A device for evaluating the effect of imbibition oil displacement and a method for using the same

Abstract

The present invention relates to an imbibition oil recovery effect evaluation device and a method of use, which belong to the field of oil and gas development, and to an imbibition oil recovery effect evaluation device and a method of use, including a piston container, a piston is arranged in the piston container, and the internal area of ​​the piston container is divided into a solution chamber and a pressure chamber; the piston container is provided with three, namely a first piston container, a second piston container and a third piston container, and the solution chambers of the first piston container, the second piston container and the third piston container are respectively connected to the same six-way valve through a solution outlet valve; the present invention provides a fluid pressurizing device at the front end of the piston container inlet, which can simulate the pressurized pumping process of the fracturing fluid entering the formation. The acid and alkali resistant core clamp of the present invention is provided with a heating structure, which can simulate the reservoir temperature, and a confining pressure is set in the core clamp, which can simulate the overburden pressure of the formation, and the temperature and pressure conditions are closer to the real formation conditions.

Description

Technical Field

[0001] The invention belongs to the field of oil and gas development, and relates to an imbibition oil recovery effect evaluation device and a use method. Background Art

[0002] my country's low-permeability oil and gas reserves account for more than 65% of the country's oil and gas reserves, and low-permeability oil and gas reservoirs are widely distributed. Low-permeability reservoirs have poor and uneven physical properties and must be fracturing to obtain production capacity. Tight reservoirs are often developed by horizontal well fracturing. During the fracturing process, it was found that only 10% to 50% of the fracturing fluid can be discharged, and the return rate is low, which causes certain damage to the reservoir. Adding an imbibition agent to the fracturing fluid, there is no need to deal with the return fluid after fracturing. The residual fracturing fluid retained in the formation can not only replenish the formation energy, but also play a role in imbibition and oil displacement, turning the fracturing return fluid into "treasure" and improving the development effect of low-permeability reservoirs.

[0003] Existing imbibition experimental devices are mainly based on two measurement methods: volumetric method and mass method. The volumetric method is to calculate the liquid replacement amount between the solution and the core by measuring the volume of crude oil or the imbibition system solution, and to calculate the degree of recovery by recording the change of imbibition oil production over time, so as to evaluate the oil recovery effect; the weighing method is to calculate the imbibition result by measuring the weight change of the core or the imbibition system solution.

[0004] Most of the existing devices for evaluating the effect of imbibition oil recovery can only evaluate the spontaneous imbibition effect of the imbibition agent. For example, the invention patent 201310451182.X reported a quantitative evaluation method for the imbibition oil recovery effect of an imbibition agent, which involves a method for determining the spontaneous imbibition efficiency of an imbibition agent on oil sands made of a mixture of quartz sand or natural sand or a core saturated with crude oil. This is a spontaneous imbibition process and cannot simulate the whole process of the fracturing fluid being pumped into the rock under the actual formation conditions, the pressure of the overburden formation and the formation temperature, and the fracturing fluid breaking the gel and entering the rock after the pump is stopped, and the residual fracturing fluid is used as an imbibition oil recovery agent. Invention patent CN201910802792.7 discloses an imbibition agent evaluation experimental device and method for imbibition oil recovery. The device includes an imbibition bottle and an imbibition tube, which can perform imbibition oil recovery experiments at high temperatures and simulate the imbibition effect of formation matrix rocks under certain temperature conditions. However, it is also a spontaneous imbibition process and cannot simulate the real formation conditions. Under the condition of the rock under the pressure of the overlying rock formation, the fracturing fluid is pumped into the formation, and after the fracturing is completed and the pump is stopped, the residual liquid of the fracturing fluid enters the formation, and the residual liquid of the fracturing fluid is used as an imbibition oil-displacing agent. The above two devices do not use acid-resistant materials, and cannot evaluate the imbibition oil-displacing effect of the imbibition oil-displacing agent added to the acid fracturing fluid.

