A hydraulic fracturing simulation experiment device and method

Abstract

The present application relates to the technical field of hydraulic fracturing simulation experiment, especially to a kind of hydraulic fracturing simulation experiment device and method, it includes experimental main body box, main body linkage frame body, shaft pipe, rotary drive component, lifting drive component and water supply component, shaft pipe is provided with three, shaft pipe vertical through installation in main body linkage frame body upper side, the lower end of two shaft pipes in three shaft pipes is respectively coaxially installed with drill head frame and finishing drill ring, the remaining one shaft pipe of three shaft pipes is installed with double-head closed unit.The present application can switch working position by main body linkage frame body with three shaft pipes in turn, integrates drilling, well wall finishing and hydraulic fracturing experiment function in the same device, after finishing in the inside of drilled hole wall, double-head closed unit and hole wall are fully closed to form detection space, realize from rock sample processing to fracturing simulation full-process automation, significantly improve experimental efficiency and operation convenience.

Description

Technical Field

[0001] This invention relates to the technical field of hydraulic fracturing simulation experiments, and in particular to a hydraulic fracturing simulation experiment apparatus and method. Background Technology

[0002] In the field of oil and gas extraction, hydraulic fracturing is a crucial production enhancement measure. It involves injecting high-pressure fracturing fluid into underground rock formations to create fractures, thereby improving the efficiency of oil and gas extraction. However, actual underground geological environments are complex and diverse, encompassing various factors such as different rock properties, temperatures, and stress states. These factors interact and influence the effectiveness of hydraulic fracturing, as well as the formation and propagation of fractures. To better understand and optimize the hydraulic fracturing process, simulation experimental devices have emerged. These devices can simulate actual working conditions in a laboratory environment, helping researchers to conduct in-depth studies of the hydraulic fracturing mechanism and providing reliable theoretical basis and technical guidance for field construction.

[0003] In hydraulic fracturing simulation experiments, the extracted rock samples are placed inside the equipment. After drilling the rock samples out of the well, the upper end of the well is sealed, and water pressure is injected into the sealed well to apply hydraulic fracturing to the inner wall of the well. However, in the existing technology, the surface smoothness of the well is low during the drilling process. As a result, the sealing structure cannot fully fit and seal with the inner wall of the well when the water pressure is applied, causing water pressure leakage after the water pressure is injected, and accurate experimental data cannot be obtained. Summary of the Invention

[0004] To address the problems mentioned in the background art, the present invention provides a hydraulic fracturing simulation experimental apparatus and method.

[0005] The present invention provides a hydraulic fracturing simulation experimental device, which adopts the following technical solution: including an experimental main body box, a main body linkage frame, a shaft tube, a rotation drive assembly, a lifting drive assembly, and a water supply assembly.

[0006] The main experimental chamber has a material feeding and processing chamber, a water storage chamber, and a treatment chamber. The material feeding and processing chamber is located between the water storage chamber and the treatment chamber, and the treatment chamber is located above the material feeding and processing chamber.

[0007] The main linkage frame is installed inside the processing chamber, and the main linkage frame rotates relative to the processing chamber.

[0008] There are three shaft tubes, which are vertically installed through the upper side of the main linkage frame. Two of the three shaft tubes are coaxially mounted with a drill bit frame and a dressing drill ring at their lower ends, respectively. The remaining shaft tube is equipped with a double-headed sealing unit.

[0009] The rotary drive assembly is installed inside the processing chamber. The rotary drive assembly can drive the shaft tubes connected to the drill bit holder and the dressing drill ring to rotate. The drill bit holder and the dressing drill ring rotate with the corresponding shaft tubes.

[0010] The lifting drive assembly can drive the shaft tube to move up and down, and the lifting drive assembly is installed inside the processing chamber.

[0011] The water supply assembly is installed inside the treatment chamber and supplies water to the three shaft tubes.

[0012] The dual-head enclosed unit includes: The sealing disc assembly consists of two units, which are coaxially designed.

[0013] A telescopic adjustment assembly is provided, which is connected to an adjacent shaft tube. Two sealing disc assemblies are connected to the telescopic adjustment assembly, which adjusts the distance between the two sealing disc assemblies.

[0014] Optionally, the rotary drive assembly includes: Driven gears, there are two driven gears, which are installed through the upper surface of the main linkage frame. The driven gears rotate relative to the main linkage frame. The outer ring surfaces of the two shaft tubes connected to the drill bit frame and the dressing drill ring are non-cylindrical. The driven gears are slidably fitted onto the outer surfaces of the adjacent shaft tubes. The driven gears drive the connected shaft tubes to rotate synchronously.

[0015] A drive gear ring is rotatably mounted inside the processing chamber, and two driven gears mesh with the inner side of the drive gear ring.

[0016] Optionally, the dual-head closure unit further includes: The intermediate plate is installed through the upper surface of the main linkage frame and is slidably sleeved on the outside of the adjacent shaft tube. The telescopic adjustment component is connected to the intermediate plate.

[0017] The top plate is fixedly sleeved on the outer surface of the shaft tube and is coaxially installed with the adjacent shaft tube. The upper end of the telescopic adjustment component is connected to the top plate.

[0018] Optionally, the telescopic adjustment component includes: The driving prism has a non-circular outer ring surface and a cylindrical upper end. The cylindrical end of the driving prism rotates through the bottom surface of the top plate, and the driving prism rotates relative to the top plate.

