Imbibition oil extraction test device and method

Abstract

The invention discloses an imbibition oil extraction test device, and relates to the technical field of shale oil reservoir exploitation tests, the imbibition oil extraction test device mainly comprises an imbibition bottle, a closed container and a liquid filling device, the imbibition bottle is used for containing a rock core; the closed container can be sealed and is used for containing the imbibition bottle; the liquid filling device is connected with the closed container and used for filling the closed container with liquid, and the liquid filling device can fill the closed container with excessive liquid so as to improve the internal pressure intensity of the closed container. The invention further discloses an imbibition oil extraction test method which is implemented by using the imbibition oil extraction test device. The high-pressure environment of the oil reservoir can be fully simulated, the influence and action mechanism of the oil reservoir pressure on the imbibition oil recovery effect are revealed, and an experimental basis is provided for low-permeability tight oil and shale oil reservoir imbibition oil recovery mine field test technology decision.

Description

Technical Field

[0001] The invention relates to the technical field of shale oil reservoir production test, in particular to an imbibition oil production test device and method. Background Art

[0002] Studies have shown that imbibition oil production is an effective technical means for the development of low permeability, tight oil and shale reservoirs, and the imbibition oil production effect is closely related to the composition of the imbibition working fluid and the contact area between the imbibition tool and the rock. Therefore, the adaptability of the imbibition working fluid to the reservoir is directly related to the development effect and technical and economic benefits of the shale reservoir. At present, the evaluation of the adaptability of the imbibition working fluid to the reservoir mostly adopts two methods: nuclear magnetic resonance method and visual imbibition method. The nuclear magnetic resonance method not only has high testing costs, but also makes it difficult to achieve accurate quantitative evaluation. The existing visual imbibition method micro-pressure pump is directly connected to the imbibition bottle, and the micro-pressure pump is used to fill the imbibition bottle with water, and the top of the imbibition bottle is open. This method does not involve pressurization, but the actual pressure of the reservoir is relatively high in reality, and this experimental method cannot truly simulate the exploitation environment of the reservoir. Therefore, there is an urgent need for an imbibition oil production test device and method to solve the above problems. Summary of the invention

[0003] The purpose of the present invention is to provide an imbibition oil production test device and method to solve the problems existing in the above-mentioned prior art, which can fully simulate the high-pressure environment of the oil reservoir, and further reveal the influence and mechanism of reservoir pressure on the imbibition oil production effect, and provide an experimental basis for technical decision-making of imbibition oil production field tests in low permeability, tight oil and shale oil reservoirs.

[0004] To achieve the above object, the present invention provides the following solutions:

[0005] The present invention provides an imbibition oil production test device, comprising

[0006] A suction bottle, wherein the suction bottle is used to hold the core;

[0007] A sealed container, wherein the sealed container is used to contain the infiltration bottle;

[0008] A liquid filling device is connected to the closed container and is used to fill liquid into the closed container. The liquid filling device can fill excess liquid into the closed container to increase the internal pressure of the closed container.

[0009] Preferably, the liquid filling device includes a first conveying device and a second conveying device, the conveying end of the first conveying device is connected to the bottom of the closed container, and an emptying valve is provided on the top of the closed container. The first conveying device is used to convey liquid from the bottom of the closed container to the inside of the closed container to discharge gas through the emptying valve, and the conveying end of the second conveying device is connected to the top of the closed container. The second conveying device is used to convey excess liquid from the top of the closed container to increase the pressure inside the closed container.

[0010] Preferably, the first conveying device includes a gas cylinder and an intermediate container, the gas outlet of the gas cylinder and the inlet of the intermediate container are connected by a first pipe, and the outlet of the intermediate container is connected to the bottom of the closed container by a second pipe, wherein the gas cylinder is used to contain gas, and the intermediate container is used to contain liquid to be introduced, and the gas cylinder discharges gas to press the liquid to be introduced into the closed container, wherein the gas outlet of the gas cylinder is provided with a pressure reducing valve, and the pressure reducing valve is used to adjust the gas pressure at the gas outlet of the gas cylinder.

[0011] Preferably, a first flow valve is provided on the first pipeline, and the first flow valve is used to control the flow of gas, and a second flow valve is provided on the second pipeline, and the second flow valve is used to control the flow of the liquid to be introduced.

