimal displacement velocity and the optimal imbibition pressure.

[0034] In a possible implementation, the velocity determining module comprises:

[0035] The dynamic experiment unit is configured to perform the multiple first dynamic imbibition experiments on the experimental core by using the experimental parameters, and obtain multiple first dynamic imbibition recovery curves.

[0036] The velocity determining unit is configured to determine an optimal displacement velocity by using an inflection point of the multiple first dynamic imbibition recovery curves.

[0037] In a possible implementation, the drawing module comprises:

[0038] The summing unit is configured to perform weighted summation on the static imbibition recovery and the second dynamic imbibition recovery corresponding to the same imbibition pressure, and obtain multiple comprehensive imbibition recoveries.

[0039] The drawing unit is configured to draw the comprehensive imbibition recovery curve based on the multiple comprehensive imbibition recoveries.

[0040] In a third aspect, the present application further provides a computer device, comprising a memory and a processor.

[0041] The memory is configured to store a computer program.

[0042] The processor is configured to execute the computer program in the memory, so as to implement the method in the first aspect or any one of the first aspect.

[0043] In a fourth aspect, the present application further provides a computer readable storage medium, which stores instructions, and when the instructions are run on a computer, the computer executes the method in the first aspect or any one of the first aspect.

[0044] In the embodiment of the present application, the experimental parameters for the imbibition experiment are obtained; the experimental core is subjected to multiple first dynamic imbibition experiments by using the experimental parameters to determine the optimal displacement velocity; the experimental core is subjected to multiple static imbibition experiments by using the experimental parameters to obtain multiple static imbibition recovery curves; the experimental core is subjected to multiple second dynamic imbibition experiments by using the experimental parameters to obtain multiple second dynamic imbibition recovery curves; the comprehensive imbibition recovery curve is drawn by using the multiple static imbibition recoveries and the multiple second dynamic imbibition recoveries; the optimal imbibition pressure is determined by using the inflection point of the comprehensive imbibition recovery curve; and the imbibition oil recovery is performed by using the optimal displacement velocity and the optimal imbibition pressure. The embodiment of the present application comprehensively considers the influence of static imbibition and dynamic imbibition, and can make the obtained optimal displacement velocity and optimal imbibition pressure more accurate. The imbibition experiment is performed by using the correlation coefficient corresponding to the oil environment to be recovered, so that the obtained optimal displacement velocity and optimal imbibition pressure are more suitable for the oil environment to be recovered, and the imbibition oil recovery efficiency and the imbibition recovery rate in the actual imbibition oil recovery process can be improved. BRIEF DESCRIPTION OF DRAWINGS

[0045] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or the prior art description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0046] Figure 1 A flowchart of a volatile oil reservoir imbibition oil recovery method provided by an embodiment of the present application is shown;

[0047] Figure 2 A structural schematic diagram of an imbibition device provided by an embodiment of the present application is shown;

[0048] Figure 3 A relationship diagram between formation factors and porosity provided by an embodiment of the present application is shown;

[0049] Figure 4 A relationship diagram between water saturation and resistance increase rate provided by an embodiment of the present application is shown;

[0050] Figure 5 A dynamic imbibition recovery curve diagram under different displacement velocities provided by an embodiment of the present application is shown;

[0051] Figure 6 A change curve diagram of the final dynamic imbibition recovery under different displacement velocities provided by an embodiment of the present application is shown;

[0052] Figure 7 A comprehensive imbibition recovery curve diagram provided by an embodiment of the present application is shown;

[0053] Figure 8 A comparison diagram of experimental results of the embodiment provided by the present application and volumetric method is shown.

[0054] Figure 9 A structural diagram of a volatile oil reservoir imbibition oil production device provided by the embodiment of the present application is shown. DETAILED DESCRIPTION

[0055] To make the objectives, technical solutions, and superiorities of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described below in detail with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some, but not all of the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of the present application.

[0056] Carbonate rock oil and gas reservoirs are important oil and gas reservoirs that are currently concentratedly developed in the world, and their recoverable reserves account for more than half of the world's remaining recoverable reserves of oil and gas reservoirs, and are important fields for future oil and gas reserves and production increase. With the deepening of exploration and development of carbonate rock reservoirs, people have found a kind of reservoir fluid with high shrinkage characteristics. This kind of fluid exists in a liquid state under reservoir conditions, and its composition and thermodynamic properties are between ordinary black oil and condensate gas, and people call this kind of reservoir volatile oil reservoir. Volatile oil reservoirs have the characteristics of high volume factor, high oil compressibility, high original dissolved gas-oil ratio, high saturation pressure, high shrinkage rate, and low formation oil viscosity and density. The conventional development methods of volatile oil reservoirs include depletion development and water injection development. Due to the development of fractures in carbonate rock oil and gas reservoirs, although the injected water flows in the fractures, the complex fracture network structure is also a favorable place for imbibition. Therefore, fully utilizing the imbibition effect of the reservoir is of great significance for enhancing the recovery of volatile oil reservoirs.

[0057] The main driving force of imbibition comes from the capillary force in the matrix reservoir pores. Because the volatile oil reservoir fluid is sensitive to reservoir pressure, when the reservoir pressure is lower than the bubble point pressure, a large amount of dissolved gas in the oil is released, and oil, gas and water three-phase flow is formed in the reservoir, thereby weakening the contribution of capillary force to imbibition oil production. At the same time, the displacement speed is also a key factor affecting the imbibition oil production efficiency. Under a certain displacement speed, due to the joint action of capillary force and viscous force, the imbibition effect can be optimized. Therefore, determining the optimal imbibition pressure and optimal displacement speed is of great significance for utilizing imbibition to enhance the recovery of fractured volatile oil reservoirs.

[0058] At present, a large number of domestic and foreign researchers have studied the imbibition mechanism and production characteristics of fractured reservoirs and have made a lot of research results. However, the current methods for obtaining imbibition recovery often have some defects, resulting in inaccurate calculation of core imbibition recovery.

[0059] For example, the core imbibition recovery is calculated by weighing the weight change of the core at different time. Because the physical and chemical properties of the crude oil and the imbibition liquid are different, the imbibition can replace the crude oil in the core by the action of capillary force, but the experimental result accuracy is too low by simply calculating the core imbibition recovery through the mass difference of the core at different time.

