A simulator and experimental device, method and application thereof for overflow and leakage co-existing cracks

Abstract

The present application relates to a kind of overflow and leakage coexisting crack simulator and experimental device, method and its application, belong to drilling technology field, wherein, overflow and leakage coexisting crack simulator, including crack simulation subassembly, leakage tank and overflow tank, the side of leakage tank and overflow tank is mutually parallel and oppositely arranged, the angle of the two ends of the crack simulation subassembly is adjusted with the side of leakage tank and overflow tank respectively, to make the included angle of fluid passage in the slit plate combination of crack simulation subassembly and horizontal plane change, to realize the inclination of the fluid passage of crack simulation subassembly.The present application discloses a kind of overflow and leakage coexisting crack simulator, successfully solve the problem that existing overflow and leakage coexisting crack simulation device cannot simulate inclined crack.

Description

Technical Field

[0001] This invention belongs to the field of drilling technology, specifically relating to a fracture simulator and experimental apparatus, method and application for simultaneous overflow and leakage. Background Technology

[0002] Fractured oil and gas reservoirs are widely distributed worldwide, and fracture systems serve as the primary storage and flow channels for formation fluids. During drilling operations in fractured oil and gas reservoirs, the coexistence of leaks and spills is a common problem when encountering fracture systems. This coexistence complicates fluid exchange and pressure transmission between the formation and wellbore system, leading to sudden and rapid changes in wellbore pressure and severely impacting well control safety. Furthermore, even in shallow, high-permeability formations, leaks and spills can occur simultaneously due to the extremely high permeability of the reservoir matrix, even without encountering fracture systems. The coexistence of leaks and spills is crucial for wellbore pressure control, especially during drilling, and directly relates to well control safety.

[0003] Currently, some experimental and numerical simulation studies have been conducted on the problem of simultaneous leakage and overflow in oil and gas drilling. However, existing studies are limited by experimental methods and mainly focus on vertical fractures encountered during drilling. In reality, fracture morphologies are complex and diverse, and absolutely vertical fractures are rare. Further research is needed on the problem of simultaneous leakage and overflow under different fracture dip angles. Furthermore, current research primarily addresses the problem of simultaneous leakage and overflow in fractured systems, while there is a significant lack of research on the problem of simultaneous leakage and overflow in the reservoir matrix of high-permeability formations.

[0004] In response to this situation, it is necessary to develop experimental devices and methods that can simulate the coexistence of leakage in fractured formations and high-permeability formations with different fracture dip angles. This will enable further in-depth research into the mechanism and key control factors of the leakage coexistence problem, providing support for solving the complex wellbore issues caused by leakage coexistence and ensuring the safety of wellbore flow in oil and gas drilling.

[0005] In summary, existing crack simulation devices that simulate both overflow and leakage cannot simulate inclined cracks. Summary of the Invention

[0006] To address the aforementioned problems, the present invention aims to provide a crack simulator, experimental apparatus, method, and application for coexisting overflow and leakage, which solves the problem that existing crack simulation devices for coexisting overflow and leakage cannot simulate inclined cracks.

[0007] To achieve the above objectives, the present invention adopts the following technical solution:

[0008] In a first aspect, the present invention discloses a crack simulator with both overflow and leakage, including...

[0009] A crack simulation component includes a crack plate assembly, which comprises a front support plate and a rear guard plate. The rear guard plate is detachably connected to the front support plate to form the crack plate assembly. A left disk and a right disk are fixed to both ends of the front support plate of the crack plate assembly, respectively. A fluid channel is provided inside the crack plate assembly. The fluid channel inside the crack plate assembly is a crack or a permeable layer. Through holes are provided on the left disk and the right disk, respectively, and the through holes on the left disk and the right disk are connected to the fluid channel inside the crack plate assembly.

[0010] The leak tank and the overflow tank are detachably connected to the two ends of the seam plate assembly on their sides, and the through hole of the left disc is connected to the interior of the leak tank, and the through hole of the right disc is connected to the interior of the overflow tank.

[0011] The sides of the leak tank and the overflow tank are parallel to each other and arranged opposite each other. The angles between the two ends of the crack simulation component and the sides of the leak tank and the overflow tank are adjusted so that the angle between the fluid channel in the crack plate assembly of the crack simulation component and the horizontal plane changes, thereby achieving the tilting of the fluid channel of the crack simulation component.

[0012] Optionally, the fluid channel inside the seam plate assembly is a crack, and the angle between the crack of the crack simulation component and the horizontal plane constitutes the crack inclination angle. First, the two ends of the crack simulation component are removed from the sides of the leak tank and the overflow tank respectively. After rotating the crack simulation component, the two ends of the crack simulation component are installed on the sides of the leak tank and the overflow tank respectively, so that the crack inclination angle of the crack simulation component is changed.