[0012] Preferably, the second conveying device includes a liquid filling pump, the liquid inlet end of the liquid filling pump is connected to the liquid to be introduced, and the liquid outlet end is connected to the top of the closed container; wherein a third flow valve and a pressure gauge are provided on the connecting pipe between the liquid outlet end and the closed container, the third flow valve is used to control the flow rate of the liquid to be introduced, and the pressure gauge is used to read the pressure value.

[0013] Preferably, a three-way pipe is connected to the top of the closed container, a first end of the three-way pipe is connected to the closed container, a second end is connected to the drain valve for gas discharge, and a third end is connected to the liquid outlet.

[0014] Preferably, it also includes a lifting rack, which includes a cylindrical lower bottom, a hollow upper layer and a flexible lifting rope, the cylindrical lower bottom is fixedly connected to the hollow upper layer, the flexible lifting rope is arranged at the top of the hollow upper layer, the cylindrical lower bottom includes a bottom film and a side wall, the bottom film is provided with a plurality of holes, the infiltration bottle includes a fixedly connected wide-mouth bottle and a capillary metering tube, the liquid inlet of the wide-mouth bottle is fixedly provided on the bottom film, the side wall is used to accommodate the wide-mouth bottle, the capillary metering tube is arranged inside the hollow upper layer, wherein the capillary metering tube is provided with scale lines and a cock valve, the scale lines are arranged on the side of the capillary metering tube along the length direction of the capillary metering tube, and the cock valve is arranged on the top of the capillary metering tube.

[0015] Preferably, it further comprises an insulated box, wherein the intermediate container and the sealed container are arranged in the insulated box.

[0016] The present invention also provides an imbibition oil recovery test method, which is implemented using the above-mentioned imbibition oil recovery test device, comprising the following steps:

[0017] S1: placing the infiltration bottle into the sealed container, and injecting the surfactant solution through the liquid filling device until the surfactant solution overflows;

[0018] S2: The sealed container is sealed, and the liquid filling device continues to fill the liquid until the pressure in the sealed container reaches a predetermined value;

[0019] S3: After the core and liquid in the sealed container have interacted for a predetermined time, the sealed container is depressurized. After the closed container is depressurized, the sealed container is opened and the imbibition bottle is taken out, the captured oil volume data of the imbibition bottle is read, and the imbibition recovery rate is calculated.

[0020] Preferably, before step S1, the following steps are also included:

[0021] S101: collecting target reservoir cores and oil, preparing injection water and surfactant, preparing a surfactant solution with injection water, with a concentration of Cs=0.05% to 0.30%, and the target reservoir cores collected are columnar cores with geometric dimensions of: diameter (Φ)×length (L), Φ=2.5 to 3.8 cm, L=5 to 10 cm;

[0022] S102: the columnar core is evacuated and injected with the injection water until saturation, the porosity is calculated, and then the oil is used to drive water, the produced water is collected, the oil volume is determined, and the oil saturation is calculated;

[0023] S103: Open the upper end cover of the sealed container, and use a liquid filling device to inject the surfactant solution into the sealed container until the filling level reaches 90%-95%.

[0024] Compared with the prior art, the present invention has achieved the following technical effects:

[0025] The imbibition bottle of the present invention is used for containing rock cores, and the sealed container can be sealed. The sealed container is used for containing the imbibition bottle. The liquid filling device is connected to the sealed container and is used for filling liquid into the sealed container. The liquid filling device can fill excess liquid into the sealed container to increase the internal pressure of the sealed container. The sealed container is used to contain the imbibition bottle, and the liquid filling device pressurizes the sealed container and can fill liquid according to the actual predetermined pressure. Since the sealed container can be sealed, the liquid filling device can fill excess liquid into the sealed container to provide a greater pressure, fully simulating the high-pressure environment of the oil reservoir, thereby revealing the influence of the oil reservoir pressure on the imbibition oil production effect and the mechanism of action, and providing an experimental basis for the technical decision-making of the imbibition oil production field test of low permeability, tight oil and shale oil reservoirs. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0027] Figure 1 It is a structural schematic diagram of an imbibition oil recovery test device in some embodiments of the present invention;

[0028] Figure 2 A front view of a lifting rack in some embodiments of the present invention;

[0029] Figure 3 for Figure 2 Sectional view at AA;

[0030] Figure 4 A three-dimensional structural diagram of a lifting rack in some embodiments of the present invention;

[0031] Figure 5 Schematic diagram of the relationship between imbibition recovery and permeability in some embodiments of the present invention.