[0060] For another example, the core spontaneous imbibition under the simulated formation condition is that the core is placed in the imbibition device simulating the formation condition. In order to prevent the crude oil imbibed from adhering to the inside of the container, the oil-repellent agent is coated in the container, but the experimental error caused by the fact that the oil droplets imbibed cannot separate from the core surface due to the adsorption of the core surface cannot be solved, which will lead to the result of the core imbibition recovery being low.

[0061] Because the volatile reservoir fluid property is greatly affected by the pressure, it is very important to determine the optimal displacement speed and the optimal imbibition pressure of the volatile reservoir to improve the imbibition recovery of the volatile reservoir, and a method is urgently needed to accurately measure the core imbibition recovery while determining the optimal imbibition pressure and the optimal displacement speed of the volatile reservoir.

[0062] Therefore, the embodiment of the present application provides a volatile reservoir imbibition oil production method, which can continuously and accurately measure the imbibition recovery, and obtain the optimal imbibition pressure and the optimal displacement speed, so as to improve the imbibition recovery of the volatile reservoir under the condition of the optimal imbibition pressure and the optimal displacement speed.

[0063] Please refer to Figure 1 , which shows the flow chart of the volatile reservoir imbibition oil production method provided by the embodiment of the present application, and the embodiment of the present application at least includes the following steps:

[0064] S11, obtaining experimental parameters for imbibition experiment.

[0065] The experimental parameters are used to calculate the imbibition recovery when the imbibition experiment is performed. In the embodiment of the present application, the experimental parameters can include the relevant parameters corresponding to the experimental core and the relevant coefficients corresponding to the oil production environment. The relevant parameters corresponding to the experimental core can include the effective porosity of the core and the dry core resistivity, and the relevant coefficients corresponding to the oil production environment can include the lithology first coefficient, the lithology second coefficient, the cementation coefficient and the saturation index. The lithology first coefficient, the lithology second coefficient, the cementation coefficient and the saturation index corresponding to different oil production environments are different. The oil production environment refers to the region and the layer position to be produced.

[0066] The core effective porosity is the core porosity of the experimental core, the dry core resistivity is the resistivity of the experimental core in a completely dry state, the lithology first coefficient and the lithology second coefficient are coefficients related to lithology, the cementation coefficient is a cementation coefficient related to the cementation condition and the pore structure of the rock, and the saturation index is a saturation index related to the distribution of oil, gas and water in the pores.

[0067] In one possible implementation of determining the correlation coefficient corresponding to the oil production environment, the following steps can be performed:

[0068] S111, obtaining the effective porosity of the pre-experimental core, the water saturation of the pre-experimental core, the formation factor corresponding to the oil production environment, and the core resistivity increase rate corresponding to the oil production environment.

[0069] In the embodiments of the present application, the formation factor corresponding to the oil production environment and the core resistivity increase rate corresponding to the oil production environment can be calculated by the following formula:

[0070]

[0071] In the formula, F represents the formation factor, R op represents the resistivity of the pre-experimental core in a 100% saturated formation water state, R wp represents the resistivity of the pre-experimental core in a bound water state, I represents the core resistivity increase rate, and R wtp represents the resistivity of the pre-experimental core in a formation water containing state at time t.

[0072] S112, fitting the formation factor and the effective porosity of the pre-experimental core by a power function to obtain the lithology first coefficient corresponding to the oil production environment and the cementation coefficient corresponding to the oil production environment.

[0073] The formation factor has another calculation method as follows: In the formula, a represents the lithology first coefficient, m represents the cementation coefficient, and φ p represents the effective porosity of the pre-experimental core.

[0074] Therefore, in the double logarithmic coordinates, the intersection graph of the formation factor and the effective porosity of the pre-experimental core can be drawn for multiple pre-experimental cores from the same oil production environment, and the lithology first coefficient and the cementation coefficient can be obtained by fitting the formation factor and the effective porosity of the pre-experimental core by a power function.

[0075] S113, fitting the core resistivity increase rate and the water saturation of the pre-experimental core by a power function to obtain the lithology second coefficient corresponding to the oil production environment and the saturation index corresponding to the oil production environment.

[0076] The core resistivity increase rate has another calculation method as follows: Wherein, b represents the lithology second coefficient, n represents the saturation index, S wtp represents the pre-experiment core water saturation at time t.

[0077] Therefore, in the double logarithmic coordinates, the core resistance increase rate and the pre-experiment core water saturation of multiple pre-experiment cores from the same oil production environment can be plotted, and the lithology second coefficient and the saturation index can be obtained by fitting the core resistance increase rate and the pre-experiment core water saturation curve through the power function.

[0078] The embodiments of the present application calculate the lithology first coefficient, the lithology second coefficient, the cementation coefficient and the saturation index corresponding to the to-be-oil-production environment by using multiple cores from the same area and the same layer through the pre-experiment, so that the subsequent imbibition experiment is more targeted, the experimental result is more in line with the actual oil production environment, and necessary parameters are provided for subsequent calculation of imbibition recovery.

[0079] S12, multiple first dynamic imbibition experiments are performed on the experimental core by using the experimental parameters to determine the optimal displacement velocity.

[0080] After obtaining the experimental parameters, the experimental imbibition pressure and the experimental displacement velocity are set to perform the first dynamic imbibition experiment. The displacement velocities corresponding to different first dynamic imbibition experiments are different, and the imbibition pressures corresponding to different first dynamic imbibition experiments are the same. The imbibition pressure for performing the first dynamic imbibition experiment can be the reservoir saturation pressure, or other set pressure values. That is, the embodiments of the present application perform dynamic imbibition experiments on the experimental core under different displacement velocities.

[0081] The reservoir saturation pressures corresponding to different oil production environments are different, and therefore, when the imbibition pressure of the first dynamic imbibition experiment is set, the reservoir saturation pressure corresponding to the to-be-oil-production environment needs to be obtained.

[0082] Wherein, one implementation of the multiple first dynamic imbibition experiments performed on the experimental core by using the experimental parameters to determine the optimal displacement velocity can include:

[0083] S121, multiple first dynamic imbibition experiments are performed on the experimental core by using the experimental parameters to obtain multiple first dynamic imbibition recovery curves.

[0084] The first dynamic imbibition recovery curves corresponding to different first dynamic imbibition experiments are different, for example, 8 experimental displacement velocities are set, and then 8 first dynamic imbibition experiments are performed to obtain 8 first dynamic imbibition recovery curves.

[0085] During the imbibition experiment, the oil saturation of the experimental core at each moment can be calculated by using the core resistivity at each moment, and then the imbibition recovery at each moment can be calculated by using the oil saturation of the experimental core at the initial moment and the oil saturation of the experimental core at each moment, and finally the imbibition recovery curve can be drawn by using the imbibition recovery at each moment.

