Three-dimensional model for fractured reservoir simulation experiment, injection-production system and injection-production method

Abstract

The invention discloses a three-dimensional model for a fractured reservoir simulation experiment, an injection-production system and an injection-production method, and relates to the technical field of oil and gas field development. An annular cavity is formed between the outer wall of a rubber cylinder and the inner wall of a cylinder body, sealing covers cover openings in the two ends of the rubber cylinder, and the edges of the sealing covers are connected with the inner wall of the cylinder body in a sealed mode to seal the annular cavity; the first flange cover is detachably connected with the cylinder body so as to cover the top opening of the cylinder body, a rock block module composed of a plurality of simulation rock blocks is arranged in the rubber cylinder, gaps among the simulation rock blocks are filled with fillers, the rock block module is provided with an injection well and a production well, the sealing cover is provided with a plurality of through holes, the first flange cover is provided with a first well hole and a second well hole, and the second flange cover is provided with a second well hole. The first well hole is communicated with the injection well through the through hole, the second well hole is communicated with the production well through the through hole, and a water injection opening is formed in the side wall of the barrel. The model is of a three-dimensional structure, the complex structure of the actual fractured reservoir can be better reflected, and therefore the flow characteristics of the fractured reservoir and dynamic fluid exchange between fractures and a matrix can be accurately simulated.

Description

Technical Field

[0001] The present application relates to the technical field of oil and gas field development, and in particular to a three-dimensional model, an injection-production system and an injection-production method for a fracture-type reservoir simulation experiment. Background Art

[0002] Fractured reservoirs are widely distributed in carbonate and sandstone formations around the world. They are a special type of reservoir with a natural fracture system. Due to the heterogeneity and complex pore structure of fractured reservoirs, their reservoir seepage behavior is different from that of general porous reservoirs. Fractures are the main flow channels for oil and gas, and the reservoir matrix is ​​the main storage space for oil and gas. The two present "dual medium" characteristics during the development process. The fluid exchange and flow behavior of fractures and matrices are affected by multiple factors such as fracture structure, fluid viscosity, and displacement pressure. This complexity brings huge challenges to the development of fractured reservoirs.

[0003] At present, the development of fractured oil reservoirs mainly relies on water injection, gas injection and thermal recovery. However, due to the strong conductivity of fractures and the low permeability of the matrix, the "dominant channel" phenomenon is prone to occur during the displacement process, which makes the injected fluid quickly break through the fractures, while the oil and gas in the matrix are difficult to fully mobilize, resulting in low oil displacement efficiency and unsatisfactory recovery rate. Therefore, in-depth research on the seepage mechanism of fractured oil reservoirs, optimization of injection and production process parameters, and improvement of recovery rate have become the key to the development of fractured oil reservoirs.

[0004] In existing research, most fractured reservoir physical simulation experiments use two-dimensional experimental models to study the flow behavior of fluids in fractures. Two-dimensional experimental models are usually plane or nearly plane structures, and are mainly used to study the flow behavior of fluids in fractures. However, due to their planar characteristics, they are difficult to fully reflect the three-dimensional spatial exchange characteristics between fractures and matrix, and cannot accurately simulate the flow characteristics of fluids in three-dimensional space.

[0005] Therefore, how to accurately simulate the flow characteristics of fractured reservoirs and the dynamic fluid exchange between fractures and the matrix is ​​a problem that needs to be solved by those skilled in the art. Summary of the invention

[0006] The purpose of this application is to provide a three-dimensional model, injection-production system and injection-production method for a fractured reservoir simulation experiment, which is used to solve the problem that a two-dimensional experimental model is difficult to fully reflect the three-dimensional spatial exchange characteristics between fractures and matrix, and cannot accurately simulate the flow characteristics of fluids in three-dimensional space.

[0007] In order to solve the above technical problems, the present application provides a three-dimensional model for fracture type reservoir simulation experiment, including: a rock block module, a rubber cylinder, a cylinder body, a sealing cover and a first flange cover;

[0008] The rubber sleeve is coaxially sleeved in the cylinder, an annular cavity is provided between the outer wall of the rubber sleeve and the inner wall of the cylinder, the sealing cover is provided at the two end openings of the rubber sleeve, and the edge of the sealing cover is sealed and connected to the inner wall of the cylinder to close the annular cavity, the first flange cover is detachably connected to the cylinder to cover the top opening of the cylinder, the rock block module is provided in the cavity formed by the rubber sleeve and the sealing cover, the rock block module is composed of a plurality of simulated rock blocks, and the gaps between the simulated rock blocks are provided with fillers, the rock block module is provided with an injection well and a production well, the sealing cover is provided with a plurality of through holes, the first flange cover is provided with a first wellbore and a second wellbore, the first wellbore is connected to the injection well through the through hole, the second wellbore is connected to the production well through the through hole, the first wellbore is used to connect the injection pipeline, the second wellbore is used to connect the production pipeline, the side wall of the cylinder is provided with a water injection port, and the water injection port is used to connect the water injection pipeline.

[0009] In a feasible embodiment, it also includes a support seat and a clamp, wherein the clamp is arranged on the support seat, and two clamp arms of the clamp are respectively abutted against two side walls of the cylinder, and the cylinder rotates around the horizontal axis to change the height difference between the injection end of the first wellbore and the output end of the second wellbore.

[0010] In a feasible embodiment, an opening is provided at the bottom of the cylinder, and the second flange cover is detachably connected to the cylinder to cover the bottom opening of the cylinder.

[0011] In a feasible embodiment, a sealing gasket is provided at a connection between the first flange cover and the cylinder body, and at a connection between the second flange cover and the cylinder body.

