Tight reservoir horizontal well three-dimensional fracturing experiment simulation equipment

Abstract

The invention relates to the technical field of horizontal well fracturing experiment simulation equipment, in particular to tight reservoir horizontal well three-dimensional fracturing experiment simulation equipment which comprises a box base, a mounting frame and a test cylinder, the mounting frame is mounted on the box base, the test cylinder is arranged in the mounting frame, reservoir rock is stored in the test cylinder, a horizontal drill hole is formed in the center of the reservoir rock, and the horizontal drill hole is communicated with the mounting frame. A fracturing mechanism is installed on the left side of the test barrel, one end of the fracturing mechanism can penetrate through the test barrel to be located in the horizontal drill hole and conduct fracturing on the interior of the reservoir rock, the reservoir rock is sleeved with a filter screen pipe, and the filter screen pipe is coaxially fixed to the test barrel through a support. The device is reasonable and compact in structure and convenient to use, the fracturing mechanism is used for fracturing horizontal drill holes of reservoir rocks, the pumping assembly is mainly used for pumping oil gas into storage fractures of the reservoir rocks, a plurality of blowout pressure points are formed, the environment conditions of underground horizontal well fracturing are restored, and the fracturing efficiency of the reservoir rocks is improved. And the internal damage caused by the fracturing mechanism when the interior of the simulated oil gas reaches the blowout critical value is reduced through the experiment.

Description

Technical Field

[0001] This invention relates to the technical field of horizontal well fracturing experimental simulation equipment, and is a three-dimensional fracturing experimental simulation equipment for horizontal wells in tight reservoirs. Background Technology

[0002] In oil and gas extraction, internal fracturing operations are frequently performed at the extraction site to increase reservoir productivity. Fracturing uses high-pressure fluids to fracture the reservoir, releasing more oil or gas. However, if the pressure is inappropriate or the wellbore is unstable, the fracturing fluid may become uncontrollable, potentially leading to pressure spikes or blowouts. To mitigate these potential hazards and better understand and optimize the process and effectiveness of horizontal well fracturing operations in tight reservoirs, fracturing experimental simulations are necessary to obtain theoretical data support. Traditional techniques use control systems and physical simulation methods to reproduce the rock mechanics properties, fluid flow, and propagation behavior of fracturing fluids in complex geological structures deep underground.

[0003] The invention patent with announcement number CN106401551B discloses an invention providing a horizontal and segmented fracturing or synchronous fracturing simulation experimental system for simulating fracturing of cubic artificial rock samples. The system includes: a fracturing simulation component, a stress loading device, and a fracture monitoring device. The fracturing simulation component includes a simulated wellbore and an injection pipe. The simulated wellbore is located inside the artificial rock sample, with its bottom closed and its opening located outside the sample. At least two simulated perforations are arranged along the axial direction of the simulated wellbore on its wall. One end of the injection pipe is closed, and the other end is connected to the supply line. The outer diameter of the injection pipe matches the inner diameter of the simulated wellbore, allowing the injection pipe to be installed inside the simulated wellbore. At least two outlet holes are arranged along the axial direction of the injection pipe on its wall, with the spacing between the outlet holes differing from the spacing between the simulated perforations. As the injection pipe moves axially within the simulated wellbore, at most one outlet hole aligns with and connects to the simulated perforation, allowing the fracturing fluid flowing into the injection pipe to enter the artificial rock sample through the simulated perforation connected to the outlet hole. Three stress loading devices are used, each corresponding to a direction perpendicular to the outer surface of the artificial rock sample, and the directions corresponding to different fracturing simulation components are perpendicular to each other. The sensors of the fracture monitoring device are installed on the surface of the artificial rock sample. It can study the influence of fluid forces on fracture formation and propagation under the premise of simulating hydraulic fracturing in actual mining operations, using liquid as the fracturing medium; however, its fracturing test mode is singular, unable to flexibly adjust different parameters and fracturing orientations, and it is difficult to reproduce fracturing operations under different scenarios.