[0086] Specifically, the relationship between the core resistivity and the oil saturation of the experimental core can be constructed according to the Archie formula and the core saturation conservation equation.

[0087] Archie formula:

[0088]

[0089] Core saturation conservation equation:

[0090] S ot +S wt =1;

[0091] The relationship between the core resistivity and the oil saturation of the experimental core can be obtained by combining the Archie formula and the core saturation conservation equation.

[0092]

[0093] The formula for calculating the imbibition recovery of the experimental core at different moments by using the oil saturation of the experimental core at the initial moment and the oil saturation of the experimental core at different moments is as follows:

[0094]

[0095] Wherein, R o is the core resistivity of the experimental core in the state of 100% saturated formation water, the unit is Ω·m, R wt is the core resistivity of the experimental core in the state of containing formation water at t moment, R d is the dry core resistivity, φ is the effective porosity of the experimental core, S wt is the water saturation of the experimental core at t moment, S ot is the oil saturation of the experimental core at t moment, η is the imbibition recovery, and S oti is the oil saturation of the experimental core at the initial moment. The initial moment refers to the starting moment of the imbibition experiment of the experimental core.

[0096] S122, determining the optimal displacement speed by using the inflection points of the plurality of first dynamic imbibition recovery curves.

[0097] The imbibition recovery will continue to increase with the growth of time. In the embodiments of the present application, the inflection point of the imbibition recovery curve can be understood as the turning point of the change of the imbibition recovery rate, for example, the inflection point of the imbibition recovery curve can be the point at which the imbibition recovery rate begins to slow down.

[0098] In order to determine the optimal displacement speed, it is necessary to determine the optimal first dynamic imbibition recovery curve. The first dynamic imbibition recovery rate corresponding to the inflection point of the optimal first dynamic imbibition recovery curve is higher than the first dynamic imbibition recovery rate corresponding to the inflection point of other first dynamic imbibition recovery curves, and the other first dynamic imbibition recovery curves are the first dynamic imbibition recovery curves other than the optimal first dynamic imbibition recovery curve in the plurality of first dynamic imbibition recovery curves.

[0099] Since the first dynamic imbibition recovery rate corresponding to the inflection point of the optimal first dynamic imbibition recovery curve is higher than the first dynamic imbibition recovery rate corresponding to the inflection point of other first dynamic imbibition recovery curves, the displacement speed corresponding to the optimal first dynamic imbibition recovery curve is determined as the optimal displacement speed.

[0100] The embodiment of the present application can determine the optimal displacement speed by using a plurality of different displacement speeds to perform dynamic imbibition experiments, which is a result driven by data without being affected by subjective factors, and can improve the efficiency of imbibition oil recovery.

[0101] S13, performing a plurality of static imbibition experiments on the experimental core by using the experimental parameters to obtain a plurality of static imbibition recovery curves.

[0102] After obtaining the experimental parameters, the experimental imbibition pressure is set to perform the static imbibition experiment. Different static imbibition experiments correspond to different imbibition pressures, that is, the embodiment of the present application performs static imbibition experiments on the experimental core under different imbibition pressures. It can be understood that each static imbibition recovery curve corresponds to an imbibition pressure.

[0103] The order of S12 and S13 is not limited in the embodiment of the present application. The plurality of static imbibition experiments on the experimental core by using the experimental parameters can be performed before the plurality of first dynamic imbibition experiments on the experimental core by using the experimental parameters; or the plurality of static imbibition experiments on the experimental core by using the experimental parameters can be performed after the plurality of first dynamic imbibition experiments on the experimental core by using the experimental parameters; or the plurality of first dynamic imbibition experiments on the experimental core by using the experimental parameters and the plurality of static imbibition experiments on the experimental core by using the experimental parameters can be performed at the same time.

[0104] S14, performing a plurality of second dynamic imbibition experiments on the experimental core by using the experimental parameters to obtain a plurality of second dynamic imbibition recovery curves.

[0105] After the optimal displacement speed is obtained, the experimental displacement speed and the experimental imbibition pressure are set to perform a second dynamic imbibition experiment. Different second dynamic imbibition experiments correspond to different imbibition pressures, and different second dynamic imbibition experiments correspond to the same displacement speed. The displacement speed for performing the second dynamic imbibition experiment is the optimal displacement speed. That is, the embodiments of the present application perform dynamic imbibition experiments on the experimental core under different imbibition pressures.

[0106] S15, drawing a comprehensive imbibition recovery curve by using the plurality of static imbibition recoveries and the plurality of second dynamic imbibition recoveries.

[0107] In the entire imbibition process, not only is there static imbibition mainly acting on capillary force, but also is there dynamic imbibition under the joint action of capillary force and displacement pressure difference, so it is a coupled action for imbibition, and the comprehensive imbibition recovery needs to be calculated by using the static imbibition recovery and the dynamic imbibition recovery.

[0108] The plurality of static imbibition recoveries are obtained from a plurality of static imbibition recovery curves, and different static imbibition recoveries correspond to different static imbibition recovery curves. The plurality of second dynamic imbibition recoveries are obtained from a plurality of second dynamic imbibition recovery curves, and different second dynamic imbibition recoveries correspond to different second dynamic imbibition recovery curves. The embodiments of the present application obtain one static imbibition recovery from each static imbibition recovery curve and obtain one second dynamic imbibition recovery from each second dynamic imbibition recovery curve.

[0109] Specifically, a plurality of static imbibition recoveries corresponding to a preset time can be obtained from a plurality of static imbibition recovery curves, and a plurality of second dynamic imbibition recoveries corresponding to the preset time can be obtained from a plurality of second dynamic imbibition recovery curves, or a plurality of static imbibition recoveries corresponding to a preset pore volume (PV) can be obtained from a plurality of static imbibition recovery curves, and a plurality of second dynamic imbibition recoveries corresponding to the preset PV can be obtained from a plurality of second dynamic imbibition recovery curves.

[0110] One implementation of drawing a comprehensive imbibition recovery curve by using the plurality of static imbibition recoveries and the plurality of dynamic imbibition recoveries can include:

[0111] S151, performing weighted summation on the static imbibition recovery and the second dynamic imbibition recovery corresponding to the same imbibition pressure to obtain a plurality of comprehensive imbibition recoveries.