[0012] The present application also provides an injection and production system for a fractured oil reservoir simulation experiment, comprising: a first container filled with formation water, a first displacement pump, a six-way valve, a second container filled with crude oil, a second displacement pump, an injection pipeline, a production pipeline, a back pressure control valve, a third displacement pump, a measuring cylinder, an electronic balance, a water injection pipeline, a plunger pump, a first pressure gauge, a second pressure gauge, a third pressure gauge, a fourth pressure gauge, a fifth pressure gauge and the three-dimensional model;

[0013] The first container is respectively connected to the first displacement pump and the six-way valve, the second container is respectively connected to the second displacement pump and the six-way valve, the injection pipeline is respectively connected to the six-way valve and the first wellbore of the three-dimensional model, the production pipeline is respectively connected to the back pressure control valve and the second wellbore of the three-dimensional model, the back pressure control valve is respectively connected to the third displacement pump and the measuring cylinder, the measuring cylinder is arranged on the electronic balance, the water injection pipeline is respectively connected to the plunger pump and the water injection port of the three-dimensional model, a first pressure gauge is arranged on the pipeline connecting the first container and the six-way valve, a second pressure gauge is arranged on the pipeline connecting the second container and the six-way valve, a third pressure gauge is arranged on the production pipeline, a fourth pressure gauge is arranged on the pipeline connecting the third displacement pump and the back pressure control valve, and a fifth pressure gauge is arranged on the water injection pipeline.

[0014] The present application also provides an injection-production method for a fractured oil reservoir simulation experiment, which is applied to an injection-production system for the fractured oil reservoir simulation experiment, comprising:

[0015] Preprocessing the three-dimensional model so that the formation water and crude oil of the simulated rock block in the three-dimensional model are both in a saturated state, and aging the crude oil of the simulated rock block;

[0016] Water is injected into the interior of the three-dimensional model to carry out a displacement simulation experiment, and the oil production, water production and pressure detected by the pressure gauges on each pipeline in the displacement simulation experiment are recorded.

[0017] In a feasible embodiment, the preprocessing of the three-dimensional model includes:

[0018] Controlling the plunger pump to inject water into the annular cavity between the rubber cylinder and the cylinder body of the three-dimensional model to apply confining pressure to the simulated rock block of the three-dimensional model to simulate the formation pressure;

[0019] Performing an airtightness test on the three-dimensional model, and determining whether the airtightness of the three-dimensional model meets a preset standard;

[0020] If the preset standard is met, the three-dimensional model is vacuumed;

[0021] Controlling a first displacement pump to inject formation water into the three-dimensional model until the formation water in the simulated rock block is saturated;

[0022] The second displacement pump is controlled to inject crude oil into the three-dimensional model until the simulated rock block is saturated with crude oil.

[0023] In a feasible embodiment, aging the crude oil of the simulated rock block comprises:

[0024] The three-dimensional model is placed in a constant temperature box, the fractured oil reservoir temperature is set, and the model is left to stand for a preset period of time to age the crude oil.

[0025] In a feasible embodiment, controlling the first displacement pump to inject formation water into the three-dimensional model includes:

[0026] Adjusting the inclination angle of the three-dimensional model so that the first wellbore of the three-dimensional model is located below the second wellbore of the three-dimensional model;

[0027] Controlling the first displacement pump to drive the formation water in the first container to be injected into the three-dimensional model through the injection pipe at a constant flow rate;

[0028] Accordingly, controlling the second displacement pump to inject crude oil into the three-dimensional model includes:

[0029] Adjusting the inclination angle of the three-dimensional model so that the second wellbore of the three-dimensional model is located below the first wellbore of the three-dimensional model;

[0030] The second displacement pump is controlled to drive the crude oil in the second container to be injected into the three-dimensional model through the injection pipeline at a constant flow rate.

[0031] In a feasible embodiment, performing an airtightness test on the three-dimensional model and determining whether the airtightness of the three-dimensional model meets a preset standard includes:

[0032] Closing the second wellbore of the three-dimensional model, and delivering gas into the three-dimensional model through the first wellbore of the three-dimensional model so that the pressure of the three-dimensional model reaches a set pressure;

[0033] After a preset time period, obtaining a current pressure of the three-dimensional model, and determining a difference between the set pressure and the current pressure;

[0034] If the difference is greater than or equal to a set value, the air tightness of the three-dimensional model does not meet the preset standard;

[0035] If the difference is less than a set value, the airtightness of the three-dimensional model meets the preset standard.

[0036] The present application provides a three-dimensional model of a fracture-type reservoir simulation experiment, comprising: a rock block module, a rubber cylinder, a cylinder body, a sealing cover and a first flange cover; the rubber cylinder is coaxially sleeved in the cylinder body, an annular cavity is provided between the outer wall of the rubber cylinder and the inner wall of the cylinder body, the sealing cover is provided to cover the two end openings of the rubber cylinder, and the edge of the sealing cover is sealed and connected to the inner wall of the cylinder body to close the annular cavity, the first flange cover is detachably connected to the cylinder body to cover the top opening of the cylinder body, the rock block module is provided in a cavity formed by the rubber cylinder and the sealing cover, the rock block module is composed of a plurality of simulated rock blocks, and fillers are provided in the gaps between the simulated rock blocks, the rock block module is provided with an injection well and a production well, a plurality of through holes are provided on the sealing cover, a first well hole and a second well hole are provided on the first flange cover, the first well hole is connected to the injection well through the through hole, the second well hole is connected to the production well through the through hole, the first well hole is used to connect the injection pipeline, the second well hole is used to connect the production pipeline, and a water injection port is provided on the side wall of the cylinder body, and the water injection port is used to connect the water injection pipeline. The model constructed in the present application is a three-dimensional structure, which can more accurately reflect the complex structure of the actual fractured reservoir compared to the two-dimensional model, thereby being able to accurately simulate the flow characteristics of the fractured reservoir and the dynamic fluid exchange between the fracture and the matrix.

[0037] The beneficial effects of the injection-production system and injection-production method for a fractured oil reservoir simulation experiment provided in the present application correspond to the three-dimensional model, and the effects are as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0039] Figure 1 A schematic diagram of the end face of the injection end of a three-dimensional model of a fractured reservoir simulation experiment provided in an embodiment of the present application;

[0040] Figure 2 A rock module structure diagram of a three-dimensional model of a fractured reservoir simulation experiment provided in an embodiment of the present application;

[0041] Figure 3 A cross-sectional view of a rock block module of a three-dimensional model of a fractured reservoir simulation experiment provided in an embodiment of the present application;

[0042] Figure 4 A front view of a three-dimensional model of a fractured reservoir simulation experiment provided in an embodiment of the present application;

[0043] Figure 5 A side view of a three-dimensional model of a fractured reservoir simulation experiment provided in an embodiment of the present application;

[0044] Figure 6 A structural diagram of an injection-production system for a fractured reservoir simulation experiment provided in an embodiment of the present application;

[0045] Figure 7 A flow chart of an injection-production method for a fractured reservoir simulation experiment provided in an embodiment of the present application.