[0019] The double-threaded shaft is coaxially mounted with the drive shaft. Two sealing discs mesh with both ends of the double-threaded shaft. When the double-threaded shaft rotates in both directions, it drives the two sealing discs to move closer to each other or further away from each other.

[0020] Optionally, the sealing disc assembly includes: A cylinder, which is coaxially arranged with an adjacent shaft tube, and the cylinder is threadedly sleeved on the outside of a double-threaded shaft.

[0021] The upper sealing disc is slidably sleeved on the outside of the cylinder, and the upper sealing disc has a hole-like structure at the mounting position of the double-threaded shaft.

[0022] The lower sealing disc is slidably sleeved on the outside of the cylinder. The lower sealing disc is located below the upper sealing disc. The lower sealing disc has a hole-like structure at the installation location of the double-threaded shaft. The outer diameter of the upper sealing disc and the outer diameter of the lower sealing disc are equal to the outer diameter of the dressing drill ring.

[0023] The sealing ring is located between the upper sealing disc and the lower sealing disc. The outer ring of the upper sealing disc and the lower sealing disc are both chamfered on the side closest to each other, and the inner ring of the upper and lower surfaces of the sealing ring are also chamfered.

[0024] Optionally, the upper surface of the top plate is rotatably perforated by a side rib shaft, which rotates relative to the top plate. The upper cylinder of the two cylinders is coaxially installed with the adjacent shaft tube, and the lower cylinder of the two cylinders has a sealing disc attached to its upper side, which is elastically connected to the adjacent cylinder.

[0025] Both the drive shaft and the side shaft are fitted with sliding sleeves on their outer sides, and the sleeves rotate through the bottom surface of the intermediate disk.

[0026] Both cylinders have a vertically rotating bidirectional threaded cylinder running through their inner sides. Both bidirectional threaded cylinders are slidably sleeved on the outer surface of the drive shaft. The upper and lower sealing discs connected to the same cylinder are respectively threaded onto the two ends of the same bidirectional threaded cylinder.

[0027] Optionally, the water supply assembly includes three inner water supply pipes and a synchronization ring. The three inner water supply pipes are slidably inserted into the inner side of the three shaft pipes, and the synchronization ring is installed on the inner wall of the processing chamber and fixedly sleeved on the upper end of the three inner water supply pipes.

[0028] It also includes a flexible telescopic water supply pipe, the upper end of which is installed through the inner wall of the processing chamber, and the lower inner diameter of the flexible telescopic water supply pipe is matched with the upper outer diameter of the shaft tube. When the lifting drive assembly drives the shaft tube to the uppermost side, it pushes the flexible telescopic water supply pipe to disengage from the lower shaft tube.

[0029] Optionally, the lifting drive assembly includes: A drive threaded shaft is rotatably mounted inside the processing chamber, and the drive threaded shaft rotates relative to the processing chamber.

[0030] The lifting frame is threaded onto the outer surface of the drive threaded shaft. The lifting frame is vertically slidably connected to the main linkage frame. A vertical rod is provided on the upper side of the lifting frame, and the upper end of the vertical rod is connected to the lower end of the elastic telescopic water supply pipe.

[0031] The lifting concave ring is provided in three parts. The three lifting concave rings are coaxially installed on the upper end of three shaft tubes. The outer ring surface of the lifting concave ring is provided with a ring groove. The lifting frame is located between the three lifting concave rings. The three lifting concave rings are evenly distributed in a circumferential array around the axis of the drive threaded shaft. The end of the lifting frame away from the drive threaded shaft is located inside the ring groove of the lifting concave ring.

[0032] Optionally, each lifting concave ring is provided with a fixing plate on the side away from the drive threaded shaft. The fixing plate is fixedly installed inside the processing chamber. A locking block is provided on the side of the fixing plate near the adjacent shaft tube. The locking block is elastically connected to the adjacent fixing plate. The locking block is located inside the annular groove of the adjacent lifting concave ring. The end of the locking block away from the fixing plate is in the shape of an isosceles trapezoid. Both the top and bottom surfaces of the end of the locking block away from the fixing plate are inclined surfaces.

[0033] The method of using the hydraulic fracturing simulation experimental device includes the following steps: S1. Place the processed rock sample inside the material feeding and processing chamber of the main experimental box.

[0034] S2. The main linkage frame drives the shaft tube on which the drill bit frame is installed to rotate to the upper side of the placed time-delay sample. The rotation drive component drives the corresponding shaft tube to rotate the drill bit frame. The lifting drive component drives the drill bit frame to move downward to drill an experimental well hole in the rock sample.

[0035] S3. After drilling the rock sample out of the well, the drill bit holder is disengaged from the drilled well. Then, the main linkage frame controls the dressing drill ring to rotate to the upper side of the drilled well. Then, the lifting drive component controls the rotating dressing drill ring to move downward. The dressing drill ring grinds and finishes the inner wall of the drilled well, increasing the smoothness of the well.

[0036] S4. After the wellbore grinding of the rock sample is completed, the lifting drive assembly controls the dressing drill ring to disengage from the wellbore, and then the main linkage frame drives the double-head sealing unit to move into the dressed wellbore. Then the lifting drive assembly controls the double-head sealing unit to insert into the wellbore.

[0037] S5. During drilling with the drill bit holder and the dressing ring, the water supply assembly flushes water into the shaft tube connecting the drill bit holder and the dressing ring. The water flow cleans up the drilled debris. When the double-ended sealing unit is in the drilled well, the double-ended sealing unit forms a closed space at one end in the well. The water supply assembly flushes water into the shaft tube connected to the double-ended sealing unit, and the water flow enters the inner side of the double-ended sealing unit to apply hydraulic fracturing simulation experiment to the well wall.