[0032] In the figure: 1-gas cylinder; 2-pressure reducing valve; 3-first flow valve; 4-intermediate container; 5-second flow valve; 6-lifting bracket; 61-cylindrical bottom; 62-hollow upper layer; 63-flexible lifting rope; 7-sealed container; 8-core; 9-cock valve; 10-infiltration bottle; 11-tee pipe; 12-emptying valve; 13-third flow valve; 14-pressure gauge; 15-filling pump; 16-insulation box. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] The purpose of the present invention is to provide an imbibition oil production test device and method to solve the problems existing in the prior art, which can fully simulate the high-pressure environment of the oil reservoir, and further reveal the influence and mechanism of reservoir pressure on the imbibition oil production effect, and provide an experimental basis for technical decision-making of imbibition oil production field tests in low permeability, tight oil and shale oil reservoirs.

[0035] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the present invention is further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] Embodiment 1

[0037] like Figure 1-Figure 5 As shown, the present invention provides an imbibition oil production test device, including an imbibition bottle 10, a closed container 7 and a liquid filling device. The imbibition bottle 10 is used to hold a core 8. The closed container 7 can be sealed. The closed container 7 is used to hold the imbibition bottle 10. The liquid filling device is connected to the closed container 7 and is used to fill liquid into the closed container 7. The liquid filling device can fill excess liquid into the closed container 7 to increase the internal pressure of the closed container 7. The closed container 7 is used to hold the imbibition bottle 10. The liquid filling device pressurizes the closed container 7 and can fill liquid according to the actual predetermined pressure. Since the closed container 7 can be sealed, the liquid filling device can fill excess liquid into the closed container 7 to provide a greater pressure, fully simulating the high-pressure environment of the reservoir, thereby revealing the influence of reservoir pressure on the imbibition oil production effect and the mechanism of action, and providing an experimental basis for the technical decision-making of imbibition oil production field tests in low permeability, tight oil and shale reservoirs.

[0038] In some embodiments, the liquid filling device includes a first conveying device and a second conveying device, the conveying end of the first conveying device is connected to the bottom of the sealed container 7, and the first conveying device is used to convey liquid from the bottom of the sealed container 7 to the inside of the sealed container 7 to discharge gas, and the conveying end of the second conveying device is connected to the top of the sealed container 7, and the second conveying device is used to convey excess liquid from the top of the sealed container 7 to increase the pressure inside the sealed container 7. The first conveying device conveys liquid from the bottom of the sealed container 7 to the inside to discharge gas, and the method of injecting liquid from the bottom can utilize the upward flow characteristics of the liquid to more effectively drive out and discharge the gas accumulated in the upper part of the sealed container 7 and other positions step by step, so that the gas is discharged more thoroughly, ensuring that subsequent tests are carried out in an environment with as little gas interference as possible, and improving the accuracy and reliability of the test. The second conveying device conveys excess liquid from the top of the closed container 7 to increase the internal pressure. The conveying method specially designed for increasing the pressure can more accurately control the amount of liquid injected, thereby realizing precise regulation of the internal pressure of the closed container 7. It can flexibly and accurately create a corresponding high-pressure environment according to different experimental requirements, which is helpful to study the differences in the effects of imbibition oil recovery under different pressure conditions. The first conveying device and the second conveying device cooperate with each other. First, the first conveying device completes the basic work of exhausting air, laying the foundation for creating a stable liquid environment, and then the second conveying device further increases the pressure on this basis. The orderly cooperation allows the entire liquid filling device to ensure a good environment inside the closed container 7 while also efficiently and accurately realizing the function of increasing the internal pressure, which can better simulate the real and complex high-pressure environment of the reservoir.

[0039] In some embodiments, the first conveying device includes a gas cylinder 1 and an intermediate container 4, the inlets of the gas cylinder 1 and the intermediate container 4 are connected through a first pipe, and the outlet of the intermediate container 4 is connected to the bottom of the closed container 7 through a second pipe, wherein the gas cylinder 1 is used to contain gas, and the intermediate container 4 is used to contain liquid to be introduced, and the gas cylinder 1 discharges gas to press the liquid to be introduced into the closed container 7, wherein the gas outlet of the gas cylinder 1 is provided with a pressure reducing valve 2, and the pressure reducing valve 2 is used to adjust the pressure of the gas outlet of the gas cylinder 1. The pressure reducing valve 2 can effectively adjust the pressure of the gas outlet of the gas cylinder 1, and the operator can control the gas pressure according to the specific experimental requirements and the actual conditions such as the pressure bearing capacity of the intermediate container 4 and the closed container 7, and then accurately control the pressure of the liquid to be introduced when it is pressed into the closed container 7, to ensure that the entire conveying process is carried out under appropriate pressure conditions. The intermediate container 4 can be used to prepare the liquid in advance and can play a certain buffering role.