[0112] The plurality of static imbibition recoveries come from different imbibition pressures, and the plurality of second dynamic imbibition recoveries also come from different imbibition pressures, so performing weighted summation on the static imbibition recovery and the second dynamic imbibition recovery corresponding to the same imbibition pressure can obtain the plurality of comprehensive imbibition recoveries. Different comprehensive imbibition recoveries correspond to different imbibition pressures.

[0113] The formula of the weighted sum is:

[0114] η c = f s η s + f d η d ;

[0115] wherein η c represents the comprehensive imbibition recovery rate, η s represents the static imbibition recovery rate, η d represents the second dynamic imbibition recovery rate, f s represents the weight corresponding to the static imbibition recovery rate, f d represents the weight corresponding to the second dynamic imbibition recovery rate, f s + f d = 1.

[0116] The CRITIC weight method can be used to determine the weight corresponding to the static imbibition recovery rate and the weight corresponding to the second dynamic imbibition recovery rate in the embodiments of the present application.

[0117] S152, a comprehensive imbibition recovery rate curve is drawn based on the plurality of comprehensive imbibition recovery rates.

[0118] After the plurality of comprehensive imbibition recovery rates are obtained, the imbibition pressure is taken as the abscissa and the imbibition recovery rate is taken as the ordinate to draw the comprehensive imbibition recovery rate curve.

[0119] The comprehensive imbibition recovery rate is obtained by using the weighted sum in the embodiments of the present application, which can fully consider the importance of the static imbibition recovery rate and the second dynamic imbibition recovery rate, so that the obtained comprehensive imbibition recovery rate is more accurate.

[0120] S16, the inflection point of the comprehensive imbibition recovery rate curve is used to determine the optimal imbibition pressure.

[0121] In the embodiments of the present application, the pressure corresponding to the inflection point of the comprehensive imbibition recovery rate curve is the optimal imbibition pressure.

[0122] S17, imbibition oil recovery is performed by using the optimal displacement speed and the optimal imbibition pressure.

[0123] After the optimal displacement speed and the optimal imbibition pressure are obtained, the volatile oil reservoir can be imbibed and recovered according to the optimal displacement speed and the optimal imbibition pressure.

[0124] In the embodiment of the present application, the experimental parameters for the imbibition experiment are obtained; the experimental core is subjected to multiple first dynamic imbibition experiments by using the experimental parameters to determine the optimal displacement velocity; the experimental core is subjected to multiple static imbibition experiments by using the experimental parameters to obtain multiple static imbibition recovery curves; the experimental core is subjected to multiple second dynamic imbibition experiments by using the experimental parameters to obtain multiple second dynamic imbibition recovery curves; the comprehensive imbibition recovery curve is drawn by using the multiple static imbibition recoveries and the multiple second dynamic imbibition recoveries; the optimal imbibition pressure is determined by using the inflection point of the comprehensive imbibition recovery curve; and the imbibition oil recovery is performed by using the optimal displacement velocity and the optimal imbibition pressure. The embodiment of the present application comprehensively considers the influences of static imbibition and dynamic imbibition, and can make the obtained optimal displacement velocity and optimal imbibition pressure more accurate. The imbibition experiment is performed by using the correlation coefficient corresponding to the oil environment to be recovered, so that the obtained optimal displacement velocity and optimal imbibition pressure are more suitable for the oil environment to be recovered, the imbibition oil recovery efficiency can be improved, the imbibition recovery in the actual imbibition oil recovery process can be improved, the exploitation cost of the volatile oil reservoir can be reduced, and guidance for improving the actual oil recovery in the mine field is provided.

[0125] In order to accurately measure the imbibition recovery in the imbibition experiment process, the embodiment of the present application provides an imbibition device, as shown in the figure, Figure 2 The imbibition device includes an injection pump 6, an intermediate container 4, a resistivity instrument 11, a special core holder 14, a constant temperature box 20, a confining pressure pump 18, an oil-water meter 27 and a control system 1. The lower end of the intermediate container 4 is connected with the injection pump 6 through a two-way valve 5, and the upper end of the intermediate container 4 is connected with the inlet end of the special core holder 14 through a six-way 3, a two-way valve 9 and a three-way 10, wherein the six-way 3 is provided with a pressure sensor 2, and the three-way 10 is provided with a pressure sensor 8; the inside of the special core holder 14 is provided with a core, and the core is placed in a rubber sleeve 13, the rubber sleeve 13 is pressurized by the confining pressure pump 18 to tightly hold the core, so as to simulate the stress state of the rock in the real reservoir; the left and right ends of the inside of the special core holder 14 are both provided with copper sheets, the left copper sheet 12 and the right copper sheet 19 are connected with the resistivity instrument 11 to measure the core resistivity at different times; the first outlet end of the special core holder 14 is connected with the hand pump 18 through the two-way valve 15 and the three-way 16, the three-way 16 is provided with a pressure sensor 17 to simulate the formation confining pressure; the second outlet end of the special core holder 14 is connected with the back pressure pump 23 through the two-way valve 21, the three-way 26, the two-way valve 25 and the three-way 24, to control the pressure of the second outlet end, the back pressure valve 26 is also connected with the oil-water meter 27, and the three-way 24 is provided with a pressure sensor 22; the control system 1 can monitor the data of each pressure sensor, inverses the core oil saturation by the core resistivity value, and finally calculates the core imbibition recovery by the change of the oil saturation.

[0126] The injection pump 6 can be a constant-speed constant-pressure pump, which is connected with the control system 1 through a data acquisition card, and the control system 1 can also dynamically control the injection speed and injection pressure and other parameters of the constant-speed constant-pressure pump through the data acquisition card. In the embodiment of the application, the measurement accuracy of the constant-speed constant-pressure pump is not less than 0.0001 milliliter per minute (ml / min), and the continuous measurement time is not less than 48 hours (h).

[0127] The intermediate container 4 and the special core holder 14 are placed in the thermostat 20, and the temperature of the thermostat 20 can be set to the actual reservoir temperature during the imbibition experiment.

[0128] The experimental core for the imbibition experiment can be a man-made core or a natural core. The size of the core varies according to the specifications of the special core holder 14, and in the embodiment of the application, the length of the core can be 5 centimeters (cm) and the diameter can be 2.5 cm.

[0129] The maximum working pressure of the special core holder 14 can be 60 megapascals (MPa), the maximum temperature resistance can be 120 DEG C, and the material can be stainless steel, specifically 316L.