[0005] In order to simulate the process of fracturing fluid entering rock under temperature and pressure conditions close to formation conditions, as well as the imbibition process of the residual fracturing fluid as an imbibition oil-displacing agent in the formation after fracturing, and to measure the imbibition oil-displacing effects of different imbibition oil-displacing agents added to the fracturing fluid, an imbibition oil-displacing effect evaluation device was designed, and its use method was given. The device can not only evaluate the imbibition oil-displacing effect of imbibition oil-displacing agents added to conventional water-based fracturing fluids, but also evaluate the imbibition oil-displacing effect of imbibition oil-displacing agents added to acidic fracturing fluids. The device covers a wide range of fracturing fluid types, is easy to operate, and has high credibility of experimental results, which are close to actual formation temperature and pressure conditions. Summary of the invention

[0006] The purpose of the present invention is to provide an imbibition oil recovery effect evaluation device and a method for use, which can evaluate the imbibition oil recovery effect of various water-based fracturing fluids with added imbibition agents in cores with different permeabilities, and is close to the actual state of the fracturing fluid in the formation.

[0007] The present invention discloses an imbibition oil displacement effect evaluation device, comprising a piston container, a piston is arranged in the piston container, and the inner area of ​​the piston container is divided into a solution chamber and a pressure chamber; the piston container is provided with three, namely a first piston container, a second piston container and a third piston container, the solution chambers of the first piston container, the second piston container and the third piston container are respectively connected to the same six-way valve through a solution outlet valve, the pressure chambers of the first piston container, the second piston container and the third piston container are respectively connected to the same pressurizing pipeline through a pressurizing valve, and the pressurizing pipeline is connected with a fluid pressurizing device;

[0008] The six-way valve is connected to a solution input pipe, and the solution input pipe is connected to a first acid-alkali resistant core clamp and a second acid-alkali resistant core clamp through a first solution inlet valve and a second solution inlet valve respectively;

[0009] The first acid-alkali resistant core clamp is connected to a first outlet for imbibed oil via a first outlet valve;

[0010] The second acid-alkali resistant core holder is connected to a second outlet for imbibition oil through a second outlet valve;

[0011] The first acid-alkali resistant core clamp and the second acid-alkali resistant core clamp are also connected to a confining pressure device, and the first acid-alkali resistant core clamp and the second acid-alkali resistant core clamp are both provided with a heating structure;

[0012] The solution chambers of the first piston container, the second piston container and the third piston container are filled with different types of water-based fracturing fluids.

[0013] Preferably, the confining pressure device comprises a manual pump, the manual pump is connected to a first confining pressure pipeline and a second confining pressure pipeline through a confining pressure outlet main valve, and one end of the first confining pressure pipeline away from the confining pressure outlet main valve is connected to the middle of the first acid-alkali resistant core clamp;

[0014] One end of the second confining pressure pipeline away from the confining pressure outlet main valve is connected to the middle part of the second acid and alkali resistant core clamp;

[0015] The first confining pressure pipeline is provided with a first confining pressure inlet valve, and the second confining pressure pipeline is provided with a second confining pressure inlet valve;

[0016] A pressure gauge is provided on the first confining pressure pipeline between the first acid-alkali resistant core clamp and the first confining pressure inlet valve, and a pressure gauge is also provided on the second confining pressure pipeline between the second acid-alkali resistant core clamp and the second confining pressure inlet valve.

[0017] Preferably, a vent valve is provided on the pipeline between the solution chamber of the first piston container, the second piston container and the third piston container and the connected solution outlet valve.

[0018] Preferably, the pressurizing pipeline is connected with a first pressure sensor, and the solution input pipe is connected with a second pressure sensor.

[0019] Preferably, the fluid pressurizing device is a piston container pressurizing pump.

[0020] Or preferably, the first piston container is a first piston container made of 316L material, the volume of the first piston container is 1000mL, and the pressure resistance is 50MPa.

[0021] Preferably, the second piston container is a second piston container made of 316L material, the volume of the second piston container is 1000 mL, and the pressure resistance is 50 MPa.

[0022] Preferably, the third piston container is a third piston container made of HC276 material, the volume of the third piston container is 200 mL, and the pressure resistance is 50 MPa.