[0046] The reference numerals are as follows: 1-rock module, 101-simulated rock, 102-filler, 103-injection well, 104-production well, 2-rubber cylinder, 3-cylinder, 4-bolt, 5-support seat, 6-clamp, 7-universal wheel, 8-first flange cover, 801-first wellbore, 802-second wellbore, 9-second flange cover, 10-injection pipeline, 11-production pipeline, 12-three-dimensional model, 13-first container, 14-first displacement pump, 15-first displacement pump, 16-first displacement pump, 17-first displacement pump, 18-first displacement pump, 19-first displacement pump, 20-first displacement pump, 21-first displacement pump, 22-second displacement pump, 23-first displacement pump, 24-first displacement pump, 25-first displacement pump, 26-first displacement pump, 27-first displacement pump, 28-first displacement pump, 29-first displacement pump, 30-first displacement pump, 31-first displacement pump, 32-first displacement pump, 33-first displacement pump, 34-first displacement pump, 35-first displacement pump, 36-first displacement pump, 37-first displacement pump, 38-first displacement pump, 39-first displacement pump, 40-first displacement pump, 41-first displacement pump, 42-first displacement pump, 43-first displacement pump, 44-first displacement pump, 45-first displacement pump, 46-first displacement pump, 47-first displacement pump, 48-first displacement pump, 49-first displacement pump, 50-first displacement pump, 51-first displacement pump, 52-first displacement pump, 53-first displacement pump, 54-first displacement pump, 55-first displacement pump, 56-first displacement pump, 57-first displacement pump, 5 5-six-way valve, 16-second container, 17-second displacement pump, 18-back pressure control valve, 19-third displacement pump, 20-measuring cylinder, 21-electronic balance, 22-water injection pipeline, 23-plunger pump, 24-first pressure gauge, 25-second pressure gauge, 26-third pressure gauge, 27-fourth pressure gauge, 28-fifth pressure gauge, 29-first valve, 30-second valve, 31-third valve, 32-fourth valve, 33-fifth valve. DETAILED DESCRIPTION

[0047] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0048] The core of this application is to provide a three-dimensional model, injection-production system and injection-production method for a fractured oil reservoir simulation experiment, which are used to accurately simulate the flow characteristics of fractured oil reservoirs and the dynamic fluid exchange between fractures and matrix.

[0049] In order to enable those skilled in the art to better understand the present application, the present application is further described in detail below in conjunction with the accompanying drawings and specific implementation methods.

[0050] Figure 1 This is a schematic diagram of the end face of the injection end of a three-dimensional model of a fractured reservoir simulation experiment provided in an embodiment of the present application. Figure 2 This is a structural diagram of a rock block module 1 of a three-dimensional model of a fractured reservoir simulation experiment provided in an embodiment of the present application. Figure 3 A cross-sectional view of a rock block module 1 of a three-dimensional model of a fractured reservoir simulation experiment provided in an embodiment of the present application, as shown in FIG. Figures 1 to 3As shown, the three-dimensional model 12 of the fracture type reservoir simulation experiment includes a rock block module 1, a rubber cylinder 2, a cylinder body 3, a sealing cover (not shown in the figure) and a first flange cover 8; the rubber cylinder 2 is coaxially sleeved in the cylinder body 3, an annular cavity is provided between the outer wall of the rubber cylinder 2 and the inner wall of the cylinder body 3, the sealing cover is provided to cover the two end openings of the rubber cylinder 2, and the edge of the sealing cover is sealed and connected to the inner wall of the cylinder body 3 to close the annular cavity, the first flange cover 8 is detachably connected to the cylinder body 3 to cover the top opening of the cylinder body 3, the rock block module 1 is provided in the cavity formed by the rubber cylinder 2 and the sealing cover, and the rock block module 1 is composed of a plurality of simulated rock blocks. The rock block module 101 is composed of a block 101, and the gaps between the simulated rock blocks 101 are provided with fillers 102. The rock block module 1 is provided with an injection well 103 and a production well 104. The sealing cover is provided with multiple through holes. The first flange cover 8 is provided with a first wellbore 801 and a second wellbore 802. The first wellbore 801 is connected to the injection well 103 through the through hole, and the second wellbore 802 is connected to the production well 104 through the through hole. The first wellbore 801 is used to connect to the injection pipe 10, and the second wellbore 802 is used to connect to the production pipe 11. The side wall of the cylinder 3 is provided with a water injection port, which is used to connect to the water injection pipe 22.

[0051] The rock block module 1 in the embodiment of the present application is composed of a plurality of simulated rock blocks 101, such as Figure 2 As shown, the rock module 1 is composed of 125 square simulated rock blocks 101. Of course, the shape of the rock module 1 and the number of simulated rock blocks 101 in the rock module 1 are not limited to Figure 2The one shown can be adjusted according to actual needs. Among them, the simulated rock block 101 can be carbonate rock or sandstone rock block, etc., which is selected according to the actual geological conditions of the reservoir to be simulated; the simulated rock block 101 is cut from natural outcrop rocks, which more realistically reflects the geological framework of the reservoir. There is a gap between each simulated rock block 101 of the rock block module 1, and the gap is 0.1 mm-1 mm, and fillers 102 (carbonate minerals, siliceous minerals or clay minerals) are filled in the gap of the simulated rock block 101 according to the actual geological conditions of the fracture-type reservoir to be simulated. In different reservoirs, for example, clay minerals are generally developed in the cracks of sandstone fracture-type reservoirs, and carbonate minerals and siliceous minerals are generally developed in the cracks of carbonate fracture-type reservoirs. In this regard, if a carbonate fracture-type reservoir needs to be simulated, carbonate minerals and siliceous minerals can be filled in the gaps between the simulated rock blocks 101; if a sandstone fracture-type reservoir needs to be simulated, clay minerals can be filled in the gaps between the simulated rock blocks 101. The main purpose of the gap filling filler 102 between each simulated rock block 101 is to reflect the sensitivity of the cracks. Different gap filling fillers 102 have different sensitivities to different injected fluids, which will affect the permeability of the reservoir and cause reservoir damage, thereby affecting the recovery efficiency and effect of the oil reservoir. Based on this, the three-dimensional model of the present application can also be used to study the sensitivity of minerals with fractures in different reservoirs to injected fluids. By simulating different injection conditions, the reaction of minerals in the gaps to the fluid is observed and analyzed, and the injection strategy is optimized to reduce reservoir damage and improve the recovery efficiency of the oil reservoir.

