Experimental device for simulating displacement fault solution reservoir

Abstract

The invention relates to an experimental device for simulating a displacement fault solution reservoir. The experimental device comprises a simulation assembly, an injection assembly and a measurement assembly, wherein the injection assembly and the measurement assembly are in fluid communication with the simulation assembly. The simulation assembly comprises a fault solution reservoir model used for simulating an underground fault solution reservoir. The injection assembly is constructed to be capable of injecting oil and oil displacement fluid into the fault-karst reservoir model in sequence. The measurement assembly includes a separation meter in fluid communication with the broken solution reservoir model. Wherein the separating and metering device is configured to be capable of separating oil discharged by the fault solution body oil reservoir model from oil displacement fluid and metering the separated oil. And the oil displacement effect of the fault solution reservoir is evaluated by comparing the yield of the oil injected into the simulation assembly with the yield of the oil discharged by the simulation assembly. Nitrogen foam flooding experiments with different intensities, different gas-liquid ratios and different densities can be carried out through the experimental device. And comprehensively evaluating the nitrogen foam flooding, and analyzing a physical experiment result to obtain the density and the gas-liquid ratio of the nitrogen foam system with the optimal oil displacement efficiency.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of oil reservoir exploitation, in particular to an experimental device for simulating displacement of a fractured-dissolved body reservoir. BACKGROUND

[0002] The fractured-dissolved body reservoir is a special case of the fracture-cave type reservoir. Since 2013, it has been found that deep faults control the development and reservoir formation of fracture-cave reservoirs in the 10th and 12th regions of the western Tahe region, and some reservoirs in the eastern Tahe region are also controlled by large faults. In 2015, the exploration breakthrough in the Shunbei oilfield further confirmed the existence and development effect of the fractured-dissolved body reservoir. Compared with other fracture-cave type reservoirs, the fractured-dissolved body reservoir is more special. The fractured-dissolved body reservoir is controlled by faults in terms of geological characteristics, reservoir formation and other aspects, and is also affected by upper fresh water and lower hydrothermal karstification. Therefore, the fractured-dissolved body reservoir is formed in multiple stages and has the characteristics of diversity of reservoir space distribution.

[0003] The fractured-dissolved body reservoir is essentially different from the clastic rock reservoir and has stronger heterogeneity. The main aspects are as follows:

[0004] (1) Large difference in reservoir space scale;

[0005] (2) Non-continuous distribution of reservoirs in space, strong heterogeneity;

[0006] (3) Variety of connection relationship and connection mode between reservoirs;

[0007] (4) Large holes and large fractures are mainly in pipe flow.

[0008] Foam flooding is a tertiary oil recovery method using foam formed by mixing a foaming agent solution and a gas as a displacement medium. This method has been widely used in conventional oil reservoir exploitation to improve the recovery rate of oil reservoirs. At present, the action mechanism and effect of this method on the fractured-dissolved body reservoir are not clear, and there is a lack of experimental data, so it has not been widely applied to the exploitation of the fractured-dissolved body reservoir. SUMMARY

[0009] Based on the above problems existing in the prior art, the present application provides an experimental device for simulating displacement of a fractured-dissolved body reservoir, which provides a basis for the application of foam flooding to the exploitation of the fractured-dissolved body reservoir.

[0010] The technical scheme adopted by the present application to solve the technical problem is to provide an experimental device for simulating displacement of a fractured-dissolved body reservoir, comprising,

[0011] The simulation assembly comprises a fractured-dissolved body reservoir model for simulating the fractured-dissolved body reservoir underground;

[0012] an injection assembly in communication with the fractured-cave oil reservoir model and configured to inject oil and a flooding fluid into the fractured-cave oil reservoir model in sequence;

[0013] a measurement assembly including a separation meter in fluid communication with the fractured-cave oil reservoir model,

[0014] wherein the separation meter is configured to separate the oil and the flooding fluid discharged from the fractured-cave oil reservoir model and meter the separated oil.