[0040] In some embodiments, a first flow valve 3 is provided on the first pipeline, and the first flow valve 3 is used to control the flow of gas, and a second flow valve 5 is provided on the second pipeline, and the second flow valve 5 is used to control the flow of liquid to be introduced. By adjusting the opening of the first flow valve 3, the amount of gas entering the intermediate container 4 per unit time can be accurately controlled according to actual experimental requirements, thereby indirectly and accurately regulating the speed and pressure of the liquid in the intermediate container 4 being pressed into the closed container 7. According to different imbibition oil production test scenarios, such as simulating different reservoir permeabilities, etc., by adjusting the opening and closing degree of the second flow valve 5, the flow rate of the liquid flowing into the closed container 7 can be flexibly changed, so that the liquid injection process can match the simulation experiment.

[0041] In some embodiments, the second conveying device includes a filling pump 15, the liquid inlet end of the filling pump 15 is connected to the liquid to be introduced, and the liquid outlet end is connected to the top of the closed container 7; wherein, a third flow valve 13 and a pressure gauge 14 are provided on the connecting pipe between the liquid outlet end and the closed container 7, the third flow valve 13 is used to control the flow of the liquid to be introduced, and the pressure gauge 14 is used to read the pressure value. The pressure gauge 14 makes the pressure value reading more accurate, and the filling pump 15 is preferably a hand pump. The pressure gauge is used in combination with the hand pump so that the operator can determine the amount of liquid to be filled in using the hand pump based on experience and specific experimental processes, and the control is relatively more flexible, and the structure of the hand pump is relatively simple and the cost is low. It should be noted that the filling pump 15 can also use other types of pump bodies, such as electric plunger pumps.

[0042] In some embodiments, a three-way pipe 11 is connected to the top of the sealed container 7, a first end of the three-way pipe 11 is connected to the sealed container 7, a second end is connected to a drain valve 12, the drain valve 12 is used to discharge gas, and a third end is connected to the liquid outlet. The operator can flexibly choose whether to open the drain valve 12 to discharge gas or to inject liquid into the sealed container 7 through the third end to adjust the pressure according to different stages of the experiment and actual needs, so as to facilitate the experiment.

[0043] In some embodiments, the imbibition oil production test device further comprises a lifting rack 6, the lifting rack 6 comprises a cylindrical lower bottom 61, a hollow upper layer 62 and a flexible lifting rope 63, the cylindrical lower bottom 61 is fixedly connected to the hollow upper layer 62, the flexible lifting rope 63 is arranged at the top of the hollow upper layer 62, the cylindrical lower bottom 61 comprises a bottom film and a side wall, a plurality of holes are arranged on the bottom film, the imbibition bottle 10 comprises a fixedly connected wide-mouth bottle and a capillary metering tube, the liquid inlet of the wide-mouth bottle is fixedly arranged on the bottom film, the side wall is used to accommodate the wide-mouth bottle, the capillary metering tube is arranged inside the hollow upper layer 62, the height of the cylindrical lower bottom 61 is substantially the same as the height of the wide-mouth bottle, which can protect the wide-mouth bottle from being broken to a certain extent, and the hollow upper layer 62 makes the liquid level height in the capillary metering tube visible in real time, which is convenient for observation in the experiment. The flexible lifting rope 63 arranged at the top enables the operator to conveniently lift the lifting rack 6, whether putting it into the sealed container 7 or taking it out of the sealed container 7.

[0044] In some embodiments, scale lines and a cock valve 9 are provided on the capillary metering tube. The scale lines are provided on the side of the capillary metering tube along the length direction of the capillary metering tube, and the cock valve 9 is provided on the top of the capillary metering tube. The setting of the scale lines makes the data reading of the capillary metering tube more accurate and convenient, and the cock valve 9 is very easy to operate and can be opened and closed quickly, which can better meet the experimental needs.