[0052] The rock module 1 is provided with an injection well 103 and a production well 104, wherein the injection well 103 and the production well 104 both pass through the two ends of the rock module 1; the first end of the injection well 103 is connected to one of the through holes on the sealing cover provided at the first end of the rubber cylinder 2, and the second end of the injection well 103 is connected to one of the through holes on the sealing cover provided at the second end of the rubber cylinder 2; the first end of the production well 104 is connected to one of the through holes on the sealing cover provided at the first end of the rubber cylinder 2, and the second end of the production well 104 is connected to one of the through holes on the sealing cover provided at the second end of the rubber cylinder 2. As to how to form the injection well 103 and the production well 104 in the rock module 1, it can be that a plurality of simulated rock blocks 101 with drilled holes are arranged along the axial direction of the rubber cylinder 2, and the plurality of drilled holes are connected in sequence to form the injection well 103; similarly, a plurality of other simulated rock blocks 101 with drilled holes are arranged along the axial direction of the rubber cylinder 2, and the plurality of drilled holes are connected in sequence to form the production well 104.

[0053] The rubber cylinder 2 in the embodiment of the present application can be in the shape of a cube, and the two ends of the rubber cylinder 2 are open structures. The rubber cylinder 2 can be detachably connected to the sealing cover by a bolt assembly so that the sealing cover is set on the two openings of the rubber cylinder 2. The rubber cylinder 2 and the two sealing covers enclose a cubic cavity that can accommodate the rock block module 1. The size of the cubic cavity is 250mm×250mm×250mm. The simulated rock block 101 is a cubic rock block with a side length of 49mm-50mm. The specific size of the simulated rock block 101 is determined according to the required reserved crack width, and the crack width is the gap between the simulated rock blocks 101. The outer diameter of the rubber cylinder 2 is smaller than the inner diameter of the cylinder 3. The rubber cylinder 2 is coaxially sleeved in the cylinder 3. A gap (annular cavity) is provided between the outer wall of the rubber cylinder 2 and the inner wall of the cylinder 3. The edges of the sealing covers at both ends of the rubber cylinder 2 are sealed and connected to the inner wall of the cylinder 3. The sealing cover can be made of rubber, and the edge of the sealing cover is tightly abutted against the inner wall of the cylinder 3, thereby closing the two ends of the annular cavity. Water is injected into the annular cavity to increase pressure to simulate the formation confining pressure; the rubber tube 2 can be made of rubber. When water is injected into the annular cavity to increase pressure, the rubber tube 2 is deformed to effectively transfer the pressure to the simulated rock block 101, thereby better simulating the formation confining pressure. The sealing cover is provided with a plurality of through holes. When two through holes on the sealing cover are aligned and connected with the injection well 103 and the production well 104 respectively, the remaining through holes on the sealing cover can be blocked with rubber plugs.

[0054] The embodiment of the present application does not limit the shape of the cylinder 3. The cylinder 3 can be a rounded square cylinder 3 with openings at both ends and a hollow interior, that is, the corners of the cylinder 3 are rounded; the cylinder 3 is made of stainless steel, and the thickness of the cylinder wall of the cylinder 3 is greater than or equal to 100mm, so as to ensure the pressure bearing capacity of the cylinder 3. Specifically: the outer length of the rounded square cylinder 3 is 480mm, and the inner length is 280mm. The top opening cover of the rounded square cylinder 3 is provided with a first flange cover 8, and the bottom opening cover of the rounded square cylinder 3 is provided with a second flange cover 9. The first flange cover 8 and the second flange cover 9 can be detachably connected to the cylinder 3 by bolts 4. Specifically, the edges of the first flange cover 8 and the second flange cover 9 are spaced apart to form a first screw hole, and the top opening edge and the bottom opening edge of the cylinder 3 are spaced apart to form a second screw hole, and the bolt 4 passes through the first screw hole and the second screw hole to cover the first flange cover 8 on the top opening of the cylinder 3, and the second flange cover 9 on the bottom opening of the cylinder 3. In order to prevent the fluid in the three-dimensional model 12 from flowing out through the edge of the flange cover, the connection between the first flange cover 8 and the cylinder 3 and the connection between the second flange cover 9 and the cylinder 3 are both provided with sealing gaskets, and the connection between the flange and the cylinder 3 is sealed by the clamping force of the sealing gasket and the bolt 4. Among them, the first flange cover 8 and the second flange cover 9 can be rounded squares, the side length of the flange cover is 480mm, and the thickness of the flange cover is 150mm. The flange cover can also prevent the rubber cylinder 2 and the rock block module 1 from unnecessary displacement. The first flange cover 8 is provided with a first wellbore 801 and a second wellbore 802. The number of the first wellbore 801 and the second wellbore 802 can be multiple. When one of the first wellbore 801 is connected to the injection well 103 through a through hole, the remaining first wellbore 801 can be blocked, and when one of the second wellbore 802 is connected to the production well 104 through a through hole, the remaining second wellbore 802 can be blocked.

