Simulation device for two-dimensional visual gas injection development of fractured reservoir and manufacturing method of simulation device

Abstract

The invention provides a simulation device for two-dimensional visual gas injection development of a fractured reservoir and a manufacturing method of the simulation device. The simulation device comprises a stratum simulation matrix, a gas injection simulation well and a production simulation well. Cracks are distributed in the stratum simulation matrix; and drilling lines of the gas injection simulation well and the production simulation well avoid cracks. The manufacturing method comprises the following steps: (1) setting basic parameters of the simulation device according to geological parameters and injection-production parameters of the fractured reservoir; (2) respectively preparing a gas injection simulation well, a production simulation well and a crack mold, and placing in a grinding tool; and (3) filling a geological simulation matrix into the grinding tool, taking out the crack mold, and sequentially carrying out glue injection, curing and packaging to obtain the simulation device. According to the simulation device, the actual oil reservoir fracture distribution condition is accurately simulated, the interference effect of fracture distribution on injected gas and the distribution state of remaining oil are accurately described, optimization of key injection and production parameters is achieved, and a displacement mechanism can be visually, quantitatively and qualitatively analyzed conveniently.

Description

Technical Field

[0001] The invention belongs to the technical field of oil production, and relates to a simulation device for oil reservoir development, in particular to a simulation device for two-dimensional visible gas injection development of fractured oil reservoirs and a manufacturing method thereof. Background Art

[0002] In my country, fractured reservoirs and low-permeability reservoirs with developed fractures are widely distributed and account for a large proportion. At present, the development efforts of this part of reservoirs are constantly increasing. The initial production and development of fractured oil reservoirs has high production output, which is an important production and development direction for oil and gas production and stability. After the depletion-type exploitation of fractured oil reservoirs, due to the different degrees of internal fracture development and strong heterogeneity, a large amount of residual oil still remains in the bedrock and cannot be extracted. The interference effect caused by the distribution of fractures and the difference in reservoir permeability are the main factors affecting the distribution of residual oil.

[0003] In terms of mining technology, the use of traditional water flooding technology to reduce the amount of remaining oil in fractured reservoirs not only fails to significantly reduce the distribution of remaining oil, but may even cause water to quickly appear in the oil wells and the water content to rise rapidly, which in turn causes water breakthrough or violent flooding. With the continuous development of gas flooding technology, gas injection technology has been applied on a large scale worldwide. Compared with water flooding technology, the use of gas injection displacement technology for fractured reservoirs can maintain the formation pressure while using the gas overburden effect to stably push the oil-gas interface to the lower part of the reservoir, expand the swept volume of the injected gas, and effectively improve the oil recovery efficiency, and significantly reduce the distribution of remaining oil in the reservoir.

[0004] However, due to the interference effect caused by fracture distribution and the difference in reservoir permeability, the research on gas drive direction, oil-gas interface migration, displacement range, remaining oil distribution and ultimate recovery rate is still in the qualitative evaluation category, and there is no relevant report on quantitative and qualitative evaluation from the perspective of experimental verification.

[0005] Therefore, accurate simulation of fracture distribution through indoor core physics experiments is of great significance for accurately characterizing reservoir geological characteristics, studying oil-gas interface migration, displacement sweep, remaining oil distribution, oil recovery efficiency, and later design adjustments to fractured reservoir development methods during gas drive displacement. Summary of the invention

[0006] The purpose of the present invention is to provide a simulation device for two-dimensional visual gas injection development in fractured oil reservoirs and a manufacturing method thereof. The simulation device accurately simulates the distribution of actual reservoir fractures, accurately describes the interference effect of fracture distribution on injected gas and the distribution state of residual oil, realizes the optimization of key injection and production parameters, and facilitates intuitive and quantitative and qualitative analysis of displacement mechanism.

[0007] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a simulation device for two-dimensional visual gas injection development of fractured oil reservoirs, the simulation device comprising a formation simulation matrix, at least one gas injection simulation well and at least one production simulation well.

[0009] The formation simulation matrix has at least one fracture distributed inside, for example, 1, 2, 3, 4 or 5 fractures, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0010] The drilling lines of the gas injection simulation well and the production simulation well both avoid the fracture.