[0045] In some embodiments, the imbibition oil production test device further includes an insulated box 16, and the intermediate container 4 and the pressurizing device are arranged in the insulated box 16. In the imbibition oil production test, the temperature of the liquid to be introduced into the intermediate container 4 will affect its physical and chemical properties and the subsequent imbibition effect. The insulated box 16 can create a relatively stable temperature environment for the intermediate container 4 to avoid excessive temperature changes of the liquid due to fluctuations in the external environment temperature, so that the key properties of the liquid such as viscosity and density remain relatively stable, thereby ensuring that the liquid maintains stable characteristics when being pressed into the closed container 7 and participating in the imbibition process. The pressurizing device and the imbibition bottle 10 contained therein are in the insulated box 16 to better simulate the temperature of the underground oil reservoir and restore the imbibition oil production environment to a higher degree.

[0046] Embodiment 2

[0047] This embodiment also provides an imbibition oil recovery test method, comprising:

[0048] S1: placing the infiltration bottle 10 into the sealed container 7, and injecting the surfactant solution through the liquid filling device until the surfactant solution overflows;

[0049] S2: The sealed container 7 is sealed, and the liquid filling device continues to fill the liquid until the pressure in the sealed container 7 reaches a predetermined value;

[0050] S3: After the columnar core 8 in the sealed container 7 has reacted with the liquid for a predetermined time, the sealed container 7 is depressurized, the sealed container 7 is opened, the imbibition bottle 10 is taken out, the captured oil volume data of the imbibition bottle 10 is read, and the imbibition recovery rate is calculated.

[0051] Further, a more specific test method is as follows:

[0052] Step 1: Collect the target reservoir core 8 and oil, prepare injection water, and prepare surfactant at the same time. Use injection water to prepare surfactant solution with concentration Cs = 0.05% ~ 0.30%. Take the natural core 8 to obtain a columnar core 8 with geometric dimensions: diameter (Φ) × length (L), Φ = 2.5 ~ 3.8 cm, L = 5 ~ 10 cm.

[0053] Step 2: The columnar core 8 is evacuated and water is injected to the saturation level, the porosity is calculated, the oil is used to drive water, the produced water is collected, the oil volume is determined based on the produced water, and the oil saturation is calculated.

[0054] Step 3: Place the sealed container 7 into the heat preservation box 16, open the upper end cover of the sealed container 7, and the gas cylinder 1 outputs high-pressure gas. The high-pressure gas injects the surfactant solution or injection water in the intermediate container 4 into the sealed container 7 through the second flow valve 5 at the bottom of the sealed container 7 until the filling degree reaches 90%-95%.

[0055] Step 4: Use the lifting bracket 6 to place the absorption bottle 10 (including the columnar core 8) into the sealed container 7 from the upper part of the sealed container 7, and at the same time open the cock valve 9 on the capillary metering tube of the absorption bottle 10 to exhaust the internal air of the absorption bottle 10 (it should be noted that: the liquid level of 90%-95% of the liquid filled into the sealed container 7 in step 3 is greater than the top height of the capillary metering tube of the absorption bottle 10, that is, the liquid can cover the capillary metering tube), after exhausting, close the cock valve 9, install and tighten the upper end cover of the sealed container 7, then open the drain valve 12 on the end cover, open the second flow valve 5 to continue injecting liquid to exhaust the gas in the sealed container 7 (until the liquid overflows), and then close the second flow valve 5.

[0056] Step 5: The temperature of the insulated box 16 is raised to a predetermined temperature, the third flow valve 13 is opened, and the filling pump 15 injects liquid into the sealed container 7 through the third flow valve 13 to further exhaust the gas to ensure sufficient exhaustion, and then the exhaust valve 12 is closed, and the filling pump 15 continues to inject liquid until the pressure in the sealed container 7 reaches a predetermined value.

[0057] Step 6: After the core 8 in the sealed container 7 has reacted with the liquid for a predetermined time, i.e., the imbibition oil recovery time, the drain valve 12 on the upper end cover of the sealed container 7 is opened to release the pressure, and then the end cover is opened and the imbibition bottle 10 is taken out, and the volume data of the captured oil in the scale test tube of the imbibition bottle 10 is read to calculate the imbibition recovery rate.

[0058] The specific test experiment of this embodiment is as follows:

[0059] 1 Test conditions

[0060] 1.1 Experimental Materials

[0061] The surfactant is sodium dodecylbenzene sulfonate (SDBS), with an effective content of 90%. The experimental water is simulated injection water of BZ25-1 oil field, with a density of 1.011 g / mL and ion composition as shown in Table 1.