[0055] Based on the above embodiments, Figure 4 This is a front view of a three-dimensional model of a fractured reservoir simulation experiment provided in an embodiment of the present application. Figure 5 A side view of a three-dimensional model of a fractured reservoir simulation experiment provided in an embodiment of the present application, such as Figure 4 and Figure 5 As shown, the embodiment of the present application also includes a support seat 5 and a clamp 6. The clamp 6 is arranged on the support seat 5. The two clamping arms of the clamp 6 are respectively abutted against the two side walls of the cylinder 3. The cylinder 3 rotates around the horizontal axis to change the height difference between the injection end of the first wellbore 801 and the output end of the second wellbore 802.

[0056] The two clamping arms of the clamp 6 are adjustable on the support seat 5, so as to adjust the distance between the two clamping arms to adapt to different specifications of the three-dimensional model 12. The cylinder 3 rotates around the horizontal axis to change the height difference between the injection end of the first wellbore 801 and the output end of the second wellbore 802 to construct the reservoir inclination. Figure 5 As shown, the reservoir inclination angle is θ. Based on this, in order to facilitate the transportation of the three-dimensional model 12, a universal wheel 6 with a brake device can also be provided at the bottom of the support base 5.

[0057] A three-dimensional model of a fractured reservoir simulation experiment provided in an embodiment of the present application comprises: a rock block module 1, a rubber cylinder 2, a cylinder body 3, a sealing cover and a first flange cover 8; the rubber cylinder 2 is coaxially sleeved in the cylinder body 3, an annular cavity is provided between the outer wall of the rubber cylinder 2 and the inner wall of the cylinder body 3, the sealing cover is provided at the two end openings of the rubber cylinder 2, and the edge of the sealing cover is sealed and connected with the inner wall of the cylinder body 3 to close the annular cavity, the first flange cover 8 is detachably connected to the cylinder body 3 to cover the top opening of the cylinder body 3, the rock block module 1 is provided in the cavity formed by the rubber cylinder 2 and the sealing cover, and the rock block module 1 is composed of a plurality of simulated rock blocks. The block 101 is composed of a filler 102 between the simulated rock blocks 101, the rock block module 1 is provided with an injection well 103 and a production well 104, the sealing cover is provided with a plurality of through holes, the first flange cover 8 is provided with a first wellbore 801 and a second wellbore 802, the first wellbore 801 is connected to the injection well 103 through the through hole, the second wellbore 802 is connected to the production well 104 through the through hole, the first wellbore 801 is used to connect the injection pipeline 10, the second wellbore 802 is used to connect the production pipeline 11, and the side wall of the cylinder 3 is provided with a water injection port, which is used to connect the water injection pipeline 22. The model constructed in this application is a three-dimensional structure, which can more accurately reflect the complex structure of the actual fracture-type reservoir compared to the two-dimensional model, so as to accurately simulate the flow characteristics of the fracture-type reservoir and the dynamic fluid exchange between the fracture and the matrix.

[0058] In addition, by setting the support seat 5 and the clamp 6, the height difference between the injection end of the first wellbore 801 and the output end of the second wellbore 802 can be adjusted, so that the inclination angle of the reservoir can be constructed; the simulated rock block 101 can be preferably selected from carbonate rock blocks and sandstone rock blocks according to the actual geological conditions to be simulated, so as to achieve the purpose of simulating carbonate rock fracture type reservoirs and sandstone fracture type reservoirs; the gaps between the simulated rock blocks 101 can be preferably selected from appropriate fracture widths according to the actual geological conditions to be simulated; if it is necessary to simulate a carbonate rock fracture type reservoir, carbonate rock minerals and siliceous minerals can be filled between the gaps between the simulated carbonate rock blocks, so as to achieve the purpose of more realistically simulating the complex fracture structure in the actual carbonate rock fracture type reservoir, thereby effectively improving the accuracy of the simulation experiment; if it is necessary to simulate a sandstone fracture type reservoir, clay minerals can be filled between the gaps between the simulated sandstone rock blocks, which helps to more realistically simulate the sensitivity of the reservoir fractures to the injected fluid, improve the reference significance of the physical phenomena observed in the experiment and the experimental data obtained, and promote the development of oil and gas reservoir physical simulation experiments using the three-dimensional injection and production experimental model of the fracture type reservoir as a research tool.

[0059] Figure 6 A structural diagram of an injection-production system for a fractured reservoir simulation experiment provided in an embodiment of the present application, such as Figure 6As shown, an injection and production system for a fractured oil reservoir simulation experiment includes: a first container 13 filled with formation water, a first displacement pump 14, a six-way valve 15, a second container 16 filled with crude oil, a second displacement pump 17, an injection pipeline 10, a production pipeline 11, a back pressure control valve 18, a third displacement pump 19, a measuring cylinder 20, an electronic balance 21, a water injection pipeline 22, a plunger pump 23, a first pressure gauge 24, a second pressure gauge 25, a third pressure gauge 26, a fourth pressure gauge 27, a fifth pressure gauge 28 and the above-mentioned three-dimensional model 12; the first container 13 is respectively connected to the first displacement pump 14 and the six-way valve 15, the second container 16 is respectively connected to the second displacement pump 17 and the six-way valve 15, and the injection pipeline 10 is respectively connected to the six-way valve 15 and the first wellbore 801 of the three-dimensional model 12, the production pipeline 11 is respectively connected to the back pressure control valve 18 and the second wellbore 802 of the three-dimensional model 12, the back pressure control valve 18 is respectively connected to the third displacement pump 19 and the measuring cylinder 20, the measuring cylinder 20 is arranged on the electronic balance 21, the water injection pipeline 22 is respectively connected to the plunger pump 23 and the water injection port of the three-dimensional model 12, the pipeline connecting the first container 13 and the six-way valve 15 is provided with a first pressure gauge 24, the pipeline connecting the second container 16 and the six-way valve 15 is provided with a second pressure gauge 25, the production pipeline 11 is provided with a third pressure gauge 26, the pipeline connecting the third displacement pump 19 and the back pressure control valve 18 is provided with a fourth pressure gauge 27, and the water injection pipeline 22 is provided with a fifth pressure gauge 28.

[0060] Furthermore, a first valve 29 is provided on the pipeline connecting the first displacement pump 14 and the first container 13, a second valve 30 is provided on the pipeline connecting the second displacement pump 17 and the second container 16, a third valve 31 is provided on the pipeline connecting the back pressure control valve 18 and the third pressure gauge 26, a fourth valve 32 is provided on the pipeline connecting the third displacement pump 19 and the fourth pressure gauge 27, and a fifth valve 33 is provided on the pipeline connecting the plunger pump 23 and the fifth pressure gauge 28.