[0038] In summary, the present invention has the following beneficial technical effects: This invention integrates drilling, well wall trimming, and hydraulic fracturing experimental functions into a single device by using a main linkage frame to drive three shaft tubes to switch working positions sequentially. After trimming the inner side of the drilled borehole wall, the double-headed sealing unit fully seals the borehole wall to form a detection space, realizing full automation from rock sample processing to fracturing simulation, significantly improving experimental efficiency and ease of operation.

[0039] This invention flexibly adjusts the distance between the two sealing disc groups by using the telescopic adjustment component of the double-headed sealing unit, and controls the range length between the two sealing disc groups, enabling hydraulic fracturing detection of the wellbore inner wall under different spatial ranges during testing.

[0040] This invention uses a bidirectional threaded cylinder to drive the upper and lower sealing discs to move relative to the sealing ring. When the upper and lower sealing discs move away from each other, the sealing ring elastically contracts. When the sealing disc assembly moves up and down as a whole, the sealing ring will not come into contact with or rub against the inner side of the well wall, reducing the wear of the sealing ring. When sealing is required, the upper and lower sealing discs are controlled to move closer to each other and squeeze the sealing ring, pushing the sealing ring to elastically expand outward and fully fit and seal against the inner side of the well wall. Attached Figure Description

[0041] Figure 1 This is a schematic diagram of the overall structure in an embodiment of the present invention; Figure 2 This is a schematic diagram of the internal structure of the experimental main body box in an embodiment of the present invention; Figure 3 This is a schematic diagram of the lower axial side structure of the drill bit holder and the dressing drill ring distribution in an embodiment of the present invention; Figure 4 This is a side view schematic diagram of some structures in an embodiment of the present invention; Figure 5 This is a schematic diagram of the internal structure of the processing cavity in an embodiment of the present invention; Figure 6 This is a schematic diagram of the distribution of the lifting drive component and the main linkage frame in an embodiment of the present invention; Figure 7 This is a schematic diagram of the distribution of the fixing plate and the card block in an embodiment of the present invention; Figure 8 This is a schematic diagram of the distribution of the water supply inner pipe and the shaft pipe in an embodiment of the present invention; Figure 9 This is a schematic diagram of the structure of the double-headed enclosed unit in an embodiment of the present invention; Figure 10 This is a schematic diagram of the distribution of bidirectional threaded cylinder and cylindrical structure in an embodiment of the present invention.

[0042] Reference numerals: 1. Main experimental box; 2. Main linkage frame; 3. Shaft tube; 4. Rotary drive assembly; 41. Driven gear; 42. Drive gear ring; 5. Lifting drive assembly; 51. Drive threaded shaft; 52. Lifting frame; 53. Vertical rod; 54. Lifting concave ring; 55. Fixing plate; 56. Locking block; 6. Water supply assembly; 61. Inner water supply pipe; 62. Synchronization ring; 63. Elastic telescopic water supply pipe; 7. Double-headed enclosed unit; 71. 711. Sealing disc assembly; 712. Cylinder; 713. Upper sealing disc; 714. Lower sealing disc; 715. Sealing ring; 716. Side prism shaft; 717. Sleeve shaft; 718. Bidirectional threaded cylinder; 72. Closed disc; 72. Telescopic adjustment assembly; 721. Drive prism shaft; 722. Double-ended threaded shaft; 73. Intermediate disc; 74. Top disc; 8. Drill bit holder; 9. Dressing drill ring; 10. Material unloading processing chamber; 11. Water storage chamber; 12. Processing chamber. Detailed Implementation

[0043] The following is in conjunction with the appendix Figures 1-10 The present invention will be described in further detail below.

[0044] This invention discloses a hydraulic fracturing simulation experimental device. For example... Figures 1-10 As shown, it includes the main experimental box 1, the main linkage frame 2, the shaft tube 3, the rotation drive assembly 4, the lifting drive assembly 5, and the water supply assembly 6.

[0045] The main experimental box 1 has a material feeding and processing chamber 10, a water storage chamber 11 and a processing chamber 12 inside. The material feeding and processing chamber 10 is located between the water storage chamber 11 and the processing chamber 12, and the processing chamber 12 is located on the upper side of the material feeding and processing chamber 10.

[0046] In this embodiment, the experimental main body box 1 has an opening on one side for placing rock samples into the material processing chamber 10. The rock samples are placed into the material processing chamber 10 by an external transfer machine. At the same time, a perforated structure is provided between the material processing chamber 10 and the water storage chamber 11 to allow water to flow down and block the rock debris generated during drilling on the upper side. Meanwhile, a valve pipe is installed at the bottom of the experimental main body box 1 to drain water from the inside of the water storage chamber 11.

[0047] The main linkage frame 2 is installed inside the processing chamber 12. The main linkage frame 2 rotates relative to the processing chamber 12. The main linkage frame 2 consists of a columnar structure and a ring frame. The ring frame rotates relative to the columnar structure. A suitable bearing is installed between the ring frame and the columnar structure. The columnar structure of the main linkage frame 2 is installed inside the processing chamber 12. A worm ring is installed on the outside of the ring frame. The worm ring meshes with a worm. The two ends of the worm rotate through the inner wall of the processing chamber 12. A torsion motor that drives the worm to rotate is installed on the outside of the experimental main box 1.