[0011] In the present invention, the gas injection simulation well and the production simulation well are each independently at least one, for example, can be 1, 2, 3, 4 or 5, but are not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0012] The simulation device provided by the present invention can be used in oil displacement experiments to accurately simulate key injection and production parameters of fractured oil reservoirs, accurately describe the interference effect of fracture distribution on injected gas and the distribution state of residual oil, achieve the optimization of gas injection technology in relatively fractured oil reservoirs and the precise confirmation of economic and technical boundaries, provide key information for development plan design, optimization, dynamic tracking and adjustment, facilitate intuitive and quantitative and qualitative analysis of displacement mechanism, thereby achieving stable control of oil and gas interface, expanding the swept volume of injected gas, reducing residual oil distribution, further improving crude oil recovery rate, achieving the purpose of maximizing development benefits, and providing reliable technical support for efficient gas injection development of fractured oil reservoirs.

[0013] Preferably, the material of the formation simulation matrix includes quartz sand and a curing agent.

[0014] Preferably, the average particle size of the quartz sand is 80-240 mesh, for example, it can be 80 mesh, 100 mesh, 120 mesh, 140 mesh, 160 mesh, 180 mesh, 200 mesh, 220 mesh or 240 mesh, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0015] Preferably, the curing agent comprises epoxy resin.

[0016] Preferably, the permeability of the formation simulation matrix is ​​1-10000mD, for example, it can be 1mD, 100mD, 500mD, 1000mD, 2000mD, 3000mD, 4000mD, 5000mD, 6000mD, 7000mD, 8000mD, 9000mD or 10000mD, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0017] Preferably, the porosity of the formation simulation matrix is ​​10-30%, for example, it can be 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28% or 30%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0018] In the present invention, the permeability and porosity of the formation simulation matrix are specifically adjusted by the mixing ratio of quartz sand and curing agent. As long as the permeability and porosity can be achieved within the above range, the mixing ratio of quartz sand and curing agent is not particularly limited.

[0019] Preferably, the size of the formation simulation matrix is ​​(30-60) cm×(30-60) cm×(2-3) cm, for example, it can be 30cm×30cm×2cm, 40cm×40cm×2.5cm, 50cm×50cm×2.5cm or 60cm×60cm×3cm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0020] Preferably, there are at least 3 fractures distributed inside the formation simulation matrix, for example, 3, 4, 5, 6 or 7 fractures, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0021] Preferably, the fractures are vertically evenly distributed in the formation simulation matrix.

[0022] Preferably, the type of the gas injection simulation well includes a vertical well, and a single-stage slot is used to simulate a perforation section.

[0023] Preferably, the gas injection method of the gas injection simulation well includes vertical gas injection and / or horizontal gas injection.

[0024] Preferably, the types of the production simulation wells include vertical wells and / or horizontal wells.

[0025] Preferably, the vertical well in the production simulation well adopts a single-stage slotting to simulate the perforation section.

[0026] Preferably, the horizontal well in the production simulation well adopts multiple slots to simulate the perforation section.

[0027] In a second aspect, the present invention provides a method for manufacturing the simulation device according to the first aspect, the manufacturing method comprising the following steps:

[0028] (1) Setting the basic parameters of the simulation device according to the geological parameters and injection and production parameters of the fractured reservoir;

[0029] (2) preparing a gas injection simulation well, a production simulation well, and a fracture mold respectively, and placing them inside the mold;

[0030] (3) The geological simulation matrix is ​​filled into the mold, and after the fracture mold is taken out, the glue injection, curing and packaging are performed in sequence to obtain a simulation device for two-dimensional visual gas injection development of fractured oil reservoirs.

[0031] Preferably, the geological parameters in step (1) include fracture distribution characteristics, geological physical property characteristics and residual oil distribution characteristics.

[0032] Preferably, the injection and production parameters in step (1) include well spacing, well type, well location, perforation location, gas injection medium, gas injection rate and gas injection pressure.

[0033] Preferably, the basic parameters in step (1) include matrix permeability, matrix porosity, matrix size, number of cracks, crack length and crack width.

[0034] Preferably, the gas injection simulation well and the production simulation well in step (2) are independently made of stainless steel pipes.