[0023] Preferably, the first acid-alkali resistant core clamp and the second acid-alkali resistant core clamp are both TY-4 acid-alkali resistant core clamps, manufactured by Nantong Huaxing Petroleum Instrument Co., Ltd.

[0024] A method for using an imbibition oil displacement effect evaluation device, characterized in that the method is as follows:

[0025] (1) Assemble the core saturated with crude oil on the first acid-alkali resistant core holder and the second acid-alkali resistant core holder, close the first solution inlet valve, the second solution inlet valve, the first outlet valve and the second outlet valve, open the confining pressure outlet main valve, the first confining pressure inlet valve and the second confining pressure inlet valve, and use a manual pump to apply confining pressure to the first acid-alkali resistant core holder and the second acid-alkali resistant core holder;

[0026] (2) According to the experimental requirements, different water-based fracturing fluids are filled in the solution chambers of the first piston container and the second piston container, and acidic fracturing fluids are filled in the solution chamber of the third piston container. Different imbibing agents and the same debonding agent are added to the fracturing fluids in the first piston container, the second piston container and the third piston container. After the debonding of the fracturing fluid, the solution outlet valve and the pressure valve connected to the first piston container, the second piston container or the third piston container and the corresponding valve on the six-way valve are opened according to the experimental requirements, and the fluid pressurizing device is opened to pressurize the piston container, and then Open the first solution inlet valve, the second solution inlet valve, the first outlet valve and the second outlet valve, drive the fracturing fluid in the first piston container, the second piston container or the third piston container into the first acid-alkali resistant core clamp and the second acid-alkali resistant core clamp, and when liquid flows out of the first outlet for imbibition and de-oiling and the second outlet for imbibition and de-oiling, close the first outlet valve and the second outlet valve, close the solution outlet valve and the pressurizing valve connected to the first piston container, the second piston container or the third piston container, and close the fluid pressurizing device, and allow the fracturing fluid to fully imbibe in the core for 24 hours;

[0027] (3) Opening the first outlet valve and the second outlet valve, collecting the oil and water removed by absorption at the first outlet of the oil removed by absorption and the second outlet of the oil removed by absorption, and measuring the volume of the removed crude oil with a measuring cylinder;

[0028] (4) The oil displacement and washing effect of different imbibition agents added to the fracturing fluid was evaluated by measuring the volume of crude oil removed. The larger the volume of crude oil removed, the better the oil displacement and washing effect of the imbibition agent.

[0029] Beneficial effects of the present invention:

[0030] (1) The present invention provides a fluid pressurizing device at the front end of the piston container inlet, which can simulate the pressurized pumping process of the fracturing fluid entering the formation.

[0031] (2) The acid- and alkali-resistant core holder of the present invention is provided with a heating structure to simulate the reservoir temperature, and a confining pressure is set in the core holder to simulate the overlying rock pressure of the formation. The temperature and pressure conditions are closer to the actual formation conditions.

[0032] (3) The present invention uses three piston containers, one of which is an acid-resistant piston container, which can evaluate the imbibition recovery effects of various water-based fracturing fluids including acidic fracturing fluids, and can evaluate a wide range of fracturing fluid types.

[0033] (4) The present invention adopts a six-way valve, which can be switched among the three piston containers at will, and is simple and easy to operate.

[0034] (5) The present invention designs two acid- and alkali-resistant heatable core holders, which can simultaneously evaluate the imbibition recovery effect of an imbibition recovery fracturing fluid at different permeabilities. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a schematic diagram of the connection relationship of an imbibition oil recovery effect evaluation device of the present invention.