[0004] Patent CN114607331B discloses a horizontal well segmented volumetric fracturing simulation test device. This device includes a true triaxial servo loading module, a perforation control module, a hydraulic servo pump pressure module, a hydraulic fracturing monitoring module, and a data acquisition and processing module. The patent uses a true triaxial servo loading module to apply stress to the rock sample from three directions; and by setting a perforation control module in the rock sample and using a hydraulic servo pump pressure module to provide fracturing fluid, it simulates the process of simultaneous fracturing of multiple horizontal wells. Clearly, it simply simulates horizontal well fracturing through three-dimensional loading and hydraulic fracturing. Although it can switch between different fracturing holes for venting fracturing, thus simulating the segmented fracturing process of a horizontal well, it cannot simulate the experimental reproduction of the blowout caused by different fracturing intensities at various blowout pressure points, limiting the accurate simulation of localized over-fracturing and blowout triggering mechanisms. Summary of the Invention

[0005] This invention provides a three-dimensional fracturing experimental simulation device for horizontal wells in tight reservoirs, which overcomes the shortcomings of the prior art. It can effectively solve the problem that existing three-dimensional fracturing experimental simulation devices are unable to reproduce and simulate the oil and gas pressure blowout effect in tight reservoirs and cannot obtain the destructive strength of the oil and gas flow channels during fracturing.

[0006] The technical solution of the present invention is achieved through the following measures: a three-dimensional fracturing experimental simulation device for a tight reservoir horizontal well, comprising a box base, a mounting frame, and a test cylinder. The mounting frame is installed on the box base, and the test cylinder is provided inside the mounting frame. Reservoir rock is placed inside the test cylinder, and a horizontal borehole is drilled at the center of the reservoir rock. A fracturing mechanism is installed on the left side of the test cylinder. One end of the fracturing mechanism can pass through the test cylinder and be located inside the horizontal borehole to fracture the inside of the reservoir rock. A filter screen tube is fitted over the reservoir rock, and the filter screen tube is coaxially fixed to the test cylinder by a bracket. Several pumping components are provided inside the test cylinder, and the pumping components can pump oil and gas into the reservoir rock from the outside to the inside.

[0007] The following are further optimizations and / or improvements to the above-mentioned technical solution: Preferably, the fracturing mechanism includes a transfer frame, a drive seat, a drill shaft, and a fracturing tube. The transfer frame is installed on the left side of the test cylinder, and the drive seat is slidably mounted on the transfer frame. The drill shaft is mounted on the drive seat, and the left end of the drill shaft is connected to an injection pipe. The right end of the drill shaft passes through the test cylinder and is located in a horizontal borehole. A fracturing tube is fitted on the right side of the drill shaft. Sealing plungers fitted on the drill shaft are provided on the left and right sides of the fracturing tube. The sealing plungers can seal the horizontal boreholes on the left and right sides of the fracturing tube when it expands.

[0008] Preferably, the pumping assembly includes an outer pipe frame, a fixed annular cavity, an inner nozzle, and an adjusting pipe. The outer pipe frame is fitted with a filter screen tube around its perimeter. The fixed annular cavity is installed along the circumference of the outer pipe frame and is connected to the pumping pipe. Several inner nozzles are evenly distributed along the circumference at the inner end of the fixed annular cavity. The inner nozzles are installed together with the corresponding outer pipe frames. The outer end of the inner nozzle is connected to the fixed annular cavity, and the inner end of the inner nozzle is connected to the adjusting pipe. The adjusting pipe passes through the outer pipe frame and is located within the reservoir rock fracture.

[0009] Preferably, the pumping assembly further includes an inner shaft tube seat, a flow-blocking rod, a ring connector, a hinge shaft, and a fine-tuning telescopic rod. A shaft tube seat is installed on the outer side of the fixed annular cavity corresponding to each inner nozzle position. The middle part of the flow-blocking rod is slidably installed in the shaft tube seat. A seal is provided between the shaft tube seat and the flow-blocking rod. The lower end of the flow-blocking rod is located inside the inner nozzle. The inner side of the inner nozzle is inverted trapezoidal. A hinge shaft is hinged to the outer end of the flow-blocking rod. A ring connector is installed on the outer end of the hinge shaft. Several fine-tuning telescopic rods that can push the ring connector to move outward or inward are provided between the ring connector and the fixed annular cavity.