[0061] Among them, the first displacement pump 14, the second displacement pump 17 and the third displacement pump 19 adopt high-pressure and high-precision double-cylinder displacement pumps, and the plunger pump 23 adopts a high-pressure and high-precision plunger pump 23. The first displacement pump 14 and the second displacement pump 17 are respectively used to displace the formation water in the first container 13 and the crude oil in the second container 16 into the three-dimensional model 12 in a stable pressure state; the confining pressure control module injects water and pressurizes the annular cavity between the cylinder 3 and the rubber cylinder 2 through the plunger pump 23, so that the rubber cylinder 2 is deformed and the pressure is effectively transmitted to the simulated rock block 101 to simulate the formation confining pressure; the back pressure control module controls the outlet pressure of the production well 104 of the three-dimensional model 12 through the third displacement pump 19 and the back pressure control valve 18, so that the pressure at the production well 104 is close to the actual formation pressure, ensuring The authenticity of the experimental results; the pressure acquisition module (the first pressure gauge 24, the second pressure gauge 25, and the third pressure gauge 26) is used to collect the liquid pressure in each pipeline, and monitor and record the changes in the liquid pressure in each pipeline in real time; the fluid collection device collects the produced fluid at the production well 104 of the three-dimensional model 12 through the measuring cylinder 20 and the electronic balance 21. Only when the pressure in the three-dimensional model 12 is higher than the back pressure set in the back pressure control system, will the fluid flow from the production well 104 into the measuring cylinder 20 through the back pressure control valve 18 to collect the produced liquid and record the data in real time, so as to analyze the results of the crude oil displacement experiment.

[0062] An injection-production system for a fractured reservoir simulation experiment provided in an embodiment of the present application comprises: a first container 13 filled with formation water, a first displacement pump 14, a six-way valve 15, a second container 16 filled with crude oil, a second displacement pump 17, an injection pipeline 10, a production pipeline 11, a back pressure control valve 18, a third displacement pump 19, a measuring cylinder 20, an electronic balance 21, a water injection pipeline 22, a plunger pump 23, a first pressure gauge 24, a second pressure gauge 25, a third pressure gauge 26, a fourth pressure gauge 27, a fifth pressure gauge 28 and the above-mentioned three-dimensional model 12; the first container 13 is connected to the first displacement pump 14 and the six-way valve 15 respectively, the second container 16 is connected to the second displacement pump 17 and the six-way valve 15 respectively, the injection pipeline 10 is connected to the six-way valve 15 respectively, and the The six-way valve 15 and the first wellbore 801 of the three-dimensional model 12, the production pipeline 11 is respectively connected to the back pressure control valve 18 and the second wellbore 802 of the three-dimensional model 12, the back pressure control valve 18 is respectively connected to the third displacement pump 19 and the measuring cylinder 20, the measuring cylinder 20 is arranged on the electronic balance 21, the water injection pipeline 22 is respectively connected to the plunger pump 23 and the water injection port of the three-dimensional model 12, the first container 13 is connected to the six-way valve 15 The pipeline is provided with a first pressure gauge 24, the second container 16 is connected to the six-way valve 15. The pipeline is provided with a second pressure gauge 25, the production pipeline 11 is provided with a third pressure gauge 26, the pipeline connecting the third displacement pump 19 and the back pressure control valve 18 is provided with a fourth pressure gauge 27, and the water injection pipeline 22 is provided with a fifth pressure gauge 28. The model constructed in this application is a three-dimensional structure, which can more accurately reflect the complex structure of the actual fracture-type reservoir compared with the two-dimensional model, so that the flow characteristics of the fracture-type reservoir and the dynamic fluid exchange between the fracture and the matrix can be accurately simulated.

[0063] Figure 7 A flow chart of an injection-production method for a fractured reservoir simulation experiment provided in an embodiment of the present application is shown in FIG. Figure 7 As shown, an injection-production method for a fractured oil reservoir simulation experiment is applied to the injection-production system for the fractured oil reservoir simulation experiment, comprising:

[0064] S10: Preprocessing the three-dimensional model so that the formation water and crude oil of the simulated rock block in the three-dimensional model are both in a saturated state, and aging the crude oil of the simulated rock block.

[0065] S11: injecting water into the interior of the three-dimensional model to conduct a displacement simulation experiment, and recording the oil production, water production, and pressure detected by the pressure gauges on each pipeline in the displacement simulation experiment.

[0066] Before step S10, for the simulated fractured oil reservoir, the carbonate rock simulation block 101 or the sandstone rock simulation block 101 is determined according to the actual geological characteristics of the reservoir, and the simulated rock block 101 is cut from the natural outcrop rock of the fractured oil reservoir. Some simulated rock blocks 101 are drilled to simulate the injection well 103 and the production well 104; the simulated rock blocks 101 are arranged and loaded into the rubber cylinder 2 from bottom to top, and the gaps between the simulated rock blocks 101 are determined according to the actual geological characteristics of the simulated fractured oil reservoir (the gap is 0.1 mm-1 mm), and carbonate rock minerals, siliceous minerals or clay minerals are filled in the gaps between the simulated rock blocks 101; after the simulated rock blocks 101 are loaded, the two end openings of the rubber cylinder 2 are covered with sealing covers, and the first flange cover 8 and the second flange cover 9 are covered at both ends of the cylinder 3.

[0067] In step S10, preprocessing the three-dimensional model 12 includes: controlling the plunger pump 23 to inject water into the annular cavity between the rubber cylinder 2 and the cylinder body 3 of the three-dimensional model 12 to apply confining pressure to the simulated rock block 101 of the three-dimensional model 12 to simulate the formation pressure; performing an air tightness test on the three-dimensional model 12, and judging whether the air tightness of the three-dimensional model 12 meets the preset standard; if it meets the preset standard, evacuating the three-dimensional model 12; controlling the first displacement pump 14 to inject formation water into the three-dimensional model 12 until the formation water of the simulated rock block 101 is in a saturated state; controlling the second displacement pump 17 to inject crude oil into the three-dimensional model 12 until the crude oil of the simulated rock block 101 is in a saturated state.