[0048] There are three shaft tubes 3. The shaft tubes 3 are vertically installed through the upper side of the main linkage frame 2. Two of the shaft tubes 3 are coaxially installed with a drill bit frame 8 and a dressing drill ring 9 at their lower ends, respectively. The remaining shaft tube 3 is equipped with a double-headed sealing unit 7.

[0049] In this embodiment, the outer diameter of the maximum hole drilled downward by the drill bit frame 8 is greater than the outer diameter of the shaft tube 3. When the shaft tube 3 flushes water into the borehole, the rock debris generated when the drill bit frame 8 moves downward is discharged from the gap between the shaft tube 3 and the drilled borehole under the impact of the water flow, thus cleaning the debris inside the borehole.

[0050] The rotary drive assembly 4 is installed inside the processing chamber 12. The rotary drive assembly 4 can drive the shaft tube 3 connected to the drill bit holder 8 and the dressing drill ring 9 to rotate. The drill bit holder 8 and the dressing drill ring 9 respectively follow the rotation of the corresponding shaft tube 3.

[0051] Specifically, the rotary drive assembly 4 includes a driven gear 41 and a drive gear ring 42.

[0052] Two driven gears 41 are provided. The two driven gears 41 are installed through the upper surface of the main linkage frame 2. The driven gears 41 rotate relative to the main linkage frame 2. The outer ring surfaces of the two shaft tubes 3 connected to the drill bit frame 8 and the dressing drill ring 9 are non-cylindrical. The driven gears 41 are slidably sleeved on the outer surfaces of the adjacent shaft tubes 3. The driven gears 41 drive the connected shaft tubes 3 to rotate synchronously.

[0053] The drive gear ring 42 is rotatably mounted inside the processing chamber 12, and both driven gears 41 mesh with the inner side of the drive gear ring 42.

[0054] In this embodiment, a power gear driven by a motor is installed inside the processing cavity 12. The drive gear ring 42 has two layers of gear rings on its inner side. The power gear ring meshes with one of the gear rings of the drive gear ring 42. The power gear controls the rotation of the drive gear ring 42. When the drive gear ring 42 rotates, it drives the corresponding inner shaft tube 3 to rotate by meshing with two driven gears 41.

[0055] Driven gear 41 drives the corresponding drill bit holder 8 and dressing drill ring 9 to rotate via the corresponding shaft tube 3.

[0056] The lifting drive assembly 5 can drive the shaft tube 3 to move up and down. The lifting drive assembly 5 is installed inside the processing chamber 12. The water supply assembly 6 is installed inside the processing chamber 12 and supplies water to the three shaft tubes 3.

[0057] Specifically, the water supply component 6 includes three inner water supply pipes 61, an elastic telescopic water supply pipe 63, and a synchronization ring 62. The three inner water supply pipes 61 are slidably inserted into the inner side of the three shaft pipes 3, and the synchronization ring 62 is installed on the inner wall of the processing chamber 12 and is fixedly sleeved on the upper end of the three inner water supply pipes 61.

[0058] The upper end of the elastic telescopic water supply pipe 63 is installed through the inner wall of the treatment chamber 12. The lower inner diameter of the elastic telescopic water supply pipe 63 is matched with the upper outer diameter of the shaft tube 3. When the lifting drive assembly 5 drives the shaft tube 3 to the uppermost position, it pushes the elastic telescopic water supply pipe 63 to disengage from the lower shaft tube 3.

[0059] In this embodiment, the elastic telescopic water supply pipe 63 consists of a telescopic water pipe and a spring. The upper end of the telescopic water pipe penetrates the inner wall of the processing chamber 12, and the lower end of the spring is connected to the lower end of the elastic telescopic water supply pipe 63, pushing the elastic telescopic water supply pipe 63 to extend. After the elastic telescopic water supply pipe 63 extends, it fits inside the corresponding lower water supply inner pipe 61. The portion of the water supply inner pipe 61 located inside the corresponding shaft pipe 3 is equipped with multiple equally spaced sealing rings to increase the sealing performance between the water supply inner pipe 61 and the shaft pipe 3 when the water supply inner pipe 61 is inside the shaft pipe 3. At the same time, multiple sealing rings are installed on the inner side of the lower end of the elastic telescopic water supply pipe 63 to increase the sealing performance when the lower end of the elastic telescopic water supply pipe 63 is fitted onto the upper end of the shaft pipe 3.

[0060] The double-headed sealing unit 7 includes a sealing disc assembly 71, an intermediate disc 73, a top disc 74, and a telescopic adjustment assembly 72.

[0061] There are two sealing disc assemblies 71, which are coaxially designed. The telescopic adjustment component 72 is connected to the adjacent shaft tube 3. The two sealing disc assemblies 71 are connected to the telescopic adjustment component 72. The telescopic adjustment component 72 adjusts the distance between the two sealing disc assemblies 71. By adjusting the distance between the two sealing disc assemblies 71, the range between the rock samples being tested can be controlled.

[0062] The intermediate plate 73 is installed through the upper surface of the main linkage frame 2. The intermediate plate 73 is slidably sleeved on the outside of the adjacent shaft tube 3. The telescopic adjustment component 72 is connected to the intermediate plate 73. The top plate 74 is fixedly sleeved on the outer surface of the shaft tube 3. The top plate 74 is coaxially installed with the adjacent shaft tube 3. The upper end of the telescopic adjustment component 72 is connected to the top plate 74.

[0063] The telescopic adjustment assembly 72 includes a drive shaft 721 and a double-threaded shaft 722.