[0130] The conventional methods for calculating the imbibition recovery rate, such as the mass method and the volume method, are to read the values of the measuring device (such as the imbibition bottle, the measuring cylinder, etc.) by the naked eye of the experimenter, so as to calculate the dynamic imbibition recovery rate, and the experimental accuracy is not high and the error is large. The special core holder of the embodiment of the application can record the core resistivity values of the experimental core at different times in real time, inversely calculate the change of the oil saturation of the core according to the formula of the core resistivity and the oil saturation, and finally accurately calculate the imbibition recovery rate of the core, which to some extent overcomes the error caused by the volume method and the mass method for calculating the imbibition recovery rate of the core.

[0131] The embodiment of the application proposes a comprehensive imbibition recovery rate curve, fully considers the coupling effect of static imbibition and dynamic imbibition, determines the weight corresponding to the static / dynamic imbibition recovery rate through a CRITIC weight method which objectively weights the index, and comprehensively determines the imbibition pressure. Compared with the conventional method of directly determining the optimal imbibition pressure by the dynamic imbibition result, the method of the embodiment of the application overcomes the influence of human subjective factors and makes the result more accurate.

[0132] In order to facilitate further understanding of the technical solutions provided by the embodiments of the application, the imbibition oil production method provided by the embodiments of the application is taken as an example applied to a real scene, and the imbibition oil production method provided by the embodiments of the application is exemplarily introduced as a whole.

[0133] S1, preparing an experimental core.

[0134] The experimental core of the embodiments of the present application is a natural core, which is cut into a standard core with a diameter of 2.5 cm and a length of 5 cm, and the standard core is subjected to oil washing treatment.

[0135] S2, core physical parameter testing.

[0136] The experimental core is cut along the center line in the 60° direction to form a non-penetrating fracture, the core porosity is measured by using a porosity measuring instrument, and the core permeability is measured by using a permeability measuring instrument. Through testing, the core porosity is 17.4%, and the core permeability is 8.6 millidarcy (mD).

[0137] S3, configuration of experimental environment.

[0138] The simulated formation water is configured according to the ion composition of the water quality of a certain block of an oilfield in the Middle East, and the simulated oil is prepared according to the phase state characteristics of a certain block of an oilfield in Dagang according to the volatile oil and kerosene of the block.

[0139] The experimental core is saturated with simulated formation water by vacuumizing for 24 hours (h), and the core saturated water amount is calculated by weighing the difference between the core mass before and after saturation with water; the experimental core is placed in a special core holder to saturate oil at a saturation speed of 0.1 mL / min until no water is discharged from the experimental core, and the water discharge amount of the core is recorded as the core saturated oil amount; and the wettability of the experimental rock is recovered by aging for 24 h at the reservoir temperature.

[0140] The experimental crude oil is placed in an intermediate container 4, the intermediate container 4 is placed in a thermostat 20, and the temperature of the thermostat 20 is set to the reservoir temperature. The core is placed in a special core holder 14, and the pressure of a back pressure pump 23 is set to 20 MPa (bubble point pressure), and the pressure of a confining pressure pump 18 is set to 22 MPa. The pressure of the confining pressure pump 18 can be dynamically adjusted, but the pressure of the confining pressure pump 18 needs to be higher than the injection pressure by 2 MPa.

[0141] S4, calculation of lithology first coefficient, cementation coefficient, lithology second coefficient and saturation index.

[0142] Fitting of lithology first coefficient a and cementation coefficient m: in a double logarithmic coordinate, a cross plot of formation factor F and porosity φ of multiple cores from the same region and the same layer is drawn. By combining the formula for calculating the formation factor F, the formation factor F and the porosity φ curve are fitted by a power function, and a and m are calculated. As shown in Figure 3 a is 1.1573, and m is 1.684.

[0143] Fitting of lithology second parameter b and saturation index n: in a double logarithmic coordinate, a cross plot of core resistance increase rate I and core water saturation S wThe cross plot of the core resistivity increase rate I and the core water saturation S is shown in Fig. 1. In combination with the formula for calculating the core resistivity increase rate I, the core resistivity increase rate I and the core water saturation S are fitted by a power function to obtain b and n. w The curve is shown in Fig. 2. b is 1.67 and n is 1.569. Figure 4

[0144] S5, determining the static imbibition weight and the dynamic imbibition weight.

[0145] The idea of the CRITIC weight method is that two indexes, namely, the contrast intensity and the conflict index. The contrast intensity is represented by the standard deviation. If the data standard deviation is larger, the fluctuation is larger, and the weight is higher. The conflict is represented by the correlation coefficient. If the correlation coefficient between indexes is larger, the conflict is smaller, and the weight is lower.

[0146] In order to determine the static imbibition weight and the dynamic imbibition weight, five cores are selected to perform the static imbibition experiment and the dynamic imbibition experiment, respectively. The dynamic imbibition recovery and the static imbibition recovery of the cores are recorded, and the results are shown in Table 1.

[0147] Table 1

[0148] Core label Static imbibition recovery / % Dynamic imbibition recovery / % 1 20 40 2 22 43 3 18 36 4 21 39 5 25 44

[0149] Step one: constructing an original index coefficient matrix X:

[0150]

[0151] In the application embodiment, M is 5, N is 2.

[0152] Step two: quantitative dimensionless normalization (positive index):

[0153]

[0154] In the application embodiment, M is 5, N is 2. ij The original experimental data are represented by x ij The normalized data are represented by y ij i represents the experimental group number, i = 1, 2,..., M, and j represents the evaluation index, j = 1, 2,..., N.

[0155] Step three: calculating the index variability:

[0156]

[0157] In the application embodiment, M is 5, N is 2. ij r

[0158] Step four: calculating the index fluctuation:

[0159]

[0160] wherein S j denotes the standard deviation of the jth indicator, denotes the average value of the indicator j of all experiments.

[0161] Step five: calculate the information carrying capacity C j :

[0162] C j The greater the jth evaluation indicator in the whole evaluation index system, the greater the weight should be allocated to it.

[0163] C j = S j · R j .

[0164] Step six: calculate the weight coefficient W of the jth indicator j :

[0165]

[0166] The calculation results are shown in Table 2.

[0167] Table 2

[0168] Indicator variability Indicator volatility Information carrying capacity Weight Static imbibition 2.588 0.079 0.205 44.65％ Dynamic imbibition 3.209 0.079 0.254 55.35％

[0169] As can be seen from Table 2, the weight corresponding to the static imbibition recovery rate is 0.4465, and the weight corresponding to the dynamic imbibition recovery rate is 0.5535.