[0062] The oil is a simulated oil prepared by mixing dehydrated crude oil and kerosene from the BZ25-1 oilfield, with a viscosity of 10 mPa·s and a density of 0.888 g / mL at 65°C. The core is an artificial homogeneous columnar core with geometric dimensions: diameter (φ) × length (L) = 2.5 × 10.0 cm. The parameters are shown in Table 2.

[0063] 1.2 Instruments and test procedures

[0064] 1.2.1 Instruments and Equipment

[0065] The core displacement experimental equipment mainly includes core high-pressure imbibition oil displacement experimental instruments, including pressure reducing valves, precision pressure gauges, gas cylinders, hand pumps and intermediate containers. Except for the hand pumps and gas cylinders, other components are placed in a 65℃ constant temperature box.

[0066] 1.2.2 Experimental procedures

[0067] (1) Dry the core and weigh it M, and measure its appearance and geometric dimensions. Evacuate the core at room temperature, simulate water injection, weigh the wet weight M0, and calculate the pore volume and porosity;

[0068] (2) Under the condition of reservoir temperature of 65°C, the core is subjected to "constant pressure of 10 MPa" to complete oil-water displacement (core saturated with oil) until no water is produced. The water output, i.e., saturated oil volume V0, is measured, and the oil saturation So is calculated. The core is aged for 24 h.

[0069] (3) A sodium dodecylbenzene sulfonate surfactant solution was prepared using simulated injection water and vacuumed for 2 to 3 hours to eliminate the influence of dissolved gas on the imbibition oil recovery effect;

[0070] (4) Implement step 3 above;

[0071] (5) Implement step 4 above;

[0072] (6) After the temperature of the incubator rises to 65°C, implement the above step 5;

[0073] (7) After the interaction time between the core and the liquid in the sealed container, i.e., the imbibition oil production time, reaches the predetermined three days, the drain valve on the upper end cover of the sealed container is opened to release the pressure, and then the end cover is opened and the imbibition bottle is taken out, and the volume data V1 of the captured oil in the scale test tube of the imbibition bottle is read to calculate the imbibition recovery rate.

[0074] Imbibition recovery rate:

[0075]

[0076] Where R is the imbibition recovery rate; V0 is the saturated oil volume, mL; V1 is the imbibition oil production, mL.

[0077] 1.2 Solution Design

[0078] Drug: SDBS, Cs = 0.3%;

[0079] Core permeability Kg: 2×10 -3 , 5×10 -3 , 15×10 -3 ,30×10 -3 and 60×10 -3 , μm 2 ;

[0080] Imbibition pressure: normal pressure and 5.0MPa;

[0081] Experimental temperature: 65℃;

[0082] Evaluation index: recovery rate.

[0083] 2 Results Analysis

[0084] The surfactant solution (SDBS, 3000 mg / L) was prepared using simulated water. The relationship between the normal pressure and high pressure (5 MPa) imbibition recovery and core permeability is shown in Table 3. The corresponding relationship curve is shown in Figure 5 .

[0085] From Table 3 and Figure 5 It can be seen that the core permeability and environmental pressure have an impact on the imbibition recovery rate. As the environmental pressure increases, the imbibition recovery rate increases; as the core permeability increases, the imbibition recovery rate increases.

[0086] Table 1 Water quality analysis

[0087]

[0088] Table 2 Core parameters

[0089]

[0090] Table 3 Results of imbibition recovery at normal pressure and high pressure (5MPa)

[0091]

[0092] The present invention uses specific examples to illustrate the principles and implementation methods of the present invention. The above examples are only used to help understand the method and core ideas of the present invention. At the same time, for those skilled in the art, according to the ideas of the present invention, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. An imbibition oil recovery test device, characterized in that: include A suction bottle, wherein the suction bottle is used to hold the core; A sealed container, wherein the sealed container is used to contain the infiltration bottle; A liquid filling device is connected to the closed container and is used to fill liquid into the closed container. The liquid filling device can fill excess liquid into the closed container to increase the internal pressure of the closed container.

2. The imbibition oil recovery test device according to claim 1, characterized in that: The liquid filling device includes a first conveying device and a second conveying device, the conveying end of the first conveying device is connected to the bottom of the sealed container, and an exhaust valve is provided on the top of the sealed container. The first conveying device is used to convey liquid from the bottom of the sealed container to the inside of the sealed container to discharge gas through the exhaust valve, and the conveying end of the second conveying device is connected to the top of the sealed container. The second conveying device is used to convey excess liquid from the top of the sealed container to increase the pressure inside the sealed container.