[0036] Figure markings: 1-piston container pressure pump, 2-first piston container, 3-vent valve, 4-pressurization valve, 5-solution outlet valve, 6-second piston container, 7-third piston container, 8-first pressure sensor, 9-six-way valve, 10-second solution inlet valve, 11-first solution inlet valve, 12-second acid and alkali resistant core clamp, 13-first acid and alkali resistant core clamp, 14-pressure gauge, 15-second outlet valve, 16-first outlet valve, 17-first confining pressure inlet valve, 18-second outlet for oil removal by absorption and desorption, 19-first outlet for oil removal by absorption and desorption, 20-second confining pressure inlet valve, 21-confining pressure outlet main valve, 22-manual pump, 23-second pressure sensor. DETAILED DESCRIPTION

[0037] The present invention provides an imbibition oil displacement effect evaluation device, comprising a piston container, a piston is arranged in the piston container, and the inner area of ​​the piston container is divided into a solution chamber and a pressure chamber; the piston container is provided with three, namely a first piston container 2, a second piston container 6 and a third piston container 7, the solution chambers of the first piston container 2, the second piston container 6 and the third piston container 7 are respectively connected to the same six-way valve 9 through a solution outlet valve 5, the pressure chambers of the first piston container 2, the second piston container 6 and the third piston container 7 are respectively connected to the same pressurizing pipeline through a pressurizing valve 4, and a fluid pressurizing device is connected to the pressurizing pipeline;

[0038] The six-way valve 9 is connected to a solution input pipe, and the solution input pipe is connected to a first acid-alkali resistant core clamp 13 and a second acid-alkali resistant core clamp 12 through a first solution inlet valve 11 and a second solution inlet valve 10 respectively;

[0039] The first acid-alkali resistant core holder 13 is connected to a first outlet 19 for imbibition oil through a first outlet valve 16;

[0040] The second acid-alkali resistant core holder 12 is connected to a second outlet 18 for imbibition oil through a second outlet valve 15;

[0041] The first acid-alkali resistant core clamp 13 and the second acid-alkali resistant core clamp 12 are also connected to a confining pressure device, and the first acid-alkali resistant core clamp 13 and the second acid-alkali resistant core clamp 12 are both provided with a heating structure;

[0042] The solution chambers of the first piston container 2 , the second piston container 6 and the third piston container 7 are filled with different types of water-based fracturing fluids.

[0043] The confining pressure device includes a manual pump 22, and the manual pump 22 is connected to a first confining pressure pipeline and a second confining pressure pipeline through a confining pressure outlet main valve 21, and one end of the first confining pressure pipeline away from the confining pressure outlet main valve 21 is connected to the middle of the first acid-alkali resistant core clamp 13;

[0044] One end of the second confining pressure pipeline away from the confining pressure outlet main valve 21 is connected to the middle of the second acid-alkali resistant core clamp 12;

[0045] The first confining pressure pipeline is provided with a first confining pressure inlet valve 17, and the second confining pressure pipeline is provided with a second confining pressure inlet valve 20;

[0046] A pressure gauge 14 is provided on the first confining pressure pipeline between the first acid-alkali resistant core clamp 13 and the first confining pressure inlet valve 17 , and a pressure gauge 14 is also provided on the second confining pressure pipeline between the second acid-alkali resistant core clamp 12 and the second confining pressure inlet valve 20 .

[0047] A vent valve 3 is provided on the pipeline between the solution chamber of the first piston container 2 , the second piston container 6 and the third piston container 7 and the connected solution outlet valve 5 .

[0048] The pressurizing pipeline is connected to a first pressure sensor 8, and the solution input pipe is connected to a second pressure sensor 23.

[0049] The fluid pressurizing device is a piston container pressurizing pump 1.

[0050] The first piston container 2 is a first piston container 2 made of 316L material, the volume of the first piston container 2 is 1000mL, and the pressure resistance is 50MPa.

[0051] The second piston container 6 is a second piston container 6 made of 316L material, the volume of the second piston container 6 is 1000mL, and the pressure resistance is 50MPa.

[0052] The third piston container 7 is made of HC276 material, has a capacity of 200 mL, and has a pressure resistance of 50 MPa.

[0053] The first acid-alkali resistant core holder 13 and the second acid-alkali resistant core holder 12 are both TY-4 acid-alkali resistant core holders, manufactured by Nantong Huaxing Petroleum Instrument Co., Ltd.