[0170] S6, static imbibition experiment and dynamic imbibition experiment are carried out.

[0171] Static imbibition experiment:

[0172] Close the outlet end valve, set the experimental imbibition pressure, close the inlet end valve after the pressure reaches the set value, and start the static imbibition experiment. Real-time record the change of core resistivity at different times, when the core resistivity value is constant, end the experiment, open the outlet end valve and record the oil output. Finally, the static imbibition recovery rate is calculated by using the relationship between core resistivity and oil saturation, and the core static imbibition recovery rate is calculated by combining the saturated oil volume of the core with the experimental oil output.

[0173] The static imbibition recovery rate is calculated by using the relationship between core resistivity and oil saturation, and the core static imbibition recovery rate is calculated by combining the saturated oil volume of the core with the experimental oil output, in order to compare the static imbibition recovery rates calculated twice, and highlight the accuracy of the static imbibition recovery rate calculated by using core resistivity inversion.

[0174] Dynamic imbibition experiment:

[0175] The experimental displacement velocity and the experimental imbibition pressure are set, the dynamic imbibition experiment is started, the content of the crude oil in the oil-water meter at different time is recorded in real time, when the volume of the crude oil is no longer increased and the core resistivity is no longer changed, the pump is stopped and the valve at the inlet end of the special core holder is closed. Finally, the core dynamic imbibition recovery rate is calculated by using the relationship between the core resistivity and the oil saturation, and the core dynamic imbibition recovery rate is calculated by combining the saturated oil amount of the core and the experimental oil output.

[0176] Firstly, the dynamic imbibition experiment of the experimental core at the reservoir temperature (90℃) under different displacement velocities is performed, the optimal dynamic imbibition displacement velocity is determined, and the experimental results are as shown in Figure 5 The final imbibition recovery rates under different displacement velocities are compared, as shown in Table 3. Figure 5 The experimental data in Table 3 and Figure 6 It can be seen from the change curve of the final imbibition recovery rate under different displacement velocities provided in the embodiments of the present application that the final imbibition recovery rate is the highest when the displacement velocity is 0.50 ml / min.

[0177] It can be seen that the imbibition recovery rate reaches the maximum when the curve reaches the inflection point at the displacement velocity of 0.50 ml / min. This is because the dynamic imbibition effect is the result of the joint action of capillary force and viscous force. When the displacement velocity is small, the oil imbibed is not taken out in time, resulting in poor imbibition effect; when the displacement velocity is large, the water in the fracture is directly displaced without interpenetrating flow with the crude oil in the matrix under the action of capillary force, resulting in poor imbibition effect. Therefore, the optimal dynamic imbibition displacement velocity in this experiment should be 0.50 ml / min, and the subsequent experiments can be performed at this speed.

[0178] Table 3

[0179] Displacement velocity / ml / min Imbibition recovery / % 0.05 26.29 0.2 35.18 0.5 42.19 2 40.67

[0180] Secondly, the static / dynamic imbibition experiment of the experimental core at the reservoir temperature (90℃) under different imbibition pressure conditions is performed, and Table 4 is the static / dynamic imbibition experimental data of the experimental core under different imbibition pressures.

[0181] Table 4

[0182] Pressure / MPa Static imbibition recovery / % Dynamic imbibition recovery / % 5 4.2 11.2 10 6.8 15.8 15 9.6 21.3 20 14.2 28.6 25 16.1 31.8 30 17.4 33.5 35 18.1 34.8 40 18.3 35.1

[0183] The static and dynamic imbibition experimental results of the experimental core under different imbibition pressures are combined, the static imbibition weight and the dynamic imbibition weight are brought into the weighted summation formula, the comprehensive imbibition recovery rate curve is calculated and drawn, and the results are as shown in Figure 7 ​Figure 7 The static imbibition recovery curve, the dynamic imbibition recovery curve and the comprehensive imbibition recovery curve of the experimental core under different pressures are obtained.

[0184] The inflection point of the comprehensive imbibition recovery curve is determined, and the imbibition pressure is 35 MPa. Figure 7 It can be seen that when the imbibition pressure reaches 35 MPa, the imbibition recovery rate increases slowly with the increase of the pressure, and the pressure can be determined as the optimal imbibition pressure.

[0185] Finally, the optimal displacement speed is determined by the inflection point of the dynamic imbibition recovery curve of the experimental core under different displacement speeds, which is 0.5 ml / min; and the optimal imbibition pressure is determined by the inflection point of the comprehensive imbibition recovery curve, which is 35 MPa.

[0186] It should be noted that the imbibition recovery rate of the embodiments of the present application is obtained by inversion of the relationship between core resistivity and core oil saturation, which is not affected by subjective factors and is only data driven.

[0187] The current common process of obtaining imbibition recovery rate by volume method is that the experimental personnel manually measures the oil and water volume in the measuring device at the outlet end of the experimental device to calculate the imbibition recovery rate. In order to compare the difference between the two volume methods and the method provided in the embodiments of the present application in calculating the imbibition recovery rate, the embodiments of the present application compare the dynamic imbibition recovery curves obtained by the two different methods under two different flow rates, and the experimental results are shown in Figure 8 It can be seen from the experimental results that the measured value and the inverted value have little difference, but the measured value is obviously smaller than the inverted value. According to the analysis, the reasons may be as follows: there is an error in reading the data by the experimental personnel, and the read data value may be smaller; after the core imbibition is completed, the oil displaced by imbibition is adhered in the pipeline, resulting in a smaller measured result. Compared with manual measurement, the change of core oil saturation can be inverted by real-time measurement of core resistivity, which is a continuous process, while manual measurement can only measure the core recovery rate at a certain point, which is a discontinuous process, and the experimental error is larger. In summary, the change of core oil saturation is inverted by the change of core resistivity, and the imbibition recovery rate is finally calculated, and the experimental results are more accurate.

[0188] Next, a volatile oil reservoir imbibition oil recovery device provided by the present application is introduced. The volatile oil reservoir imbibition oil recovery device introduced below can be correspondingly referred to the volatile oil reservoir imbibition oil recovery method introduced above.