[0013] The leakage tank is used to collect leaked liquid;

[0014] The overflow box is used to hold the overflowing gas;

[0015] The leaked liquid and the overflowing gas mix within the cracks of the crack simulation component to form a gas-liquid mixture, thereby conducting simulation experiments of leakage and coexistence under different crack inclination angles.

[0016] Furthermore, the seam panel assembly also includes a front seam panel and a rear seam panel.

[0017] The rear guard plate is secured to the front support plate by stacking the front and rear seam plates sequentially from front to back using several bolts.

[0018] The front seam plate and the rear seam plate are separated by a gap to form a crack, which serves as a fluid channel inside the seam plate assembly.

[0019] Preferably, the surfaces of the front seam plate corresponding to the rear seam plate and the surfaces of the rear seam plate corresponding to the front seam plate are respectively set as rough surfaces to simulate rough crack cross-sections.

[0020] Furthermore, the seam plate assembly also includes a first padding layer and a second padding layer. The rear guard plate is secured to the front support plate by stacking the first padding layer, the front seam plate, the rear seam plate, and the second padding layer sequentially from front to back using several bolts.

[0021] Furthermore, the bottom of the leakage tank is provided with a return liquid inlet and the top is provided with a return liquid outlet. A lower visual well is provided above the liquid inlet of the leakage tank, and a well drain pipe is provided at the bottom of the lower visual well. A first ball valve is provided on the well drain pipe; a waste liquid tank is provided below the first ball valve.

[0022] A visible wellbore is installed on the outlet of the leakage tank.

[0023] The upper visible wellbore, the leakage tank, and the lower visible wellbore are connected sequentially from top to bottom, forming an external channel for liquid flow.

[0024] A simulated drill pipe is inserted into the outer channel for liquid flow. The simulated drill pipe starts from the upper visible wellbore, passes through the leakage tank, and reaches the lower end of the lower visible wellbore. An annular space is formed between the outer wall of the simulated drill pipe and the outer channel for liquid flow.

[0025] The top of the upper visible wellbore is equipped with a flange cover, which has a drilling fluid inlet and a return fluid outlet.

[0026] The top end of the simulated drill pipe is connected to the drilling fluid inlet, the bottom end of the simulated drill pipe is connected to the annular space, and the top end of the annular space is connected to the return fluid outlet.

[0027] Furthermore, an air injection port is provided at the top of the overflow box;

[0028] A liquid collection pipe is provided at the top and bottom of the overflow box. Volume scale lines are provided on the pipe wall of the liquid collection pipe. A second ball valve is provided at the bottom of the liquid collection pipe. A liquid collection bucket is provided below the second ball valve.

[0029] Secondly, the present invention also discloses a crack simulation experimental device with simultaneous overflow and leakage, including a liquid storage tank, a gas-liquid separation tank, a gas storage tank, and the aforementioned crack simulator with simultaneous overflow and leakage.

[0030] The gas-liquid separator is equipped with a cover plate, and the cover plate is densely covered with vent holes;

[0031] The air storage tank is equipped with an air compressor, and the air storage tank is used to store the gas produced by the air compressor.

[0032] The outlet of the storage tank is connected to the drilling fluid inlet of the flange cover at the top of the upper visible wellbore through a first pipe.

[0033] The return fluid outlet of the flange cover at the top of the upper visible wellbore is connected to the inlet of the gas-liquid separator via a second pipe, and the outlet of the gas-liquid separator is connected to the return port of the storage tank via a third pipe.

[0034] The outlet of the gas storage tank is connected to the inlet of the overflow tank via a fourth pipe.

[0035] Thirdly, the present invention also discloses a fracture simulation experiment method with simultaneous overflow and leakage. Using the aforementioned fracture simulation experiment device with simultaneous overflow and leakage, before conducting the experiment, an air compressor is started, and the gas generated by the air compressor is stored in a gas storage tank. Drilling fluid is pre-stored in the liquid storage tank. This experimental method includes...

[0036] The drilling fluid pre-stored in the storage tank enters the drilling fluid inlet of the flange cover at the top of the upper visualized wellbore through the first pipe. The drilling fluid flows down the simulated drill pipe to the bottom of the simulated drill pipe, enters the annular space, and returns from bottom to top within the annular space to be discharged.

[0037] At the same time, the gas stored in the gas storage tank enters the overflow tank through the fourth pipe, and then reaches the leakage tank through the crack of the inclined crack simulator where overflow and leakage coexist.

[0038] The liquid returning through the annular space mixes with the gas in the leak tank to form a gas-liquid mixture.

[0039] The gas-liquid mixture flows upward along the annular space to the return fluid outlet, then flows out from the return fluid outlet and enters the gas-liquid separator through the second pipe;

[0040] The gas-liquid separator separates the gas and liquid in a gas-liquid mixture. The separated liquid flows back to the storage tank through a third pipe, and the separated gas is discharged to the atmosphere through the exhaust port of the gas-liquid separator.