[0054] A method for using an imbibition oil displacement effect evaluation device, characterized in that the method is as follows:

[0055] (1) A core saturated with crude oil is mounted on the first acid-alkali resistant core holder 13 and the second acid-alkali resistant core holder 12, the first solution inlet valve 11, the second solution inlet valve 10, the first outlet valve 16 and the second outlet valve 15 are closed, the confining pressure outlet main valve 21, the first confining pressure inlet valve 17 and the second confining pressure inlet valve 20 are opened, and the confining pressure is applied to the first acid-alkali resistant core holder 13 and the second acid-alkali resistant core holder 12 by a manual pump 22;

[0056] (2) According to the experimental requirements, different water-based fracturing fluids are filled in the solution chambers of the first piston container 2 and the second piston container 6, and acidic fracturing fluid is filled in the solution chamber of the third piston container 7. In addition, imbibition agents and debonding agents are added to the fracturing fluids in the first piston container 2, the second piston container 6 and the third piston container 7. After the debonding of the fracturing fluid, the solution outlet valve 5 and the corresponding valves on the pressure valve 4 and the six-way valve 9 connected to the first piston container 2, the second piston container 6 or the third piston container 7 are opened according to the experimental requirements, the fluid pressurizing device is turned on, the piston container is pressurized, and then the first solution inlet valve 11 is opened. , the second solution inlet valve 10, the first outlet valve 16 and the second outlet valve 15, drive the fracturing fluid in the first piston container 2 or the second piston container 6 or the third piston container 7 into the first acid-alkali resistant core clamp 13 and the second acid-alkali resistant core clamp 12, and close the first outlet valve 16 and the second outlet valve 15 when liquid flows out of the first outlet 19 for oil absorption and desorption and the second outlet 18 for oil absorption and desorption, close the solution outlet valve 5 and the pressurizing valve 4 connected to the first piston container 2 or the second piston container 6 or the third piston container 7, close the fluid pressurizing device, and allow the fracturing fluid to fully absorb in the core for 24 hours;

[0057] (3) Open the first outlet valve 16 and the second outlet valve 15, collect the oil and water removed by absorption at the first outlet 19 and the second outlet 18, and measure the volume of the removed crude oil with a measuring cylinder;

[0058] (4) The oil displacement and washing effect of different imbibition agents added to the fracturing fluid was evaluated by measuring the volume of crude oil removed. The larger the volume of crude oil removed, the better the oil displacement and washing effect of the imbibition agent.

[0059] Embodiment 1

[0060] The permeability is 1.1×10 -3 μm 2After the natural core is fully saturated with crude oil, it is installed on the first acid-alkali resistant core clamp 13, the first solution inlet valve 11 and the first outlet valve 16 are closed, the confining pressure outlet main valve 21 and the first confining pressure inlet valve 17 are opened, and the first acid-alkali resistant core clamp 13 is given confining pressure by a manual pump 22; the vent valve 3 connected to the first piston container 2 is closed, and 1L of formula 1 fracturing fluid is added to the first piston container 2. The fracturing fluid formula is: 0.3% hydroxypropyl guar gum + 1% potassium chloride + 0.1% bactericide CJSJ-1 + 0.3% imbibition agent CRS + 0.03% gel breaker ammonium persulfate. After the fracturing fluid is broken, the solution valve connected to the first piston container 2 is opened. The corresponding valves on the liquid outlet valve 5, the pressure valve 4 and the six-way valve 9 are opened, the piston container pressure pump 1 is opened to pressurize the first piston container 2, the valves of the first solution inlet valve 11 and the first outlet valve 16 are opened, and the fracturing fluid debonding liquid in the first piston container 2 is driven into the first acid-alkali resistant core clamp 13. When liquid flows out of the first outlet 19 for oil removal by absorption, the solution outlet valve 5 and the pressure valve 4 connected to the first piston container 2 are closed, and the piston container pressure pump 1 is closed to allow the fracturing fluid to fully absorb in the core for 24 hours; (3) The first outlet valve 16 is opened, and the oil and water absorbed by absorption are collected at the first outlet 19 for oil removal by absorption, and the volume of the crude oil removed is measured with a measuring cylinder. After measurement, the crude oil absorbed by absorption from the first outlet 19 for oil removal is 2.15mL.