[0015] Further, the fractured-cave oil reservoir model includes a plurality of cavities of different sizes and heights and irregular shapes, and a first flow channel and a second flow channel connecting the plurality of cavities.

[0016] Further, the cavities are configured to communicate with the first flow channel or another cavity through at least one of the second flow channels, and / or,

[0017] the second flow channels are configured to communicate with the first flow channel and the bottom, middle or top of the cavities at any angle.

[0018] Further, the fractured-cave oil reservoir model is provided with a first injection inlet and a second injection inlet for injecting the flooding fluid, and a discharge outlet for discharging the oil and the flooding fluid, the discharge outlet being away from the first injection inlet and the second injection inlet, so that the flooding fluid injected by the first injection inlet and the second injection inlet has to pass through at least two of the cavities before being discharged by the discharge outlet.

[0019] Further, the second injection inlet communicates the injection assembly and a bottom water cavity of the fractured-cave oil reservoir model, the bottom water cavity communicating with the end of the first flow channel, so that the injection assembly can inject water into the plurality of cavities through the bottom water cavity to water-flood the oil in the cavities.

[0020] Further, the first injection inlet communicates the cavities and the injection assembly, for injecting the foam generated by the injection assembly into the plurality of cavities to foam-flood the oil in the cavities.

[0021] Further, the measurement assembly further includes a gas meter in communication with the separation meter, the gas meter being configured to meter the amount of gas in the foam discharged by the discharge outlet.

[0022] Further, the simulation assembly further includes a heating box for placing the fractured-cave oil reservoir model, and a confining pressure pump connected to the fractured-cave oil reservoir model, to provide the fractured-cave oil reservoir model with the required temperature and pressure, respectively.

[0023] Further, the injection assembly comprises a constant flow pump, and a six-way valve in fluid communication with the constant flow pump, wherein a gas storage tank, an oil storage tank, a water storage tank, and a storage tank for storing a foaming agent are connected in parallel between the constant flow pump and the six-way valve.

[0024] Further, a foam generator is arranged between the six-way valve and the fractured-dissolved body oil reservoir model, and the six-way valve is configured to inject the gas in the gas storage tank and the foaming agent in the storage tank into the foam generator to form a foam for oil displacement.

[0025] The experimental device for simulating displacement of a fractured-dissolved body oil reservoir provided by the present application comprises a simulation assembly, an injection assembly in fluid communication with the simulation assembly, and a measurement assembly. The simulation assembly comprises a fractured-dissolved body oil reservoir model for simulating a fractured-dissolved body oil reservoir underground. The injection assembly is in communication with the fractured-dissolved body oil reservoir model and is configured to inject oil and oil displacement fluid into the fractured-dissolved body oil reservoir model in sequence. The measurement assembly comprises a separation meter in fluid communication with the fractured-dissolved body oil reservoir model. The separation meter is configured to separate the oil and the oil displacement fluid discharged from the fractured-dissolved body oil reservoir model and measure the separated oil. The displacement effect on the fractured-dissolved body oil reservoir is evaluated by comparing the yield of the oil injected into the simulation assembly and the oil discharged from the simulation assembly. In addition, the experimental device can also simulate the high-temperature and high-pressure environment (the maximum temperature is 350℃ and the maximum displacement pressure is 10MPa) of the fractured-dissolved body oil reservoir reservoir medium, overcoming the defect that the high-temperature and high-pressure environment of the fractured-dissolved body oil reservoir experiment is difficult to achieve. The experimental device can be used to conduct nitrogen foam flooding experiments of different intensities, different gas-liquid ratios, and different densities. The nitrogen foam flooding is comprehensively evaluated, and the density and the gas-liquid ratio of the nitrogen foam system with the optimal oil displacement efficiency are obtained by analyzing the physical experimental results. BRIEF DESCRIPTION OF DRAWINGS

[0026] The present application will be further described below in conjunction with the drawings and examples.

[0027] Figure 1 Fig. 1 shows a piping structure diagram of an experimental device for simulating displacement of a fractured-dissolved body oil reservoir.