[0010] Preferably, the filter tube is fixed with a guide rail, the outer tube frame is slidably connected to the guide rail and can move left and right, and the adjusting tube can move up and down.

[0011] Preferably, each inner nozzle is connected to a replenishment pipe on one side.

[0012] Preferably, a positioning plate is fixed to the right end of the outer side of the test tube. The positioning plate is equipped with multiple external pipes. The left ends of the external pipes are sealed and inserted into the reservoir fractures of the reservoir rock through the test tube. A pressure gauge is installed on the outside of the external pipes.

[0013] The present invention has a reasonable and compact structure and is easy to use. It uses a fracturing mechanism to fracture horizontal boreholes in reservoir rock. The pumping component is mainly used to pump oil and gas into the reservoir rock fractures and form multiple blowout pressure points to recreate the environmental conditions of underground horizontal well fracturing. The experiment simulates the internal damage caused by the fracturing mechanism when the oil and gas inside reaches the blowout critical point. Attached Figure Description

[0014] Appendix Figure 1 This is a schematic diagram of the front cross-sectional structure according to an embodiment of the present invention.

[0015] Appendix Figure 2 This is a three-dimensional structural diagram of the present invention.

[0016] Appendix Figure 3 For the appendix Figure 1 Enlarged structural diagram of the pumping assembly.

[0017] Appendix Figure 4 This is a schematic diagram of the structure from the left when the ring-shaped support is coaxial with the reservoir rock.

[0018] Appendix Figure 5This is a schematic diagram of the left-side structure when the ring joint is eccentric.

[0019] The codes in the attached diagram are as follows: 1. Box base; 11. Test cylinder; 12. Mounting frame; 13. Filter screen tube; 14. Support; 2. Fracturing mechanism; 21. Transfer frame; 22. Drive seat; 23. Drill shaft rod; 24. Fracturing tube; 25. Sealing plunger; 3. Pumping assembly; 31. Outer tube support; 32. Fixed annular cavity; 33. Pumping pipe; 34. Inner nozzle; 35. Adjusting pipe; 36. Inner shaft tube seat; 37. Ring joint frame; 38. Hinge shaft rod; 39. Fine-tuning telescopic rod; 4. Positioning plate; 41. Outer tube. Detailed Implementation

[0020] The present invention is not limited to the following embodiments, and the specific implementation can be determined according to the technical solution of the present invention and the actual situation.

[0021] In this invention, for ease of description, the description of the relative positions of the components is based on the appendix to the specification. Figure 1 The layout is described using a diagrammatic method, such as front, back, top, bottom, left, right, etc. The positional relationships are determined based on the layout direction of the attached diagram in the instruction manual.

[0022] The present invention will be further described below with reference to embodiments and accompanying drawings: Example 1: As shown in the attached document Figure 1-5 As shown, the three-dimensional fracturing experimental simulation equipment for a tight reservoir horizontal well includes a base 1, a mounting frame 12, and a test cylinder 11. The mounting frame 12 is installed on the base 1, and the test cylinder 11 is located inside the mounting frame 12. The test cylinder 11 contains reservoir rock, and a horizontal borehole is drilled at the center of the reservoir rock. A fracturing mechanism 2 is installed on the left side of the test cylinder 11. One end of the fracturing mechanism 2 can pass through the test cylinder 11 and be located inside the horizontal borehole to fracture the reservoir rock. A filter screen tube 13 is attached to the outer sleeve of the reservoir rock. The filter screen tube 13 is coaxially fixed to the test cylinder 11 by a bracket 14. Several pumping components 3 are provided inside the test cylinder 11. The pumping components 3 can pump oil and gas into the reservoir rock from the outside to the inside.