[0061] Embodiment 2

[0062] The permeability is 1.08×10 -3 μm 2After the natural core is fully saturated with crude oil, it is installed on the second acid-alkali resistant core clamp 12, the second solution inlet valve 10 and the second outlet valve 15 are closed, the confining pressure outlet main valve 21 and the second confining pressure inlet valve 20 are opened, and the second acid-alkali resistant core clamp 12 is added with confining pressure by a manual pump 22; the vent valve 3 connected to the second piston container 6 is closed, and 1L of formula 2 fracturing fluid is added to the second piston container 6. The fracturing fluid formula is: 0.3% hydroxypropyl guar gum + 1% potassium chloride + 0.1% bactericide CJSJ-1 + 0.3% imbibition agent TGF-1 + 0.03% gel breaker ammonium persulfate. After the fracturing fluid is broken, open the valve connected to the second piston container 6. The corresponding valves on the solution outlet valve 5, the pressure valve 4 and the six-way valve 9 are opened, the piston container pressure pump 1 is opened to pressurize the second piston container 6, the second solution inlet valve 10 and the second outlet valve 15 are opened, and the fracturing fluid debonding liquid in the second piston container 6 is driven into the second acid-alkali resistant core clamp 12. When liquid flows out of the second outlet 18 for oil removal by absorption, the solution outlet valve 5 and the pressure valve 4 connected to the second piston container 6 are closed, and the piston container pressure pump 1 is closed to allow the fracturing fluid to fully absorb in the core for 24 hours; (3) The second outlet valve 15 is opened, and the oil and water absorbed by absorption are collected at the second outlet 18 for oil removal by absorption, and the volume of the crude oil absorbed is measured with a measuring cylinder. After measurement, the crude oil absorbed from the second outlet 18 for oil removal by absorption is 1.5 mL. After comparison, the oil displacement and washing effect of the imbibition agent 1 in the fracturing fluid of formula 1 is better than that of the imbibition agent 2 in the fracturing fluid of formula 2.

Claims

1. An imbibition oil displacement effect evaluation device, comprising a piston container, a piston is arranged in the piston container, and the inner area of ​​the piston container is divided into a solution chamber and a pressure chamber; characterized in that: The piston container is provided in three parts, namely a first piston container (2), a second piston container (6) and a third piston container (7); the solution chambers of the first piston container (2), the second piston container (6) and the third piston container (7) are respectively connected to the same six-way valve (9) via a solution outlet valve (5); the pressure chambers of the first piston container (2), the second piston container (6) and the third piston container (7) are respectively connected to the same pressurizing pipeline via a pressurizing valve (4); and the pressurizing pipeline is connected to a fluid pressurizing device; The six-way valve (9) is connected to a solution input pipe, and the solution input pipe is connected to a first acid-alkali resistant core holder (13) and a second acid-alkali resistant core holder (12) through a first solution inlet valve (11) and a second solution inlet valve (10), respectively; The first acid-alkali resistant core holder (13) is connected to a first outlet (19) for imbibed oil via a first outlet valve (16); The second acid-alkali resistant core holder (12) is connected to a second outlet (18) for imbibed oil via a second outlet valve (15); The first acid-alkali resistant core holder (13) and the second acid-alkali resistant core holder (12) are also connected to a confining pressure device, and the first acid-alkali resistant core holder (13) and the second acid-alkali resistant core holder (12) are both provided with a heating structure; The solution chambers of the first piston container (2), the second piston container (6) and the third piston container (7) are filled with different types of water-based fracturing fluids; The confining pressure device comprises a manual pump (22), the manual pump (22) being connected to a first confining pressure pipeline and a second confining pressure pipeline via a confining pressure outlet main valve (21), and an end of the first confining pressure pipeline away from the confining pressure outlet main valve (21) being connected to the middle of a first acid-alkali resistant core clamp (13); One end of the second confining pressure pipeline away from the confining pressure outlet main valve (21) is connected to the middle of the second acid-alkali resistant core clamp (12); The first confining pressure pipeline is provided with a first confining pressure inlet valve (17), and the second confining pressure pipeline is provided with a second confining pressure inlet valve (20); A pressure gauge (14) is provided on the first confining pressure pipeline between the first acid-alkali resistant core clamp (13) and the first confining pressure inlet valve (17).