[0189] Please refer to Figure 9 , which shows the structure schematic diagram of a volatile oil reservoir imbibition oil recovery device provided by the present application, the device comprises:

[0190] The acquisition module 901 is configured to acquire experimental parameters for a wicking experiment, the experimental parameters comprising relevant parameters corresponding to an experimental core and a relevant coefficient corresponding to an oil production environment;

[0191] The speed determination module 902 is configured to perform a plurality of first dynamic wicking experiments on the experimental core by using the experimental parameters, to determine an optimal displacement speed, different first dynamic wicking experiments corresponding to different displacement speeds;

[0192] The static experiment module 903 is configured to perform a plurality of static wicking experiments on the experimental core by using the experimental parameters, to obtain a plurality of static wicking recovery curves, different static wicking experiments corresponding to different wicking pressures;

[0193] The dynamic experiment module 904 is configured to perform a plurality of second dynamic wicking experiments on the experimental core by using the experimental parameters, to obtain a plurality of second dynamic wicking recovery curves, different second dynamic wicking experiments corresponding to different wicking pressures, and different second dynamic wicking experiments corresponding to the optimal displacement speed;

[0194] The drawing module 905 is configured to draw a comprehensive wicking recovery curve by using a plurality of static wicking recoveries and a plurality of second dynamic wicking recoveries, the plurality of static wicking recoveries being obtained from the plurality of static wicking recovery curves, different static wicking recoveries corresponding to different static wicking recovery curves, and the plurality of second dynamic wicking recoveries being obtained from the plurality of second dynamic wicking recovery curves, different second dynamic wicking recoveries corresponding to different second dynamic wicking recovery curves;

[0195] The pressure determination module 906 is configured to determine an optimal wicking pressure by using an inflection point of the comprehensive wicking recovery curve;

[0196] The oil production module 907 is configured to perform wicking oil production by using the optimal displacement speed and the optimal wicking pressure.

[0197] In an embodiment of the present application, the speed determination module 902 comprises:

[0198] The dynamic experiment unit is configured to perform the plurality of first dynamic wicking experiments on the experimental core by using the experimental parameters, to obtain a plurality of first dynamic wicking recovery curves;

[0199] The speed determination unit is configured to determine the optimal displacement speed by using an inflection point of the plurality of first dynamic wicking recovery curves.

[0200] In an embodiment of the present application, the speed determination unit is specifically configured to:

[0201] determining an optimal first dynamic imbibition recovery curve, an inflection point of the optimal first dynamic imbibition recovery curve corresponding to a first dynamic imbibition recovery higher than first dynamic imbibition recoveries corresponding to inflection points of other first dynamic imbibition recovery curves, the other first dynamic imbibition recovery curves being first dynamic imbibition recovery curves other than the optimal first dynamic imbibition recovery curve among the plurality of first dynamic imbibition recovery curves;

[0202] determining the optimal first dynamic imbibition recovery curve corresponding to the optimal displacement velocity as the optimal displacement velocity.

[0203] In the embodiment of the present application, the obtaining module 901 comprises:

[0204] The obtaining unit is configured to obtain a pre-experimental core effective porosity, a pre-experimental core water saturation, a formation factor corresponding to the oil environment to be extracted, and a core resistance increase rate corresponding to the oil environment to be extracted.

[0205] The first fitting unit is configured to fit the formation factor and the pre-experimental core effective porosity curve by a power function to obtain a lithology first coefficient corresponding to the oil environment to be extracted and a cementation coefficient corresponding to the oil environment to be extracted.

[0206] The second fitting unit is configured to fit the core resistance increase rate and the pre-experimental core water saturation curve by a power function to obtain a lithology second coefficient corresponding to the oil environment to be extracted and a saturation index corresponding to the oil environment to be extracted.

[0207] In the embodiment of the present application, the drawing module 905 comprises:

[0208] The summing unit is configured to perform weighted summation on the static imbibition recovery and the second dynamic imbibition recovery corresponding to the same imbibition pressure to obtain a plurality of comprehensive imbibition recoveries.

[0209] The drawing unit is configured to draw the comprehensive imbibition recovery curve based on the plurality of comprehensive imbibition recoveries.

[0210] The embodiment of the present application also provides a computer device, comprising a memory and a processor.

[0211] The memory is configured to store a computer program.

[0212] The processor is configured to execute the computer program in the memory to implement the method in the above method embodiment.

[0213] The embodiment of the present application also provides a computer readable storage medium storing instructions, when the instructions are run on a computer, the computer executes the method in the above method embodiment.

[0214] In the embodiment of the present application, the acquisition module acquires experimental parameters for conducting the imbibition experiment; the speed determination module determines the optimal displacement speed by conducting multiple first dynamic imbibition experiments on the experimental core using the experimental parameters; the static experiment module obtains multiple static imbibition recovery curves by conducting multiple static imbibition experiments on the experimental core using the experimental parameters; the dynamic experiment module obtains multiple second dynamic imbibition recovery curves by conducting multiple second dynamic imbibition experiments on the experimental core using the experimental parameters; the drawing module draws a comprehensive imbibition recovery curve using the multiple static imbibition recoveries and the multiple second dynamic imbibition recoveries; the pressure determination module determines the optimal imbibition pressure using the inflection point of the comprehensive imbibition recovery curve; and the oil production module conducts imbibition oil production using the optimal displacement speed and the optimal imbibition pressure. The embodiment of the present application can accurately calculate the imbibition recovery by using the imbibition experiment, and comprehensively considers the influence of static imbibition and dynamic imbibition, so that the experimental result is more accurate. The optimal displacement speed and the optimal imbibition pressure obtained by using the correlation coefficient corresponding to the oil production environment make the imbibition oil production more suitable for the oil production environment, which can improve the imbibition oil production efficiency and the imbibition recovery in the actual imbibition oil production process.

[0215] It should be noted that the same or similar parts between the embodiments can be referred to each other. For the device embodiments and system embodiments, since they are basically similar to the method embodiments, the description is relatively simple, and the relevant parts can be referred to the part of the method embodiments.

[0216] For the foregoing embodiments, in order to simply describe, they are all expressed as a series of action combinations, but those skilled in the art should know that the present application is not limited to the action sequence described, because according to the present application, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should know that the embodiments described in the specification all belong to preferred embodiments, and the actions and modules involved are not necessarily required by the present application.

[0217] Finally, it should be noted that in this document, relationship terms such as first and second are used only to distinguish one entity or operation from another, and do not necessarily require or imply that there is any such actual relationship or order between these entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or equipment. Without more limitations, the element defined by the statement "including a" does not exclude the presence of another identical element in the process, method, article or equipment including the element.