[0023] Reservoir rock samples from a specific area were selected and prepared into reservoir rock samples. The internal porosity distribution was detected using nuclear magnetic resonance (NMR) technology. Then, the orientation of each pumping component 3 was adjusted. A horizontal borehole was drilled at the center of the reservoir rock to simulate a horizontal well. The fracturing mechanism 2 was inserted into the horizontal borehole to fracture the interior of the reservoir rock. The pumping component 3 was mainly used to pump oil and gas into the reservoir fractures and create multiple blowout pressure points to simulate the fracturing environment of an underground horizontal well. This simulated the experimental simulation of the blowout caused by excessive fracturing at different fracturing intensities at each blowout pressure point, which can more closely approximate the actual well site conditions, provide more reliable data and conclusions, and help to gain a deeper understanding of the reservoir properties and the mechanisms that may cause blowouts during fracturing.

[0024] The aforementioned three-dimensional fracturing experimental simulation equipment for horizontal wells in tight reservoirs can be further optimized and / or improved according to actual needs: Example 2: As shown in the attached document Figure 1 , 2 As shown, the fracturing mechanism 2 includes a transfer frame 21, a drive seat 22, a drill rod 23, and a fracturing tube 24. The transfer frame 21 is installed on the left side of the test cylinder 11. The drive seat 22 is slidably arranged on the transfer frame 21. The drill rod 23 is installed on the drive seat 22. The left end of the drill rod 23 is connected to an injection pipe. The right end of the drill rod 23 passes through the test cylinder 11 and is located in a horizontal borehole. The fracturing tube 24 is fitted on the right side of the drill rod 23. Sealing plungers 25 fitted on the drill rod 23 are provided on the left and right sides of the fracturing tube 24. The sealing plungers 25 can seal the horizontal boreholes on the left and right sides of the fracturing tube 24 when it expands.

[0025] The drive seat 22 drives the drill rod 23 to move to the right into the horizontal borehole, so that the fracturing tube 24 is in the fracturing position. Fracturing fluid is injected into the fracturing tube 24 through the injection pipe. When the fracturing fluid is injected, the hydraulic pressure causes the sealing plunger 25 to expand, sealing the area of ​​the fracturing tube 24, ensuring that the fracturing fluid is fracturing in this area, ensuring the fracturing effect, and adjusting and controlling parameters such as the pressure, flow rate, density and viscosity of the fracturing fluid.

[0026] Example 3: As shown in the attached document Figure 3 As shown, the pumping assembly 3 includes an outer pipe frame 31, a fixed annular cavity 32, an inner nozzle 34, and an adjusting pipe 35. The outer pipe frame 31 is fitted with a filter screen tube 13 around its circumference. The fixed annular cavity 32 is installed on the outer side of the outer pipe frame 31 along its circumference. The fixed annular cavity 32 is connected to the pumping pipe 33. Several inner nozzles 34 are evenly distributed along the circumference at the inner end of the fixed annular cavity 32. The inner nozzles 34 are installed together with the corresponding outer pipe frame 31. The outer end of the inner nozzle 34 is connected to the fixed annular cavity 32. The inner end of the inner nozzle 34 is connected to the adjusting pipe 35. The adjusting pipe 35 passes through the outer pipe frame 31 and is located in the reservoir rock fracture.

[0027] The reservoir oil can enter each inner nozzle 34 through the fixed annular cavity 32, and then be transported to the reservoir rock's reservoir fractures by the regulating pipe 35 of each inner nozzle 34. After fracturing, it is ejected outward from the fractures, thus simulating the experimental reproduction of the blowout caused by excessive fracturing of horizontal wells due to different fracturing intensities at each blowout pressure point.