[0028] Figure 2 Fig. 3 shows a state diagram of a water flooding process of the fractured-dissolved body oil reservoir model.

[0029] Figure 3 Fig. 4 shows a state diagram of a foam flooding process of the fractured-dissolved body oil reservoir model.

[0030] In the drawings, the reference signs are as follows: 10, injection assembly; 11, constant flow pump; 12, first pressure gauge; 13, six-way valve; 14, gas storage tank; 15, oil storage tank; 16, water storage tank; 17, storage tank; 18, foam generator; 19, second pressure gauge;

[0031] 20, simulation assembly; 21, heating tank; 22, dissolution body reservoir model; 221, cavity; 221a, first cavity; 221b, second cavity; 221c, third cavity; 221d, fourth cavity; 222, first flow channel; 223, second flow channel; 224, first injection inlet; 225, discharge outlet; 23, confining pressure pump; 24, bottom water cavity;

[0032] 30, measurement assembly; 31, separation meter; 32, gas meter;

[0033] 40, recording assembly; 41, camera; 42, computer. DETAILED DESCRIPTION

[0034] In order to make the technical problems to be solved by the present application, technical solutions and beneficial effects clearer, the present application will be described in detail in conjunction with the drawings. The drawings are simplified schematic diagrams, which only schematically illustrate the basic structure of the present application, and thus only show the configurations related to the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0035] REFERENCE Figure 1 As shown in the drawings, the experimental device for simulating displacement of dissolution body reservoir provided by the present application comprises an injection assembly 10, a simulation assembly 20 in fluid communication with the injection assembly 10, and a measurement assembly 30 for measuring oil-water-gas displacement production. The injection assembly 10, the simulation assembly 20 and the measurement assembly 30 are in fluid communication in sequence through pipes. The injection assembly 10 can inject oil and oil displacement fluid into the simulation assembly 20 in sequence to complete the displacement simulation process of the oil. Specifically, the oil displacement fluid can be water or foam. The simulation assembly 20 can more realistically simulate the distribution of the underground dissolution body reservoir and the temperature and pressure of the formation where the dissolution body reservoir is located. The measurement assembly 30 can collect and separate the oil and the oil displacement fluid discharged from the simulation assembly 20 during the displacement process, and measure the separated oil. By measuring and comparing the production of the oil injected into the simulation assembly 20 and the oil discharged from the simulation assembly 20, the oil displacement effect can be evaluated. In addition, by measuring the production of water and gas in the oil and the oil displacement fluid respectively, the experimental effect can be comprehensively evaluated, the density and gas-liquid ratio of the foam system with the optimal oil displacement efficiency can be found, and thus sufficient theoretical support and experimental data can be provided for the actual exploitation of the dissolution body reservoir.

[0036] COMBINATION Figure 1As shown, in some embodiments, the injection assembly 10 includes a constant flow pump 11, a first pressure gauge 12 for measuring the output pressure of the constant flow pump 11, and a six-way valve 13 in fluid communication with the constant flow pump 11. The pumping flow rate of the constant flow pump 11 can be adjusted within the range of 0.01-300 ml / min so that it can be displaced at a flow rate of 0.01-300 ml / min. The injection assembly 10 also includes an air storage tank 14, an oil storage tank 15, a water storage tank 16, and a storage tank 17 for storing a foaming agent connected in parallel between the constant flow pump 11 and the six-way valve 13. The input and output ends of the air storage tank 14, the oil storage tank 15, the water storage tank 16 and the storage tank 17 are all provided with valves for controlling the substances injected into the simulation assembly 20 by the constant flow pump 11. The six-way valve 13 is also fluidically connected to a foam generator 18. The input of the foam generator 18 is connected to the six-way valve 13, and the output of the foam generator 18 is connected to the simulation assembly 20 via a pipeline. The output of the six-way valve 13 is also connected to the simulation assembly 20 via a pipeline. A second pressure gauge 19 for measuring displacement pressure is also installed on the pipeline between the six-way valve 13 and the simulation assembly 20.

