Combined near wellbore area shearing simulation device

Abstract

The utility model belongs to the field of petroleum engineering, and particularly relates to a combined near wellbore area shearing simulation device, which comprises a hollow cylinder, a first sealing body, a second sealing body, a first connecting rod and a second connecting rod, the first sealing body is provided with a pipeline injection port; a plurality of cylindrical holes are formed in the wall of the hollow cylinder; the hollow column is coaxially arranged in the hollow cylinder; a column body of the hollow column is provided with a round hole corresponding to the cylindrical hole; the screen pipe is coaxially arranged in the hollow column; a first compacted sand body is filled between the outer part of the screen pipe and the hollow column; one end of the multi-section hollow cylinder is connected with the cylindrical hole, and the other end of the multi-section hollow cylinder is connected with the pipeline outflow unit; and a second compaction sand body is arranged in the multi-section hollow cylinder. The shear simulation device can accurately simulate and research the shear stress change of the near wellbore zone of the wellbore under different well completion processes, and has important significance for optimizing the well completion design and improving the stability of the wellbore.

Description

Technical Field

[0001] The utility model relates to the technical field of petroleum engineering, in particular to a combined near-wellbore zone shear simulation device. Background Art

[0002] During the development of oil and gas wells, completion technology directly affects the stability and production performance of the wellbore. Traditional completion technologies, such as fracturing, perforating, and sand packing, are often accompanied by changes in the shear stress of the rock formations surrounding the wellbore. These stress changes may lead to wellbore instability, wellbore collapse, or sand invasion, which in turn affects oil and gas production capacity and the life of the well. Therefore, accurately simulating and studying the shear stress changes in the near-wellbore zone of the wellbore and the shear stress changes of the injected well fluid under different completion technologies is of great significance for optimizing completion design, improving wellbore stability, and evaluating injection efficiency. Studies have found that polymer solutions will undergo varying degrees of shear when passing through multiple stages such as the screen, gravel pack zone, perforation zone, and near-wellbore zone. As a result, the effective viscosity of the polymer solution injected into the oil layer is often only half of the expected value or even less, making it difficult to achieve the goal of increasing production.

[0003] In the existing technology, the simulation experiments of mechanical shear are mainly based on Wu Yin's mixer shear experiment and core shear experiment; the shearing method of Wu Yin's mixer shear experiment is single mechanical shear, while the solution under real formation conditions is affected by multiple shear methods. This experiment cannot effectively simulate the actual shear effect on the solution; the core shear experiment can only simulate the shear force exerted on the solution under static conditions, and cannot simulate the shear force exerted on the solution in the near-wellbore area under continuous changes. Utility Model Content

[0004] An object of the present invention is to solve at least the above problems and / or disadvantages and to provide at least the advantages to be described hereinafter.

[0005] To solve the above problems, the utility model provides a combined near-wellbore shear simulation device. The device can, through a modular structural design, quickly switch and combine different completion processes (such as open hole, perforation, gravel packing, etc.) in a laboratory environment to study the shear stress effects of the rock formations in the near-wellbore area, or the shear stress effects of the injection fluid on the rock formations in the near-wellbore area under different completion processes.

[0006] A combined near-wellbore shear simulation device, comprising:

[0007] A hollow cylinder having openings at both ends and respectively provided with a first sealing body and a second sealing body; the first sealing body has a pipeline injection port; a plurality of cylindrical holes are opened on the wall of the hollow cylinder;

[0008] A hollow column is coaxially arranged in the hollow cylinder; a circular hole corresponding to the cylindrical hole is opened on the body of the hollow column;

[0009] A screen pipe is coaxially arranged in the hollow column; and a first compacted sand body is filled between the outside of the screen pipe and the hollow column;

[0010] A multi-section hollow circular cylinder has one end connected to the cylindrical hole and the other end connected to the pipeline outflow unit; a second compacted sand body is provided inside the multi-section hollow circular cylinder.

[0011] On the basis of the above technical solution, the present invention can also be improved as follows:

[0012] Furthermore, the second sealing body is arranged on a fixing frame, and a moving component is arranged on the bottom surface of the fixing frame.