[0035] Preferably, the inner diameter of the stainless steel tube is 2-4 mm, for example, it can be 2 mm, 2.2 mm, 2.4 mm, 2.6 mm, 2.8 mm, 3 mm, 3.2 mm, 3.4 mm, 3.6 mm, 3.8 mm or 4 mm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0036] Preferably, the shape of the fracture mold in step (2) is consistent with the morphology of actual reservoir fracture development.

[0037] Preferably, the placement positions of the gas injection simulation well, production simulation well and fracture mold inside the mold in step (2) are determined according to the actual formation environment.

[0038] Preferably, the glue injection and packaging in step (3) are performed independently using epoxy resin.

[0039] Preferably, the thickness of the package is 2-3 cm, for example, it may be 2 cm, 2.1 cm, 2.2 cm, 2.3 cm, 2.4 cm, 2.5 cm, 2.6 cm, 2.7 cm, 2.8 cm, 2.9 cm or 3 cm, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0040] The present invention uses epoxy resin to encapsulate the simulation device, thereby achieving the purpose of sealing fluid and resisting pressure. After the epoxy resin is cured, a high-pressure valve is installed at one end of the pipeline exposed outside the device to complete the preparation of the simulation device.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] The simulation device provided by the present invention can be used in oil displacement experiments to accurately simulate key injection and production parameters of fractured oil reservoirs, accurately describe the interference effect of fracture distribution on injected gas and the distribution state of residual oil, achieve the optimization of gas injection technology in relatively fractured oil reservoirs and the precise confirmation of economic and technical boundaries, provide key information for development plan design, optimization, dynamic tracking and adjustment, facilitate intuitive and quantitative and qualitative analysis of displacement mechanism, thereby achieving stable control of oil and gas interface, expanding the swept volume of injected gas, reducing residual oil distribution, further improving crude oil recovery rate, achieving the purpose of maximizing development benefits, and providing reliable technical support for efficient gas injection development of fractured oil reservoirs. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 is a schematic diagram of the structure of the simulation device provided in Example 1;

[0044] Figure 2 It is a schematic diagram of the structure of the simulation device provided in Example 2.

[0045] Among them: 1- formation simulation matrix; 2- gas injection simulation well; 3- production simulation well; 4- fracture; 5- perforation section. DETAILED DESCRIPTION

[0046] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0047] Example 1

[0048] This embodiment provides a simulation device for two-dimensional visual gas injection development of fractured oil reservoirs and a manufacturing method thereof. Figure 1As shown, the simulation device includes a formation simulation matrix 1, a gas injection simulation well 2 and a production simulation well 3; four fractures 4 are evenly distributed vertically inside the formation simulation matrix 1, and the drilling lines of the gas injection simulation well 2 and the production simulation well 3 avoid the fractures 4.

[0049] In this embodiment, the material of the formation simulation matrix 1 includes quartz sand and epoxy resin, and the average particle size of the quartz sand is 160 meshes. The permeability of the formation simulation matrix 1 is 5000 mD, the porosity is 20%, and the size is 30 cm×30 cm×2.5 cm.

[0050] In this embodiment, the type of the gas injection simulation well 2 is a vertical well, and a single-stage slit is used to simulate the perforation section 5; the gas injection method of the gas injection simulation well 2 is vertical gas injection; the type of the production simulation well 3 is a horizontal well, and multiple-stage slits are used to simulate the perforation section 5.

[0051] In this embodiment, the manufacturing method includes the following steps:

[0052] (1) setting basic parameters of the simulation device according to geological parameters and injection and production parameters of the fractured oil reservoir; the geological parameters include fracture distribution characteristics, geological physical properties and remaining oil distribution characteristics; the injection and production parameters include well spacing, well type, well location, perforation location, gas injection medium, gas injection rate and gas injection pressure; the basic parameters include matrix permeability, matrix porosity, matrix size, number of fractures, fracture length and fracture width;

[0053] (2) using a stainless steel tube with an inner diameter of 3 mm, a gas injection simulation well 2 and a production simulation well 3 are prepared respectively, and a fracture mold is prepared in combination with the morphology of actual reservoir fracture development, and the simulation well and the fracture mold are placed at specific positions inside the mold according to the actual formation environment;

[0054] (3) The geological simulation matrix 1 is filled into the mold, and after the fracture mold is taken out, the injection, curing and packaging are carried out in sequence. The injection and packaging are performed independently with epoxy resin, and the packaging thickness is 2m, thereby obtaining a simulation device for two-dimensional visual gas injection development of fractured oil reservoirs.