[0218] The above description of disclosed embodiments enables one of ordinary skill in the art to make or use the application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

[0219] The above description is merely illustrative of the preferred embodiments of the present application and various modifications and improvements will readily occur to those skilled in the art. Such modifications and improvements are intended to fall within the scope of the present application.

Claims

1. A method for oil recovery through seepage from volatile oil reservoirs, characterized in that, The method includes: The experimental parameters for the permeation experiment are obtained, including relevant parameters corresponding to the experimental core and correlation coefficients corresponding to the oil recovery environment. The experimental parameters are used to conduct multiple first dynamic adsorption experiments on the experimental core to determine the optimal displacement rate. Different first dynamic adsorption experiments correspond to different displacement rates. The process of conducting multiple first dynamic adsorption experiments on the experimental core using the experimental parameters to determine the optimal displacement rate includes: conducting the multiple first dynamic adsorption experiments on the experimental core using the experimental parameters to obtain multiple first dynamic adsorption recovery curves; and using the inflection points of the multiple first dynamic adsorption recovery curves to determine the optimal displacement rate. Multiple static seepage experiments were conducted on the experimental core using the experimental parameters, resulting in multiple static seepage recovery curves. The seepage pressures corresponding to the different static seepage experiments were different. Using the experimental parameters, multiple second dynamic permeation experiments were conducted on the experimental core to obtain multiple second dynamic permeation recovery curves. The permeation pressures corresponding to different second dynamic permeation experiments were different, and the displacement velocities corresponding to different second dynamic permeation experiments were the optimal displacement velocities. A composite oil recovery curve is plotted using multiple static oil recovery rates and multiple second dynamic oil recovery rates. The multiple static oil recovery rates are obtained from the multiple static oil recovery rate curves, and different static oil recovery rates correspond to different static oil recovery rate curves. The multiple second dynamic oil recovery rates are obtained from the multiple second dynamic oil recovery rates, and different second dynamic oil recovery rates correspond to different second dynamic oil recovery rate curves. The optimal adsorption pressure is determined by using the inflection point of the comprehensive adsorption recovery curve. Oil recovery is carried out using the optimal displacement rate and the optimal percolation pressure.

2. The method according to claim 1, characterized in that, The determination of the optimal displacement rate using the inflection points of the plurality of first dynamic adsorption recovery curves includes: Determine the optimal first dynamic seepage recovery rate curve, wherein the first dynamic seepage recovery rate corresponding to the inflection point of the optimal first dynamic seepage recovery rate curve is higher than the first dynamic seepage recovery rate corresponding to the inflection point of other first dynamic seepage recovery rate curves, wherein the other first dynamic seepage recovery rate curves are the first dynamic seepage recovery rate curves other than the optimal first dynamic seepage recovery rate curve among the plurality of first dynamic seepage recovery rate curves. The displacement velocity corresponding to the optimal first dynamic seepage recovery curve is determined as the optimal displacement velocity.

3. The method according to claim 1 or 2, characterized in that, Determining the correlation coefficient corresponding to the oil recovery environment includes: The effective porosity of the pre-experimental core, the water saturation of the pre-experimental core, the formation factors corresponding to the oil-producing environment, and the core resistivity increase rate corresponding to the oil-producing environment were obtained. By fitting the formation factors and the effective porosity curve of the pre-experimental core with a power function, the first lithology coefficient and the cementation coefficient corresponding to the oil-producing environment are obtained. By fitting the core resistivity increase rate and the water saturation curve of the pre-experimental core with a power function, the second lithology coefficient and the saturation index corresponding to the oil-producing environment are obtained.

4. The method according to claim 1 or 2, characterized in that, The method of plotting a composite oil recovery curve using multiple static oil recovery rates and multiple second dynamic oil recovery rates includes: By weighted summing of the static and dynamic seepage recovery rates corresponding to the same seepage pressure, multiple comprehensive seepage recovery rates are obtained. The integrated oil recovery rate curve is plotted based on the multiple integrated oil recovery rates.

5. A volatile oil reservoir seepage recovery device, characterized in that, The device includes: The acquisition module is used to acquire the experimental parameters for the permeation experiment, including the relevant parameters corresponding to the experimental core and the correlation coefficients corresponding to the oil recovery environment. The velocity determination module is used to conduct multiple first dynamic percolation experiments on the experimental core using the experimental parameters to determine the optimal displacement velocity. Different displacement velocities correspond to different first dynamic percolation experiments. The static experiment module is used to conduct multiple static seepage experiments on the experimental core using the experimental parameters, and obtain multiple static seepage recovery curves. The seepage pressure corresponding to different static seepage experiments is different. The dynamic experiment module is used to conduct multiple second dynamic permeation experiments on the experimental core using the experimental parameters to obtain multiple second dynamic permeation recovery curves. The permeation pressure corresponding to different second dynamic permeation experiments is different, and the displacement rate corresponding to different second dynamic permeation experiments is the optimal displacement rate. The plotting module is used to plot a composite oil recovery rate curve using multiple static oil recovery rates and multiple second dynamic oil recovery rates. The multiple static oil recovery rates are obtained from the multiple static oil recovery rate curves, and different static oil recovery rates correspond to different static oil recovery rate curves. The multiple second dynamic oil recovery rates are obtained from the multiple second dynamic oil recovery rates, and different second dynamic oil recovery rates correspond to different second dynamic oil recovery rate curves. The pressure determination module is used to determine the optimal adsorption pressure by utilizing the inflection point of the integrated adsorption recovery curve. The oil production module is used to perform seepage oil production by utilizing the optimal displacement rate and the optimal seepage pressure; The speed determination module includes: The dynamic experimental unit is used to conduct multiple first dynamic seepage experiments on the experimental core using the experimental parameters, and to obtain multiple first dynamic seepage recovery curves. The velocity determination unit is used to determine the optimal displacement velocity by utilizing the inflection points of the plurality of first dynamic adsorption recovery curves.

6. The apparatus according to claim 5, characterized in that, The drawing module includes: The summation unit is used to perform a weighted summation of the static and dynamic wicking recovery rates corresponding to the same wicking pressure to obtain multiple composite wicking recovery rates. A plotting unit is used to plot the integrated oil recovery rate curve based on the multiple integrated oil recovery rates.

7. A computer device, characterized in that, include: Memory and processor; The memory is used to store computer programs; The processor is configured to execute a computer program in the memory to implement the method according to any one of claims 1 to 4.

8. A computer-readable storage medium, characterized in that, The device stores instructions that, when executed on a computer, cause the computer to perform the method as described in any one of claims 1 to 4.

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