[0013] Furthermore, the first sealing body includes a hollow cylindrical sealing body and a T-shaped sealing body, the hollow cylindrical sealing body is installed on the hollow cylinder, the T-shaped sealing body is embedded in the hollow cylindrical sealing body, and the pipeline injection port is opened on the T-shaped sealing body.

[0014] Furthermore, the bottom end of the T-shaped sealing body is detachably connected to the top end of the screen tube.

[0015] Furthermore, the cylindrical holes are distributed in 3 rows and 4 columns on the wall of the hollow cylinder.

[0016] Furthermore, the pipeline outflow unit includes an annular hollow rod and a plurality of linear hollow rods, the linear hollow rods are connected to the annular hollow rod, and the rod bodies of the linear hollow rods are connected to the multiple hollow circular cylinders.

[0017] Furthermore, the annular hollow rod is provided with a pipeline outflow port.

[0018] Furthermore, the pipeline outflow port and the pipeline inlet are respectively provided with a first sealing cover for sealing.

[0019] Furthermore, a pressure sensor is provided at the connection between the linear hollow rod and the hollow circular cylinder.

[0020] Furthermore, the multi-section hollow circular cylinder includes a plurality of hollow circular cylinders, and the plurality of hollow circular cylinders are detachably connected in sequence to form the multi-section hollow circular cylinder.

[0021] The utility model has at least the following beneficial effects:

[0022] 1. This utility model can, in a laboratory environment, quickly switch and combine different completion processes (such as open hole, perforation, gravel packing, etc.) through modular structural design to study the shear stress effects on the rock formation and wellbore in the near-wellbore area, which is of great significance for optimizing completion design and improving wellbore stability. The device filling objects can be adjusted according to formation conditions and the shear environment under different completion methods can be simulated. The seepage characteristics of porous media in the near-wellbore area can be simulated. The device can achieve efficient disassembly and assembly, and can accurately and realistically simulate the shear environment of the wellbore when the working fluid enters the near-wellbore area.

[0023] 2. The detachable screen allows operators to disassemble and assemble it according to the completion process requirements, thus simulating different completion process environments.

[0024] 3. The setting between any two hollow circular cylinders can be disassembled, so that the number of sections of multiple hollow circular cylinders can be assembled according to needs, so that operators can choose the permeability and porosity of the compacted sand body to be filled and whether to fill it according to the relevant parameters of the target formation, realizing the simulation of different shear environments and improving the applicability of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of a combined near-wellbore zone shear simulation device of the utility model.

[0026] Figure 2 It is a schematic diagram of the cross-sectional structure of the combined near-wellbore zone shear simulation device of the utility model.

[0027] Figure numerals: 100-hollow cylinder, 110-cylindrical hole, 200-first sealing body, 210-pipeline injection port, 220-hollow cylindrical sealing body, 230-T-shaped sealing body, 300-second sealing body, 310-fixed frame, 320-moving assembly, 400-hollow column, 500-screen pipe, 600-first compacted sand body, 700-multi-section hollow circular cylinder, 710-hollow circular body, 730-second compacted sand body, 800-pipeline outflow unit, 810-annular hollow rod, 811-pipeline outflow port, 820-linear hollow rod, 900-first sealing cover, 910-second sealing cover, 920-third sealing cover. DETAILED DESCRIPTION

[0028] The present invention will be described in further detail below in conjunction with the accompanying drawings so that those skilled in the art can implement the invention with reference to the description.

[0029] It should be understood that terms such as “having,” “including,” and “comprising” used herein do not preclude the existence or addition of one or more other elements or combinations thereof.

[0030] In order to make the purpose, technical solutions and advantages of the embodiments of the patent of the present invention clearer, the technical solutions of the embodiments of the patent of the present invention will be clearly and completely described below in conjunction with the drawings of the embodiments of the patent of the present invention. Unless otherwise defined, the technical terms or scientific terms used in this disclosure should be the usual meanings understood by people with ordinary skills in the field to which this disclosure belongs. The words "including" or "comprising" and the like used in this disclosure mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Up", "down", "left", "right" and the like are only used to indicate relative position relationships. When the absolute position of the described object changes, the relative position relationship may also change accordingly.