2. The device for evaluating the effect of imbibition oil displacement according to claim 1, characterized in that: A vent valve (3) is provided on the pipeline between the solution chamber of the first piston container (2), the second piston container (6) and the third piston container (7) and the connected solution outlet valve (5).

3. A device for evaluating the effect of imbibition oil displacement as claimed in claim 2, characterized in that: The pressurizing pipeline is connected to a first pressure sensor (8), and the solution input pipe is connected to a second pressure sensor (23).

4. A device for evaluating the effect of imbibition oil displacement as claimed in claim 3, characterized in that: The fluid pressurizing device is a piston container pressurizing pump (1).

5. A device for evaluating the effect of imbibition oil displacement according to any one of claims 1 to 4, characterized in that: The first piston container (2) is a first piston container (2) made of 316L material, the volume of the first piston container (2) is 1000 mL, and the pressure resistance is 50 MPa.

6. The device for evaluating the effect of imbibition oil displacement according to claim 5, characterized in that: The second piston container (6) is a second piston container (6) made of 316L material, the volume of the second piston container (6) is 1000 mL, and the pressure resistance is 50 MPa.

7. The device for evaluating the effect of imbibition oil displacement according to claim 6, characterized in that: The third piston container (7) is a third piston container (7) made of HC276 material, the volume of the third piston container (7) is 200 mL, and the pressure resistance is 50 MPa.

8. The device for evaluating the effect of imbibition oil displacement according to claim 7, characterized in that: The first acid-alkali resistant core clamp (13) and the second acid-alkali resistant core clamp (12) are both TY-4 acid-alkali resistant core clamps.

9. The method for using the imbibition oil displacement effect evaluation device according to claim 1, characterized in that: The method is as follows: (1) A core saturated with crude oil is mounted on the first acid-alkali resistant core holder (13) and the second acid-alkali resistant core holder (12), the first solution inlet valve (11), the second solution inlet valve (10), the first outlet valve (16) and the second outlet valve (15) are closed, the confining pressure outlet main valve (21), the first confining pressure inlet valve (17) and the second confining pressure inlet valve (20) are opened, and confining pressure is applied to the first acid-alkali resistant core holder (13) and the second acid-alkali resistant core holder (12) using a manual pump (22); (2) Different water-based fracturing fluids are filled in the solution chambers of the first piston container (2) and the second piston container (6), and acidic fracturing fluid is filled in the solution chamber of the third piston container (7). The fracturing fluids in the first piston container (2), the second piston container (6) and the third piston container (7) are all added with an imbibing agent and a gel breaker. After the fracturing fluid is broken, the solution outlet valve (5) and the pressure valve (4) and the corresponding valve on the six-way valve (9) connected to the first piston container (2) or the second piston container (6) or the third piston container (7) are opened, the fluid pressurizing device is turned on, the piston container is pressurized, and then the first solution inlet valve (11) and the second solution inlet valve (12) are opened. 0), the first outlet valve (16) and the second outlet valve (15), drive the fracturing fluid in the first piston container (2) or the second piston container (6) or the third piston container (7) into the first acid-alkali resistant core clamp (13) and the second acid-alkali resistant core clamp (12), and when liquid flows out of the first outlet (19) and the second outlet (18) of the imbibition oil, close the first outlet valve (16) and the second outlet valve (15), close the solution outlet valve (5) and the pressurizing valve (4) connected to the first piston container (2) or the second piston container (6) or the third piston container (7), and close the fluid pressurizing device to allow the fracturing fluid to fully imbibe in the core for 24 hours; (3) opening the first outlet valve (16) and the second outlet valve (15), collecting the oil and water removed by absorption at the first outlet (19) and the second outlet (18), and measuring the volume of the removed crude oil with a measuring cylinder; (4) The oil displacement and washing effect of different imbibition agents added to the fracturing fluid was evaluated by measuring the volume of crude oil removed. The larger the volume of crude oil removed, the better the oil displacement and washing effect of the imbibition agent.

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