[0064] The outer ring of the drive shaft 721 is non-circular, and the upper end of the drive shaft 721 is cylindrical. The cylindrical end of the drive shaft 721 rotates through the bottom surface of the top plate 74, and the drive shaft 721 rotates relative to the top plate 74. An adjustment motor that controls the rotation of the drive shaft 721 is installed on the upper surface of the top plate 74.

[0065] The double-threaded shaft 722 is coaxially mounted with the drive shaft 721. The two sealing disc assemblies 71 are engaged with both ends of the double-threaded shaft 722. When the double-threaded shaft 722 rotates in both directions, it drives the two sealing disc assemblies 71 to move closer or further away from each other. The double-threaded shaft 722 and the drive shaft 721 rotate synchronously.

[0066] Specifically, the sealing disc assembly 71 includes a cylinder 711, an upper sealing disc 712, a lower sealing disc 713, and a sealing ring 714.

[0067] The cylinder 711 is coaxially arranged with the adjacent shaft tube 3. The cylinder 711 is threaded onto the outside of the double-threaded shaft 722. During the forward and reverse rotation of the double-threaded shaft 722, the two cylinders 711 are driven to move closer or further away from each other. A sealing structure is installed at the connection between the double-threaded shaft 722 and the cylinder 711 to effectively reduce water leakage.

[0068] The upper sealing disc 712 is slidably sleeved on the outside of the cylinder 711. The upper sealing disc 712 has a hole-like structure at the mounting location of the double-threaded shaft 722. The lower sealing disc 713 is slidably sleeved on the outside of the cylinder 711. The lower sealing disc 713 is located below the upper sealing disc 712. The lower sealing disc 713 has a hole-like structure at the mounting location of the double-threaded shaft 722. The outer diameters of the upper sealing disc 712 and the lower sealing disc 713 are equal to the outer diameter of the dressing drill ring 9. The sealing ring 714 is located between the upper sealing disc 712 and the lower sealing disc 713. The outer rings of the upper sealing disc 712 and the lower sealing disc 713 are chamfered on the side closest to each other. The inner rings of the upper and lower surfaces of the sealing ring 714 are also chamfered.

[0069] A side rib shaft 715 is rotatably passed through the upper surface of the top plate 74. The side rib shaft 715 rotates relative to the top plate 74. The upper cylinder 711 of the two cylinders 711 is coaxially installed with the adjacent shaft tube 3. The lower cylinder 711 of the two cylinders 711 has a sealing disc 718 attached to its upper side. The sealing disc 718 is elastically connected to the adjacent cylinder 711. When the cylinder 711 moves downward, the water remaining inside the drilled well hole is filled into the space between the two cylinders 711 from the axis of the lower cylinder 711. At the same time, when the upper shaft tube 3 is filled with water, the sealing disc 718 is attached to and sealed to the lower cylinder 711 under the elastic connection with the cylinder 711.

[0070] Both the drive shaft 721 and the side shaft 715 are fitted with sliding sleeve shafts 716, which rotate through the bottom surface of the intermediate disk 73.

[0071] Both cylinders 711 have a bidirectional threaded cylinder 717 that rotates vertically through their inner sides. Both bidirectional threaded cylinders 717 are slidably sleeved on the outer surface of the drive shaft 721. The upper sealing disc 712 and the lower sealing disc 713, which are connected to the same cylinder 711, are respectively threaded onto the two ends of the same bidirectional threaded cylinder 717.

[0072] In this embodiment, as the bidirectional threaded cylinder 717 rotates, it causes the meshing upper sealing disc 712 and lower sealing disc 713 to move closer or further apart. When the upper sealing disc 712 and lower sealing disc 713 move further apart, the sealing ring 714 retracts between the upper sealing disc 712 and lower sealing disc 713 due to its own elasticity, reducing the wear on the sealing ring 714 when the cylinder 711 moves up and down. At the same time, the chamfer between the upper sealing disc 712 and lower sealing disc 713 is respectively related to the sealing ring 714. 4. When the inner ring is in contact with the upper and lower bevels, ensure that the sealing ring 714 is coaxial with the upper sealing disc 712 and the lower sealing disc 713. When the bidirectional threaded cylinder 717 rotates and drives the upper sealing disc 712 and the lower sealing disc 713 to approach each other, it squeezes the sealing ring 714 between them. The chamfer between the upper sealing disc 712 and the lower sealing disc 713 applies pressure to the chamfer on both sides of the sealing ring 714, pushing the sealing ring 714 to expand outward, so that the sealing ring 714 fully fits the inner wall of the drilled well when it expands outward.

[0073] The lifting drive assembly 5 includes a drive threaded shaft 51, a lifting frame 52, and a lifting concave ring 54.

[0074] The drive threaded shaft 51 is rotatably installed inside the processing chamber 12. The drive threaded shaft 51 rotates relative to the processing chamber 12. The lifting frame 52 is threadedly sleeved on the outer surface of the drive threaded shaft 51. The lifting frame 52 is vertically slidably connected to the main linkage frame 2. A vertical rod 53 is provided on the upper side of the lifting frame 52. The upper end of the vertical rod 53 is connected to the lower end of the elastic telescopic water supply pipe 63.

[0075] In this embodiment, a motor is installed on the upper side of the experimental main body box 1 to apply power to the drive threaded shaft 51. When the drive threaded shaft 51 rotates forward and backward, it drives the lifting frame 52 to move up and down respectively. When the lifting frame 52 moves to the uppermost side, it pushes the vertical rod 53 to push the elastic telescopic water supply pipe 63 to retract. The elastic telescopic water supply pipe 63 disengages from the corresponding lower shaft tube 3, so that the shaft tube 3 can rotate with the main body linkage frame 2.