[0031] See also Figures 1 to 2 , a combined near-wellbore zone shear simulation device, comprising:

[0032] The hollow cylinder 100 has openings at both ends and is respectively provided with a first sealing body 200 and a second sealing body 300. The first sealing body 200 and the second sealing body 300 serve to seal the hollow cylinder 100. The hollow cylinder 100 is used to simulate a wellbore. It should be noted that the hollow cylinder 100 is preferably made of a high-strength alloy material with the characteristics of high pressure resistance, high temperature resistance, and corrosion resistance, and can simulate the wellbore environment under different completion conditions. The inner surface of the hollow cylinder 100 is precisely machined to ensure that the roughness and friction coefficient are consistent with the inner wall of the actual wellbore, thereby accurately simulating the mechanical interaction between the wellbore and the formation, and better simulating the actual environment.

[0033] The first sealing body 200 has a pipeline injection port 210, which provides a liquid inflow channel; a plurality of cylindrical holes 110 are opened on the wall of the hollow cylinder 100; the second sealing body 300 is arranged on a fixed frame 310, and a moving component 320 is provided on the bottom surface of the fixed frame 310 for moving the shear simulation device as a whole. It can be understood that the moving component 320 can be a universal wheel, which belongs to the existing technology product. The installation method of the universal wheel and the fixed frame 310 also belongs to the existing technology and will not be repeated here.

[0034] The hollow column 400 is detachably and coaxially arranged in the hollow cylinder 100; a circular hole corresponding to the cylindrical hole 110 is opened on the column body of the hollow column 400; the hollow column 400 is preferably a hollow cement column, and the circular holes opened on the hollow column 400 correspond one-to-one with the cylindrical hole 110 to simulate the perforation completion process; it is worth noting that when there is no need to test the fluid flow conditions of one or more perforation holes, the second sealing cover 910 can be used to seal the cylindrical hole 110.

[0035] A screen 500 is detachably coaxially disposed within the hollow column 400 ; a first compacted sand body 600 is filled between the exterior of the screen 500 and the hollow column 400 . The first compacted sand body 600 may be gravel. The screen 500 may be a slotted liner or a wire-wound screen to simulate a gravel-fill completion method.

[0036] A multi-section hollow circular cylinder 700 has one end connected to the cylindrical hole 110 and the other end connected to the pipeline outflow unit 800; a second compacted sand body 730 is provided inside the multi-section hollow circular cylinder 700, and the multi-section hollow circular cylinder 700 is connected to the cylindrical hole 110 to provide a liquid flow channel. It should be noted that the second compacted sand body 730 can be selected according to the test content, mainly to simulate the properties of the rock formation near the wellbore of the wellbore or as a liquid sampling channel.

[0037] Of course, in other embodiments, no components are installed in the hollow cylinder 100 to simulate an open hole completion process.

[0038] Specifically, the modular design allows for rapid switching and combining of different completion techniques, such as openhole, perforation, and gravel packing, to assess the shear stress effects on the near-wellbore rock formation and wellbore, significantly impacting completion design optimization and improving wellbore stability. The device's filler can be adjusted based on formation conditions, simulating the shear environment under different completion methods. The device can also simulate the seepage characteristics of porous media near the wellbore. This allows for efficient disassembly and assembly of the device, accurately and realistically simulating the shear environment experienced by the influent fluid entering the near-wellbore area. The detachable screen 500 allows operators to disassemble and assemble it according to completion process requirements, enabling simulation of diverse completion process environments.

[0039] Based on the above, in some embodiments, the first sealing body 200 includes a hollow cylindrical sealing body 220 and a T-shaped sealing body 230. The hollow cylindrical sealing body 220 is installed on the hollow cylinder 100, and the T-shaped sealing body 230 is embedded in the hollow cylindrical sealing body 220. The pipeline injection port 210 is opened on the T-shaped sealing body 230. The hollow cylindrical sealing body 220 and the T-shaped sealing body 230 can be connected by flanges, and the hollow cylindrical sealing body 220 and the hollow cylinder 100 are threaded and sealed, thereby achieving rapid assembly or disassembly; further, the bottom end of the T-shaped sealing body 230 is detachably connected to the top end of the screen tube 500. Specifically, the bottom end of the T-shaped sealing body 230 and the screen tube 500 can be connected by a bayonet. Furthermore, the cylindrical holes 110 are distributed in 3 rows and 4 columns on the wall of the hollow cylinder 100.