[0037] Combine Figure 1 As shown, in some embodiments, the simulation assembly 20 includes a heating box 21, a fractured-solid reservoir model 22 installed in the heating box 21, and a confining pressure pump 23 connected to the fractured-solid reservoir model 22. Driven by an external power source, the heating box 21 can raise its internal temperature to 350°C to simulate the high-temperature environment of the fractured-solid reservoir model 22. The confining pressure pump 23 can provide confining pressure to the fractured-solid reservoir model 22 to simulate the high-pressure environment of the fractured-solid reservoir.

[0038] Combine Figure 2 and Figure 3 As shown, the fault-karst reservoir model 22 includes a plurality of cavities 221 for simulating underground oil storage caves, and a first flow channel 222 and a second flow channel 223 for fluidly connecting the plurality of cavities 221. The plurality of cavities 221 are irregular in shape and vary in size and height. A cavity 221 can be connected to a first flow channel 222 or another cavity 221 through at least one second flow channel 223. The plurality of cavities 221 include a first cavity 221a connected to one second flow channel 223, a second cavity 221b connected to two second flow channels 223, and a third cavity 221c connected to three second flow channels 223. Similarly, the plurality of cavities 221 may also include a fourth cavity 221d and a fifth cavity (not shown).

[0039] The second flow channel 223 is connected to the first flow channel 222 or the cavity 221 at different angles, and can be connected to the bottom, middle or upper part of the cavity 221. In the embodiment, the first flow channel 222 and the second flow channel 223 are used to simulate the fissure connecting the underground cave. Two first flow channels 222 are provided, and the inner diameter of the first flow channel 222 is larger than that of the second flow channel 223. The fractured-cave reservoir model 22 further comprises a bottom water cavity 24 connected to the lower end of the first flow channel 222, so as to facilitate the simultaneous injection of water into the two first flow channels 222.

[0040] The fractured-cave reservoir model 22 is provided with a first injection port 224 for injecting foam, a second injection port (not shown) for injecting water, and a discharge port 225 for discharging water and oil. In some embodiments, the first injection port 224 is connected to one of the second cavities 221b at the upper left corner of the fractured-cave reservoir model 22. The cavity 221 can be connected to the foam generator 18 through the first injection port 224, so that the foam can enter the cavities 221 and displace the oil from top to bottom. The second injection port is connected to the bottom water cavity 24. The cavities 221 and the six-way valve 13 can be connected through the second injection port, so that water can enter the cavities 221 from the bottom water cavity 24 and displace the oil from bottom to top. In some embodiments, since the second flow channel 223 can be connected to the bottom, middle or upper part of the cavity 221, the water cannot completely displace the oil in the cavities 221. At this time, foam displacement is needed.

[0041] In some embodiments, the fractured-cave reservoir model 22 can be made of two transparent glass plates that are attached to each other and can withstand the high temperature generated by the heating box 21 and the confining pressure provided by the confining pressure pump 23. The same grooves are engraved on the surfaces of the two glass plates using a machine tool, and then sealing materials such as sealant are provided on the edges of the grooves. Finally, the two glass plates with grooves are attached to each other, and the cavities 221, the first flow channels 222 and the second flow channels 223 are obtained. In addition, a plurality of bolts are provided on the two glass plates to ensure that the two glass plates are tightly attached to each other.

[0042] Referring again to Figure 1 As shown, the measurement assembly 30 comprises a separation meter 31 connected to the discharge port 225, and a gas metering device connected to the separation meter 31. The separation meter 31 can separate the water-oil-gas three-phase mixture discharged from the discharge port 225, and measure the water and oil therein. The separated gas is measured by the gas meter 32.

[0043] In some embodiments, the experimental device further comprises a recording assembly 40 disposed on one side of the simulation assembly 20. The recording assembly 40 comprises a camera 41 for shooting and recording the fractured-cavity oil reservoir model 22, and a computer 42 electrically connected with the camera 41. Under the electrical driving of an external power source, the camera 41 can record the whole process of water flooding and foam flooding of the fractured-cavity oil reservoir model 22, and then upload the process to the computer 42 and store it for later observation and analysis.