[0068] The simulation of the formation pressure is specifically as follows: water is injected into the annular cavity between the rubber cylinder 2 and the cylinder body 3 until the annular cavity is filled with water, and at the same time, the annular cavity is pressurized by the plunger pump 23 .

[0069] Performing an air tightness test on the three-dimensional model 12 and determining whether the air tightness of the three-dimensional model 12 meets the preset standard includes: closing the second wellbore 802 of the three-dimensional model 12, and delivering gas (nitrogen) into the three-dimensional model 12 through the first wellbore 801 of the three-dimensional model 12, so that the pressure of the three-dimensional model 12 reaches a set pressure (the set pressure may be 3 MPa); after a preset time period (the preset time period may be 12 hours), obtaining the current pressure of the three-dimensional model 12, and determining the difference between the set pressure and the current pressure; if the difference is greater than or equal to the set value, the air tightness of the three-dimensional model 12 does not meet the preset standard; if the difference is less than the set value (indicating that the current pressure of the three-dimensional model 12 is slightly different from the set pressure), the air tightness of the three-dimensional model 12 meets the preset standard, which means that the air tightness is good.

[0070] Controlling the first displacement pump 14 to inject formation water into the three-dimensional model 12 includes: adjusting the inclination angle of the three-dimensional model 12 so that the first wellbore 801 of the three-dimensional model 12 is located below the second wellbore 802 of the three-dimensional model 12 (that is, the injection pipe 10 is located below the production pipe 11); controlling the first displacement pump 14 to drive the formation water in the first container 13 to be injected into the three-dimensional model 12 through the injection pipe 10 at a constant flow rate; after the production pipe 11 has stable liquid discharge, stopping the injection of formation water to simulate that the formation water of the rock block 101 is in a saturated state.

[0071] Controlling the second displacement pump 17 to inject crude oil into the three-dimensional model 12 includes: adjusting the inclination angle of the three-dimensional model 12 so that the second wellbore 802 of the three-dimensional model 12 is located below the first wellbore 801 of the three-dimensional model 12 (that is, the injection pipeline 10 is located above the production pipeline 11); controlling the second displacement pump 17 to drive the crude oil in the second container 16 to be injected into the three-dimensional model 12 through the injection pipeline 10 at a constant flow rate; after the production pipeline 11 has stable liquid discharge, stopping the injection of crude oil, simulating the formation water of the rock block 101 to be in a saturated state, and calculating the saturation amount at the same time.

[0072] Aging the crude oil of the simulated rock block 101 includes placing the three-dimensional model 12 in a constant temperature box, setting the fractured reservoir temperature, and leaving it to stand for a preset period of time (which may be two weeks) to age the crude oil.

[0073] In step S11, the various parts of the injection and production system are connected and the crude oil displacement development stage is entered. The oil production, water production and pressure change characteristics of each pipeline during the crude oil displacement simulation experiment are recorded in real time. The oil production, water production and pressure change characteristics can be used to analyze the production dynamic characteristics of the three-dimensional injection and production experimental model of the fractured oil reservoir. The volume of oil and water can be directly measured by the measuring cylinder 20.

[0074] An injection and production method for a fractured oil reservoir simulation experiment provided in an embodiment of the present application is applied to the injection and production system for the fractured oil reservoir simulation experiment, including: pre-processing the three-dimensional model 12, so that the formation water and crude oil of the simulated rock block 101 in the three-dimensional model 12 are both in a saturated state, and aging the crude oil of the simulated rock block 101; injecting water into the interior of the three-dimensional model 12 to perform a displacement simulation experiment, and recording the oil production, water production, and pressure detected by the pressure gauges on each pipeline in the displacement simulation experiment. The model of the injection and production system is a three-dimensional structure, which can more accurately reflect the complex structure of an actual fractured oil reservoir than a two-dimensional model, so that it can accurately simulate the flow characteristics of the fractured oil reservoir and the dynamic fluid exchange between the fracture and the matrix, improve the accuracy of the simulation experiment, and improve the reference significance of the physical phenomena observed in the experiment and the experimental data obtained.

[0075] The three-dimensional model, injection and production system and injection and production method of the fractured reservoir simulation experiment provided by the present application are introduced in detail above. The various embodiments in the specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same and similar parts between the various embodiments can be referred to each other. For the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and the relevant parts can be referred to the method part description. It should be pointed out that for ordinary technicians in this technical field, without departing from the principles of the present application, several improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the claims of the present application.

[0076] It should also be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

Claims

1. A three-dimensional model for fractured reservoir simulation experiment, characterized in that: include: A rock block module (1), a rubber cylinder (2), a cylinder body (3), a sealing cover and a first flange cover (8); The rubber cylinder (2) is coaxially sleeved in the cylinder (3); an annular cavity is provided between the outer wall of the rubber cylinder (2) and the inner wall of the cylinder (3); the sealing cover is provided to cover the two end openings of the rubber cylinder (2); the edge of the sealing cover is sealingly connected to the inner wall of the cylinder (3) to close the annular cavity; the first flange cover (8) is detachably connected to the cylinder (3) to cover the top opening of the cylinder (3); the rock block module (1) is provided in the cavity formed by the rubber cylinder (2) and the sealing cover; the rock block module (1) is composed of a plurality of simulated rock blocks (101); and fillers (101) are provided in the gaps between the simulated rock blocks (101). 02), the rock block module (1) is provided with an injection well (103) and a production well (104), the sealing cover is provided with a plurality of through holes, the first flange cover (8) is provided with a first well hole (801) and a second well hole (802), the first well hole (801) is connected to the injection well (103) via the through hole, the second well hole (802) is connected to the production well (104) via the through hole, the first well hole (801) is used to connect to the injection pipeline (10), the second well hole (802) is used to connect to the production pipeline (11), and the side wall of the cylinder (3) is provided with a water injection port, the water injection port is used to connect to the water injection pipeline (22).