[0040] Based on the above, in some embodiments, the pipeline outflow unit 800 includes an annular hollow rod 810 and a plurality of linear hollow rods 820. The linear hollow rods 820 are connected to the annular hollow rod 810, and the shafts of the linear hollow rods 820 are connected to the multi-segment hollow circular cylinders 700. Specifically, the linear hollow rods 820 and the annular hollow rods 810 are connected by flanges, which are conventional. It is understood that when the cylindrical holes 110 are arranged in three rows and four columns, the number of multi-segment hollow cylinders 700 is correspondingly twelve, and the number of linear hollow rods 820 is four. Any linear hollow rod 820 is connected to a multi-segment hollow cylinder 700 connected to a row of cylindrical holes 110. Specifically, the shafts of the linear hollow rods 820 are sequentially provided with three connection ports along their axes, which are connected to corresponding multi-segment hollow cylinders 700. It should be noted that a third sealing cover 920 may be provided at the connection port for sealing.

[0041] Furthermore, the annular hollow rod 810 is provided with a pipeline outflow port 811 , which provides a liquid discharge channel.

[0042] Furthermore, the pipeline outflow port 811 and the pipeline injection port 210 are respectively provided with a first sealing cover 900 for blocking. The first sealing cover 900 is used to seal the pipeline outflow port 811 and the pipeline injection port 210 when necessary to ensure the sealing of the shear simulation device.

[0043] Based on the above, in some embodiments, a pressure sensor is provided at the connection between the linear hollow rod 820 and the multi-segment hollow circular cylinder 700. The pressure sensor is connected to a computer to display the pressure of the injection fluid reaching the multi-segment hollow circular cylinder 700 through the wellbore.

[0044] Furthermore, the multi-segment hollow circular cylinder 700 includes multiple hollow circular cylinders 710, which are sequentially detachably connected to form the multi-segment hollow circular cylinder 700. Any two of the hollow circular cylinders 710 are flange-connected, and the detachable arrangement between any two hollow circular cylinders 710 allows the multi-segment hollow circular cylinder 700 to be assembled in any desired number of sections. This allows operators to select the permeability and porosity of the compacted sand body to be filled, as well as whether to fill it, based on parameters related to the target formation. This enables simulation of different shear environments and improves the applicability of the device. It should be noted that there are three types of filling the multi-segment hollow circular cylinder 700 with the second compacted sand body 730: one in which all sections are filled with the second compacted sand body 730; two in which some sections are filled with the second compacted sand body 730, with the remaining sections left unfilled; and three in which all sections are left unfilled.

[0045] Of course, in other embodiments, the pressure and temperature of the shear simulation device can be controlled by a pressure and temperature control system. The pressure and temperature control system is a prior art and can include a sealed cabin, a high-pressure pump, a heating device, and a temperature control system. The shear simulation device is housed within the sealed cabin. The sealed cabin is made of high-strength materials and can withstand high pressures of up to hundreds of MPa. The inner wall is coated with a corrosion-resistant coating to prevent material degradation in high-temperature and high-pressure environments. The high-pressure pump injects liquid into the sealed cabin through a pipeline to simulate the high-pressure environment downhole. The heating device simulates the high-temperature conditions downhole by heating with a resistance wire or circulating a hot fluid. The temperature control system monitors the temperature in the cabin in real time through a built-in temperature sensor and ensures temperature stability and adjustability through feedback control, controlling pressure and temperature changes to meet the environmental requirements of different completion processes. Of course, stress can also be applied and controlled by a pressure loading system to fill the interior of the hollow cylinder 100 with liquid.

[0046] When the present invention is used in practice, according to actual conditions, the pre-selected wellbore simulation components (screen 500, hollow column 400) are installed in the hollow cylinder 100 and fixed through flange connections, and then the hollow cylindrical sealing body 220 and the T-shaped sealing body 230 are installed to ensure the tightness and sealing of the hollow cylinder 100 to avoid leakage when shear force or pressure is applied; at the same time, the pressure sensor and temperature sensor are calibrated to ensure their measurement accuracy.