3. The imbibition oil recovery test device according to claim 2, characterized in that: The first conveying device includes a gas cylinder and an intermediate container, wherein the gas outlet of the gas cylinder and the inlet of the intermediate container are connected via a first pipe, and the outlet of the intermediate container is connected to the bottom of the closed container via a second pipe, wherein the gas cylinder is used to contain gas, and the intermediate container is used to contain liquid to be introduced, and the gas cylinder discharges gas to press the liquid to be introduced into the closed container, wherein the gas outlet of the gas cylinder is provided with a pressure reducing valve, and the pressure reducing valve is used to adjust the gas pressure at the gas outlet of the gas cylinder.

4. The imbibition oil recovery test device according to claim 3, characterized in that: The first pipeline is provided with a first flow valve, and the first flow valve is used to control the flow of gas. The second pipeline is provided with a second flow valve, and the second flow valve is used to control the flow of the liquid to be introduced.

5. The imbibition oil recovery test device according to claim 2, characterized in that: The second conveying device includes a liquid filling pump, the liquid inlet end of the liquid filling pump is connected to the liquid to be introduced, and the liquid outlet end is connected to the top of the closed container; wherein a third flow valve and a pressure gauge are provided on the connecting pipe between the liquid outlet end and the closed container, the third flow valve is used to control the flow of the liquid to be introduced, and the pressure gauge is used to read the pressure value.

6. The imbibition oil recovery test device according to claim 5, characterized in that: A three-way pipe is connected to the top of the closed container, a first end of the three-way pipe is connected to the closed container, a second end is connected to the drain valve for gas discharge, and a third end is connected to the liquid outlet.

7. The imbibition oil recovery test device according to claim 1, characterized in that: It also includes a lifting rack, which includes a cylindrical lower bottom, a hollow upper layer and a flexible lifting rope, the cylindrical lower bottom is fixedly connected to the hollow upper layer, the flexible lifting rope is arranged at the top of the hollow upper layer, the cylindrical lower bottom includes a bottom film and a side wall, the bottom film is provided with a plurality of holes, the infiltration bottle includes a fixedly connected wide-mouth bottle and a capillary metering tube, the liquid inlet of the wide-mouth bottle is fixedly provided on the bottom film, the side wall is used to accommodate the wide-mouth bottle, the capillary metering tube is arranged inside the hollow upper layer, wherein the capillary metering tube is provided with scale lines and a cock valve, the scale lines are arranged on the side of the capillary metering tube along the length direction of the capillary metering tube, and the cock valve is arranged on the top of the capillary metering tube.

8. The imbibition oil recovery test device according to claim 3, characterized in that: It also includes an insulated box, in which the intermediate container and the sealed container are arranged.

9. An imbibition oil recovery test method, characterized in that: The imbibition oil recovery test device according to any one of claims 1 to 8 is used for implementation, comprising the following steps S1: placing the infiltration bottle into the sealed container, and injecting the surfactant solution through the liquid filling device until the surfactant solution overflows; S2: The sealed container is sealed, and the liquid filling device continues to fill the liquid until the pressure in the sealed container reaches a predetermined value; S3: After the core and liquid in the sealed container have interacted for a predetermined time, the sealed container is depressurized. After the closed container is depressurized, the sealed container is opened and the imbibition bottle is taken out, the captured oil volume data of the imbibition bottle is read, and the imbibition recovery rate is calculated.

10. The imbibition oil recovery test method according to claim 9, characterized in that: Before step S1, the following steps are also included: S101: collecting target reservoir cores and oil, preparing injection water and surfactant, preparing a surfactant solution with injection water, with a concentration of Cs=0.05% to 0.30%, and the target reservoir cores collected are columnar cores with geometric dimensions of: diameter (Φ)×length (L), Φ=2.5 to 3.8 cm, L=5 to 10 cm; S102: the columnar core is evacuated and injected with the injection water until saturation, the porosity is calculated, and then the oil is used to drive water, the produced water is collected, the oil volume is determined, and the oil saturation is calculated; S103: Open the upper end cover of the sealed container, and use a liquid filling device to inject the surfactant solution into the sealed container until the filling level reaches 90%-95%.

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