[0028] Example 4: As shown in the appendix Figure 3-5As shown, the pumping assembly 3 also includes an inner shaft tube seat 36, a flow-blocking rod, a ring connector 37, a hinge shaft rod 38, and a fine-tuning telescopic rod 39. The shaft tube seat 36 is connected to the outside of the fixed annular cavity 32 corresponding to the position of each inner nozzle 34. The middle part of the flow-blocking rod is slidably installed in the shaft tube seat 36. A seal is provided between the shaft tube seat 36 and the flow-blocking rod. The lower end of the flow-blocking rod is located in the inner nozzle 34. The inner side of the inner nozzle 34 is inverted trapezoidal. The outer end of the flow-blocking rod is hinged to the hinge shaft rod 38. The outer end of the hinge shaft rod 38 is installed with the ring connector 37. Several fine-tuning telescopic rods 39 that can push the ring connector 37 to move outward or inward are provided between the ring connector 37 and the fixed annular cavity 32.

[0029] The inner nozzle 34 has a trapezoidal cross-section, and a flow-blocking component is fixed at the end of the flow-blocking rod. The flow-blocking component can adjust the distance between itself and the inner wall of the inner nozzle 34 when the flow-blocking rod moves inward and outward, thereby adjusting the flow rate of the inner nozzle 34. In the initial state, the annular frame 37 is coaxial with the reservoir rock, and the distance between the flow-blocking rods at each position and the inner nozzle 34 is consistent, resulting in the same flow rate, uniform oil and gas delivery, and constant pressure. When the fine-tuning telescopic rod 39 extends upward, the center of the annular frame 37 moves upward, and the flow-blocking rod located at the upper part moves upward away from the inner end of the inner nozzle 34, increasing the flow rate. The flow-blocking rod located at the lower part moves upward closer to the inner end of the inner nozzle 34, decreasing the flow rate. This can form the main pressure point and the low pressure point of the blowout. Multiple pumping components 3 are arranged from different directions to form multiple main pressure points of the blowout, thereby accurately reducing the oil and gas reservoir pressure caused by the blowout effect under different fracturing conditions.

[0030] Example 5: As shown in the attached document Figure 3 As shown, a guide rail is fixed on the filter tube 13, and the outer tube frame 31 is slidably connected to the guide rail and can move left and right. The adjusting tube 35 can move up and down. The outer tube frame 31 can move left and right relative to the filter tube 13 on the guide rail, thereby adjusting the left and right position of the outer tube frame 31 on the reservoir rock. The adjusting tube 35 can move up and down, and can be lengthened or shortened according to the location of the fracture.

[0031] Example 6: As shown in the appendix Figure 3 As shown, each inner nozzle 34 is connected to a refueling pipe on one side. By setting the refueling pipe, oil and gas delivery can be increased to the fracture at a specified location as needed.

[0032] Example 7: As attached Figure 1 As shown, a positioning disk 4 is fixed to the right end of the outer side of the test cylinder 11. Multiple external connecting pipes 41 are mounted on the positioning disk 4. The left ends of each external connecting pipe 41 are sealed and inserted into the reservoir fractures of the reservoir rock through the test cylinder 11. A pressure gauge is installed on the outside of each external connecting pipe 41. The pressure gauge on the external connecting pipe 41 can monitor the oil and gas pressure in the reservoir rock in real time, so that a small amount of oil and gas can be discharged from the external connecting pipe 41 when the pressure exceeds the experimental pressure.

[0033] The above technical features constitute various embodiments of the present invention, which have strong adaptability and implementation effect. Unnecessary technical features can be added or removed according to actual needs to meet the needs of different situations.

Claims

1. A three-dimensional fracturing experimental simulation device for horizontal wells in tight reservoirs, characterized in that... The test chamber includes a base, a mounting frame, and a test cylinder. The mounting frame is installed on the base, and the test cylinder is located inside the mounting frame. The test cylinder contains reservoir rock, and a horizontal borehole is drilled at the center of the reservoir rock. A fracturing mechanism is installed on the left side of the test cylinder. One end of the fracturing mechanism can pass through the test cylinder and be located inside the horizontal borehole to fracture the reservoir rock. A filter screen tube is fitted over the reservoir rock and is coaxially fixed to the test cylinder by a bracket. Several pumping components are installed inside the test cylinder, which can pump oil and gas into the reservoir rock from the outside to the inside.