[0044] In combination Figures 1-3 As shown in some embodiments, first, the valves of the input end and the output end of the oil storage tank 15 are opened, and the six-way valve 13 is adjusted, so that the constant-flow pump 11-the oil storage tank 15-the six-way valve 13-the pipeline where the fractured-cavity oil reservoir model 22 is located are connected. Under the electrical driving of an external power source and in cooperation with a vacuum pump (not shown), the constant-flow pump 11 can make the oil in the oil storage tank 15 enter and fill the cavities 221 of the fractured-cavity oil reservoir model 22 through the six-way valve 13. The heating box 21 and the confining pressure pump 23 are opened, so that the fractured-cavity oil reservoir model 22 is in a predetermined temperature and pressure environment. The valves of the input end and the output end of the oil storage tank 15 are closed, the valves of the input end and the output end of the water storage tank 16 are opened, and the six-way valve 13 is adjusted, so that the constant-flow pump 11-the water storage tank 16-the six-way valve 13-the pipeline where the fractured-cavity oil reservoir model 22 is located are connected. The constant-flow pump 11 makes the water in the water storage tank 16 enter the bottom water cavity 24 of the fractured-cavity oil reservoir model 22 through the second injection port and the six-way valve 13. Under the continuous pumping action of the constant-flow pump 11, the water enters the cavities 221 through the first flow channel 222 and the second flow channel 223 from the bottom water cavity 24, so as to displace the oil in the cavities 221. The displaced oil and water enter the separation meter 31 through the discharge port 225 for separation and metering.

[0045] When the displacement yield of the oil decreases, the valves of the input end and the output end of the water storage tank 16 are closed, the valves of the input end and the output end of the storage tank 17 and the gas storage tank 14 are opened. The six-way valve 13 is adjusted, so that the constant-flow pump 11-the storage tank 17 / the gas storage tank 14-the six-way valve 13-the foam generator 18-the pipeline where the fractured-cavity oil reservoir model 22 is located are connected. Under the electrical driving of an external power source, the foaming agent in the storage tank 17 and the gas in the gas storage tank 14 enter the foam generator 18 and form foam. The foam enters the cavities 221 of the fractured-cavity oil reservoir model 22 through the first injection port 224, so as to displace the remaining oil in the cavities 221. Finally, until no oil is produced from the discharge port 225. Through the metering of the separation meter 31 on the water and oil yield, and the metering of the gas meter 32 on the discharged gas, the displacement effect of the foam flooding on the fractured-cavity oil reservoir model 22 is evaluated. The camera 41 records the whole process of water flooding and foam flooding of the fractured-cavity oil reservoir model 22, and records the displacement time.

[0046] In some preferred embodiments, the displacement intensity of water flooding and / or foam flooding is adjusted by adjusting the output pressure of the constant flow pump 11.

[0047] In some preferred embodiments, the foam with different gas-liquid ratios is obtained by adjusting the valve opening degree of the input end of the storage tank 17 and the gas storage tank 14, so as to study the displacement effect of the foam with different gas-liquid ratios on the faulted-soluble oil reservoir.

[0048] In some preferred embodiments, the foam with different densities is obtained by adjusting the foam generator 18, so as to study the displacement effect of the foam with different densities on the faulted-soluble oil reservoir.

[0049] In some other preferred embodiments, the water and oil are dyed for the purpose of observation and recording by the camera 41 during the water flooding and foam flooding. Figure 2 and Figure 3 As shown in the figures, the darker part in the cavity 221 indicated by the arrow A is water, the lighter part in the cavity 221 indicated by the arrow B is oil, and the foam in the cavity 221 indicated by the arrow C.

[0050] In the description of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "mounting", "connection", "linking" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection or integral connection, it can be mechanical connection, it can be direct connection or indirect connection through intermediate medium, it can be internal communication of two elements or interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0051] It should be understood that the terms "length", "width", "upper", "lower", "front and back", "left and right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0052] The above is based on the ideal embodiments of the present application, and through the above description, relevant personnel can make various changes and modifications without deviating from the scope of the present application. The technical scope of the present application is not limited to the content in the specification, and must be determined according to the scope of the claims.