[0047] Taking the simulated perforation completion process as an example, the pressure and temperature control system is activated until the experimental preset pressure and temperature values ​​are reached, simulating a downhole high-pressure and high-temperature system. The wellbore fluid enters the pressure loading system through the pipeline injection port 210. After reaching the preset liquid level, the hydraulic pump of the pressure loading system is activated to inject it into the hollow cylinder 100, and the injection pressure is gradually increased to the set value. During this process, the wellbore fluid first enters the screen 500, seeps through the screen 500 to the first compacted sand body 600, then passes through the circular hole of the hollow column 400 to the cylindrical hole 110 on the hollow cylinder 100, flows from the cylindrical hole 100 into the multi-segment hollow circular cylinder 700, and seeps in the second compacted sand body 730 in a linear flow direction. The pressure change of the wellbore fluid as it passes through the wellbore and reaches the multi-segment hollow circular cylinder 700 is observed through a computer-connected pressure sensor. When it is necessary to measure the performance of the working fluid, samples can be selected from the pipeline outlet 811 of the annular hollow rod 810 for performance testing and the working fluid is discharged from it.

[0048] Although the embodiments of the present invention have been disclosed as above, they are not limited to the applications listed in the description and implementation methods. They can be fully applied to various fields suitable for the present invention. For those familiar with the art, additional modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and the scope of equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein. Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the invention.

Claims

1. A combined near-wellbore shear simulation device, characterized in that: include: A hollow cylinder (100) has openings at both ends and is respectively provided with a first sealing body (200) and a second sealing body (300); the first sealing body (200) has a pipeline injection port (210); a plurality of cylindrical holes (110) are opened on the wall of the hollow cylinder (100); A hollow column (400) is detachably and coaxially arranged in the hollow cylinder (100); a circular hole corresponding to the cylindrical hole (110) is formed on the body of the hollow column (400); A screen tube (500) is detachably coaxially arranged in the hollow column (400); and a first compacted sand body (600) is filled between the outside of the screen tube (500) and the hollow column (400); A multi-section hollow circular cylinder (700) is connected at one end to the cylindrical hole (110) and at the other end to the pipeline outflow unit (800); a second compacted sand body (730) is provided inside the multi-section hollow circular cylinder (700).

2. A combined near-wellbore shear simulation device according to claim 1, characterized in that: The second sealing body (300) is arranged on a fixed frame (310), and a moving component (320) is arranged on the bottom surface of the fixed frame (310).

3. The combined near-wellbore shear simulation device according to claim 1, characterized in that: The first sealing body (200) comprises a hollow cylindrical sealing body (220) and a T-shaped sealing body (230), wherein the hollow cylindrical sealing body (220) is mounted on the hollow cylinder (100), the T-shaped sealing body (230) is embedded in the hollow cylindrical sealing body (220), and the pipeline injection port (210) is opened on the T-shaped sealing body (230).

4. A combined near-wellbore shear simulation device according to claim 3, characterized in that: The bottom end of the T-shaped sealing body (230) is detachably connected to the top end of the screen tube (500).

5. The combined near-wellbore shear simulation device according to claim 1, characterized in that: The cylindrical holes (110) are distributed in three rows and four columns on the wall of the hollow cylinder (100).

6. The combined near-wellbore shear simulation device according to claim 1, characterized in that: The pipeline outflow unit (800) comprises an annular hollow rod (810) and a plurality of linear hollow rods (820), wherein the linear hollow rods (820) are connected to the annular hollow rod (810), and the rod bodies of the linear hollow rods (820) are connected to the multi-section hollow circular cylinders (700).

7. The combined near-wellbore shear simulation device according to claim 6, characterized in that: The annular hollow rod (810) is provided with a pipeline outflow outlet (811).

8. A combined near-wellbore shear simulation device according to claim 1 or 7, characterized in that: The pipeline outflow port (811) and the pipeline injection port (210) are respectively provided with a first sealing cover (900) for sealing.

9. The combined near-wellbore shear simulation device according to claim 6, characterized in that: A pressure sensor is provided at the connection between the linear hollow rod (820) and the multi-section hollow circular cylinder (700).

10. The combined near-wellbore shear simulation device according to claim 1, characterized in that: The multi-section hollow circular cylinder (700) comprises a plurality of hollow circular cylinders (710), and the plurality of hollow circular cylinders (710) are detachably connected in sequence to form the multi-section hollow circular cylinder (700).

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