2. The three-dimensional fracturing experimental simulation equipment for tight reservoir horizontal wells according to claim 1, characterized in that... The fracturing mechanism includes a transfer frame, a drive seat, a drill spindle, and a fracturing tube. The transfer frame is installed on the left side of the test tube, and the drive seat is slidably mounted on the transfer frame. The drill spindle is mounted on the drive seat, and the left end of the drill spindle is connected to an injection pipe. The right end of the drill spindle passes through the test tube and is located in a horizontal borehole. A fracturing tube is fitted on the right side of the drill spindle. Sealing plungers fitted on the drill spindle are provided on the left and right sides of the fracturing tube. The sealing plungers can seal the horizontal boreholes on the left and right sides of the fracturing tube when it expands.

3. The three-dimensional fracturing experimental simulation equipment for tight reservoir horizontal wells according to claim 1 or 2, characterized in that... The pumping assembly includes an outer pipe frame, a fixed annular cavity, inner nozzles, and a regulating pipe. The outer pipe frame is fitted with a filter screen tube around its perimeter. The fixed annular cavity is installed along the circumference of the outer pipe frame and is connected to the pumping pipe. Several inner nozzles are evenly distributed along the circumference at the inner end of the fixed annular cavity. The inner nozzles are installed together with the corresponding outer pipe frames. The outer end of the inner nozzle is connected to the fixed annular cavity, and the inner end of the inner nozzle is connected to the regulating pipe. The regulating pipe passes through the outer pipe frame and is located within the reservoir rock fractures.

4. The three-dimensional fracturing experimental simulation equipment for tight reservoir horizontal wells according to claim 3, characterized in that... The pumping assembly also includes an inner shaft tube seat, a flow-blocking rod, a ring connector, a hinge shaft, and a fine-tuning telescopic rod. The shaft tube seat is installed on the outside of the fixed ring cavity corresponding to each inner nozzle position. The middle part of the flow-blocking rod is slidably installed in the shaft tube seat. A seal is provided between the shaft tube seat and the flow-blocking rod. The lower end of the flow-blocking rod is located inside the inner nozzle. The inner side of the inner nozzle is inverted trapezoidal. The outer end of the flow-blocking rod is hinged to a hinge shaft. The outer end of the hinge shaft is installed with a ring connector. Several fine-tuning telescopic rods that can push the ring connector to move outward or inward are provided between the ring connector and the fixed ring cavity.

5. The three-dimensional fracturing experimental simulation equipment for tight reservoir horizontal wells according to claim 3, characterized in that... The filter tube is fixed with a guide rail, and the outer tube frame is slidably connected to the guide rail, allowing it to move left and right. The adjustment tube can move inward and outward.

6. The three-dimensional fracturing experimental simulation equipment for tight reservoir horizontal wells according to claim 4, characterized in that... The filter tube is fixed with a guide rail, and the outer tube frame is slidably connected to the guide rail, allowing it to move left and right. The adjustment tube can move in the inward and outward directions.

7. The three-dimensional fracturing experimental simulation equipment for tight reservoir horizontal wells according to claim 3, characterized in that... Each inner nozzle is connected to a refill pipe on one side.

8. The three-dimensional fracturing experimental simulation equipment for tight reservoir horizontal wells according to claim 4, 5, or 6, characterized in that... Each inner nozzle 34 has a refill pipe connected to one side.

9. The three-dimensional fracturing experimental simulation equipment for tight reservoir horizontal wells according to claim 3, characterized in that... Each inner nozzle is connected to a refill pipe on one side.

10. The three-dimensional fracturing experimental simulation equipment for horizontal wells in tight reservoirs according to any one of claims 1, 2, 4, 5, 6, 7, or 9, characterized in that... A positioning plate is fixed to the right side of the test tube. Multiple external pipes are installed on the positioning plate. The left ends of the external pipes are sealed and inserted into the reservoir fractures of the reservoir rock through the test tube. A pressure gauge is installed on the outside of the external pipe.

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