[0076] There are three lifting concave rings 54. The three lifting concave rings 54 are coaxially installed on the upper end of the three shaft tubes 3. The outer ring surface of the lifting concave ring 54 is provided with an annular groove. The lifting frame 52 is located between the three lifting concave rings 54. The three lifting concave rings 54 are evenly distributed in a circumferential array around the axis of the drive threaded shaft 51. The end of the lifting frame 52 away from the drive threaded shaft 51 is located inside the annular groove of the lifting concave ring 54.

[0077] When the shaft tube 3 rotates with the main linkage frame 2 to the lower side of the elastic telescopic water supply pipe 63, the lifting frame 52 moves away from the drive threaded shaft 51 and inserts into the annular groove of the corresponding lifting concave ring 54. When the lifting frame 52 moves up and down, it can drive the shaft tube 3 on the lower side of the elastic telescopic water supply pipe 63 to move up and down respectively.

[0078] Each lifting concave ring 54 is provided with a fixing plate 55 on the side away from the drive threaded shaft 51. The fixing plate 55 is fixedly installed inside the processing chamber 12. A locking block 56 is provided on the side of the fixing plate 55 near the adjacent shaft tube 3. The locking block 56 is elastically connected to the adjacent fixing plate 55. The locking block 56 is connected to the fixing plate 55 through an elastic telescopic rod. Pushing the locking block 56 away from the fixing plate 55, the locking block 56 is located inside the annular groove of the adjacent lifting concave ring 54. When the shaft tube 3 moves to the uppermost side, the inclined surface of the locking block 56 contacts the outer annular surface of the lifting concave ring 54. Under the thrust of the inclined surface, the locking block 56 gradually approaches the fixing plate 55, so that the locking block 56 enters the annular groove of the lifting concave ring 54. The end of the locking block 56 away from the fixing plate 55 is in the shape of an isosceles trapezoid. Both the top and bottom surfaces of the end of the locking block 56 away from the fixing plate 55 are inclined surfaces.

[0079] The method of using the hydraulic fracturing simulation experimental device includes the following steps: S1. Place the processed rock sample inside the material feeding and processing chamber 10 of the main experimental box 1.

[0080] S2. The main linkage frame 2 drives the shaft tube 3, on which the drill bit frame 8 is installed, to rotate to the upper side of the placed delay sample. The rotation drive component 4 drives the corresponding shaft tube 3 to rotate the drill bit frame 8. The lifting drive component 5 drives the drill bit frame 8 to move downward to drill an experimental well hole for the rock sample.

[0081] S3. After drilling the rock sample out of the well hole, the drill bit holder 8 is disengaged from the drilled well hole. Then, the main linkage frame 2 controls the dressing drill ring 9 to rotate to the upper side of the drilled well hole. Then, the lifting drive component 5 controls the rotating dressing drill ring 9 to move downward. The dressing drill ring 9 grinds and trims the inner wall of the drilled well hole to increase the smoothness of the well hole.

[0082] S4. After the wellbore grinding of the rock sample is completed, the lifting drive assembly 5 controls the trimming drill ring 9 to disengage from the wellbore, and then the main linkage frame 2 drives the double-head sealing unit 7 to move into the trimmed wellbore, and then the lifting drive assembly 5 controls the double-head sealing unit 7 to insert into the wellbore.

[0083] S5. During drilling with the drill bit holder 8 and the dressing ring 9, the water supply assembly 6 flushes water into the shaft tube 3 connecting the drill bit holder 8 and the dressing ring 9. The water flow cleans up the drilled debris. When the double-ended sealing unit 7 is in the drilled well, the double-ended sealing unit 7 forms a closed space at one end in the well. The water supply assembly 6 flushes water into the shaft tube 3 connected to the double-ended sealing unit 7. The water flow enters the inner side of the double-ended sealing unit 7 and applies hydraulic fracturing simulation experiment to the well wall.

[0084] The working principle is as follows: the main experimental box 1 serves as the basic carrier of the device, the internal material processing chamber 10 is used to place rock samples, the water storage chamber 11 stores experimental water, and the processing chamber 12 provides installation and operating space for each functional component.

[0085] The main linkage frame 2 drives the three shaft tubes 3 to switch working positions in sequence through power rotation, realizing the process conversion of drilling, dressing and fracturing experiments. The rotation drive component 4 drives the drill bit frame 8 and dressing drill ring 9 to rotate at high speed through the meshing transmission of the drive gear ring 42 and the driven gear 41.

[0086] When the drill bit holder 8 rotates to the upper side of the rock sample, the drill bit holder 8 moves downward under the action of the lifting drive component 5 to drill. After the main linkage frame 2 drives the trimming drill ring 9 to rotate to the upper side of the drilled hole, the trimming drill ring 9 moves downward to trim the drilled hole, increase the smoothness of the drilled hole, and realize rock drilling and well wall trimming.

[0087] The water supply assembly 6 supplies water to the shaft tube 3 through the inner water supply pipe 61 and the elastic telescopic water supply pipe 63, providing a water source for borehole cooling, debris removal and hydraulic fracturing experiments.