Claims

1. An experimental device for simulating displacement of a fractured-dissolved reservoir, comprising, a simulation assembly (20) including a fractured-dissolved reservoir model (22) for simulating a fractured-dissolved reservoir in the ground; an injection assembly (10) in communication with the fractured-dissolved reservoir model (22) and configured to inject oil and a displacement fluid into the fractured-dissolved reservoir model (22) in sequence; a measurement assembly (30) including a separation meter (31) in fluid communication with the fractured-dissolved reservoir model (22), wherein the separation meter (31) being configured to separate and meter the oil and the displacement fluid discharged from the fractured-dissolved reservoir model (22).

2. The experimental setup for simulating displacement of a residual body oil reservoir according to claim 1, wherein, the fractured-dissolved reservoir model (22) including a plurality of cavities (221) of different sizes and heights and irregular shapes, and a first flow channel (222) and a second flow channel (223) in communication with the plurality of cavities (221).

3. The experimental setup for simulating displacement of a residual body oil reservoir according to claim 2, wherein, the cavities (221) being configured to communicate with the first flow channel (222) or another cavity (221) through at least one of the second flow channels (223), and / or, the second flow channels (223) being configured to communicate with the first flow channel (222) and the bottom, middle or top of the cavities (221) at any angle.

4. The experimental setup for simulating displacement of a residual body oil reservoir of claim 2, wherein, the fractured-dissolved reservoir model (22) being provided with a first injection port (224) and a second injection port for injecting the displacement fluid, and a discharge port (225) for discharging the oil and the displacement fluid, the discharge port (225) being away from the first injection port (224) and the second injection port, so that the displacement fluid injected through the first injection port (224) and the second injection port has to pass through at least two of the cavities (221) before being discharged through the discharge port (225).

5. The experimental apparatus for simulating displacement of a residual body oil reservoir according to claim 4, wherein the second injection port being in communication with the injection assembly (10) and a bottom water cavity (24) of the fractured-dissolved reservoir model (22), the bottom water cavity (24) being in communication with the end of the first flow channel (222), so that the injection assembly (10) can inject water through the bottom water cavity (24) into the plurality of cavities (221) to water-flood the oil in the cavities (221).

6. The experimental setup for simulating displacement of a residual body oil reservoir of claim 4, wherein, the first injection port (224) being in communication with the cavities (221) and the injection assembly (10) for injecting the foam generated by the injection assembly (10) into the plurality of cavities (221) to foam-flood the oil in the cavities (221).

7. The experimental apparatus for simulating displacement of a residual dissolution body reservoir according to claim 6, wherein the measurement assembly (30) further includes a gas meter (32) in communication with the separation meter (31), the gas meter (32) being configured to meter the amount of gas in the foam discharged through the discharge port (225).

8. The experimental setup for simulating displacement of a residual body oil reservoir of claim 1, wherein, the simulation assembly (20) further includes a heating box (21) for placing the fractured-dissolved reservoir model (22), and a confining pressure pump (23) connected to the fractured-dissolved reservoir model (22) to provide the fractured-dissolved reservoir model (22) with the required temperature and pressure, respectively.

9. The experimental setup for simulating displacement of a residual body oil reservoir according to any one of claims 1-8, characterized in that, The injection assembly (10) comprises a constant flow pump (11) and a six-way valve (13) in fluid communication with the constant flow pump (11), the constant flow pump (11) being connected in parallel with a gas storage tank (14), an oil storage tank (15), a water storage tank (16) and a storage tank (17) for storing a foaming agent.

10. The experimental apparatus for simulating displacement of a residual dissolution body oil reservoir according to claim 9, wherein, A foam generator (18) is provided between the six-way valve (13) and the fractured-solution reservoir model (22), the six-way valve (13) being configured to inject gas from the gas storage tank (14) and a foaming agent from the storage tank (17) into the foam generator (18) to form a foam for oil displacement.

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