[0055] Example 2

[0056] This embodiment provides a simulation device for two-dimensional visual gas injection development of fractured oil reservoirs and a manufacturing method thereof. Figure 2 As shown, the simulation device includes a formation simulation matrix 1, two gas injection simulation wells 2 and two production simulation wells 3; three fractures 4 are evenly distributed vertically inside the formation simulation matrix 1, and the drilling lines of the gas injection simulation wells 2 and the production simulation wells 3 avoid the fractures 4.

[0057] In this embodiment, the material of the formation simulation matrix 1 includes quartz sand and epoxy resin, and the average particle size of the quartz sand is 160 meshes. The permeability of the formation simulation matrix 1 is 5000 mD, the porosity is 20%, and the size is 60 cm×60 cm×2.5 cm.

[0058] In this embodiment, the gas injection simulation well 2 and the production simulation well 3 are independently vertical wells, and the gas injection method of one of the gas injection simulation wells 2 is vertical gas injection, and the gas injection method of the other gas injection simulation well 2 is horizontal gas injection.

[0059] In this embodiment, the manufacturing method includes the following steps:

[0060] (1) setting basic parameters of the simulation device according to geological parameters and injection and production parameters of the fractured oil reservoir; the geological parameters include fracture distribution characteristics, geological physical properties and remaining oil distribution characteristics; the injection and production parameters include well spacing, well type, well location, perforation location, gas injection medium, gas injection rate and gas injection pressure; the basic parameters include matrix permeability, matrix porosity, matrix size, number of fractures, fracture length and fracture width;

[0061] (2) using a stainless steel tube with an inner diameter of 3 mm, a gas injection simulation well 2 and a production simulation well 3 are prepared respectively, and a fracture mold is prepared in combination with the morphology of actual reservoir fracture development, and the simulation well and the fracture mold are placed at specific positions inside the mold according to the actual formation environment;

[0062] (3) The geological simulation matrix 1 is filled into the mold, and after the fracture mold is taken out, the injection, curing and packaging are carried out in sequence. The injection and packaging are independently performed with epoxy resin, and the packaging thickness is 3 cm, thereby obtaining a simulation device for two-dimensional visual gas injection development of fractured oil reservoirs.

[0063] Application Example 1

[0064] This application example uses the simulation device provided in Example 1 to simulate the two-dimensional visual gas injection development of fractured oil reservoirs, specifically using vertical gas injection technology. During the oil displacement experiment, gas is always injected from the top of the device, and different displacement mode combinations of gas injection media, gas injection pressures and gas injection speeds are selected according to the experimental plan, the back pressure components are adjusted, and the inlet and outlet valves are controlled to conduct displacement experiments. After a set of experiments is completed, other displacement mode combinations are selected to carry out subsequent experiments. In this way, the same set of simulation devices is used to specifically study the displacement process when changing one of the key parameters such as gas injection media, gas injection pressure and gas injection speed, and keeping other parameters stable. Compare multiple groups of experiments to obtain conclusive results to achieve the purpose of the experiment.

[0065] In this application example, while conducting the oil displacement experiment, high-speed camera equipment is used to track and shoot the migration process of oil, gas and water in the matrix to accurately describe the gas displacement direction, the advancement of the oil-gas interface, the displacement range, the interference effect of fracture distribution on the injected gas, and the distribution status of the remaining oil.

[0066] Application Example 2

[0067] This application example uses the simulation device provided in Example 2 to simulate the two-dimensional visual gas injection development of fractured oil reservoirs. According to the experimental plan, the injection and production well combination is selected, and the valves of other wells are closed so that they do not participate in the entire oil recovery experiment process. After one set of experiments is completed, another injection and production well combination is selected to carry out subsequent experiments. In this way, the same set of simulation devices is used to realize the simulation of different injection and production methods, and achieve different experimental purposes.

[0068] In this application example, while conducting the oil displacement experiment, high-speed camera equipment is used to track and shoot the migration process of oil, gas and water in the matrix to accurately describe the gas displacement direction, the advancement of the oil-gas interface, the displacement range, the interference effect of fracture distribution on the injected gas, and the distribution status of the remaining oil.