[0088] The dual-head sealing unit 7 adjusts the distance between the two sealing disc assemblies 71 via the telescopic adjustment component 72. When the dual-head sealing unit 7 is located inside the drilled borehole, the telescopic adjustment component 72 drives the dual-head threaded shaft 722 to rotate via the drive shaft 721, enabling the two sealing disc assemblies 71 to move synchronously closer or further apart. The sealing disc assemblies 71, through the bidirectional threaded cylinder 717, drive the upper sealing disc 712 and the lower sealing disc 713 to compress the sealing ring 714, causing it to expand outward and fit tightly against the well wall, achieving a reliable seal and forming a closed space within the borehole, providing conditions for hydraulic fracturing experiments.

[0089] The above are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A hydraulic fracturing simulation experimental device, characterized in that, include: The experimental main body box (1) has a material feeding and processing chamber (10), a water storage chamber (11) and a processing chamber (12) inside. The material feeding and processing chamber (10) is located between the water storage chamber (11) and the processing chamber (12), and the processing chamber (12) is located on the upper side of the material feeding and processing chamber (10). The main linkage frame (2) is installed in the processing cavity (12) and rotates relative to the processing cavity (12). Shaft tube (3), three shaft tubes (3) are provided. The shaft tube (3) is vertically installed on the upper side of the main linkage frame (2). Two of the shaft tubes (3) are coaxially installed with a drill bit frame (8) and a trimming drill ring (9) at their lower ends respectively. The remaining shaft tube (3) is equipped with a double-headed sealing unit (7). Rotary drive assembly (4) is installed inside the processing chamber (12). The rotary drive assembly (4) can drive the shaft tube (3) connected to the drill bit frame (8) and the dressing drill ring (9) to rotate. The drill bit frame (8) and the dressing drill ring (9) respectively follow the corresponding shaft tube (3) to rotate. The lifting drive assembly (5) is capable of driving the shaft tube (3) to move up and down. The lifting drive assembly (5) is installed inside the processing cavity (12). Water supply assembly (6), which is installed inside the processing chamber (12) and supplies water to the three shaft tubes (3); The double-headed enclosed unit (7) includes: Two sealing disc assemblies (71) are provided, and the two sealing disc assemblies (71) are coaxially designed; Telescopic adjustment assembly (72) is connected to the adjacent shaft tube (3), and two sealing disc groups (71) are connected to the telescopic adjustment assembly (72). The telescopic adjustment assembly (72) adjusts the distance between the two sealing disc groups (71).

2. The hydraulic fracturing simulation experimental device according to claim 1, characterized in that: The rotary drive assembly (4) includes: Driven gear (41), there are two driven gears (41), which are installed through the upper surface of the main linkage frame (2). The driven gears (41) rotate relative to the main linkage frame (2). The outer ring surface of the two shaft tubes (3) connected to the drill bit frame (8) and the dressing drill ring (9) is non-cylindrical. The driven gears (41) are slidably sleeved on the outer surface of the adjacent shaft tubes (3). The driven gears (41) drive the connected shaft tubes (3) to rotate synchronously. A drive gear ring (42) is rotatably mounted inside the processing chamber (12), and two driven gears (41) mesh with the inner side of the drive gear ring (42).

3. The hydraulic fracturing simulation experimental device according to claim 2, characterized in that: The double-headed enclosed unit (7) also includes: The intermediate plate (73) is installed through the upper surface of the main linkage frame (2). The intermediate plate (73) is slidably sleeved on the outside of the adjacent shaft tube (3). The telescopic adjustment component (72) is connected to the intermediate plate (73). Top plate (74), which is fixedly sleeved on the outer surface of shaft tube (3), and coaxially installed with the adjacent shaft tube (3), and the upper end of telescopic adjustment component (72) is connected to top plate (74).

4. The hydraulic fracturing simulation experimental device according to claim 3, characterized in that: The telescopic adjustment assembly (72) includes: The outer ring of the driving prism (721) is non-circular, and the upper end of the driving prism (721) is cylindrical. The cylindrical end of the driving prism (721) rotates through the bottom surface of the top plate (74), and the driving prism (721) rotates relative to the top plate (74). The double-ended threaded shaft (722) is coaxially mounted with the drive shaft (721). Two sealing disc assemblies (71) mesh with both ends of the double-ended threaded shaft (722). When the double-ended threaded shaft (722) rotates in both directions, it drives the two sealing disc assemblies (71) to move closer to each other or further away from each other.

5. The hydraulic fracturing simulation experimental device according to claim 4, characterized in that: The sealing disc assembly (71) includes: A cylindrical tube (711) is coaxially arranged with the adjacent shaft tube (3), and the cylindrical tube (711) is threadedly sleeved on the outside of the double-threaded shaft (722); The upper sealing disc (712) is slidably sleeved on the outside of the cylinder (711), and the upper sealing disc (712) has a hole structure at the mounting position of the double-threaded shaft (722); The lower sealing disc (713) is slidably sleeved on the outside of the cylinder (711). The lower sealing disc (713) is located below the upper sealing disc (712). The lower sealing disc (713) has a hole-like structure at the installation location of the double-threaded shaft (722). The outer diameter of the upper sealing disc (712) and the outer diameter of the lower sealing disc (713) are equal to the outer diameter of the dressing drill ring (9). The sealing ring (714) is located between the upper sealing disc (712) and the lower sealing disc (713). The outer ring of the upper sealing disc (712) and the lower sealing disc (713) are chamfered on the side close to each other. The inner ring of the upper and lower surfaces of the sealing ring (714) are also chamfered.