2. The three-dimensional model for fracture reservoir simulation experiment according to claim 1, characterized in that: It also includes a support seat (5) and a clamp (6), wherein the clamp (6) is arranged on the support seat (5), and two clamping arms of the clamp (6) are respectively in contact with two side walls of the cylinder (3), and the cylinder (3) rotates around a horizontal axis to change the height difference between the injection end of the first wellbore (801) and the output end of the second wellbore (802).

3. The three-dimensional model for fracture reservoir simulation experiment according to claim 1, characterized in that: The bottom of the cylinder (3) is provided with an opening, and the second flange cover (9) is detachably connected to the cylinder (3) to cover the bottom opening of the cylinder (3).

4. The three-dimensional model for fracture reservoir simulation experiment according to claim 3, characterized in that: Sealing gaskets are provided at the connection between the first flange cover (8) and the cylinder (3) and at the connection between the second flange cover (9) and the cylinder (3).

5. An injection-production system for fractured reservoir simulation experiment, characterized in that: include: A first container (13) containing formation water, a first displacement pump (14), a six-way valve (15), a second container (16) containing crude oil, a second displacement pump (17), an injection pipeline (10), a production pipeline (11), a back pressure control valve (18), a third displacement pump (19), a measuring cylinder (20), an electronic balance (21), a water injection pipeline (22), a plunger pump (23), a first pressure gauge (24), a second pressure gauge (25), a third pressure gauge (26), a fourth pressure gauge (27), a fifth pressure gauge (28), and a three-dimensional model (12) according to any one of claims 1 to 4; The first container (13) is respectively connected to the first displacement pump (14) and the six-way valve (15); the second container (16) is respectively connected to the second displacement pump (17) and the six-way valve (15); the injection pipeline (10) is respectively connected to the six-way valve (15) and the first wellbore (801) of the three-dimensional model (12); the production pipeline (11) is respectively connected to the back pressure control valve (18) and the second wellbore (802) of the three-dimensional model (12); the back pressure control valve (18) is respectively connected to the third displacement pump (19) and the measuring cylinder (20); the measuring cylinder (20) is arranged on the electric On the sub-balance (21), the water injection pipeline (22) is respectively connected to the plunger pump (23) and the water injection port of the three-dimensional model (12); a first pressure gauge (24) is provided on the pipeline connecting the first container (13) and the six-way valve (15); a second pressure gauge (25) is provided on the pipeline connecting the second container (16) and the six-way valve (15); a third pressure gauge (26) is provided on the production pipeline (11); a fourth pressure gauge (27) is provided on the pipeline connecting the third displacement pump (19) and the back pressure control valve (18); and a fifth pressure gauge (28) is provided on the water injection pipeline (22).

6. An injection-production method for fractured reservoir simulation experiment, characterized in that: The injection-production system used in the fractured reservoir simulation experiment of claim 5 comprises: Preprocessing the three-dimensional model (12) so that the formation water and crude oil of the simulated rock block (101) in the three-dimensional model (12) are both in a saturated state, and aging the crude oil in the simulated rock block (101); Water is injected into the interior of the three-dimensional model (12) to carry out a displacement simulation experiment, and the oil production, water production and pressure detected by the pressure gauges on each pipeline in the displacement simulation experiment are recorded.

7. The injection-production method for fractured reservoir simulation experiment according to claim 6, characterized in that: The preprocessing of the three-dimensional model (12) comprises: Controlling the plunger pump (23) to inject water into the annular cavity between the rubber cylinder (2) and the cylinder body (3) of the three-dimensional model (12) so as to apply confining pressure to the simulated rock block (101) of the three-dimensional model (12) to simulate formation pressure; Performing an airtightness test on the three-dimensional model (12), and determining whether the airtightness of the three-dimensional model (12) meets a preset standard; If the preset standard is met, evacuating the three-dimensional model (12); Controlling a first displacement pump (14) to inject formation water into the three-dimensional model (12) until the formation water in the simulated rock block (101) is saturated; The second displacement pump (17) is controlled to inject crude oil into the three-dimensional model (12) until the simulated rock block (101) is saturated with crude oil.

8. The injection-production method for fractured reservoir simulation experiment according to claim 6, characterized in that: Aging the crude oil in the simulated rock block (101) comprises: The three-dimensional model (12) is placed in a constant temperature box, the fractured oil reservoir temperature is set, and the model is left to stand for a preset period of time to age the crude oil.

9. The injection-production method for fractured reservoir simulation experiment according to claim 7, characterized in that: Controlling a first displacement pump (14) to inject formation water into the three-dimensional model (12) comprises: Adjusting the inclination angle of the three-dimensional model (12) so that the first wellbore (801) of the three-dimensional model (12) is located below the second wellbore (802) of the three-dimensional model (12); Controlling the first displacement pump (14) to drive the formation water in the first container (13) to be injected into the three-dimensional model (12) through the injection pipe (10) at a constant flow rate; Accordingly, controlling the second displacement pump (17) to inject crude oil into the three-dimensional model (12) comprises: Adjusting the inclination angle of the three-dimensional model (12) so that the second wellbore (802) of the three-dimensional model (12) is located below the first wellbore (801) of the three-dimensional model (12); The second displacement pump (17) is controlled to drive the crude oil in the second container (16) to be injected into the three-dimensional model (12) through the injection pipeline (10) at a constant flow rate.

10. The injection-production method for fractured reservoir simulation experiment according to claim 7, characterized in that: Performing an airtightness test on the three-dimensional model (12) and determining whether the airtightness of the three-dimensional model (12) meets a preset standard comprises: The second wellbore (802) of the three-dimensional model (12) is closed, and gas is delivered into the three-dimensional model (12) through the first wellbore (801) of the three-dimensional model (12), so that the pressure of the three-dimensional model (12) reaches a set pressure; After a preset time period, obtaining the current pressure of the three-dimensional model (12), and determining the difference between the set pressure and the current pressure; If the difference is greater than or equal to a set value, the airtightness of the three-dimensional model (12) does not meet a preset standard; If the difference is less than a set value, the airtightness of the three-dimensional model (12) meets a preset standard.

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