[0069] It can be seen that the simulation device provided by the present invention can be used in oil displacement experiments to accurately simulate the key injection and production parameters of fractured reservoirs, accurately describe the interference effect of fracture distribution on injected gas and the distribution state of residual oil, achieve the optimization of gas injection technology in reservoirs with relatively developed fractures and the accurate confirmation of economic and technical boundaries, provide key information for development plan design, optimization, dynamic tracking and adjustment, facilitate intuitive and quantitative and qualitative analysis of displacement mechanism, and thus achieve stable control of oil and gas interface, expand the volume swept by injected gas, reduce residual oil distribution, further improve crude oil recovery rate, achieve the purpose of maximizing development benefits, and provide reliable technical support for efficient development of fractured reservoirs by gas injection.

[0070] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A simulation device for two-dimensional visual gas injection development of fractured oil reservoirs, characterized in that: The simulation device includes a formation simulation matrix, at least one gas injection simulation well and at least one production simulation well; The formation simulation matrix has at least one fracture distributed inside; The drilling lines of the gas injection simulation well and the production simulation well both avoid the fracture.

2. The simulation device according to claim 1, characterized in that The material of the formation simulation matrix includes quartz sand and a curing agent; Preferably, the average particle size of the quartz sand is 80-240 mesh; Preferably, the curing agent comprises epoxy resin.

3. The simulation device according to claim 1 or 2, characterized in that: The permeability of the formation simulation matrix is ​​1-10000 mD; Preferably, the porosity of the formation simulation matrix is ​​10-30%; Preferably, the size of the formation simulation matrix is ​​(30-60) cm×(30-60) cm×(2-3) cm.

4. The simulation device according to any one of claims 1 to 3, characterized in that: There are at least three fractures distributed inside the formation simulation matrix; Preferably, the fractures are vertically evenly distributed in the formation simulation matrix.

5. The simulation device according to any one of claims 1 to 4, characterized in that: The type of the gas injection simulation well includes a vertical well, and a single-stage slot is used to simulate a perforation section; Preferably, the gas injection method of the gas injection simulation well includes vertical gas injection and / or horizontal gas injection.

6. The simulation device according to any one of claims 1 to 5, characterized in that: The types of the production simulation wells include vertical wells and / or horizontal wells; Preferably, the vertical well in the production simulation well adopts a single-stage slotting to simulate the perforation section; Preferably, the horizontal well in the production simulation well adopts multiple slots to simulate the perforation section.

7. A method for manufacturing a simulation device according to any one of claims 1 to 6, characterized in that: The production method comprises the following steps: (1) Setting the basic parameters of the simulation device according to the geological parameters and injection and production parameters of the fractured reservoir; (2) preparing a gas injection simulation well, a production simulation well, and a fracture mold respectively, and placing them inside the mold; (3) The geological simulation matrix is ​​filled into the mold, and after the fracture mold is taken out, the glue injection, curing and packaging are performed in sequence to obtain a simulation device for two-dimensional visual gas injection development of fractured oil reservoirs.

8. The method according to claim 7, characterized in that: The geological parameters in step (1) include fracture distribution characteristics, geological physical properties characteristics and remaining oil distribution characteristics; Preferably, the injection and production parameters in step (1) include well spacing, well type, well location, perforation location, gas injection medium, gas injection speed and gas injection pressure; Preferably, the basic parameters in step (1) include matrix permeability, matrix porosity, matrix size, number of cracks, crack length and crack width.

9. The production method according to claim 7 or 8, characterized in that: The gas injection simulation well and the production simulation well in step (2) are independently prepared from stainless steel pipes; Preferably, the inner diameter of the stainless steel tube is 2-4 mm; Preferably, the shape of the fracture mold in step (2) is consistent with the morphology of actual reservoir fracture development; Preferably, the placement positions of the gas injection simulation well, production simulation well and fracture mold inside the mold in step (2) are determined according to the actual formation environment.

10. The production method according to any one of claims 7 to 9, characterized in that: The glue injection and packaging in step (3) are independently performed using epoxy resin; Preferably, the thickness of the package is 2-3 cm.

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