6. The hydraulic fracturing simulation experimental device according to claim 5, characterized in that: The top plate (74) has a side rib shaft (715) that rotates through its upper surface. The side rib shaft (715) rotates relative to the top plate (74). The upper cylinder (711) of the two cylinders (711) is coaxially installed with the adjacent shaft tube (3). The lower cylinder (711) of the two cylinders (711) has a sealing disc (718) attached to its upper side. The sealing disc (718) is elastically connected to the adjacent cylinder (711). Both the drive shaft (721) and the side shaft (715) are fitted with sliding sleeve shafts (716) on their outer sides, and the sleeve shafts (716) rotate through the bottom surface of the intermediate disk (73). The inner sides of the two cylinders (711) are vertically rotated through the bidirectional threaded cylinder (717). The two bidirectional threaded cylinders (717) are slidably sleeved on the outer surface of the drive shaft (721). The upper sealing disc (712) and the lower sealing disc (713) connected to the same cylinder (711) are respectively threaded on both ends of the same bidirectional threaded cylinder (717).

7. The hydraulic fracturing simulation experimental device according to claim 1, characterized in that: The water supply assembly (6) includes three water supply inner pipes (61) and a synchronization ring (62). The three water supply inner pipes (61) are slidably inserted into the inner side of the three shaft pipes (3). The synchronization ring (62) is installed on the inner wall of the processing chamber (12) and is fixedly sleeved on the upper end of the three water supply inner pipes (61). It also includes an elastic telescopic water supply pipe (63), the upper end of which is installed through the inner wall of the processing chamber (12), and the lower inner diameter of the elastic telescopic water supply pipe (63) is matched with the upper outer diameter of the shaft tube (3). When the lifting drive assembly (5) drives the shaft tube (3) to the uppermost position, it pushes the elastic telescopic water supply pipe (63) to disengage from the lower shaft tube (3).

8. The hydraulic fracturing simulation experimental device according to claim 7, characterized in that: The lifting drive assembly (5) includes: A drive threaded shaft (51) is rotatably mounted inside the processing chamber (12), and the drive threaded shaft (51) rotates relative to the processing chamber (12). The lifting frame (52) is threaded onto the outer surface of the drive threaded shaft (51). The lifting frame (52) is vertically slidably connected to the main linkage frame (2). A vertical rod (53) is provided on the upper side of the lifting frame (52). The upper end of the vertical rod (53) is connected to the lower end of the elastic telescopic water supply pipe (63). The lifting concave ring (54) is provided in three parts. The three lifting concave rings (54) are coaxially installed on the upper end of the three shaft tubes (3). The outer ring surface of the lifting concave ring (54) is provided with a ring groove. The lifting frame (52) is located between the three lifting concave rings (54). The three lifting concave rings (54) are evenly distributed in a circumferential array around the axis of the drive threaded shaft (51). The end of the lifting frame (52) away from the drive threaded shaft (51) is located inside the ring groove of the lifting concave ring (54).

9. The hydraulic fracturing simulation experimental device according to claim 8, characterized in that: Each lifting concave ring (54) is provided with a fixing plate (55) on the side away from the drive threaded shaft (51). The fixing plate (55) is fixedly installed inside the processing chamber (12). A locking block (56) is provided on the side of the fixing plate (55) near the adjacent shaft tube (3). The locking block (56) is elastically connected to the adjacent fixing plate (55). The locking block (56) is located inside the annular groove of the adjacent lifting concave ring (54). The end of the locking block (56) away from the fixing plate (55) is in the shape of an isosceles trapezoid. The top and bottom surfaces of the end of the locking block (56) away from the fixing plate (55) are inclined surfaces.

10. The method of using the hydraulic fracturing simulation experimental apparatus according to any one of claims 1-9, characterized in that: Includes the following steps: S1. Place the processed rock sample inside the material feeding and processing chamber (10) of the main experimental box (1); S2. The main linkage frame (2) drives the shaft tube (3) on which the drill bit frame (8) is installed to rotate to the upper side of the placed delay sample. The rotation drive component (4) drives the drill bit frame (8) to rotate by driving the corresponding shaft tube (3). The lifting drive component (5) drives the drill bit frame (8) to move downward to drill the experimental well hole of the rock sample. S3. After drilling the rock sample out of the well hole, the drill bit frame (8) is disengaged from the drilled well hole. Then the main linkage frame (2) controls the dressing drill ring (9) to rotate to the upper side of the drilled well hole. Then the lifting drive assembly (5) controls the rotating dressing drill ring (9) to move downward. The dressing drill ring (9) grinds and trims the inner wall of the drilled well hole to increase the smoothness of the well hole. S4. After the well hole of the rock sample is polished, the lifting drive assembly (5) controls the trimming drill ring (9) to disengage from the well hole, and then the main linkage frame (2) drives the double-head sealing unit (7) to move into the trimmed well hole, and then the lifting drive assembly (5) controls the double-head sealing unit (7) to insert into the well hole; S5. In the drilling process between the drill bit holder (8) and the dressing ring (9), the water supply assembly (6) flushes water into the shaft tube (3) connecting the drill bit holder (8) and the dressing ring (9). The water flow cleans up the drilled debris. When the double-ended sealing unit (7) is in the drilled well, the double-ended sealing unit (7) forms a closed space at one end in the well. The water supply assembly (6) flushes water into the shaft tube (3) connected to the double-ended sealing unit (7). The water flow enters the inner side of the double-ended sealing unit (7) and applies hydraulic fracturing simulation experiment to the well wall.

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