[0041] When simulating the coexistence of overflow and leakage under different crack inclination angles, if it is necessary to change the crack inclination angle of the crack simulation component, first remove both ends of the crack simulation component from the sides of the leakage tank and the overflow tank respectively, rotate the crack simulation component, and then install both ends of the crack simulation component on the sides of the leakage tank and the overflow tank respectively, so that the crack inclination angle of the crack simulation component is changed.

[0042] Fourthly, the present invention also discloses the application of the aforementioned fracture simulator with both overflow and leakage in drilling simulation of permeable formations.

[0043] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0044] (I) This invention discloses a crack simulator with simultaneous overflow and leakage, including a crack simulation component, a leakage tank, and an overflow tank. The crack simulation component includes a crack plate assembly, which includes a front support plate and a rear guard plate. The rear guard plate is detachably connected to the front support plate to form the crack plate assembly. A left disc and a right disc are fixed to both ends of the front support plate of the crack plate assembly, respectively. A fluid channel is provided inside the crack plate assembly. The fluid channel inside the crack plate assembly is a crack or a permeable layer. Through holes are provided on the left and right discs, respectively. The components are respectively connected to the fluid channels inside the crack simulation assembly; the sides of the leakage tank and the overflow tank are detachably connected to both ends of the crack simulation assembly, with the through hole of the left disc connected to the interior of the leakage tank and the through hole of the right disc connected to the interior of the overflow tank; wherein, the sides of the leakage tank and the overflow tank are parallel to each other and arranged opposite to each other. By adjusting the angles of the two ends of the crack simulation component with the sides of the leakage tank and the overflow tank, the angle between the fluid channels inside the crack simulation assembly and the horizontal plane changes, thereby achieving the tilting of the fluid channels of the crack simulation component. This invention discloses a crack simulator with both leakage and overflow, successfully solving the problem that existing crack simulation devices with both leakage and overflow cannot simulate tilted cracks.

[0045] (II) This invention discloses a crack simulator with both overflow and leakage. The fluid channel inside the crack plate assembly is a crack. The crack plate assembly also includes a front crack plate and a rear crack plate. A gap is left between the front crack plate and the rear crack plate to form a crack as a fluid channel inside the crack plate assembly. The surface of the front crack plate corresponding to the rear crack plate and the surface of the rear crack plate corresponding to the front crack plate are respectively set as rough surfaces to simulate a rough crack cross section, thereby solving the problem that existing crack simulators with both overflow and leakage cannot simulate rough cracks.

[0046] (III) This invention discloses the application of a fracture simulator with both overflow and leakage in permeable formation drilling simulation. The rear liner is fastened to the front support plate by several bolts, and a sand storage cavity is formed between the rear liner and the front support plate to store sand and gravel simulating a sandy and gravelly formation to simulate a permeable layer. Several sand filling ports are provided on the top wall of the front support plate to receive sand and gravel simulating a sandy and gravelly formation. A permeable formation drilling simulation experiment with both overflow and leakage is carried out until the fracture simulator with both overflow and leakage can carry out permeable formation drilling simulation experiment. The fracture simulator with both overflow and leakage disclosed in this invention can be applied in permeable formation drilling simulation. Attached Figure Description

[0047] Figure 1 This is a frontal three-dimensional view of the crack simulation component provided in Embodiment 1 of the present invention;

[0048] Figure 2 yes Figure 1 An exploded view of the front of the crack simulation component;

[0049] Figure 3 This is a three-dimensional view of the back of the crack simulation component provided in Embodiment 1 of the present invention;

[0050] Figure 4 yes Figure 3 A three-dimensional view of the back of a crack simulator consisting of a leakage tank and an overflow tank installed at both ends of the crack simulation component.

[0051] Figure 5 yes Figure 4 A schematic diagram of a crack simulator in which overflow and leakage coexist, and the crack inclination angle is changed by rotation;

[0052] Figure 6 This is a schematic diagram of the overall structure of the visualization simulation device for simultaneous overflow and leakage provided in Embodiment 2 of the present invention.

[0053] Explanation of reference numerals in the attached figures:

[0054] 1-Crack simulation component, 10-Crack plate assembly, 100-Through hole, 101-Left disk, 102-Right disk, 11-Front support plate, 12-Rear guard plate, 120-Bolt, 13-Front seam plate, 14-Rear seam plate;

[0055] 2-Leakage tank; 21-Return fluid inlet; 22-Return fluid outlet; 23-Lower visible wellbore; 24-First ball valve; 25-Upper visible wellbore; 26-Flange cover; 27-Waste liquid tank;

[0056] 3-Overflow box, 31-Gas inlet, 32-Collection pipe, 33-Second ball valve, 34-Collection bucket;

[0057] 4-Liquid storage tank, 40-Gas-liquid separator, 41-Vent vent;

[0058] 5 - Air tank; 50 - Air compressor;

[0059] 60 - Sand filling port, 61 - Sand filling port plug. Detailed Implementation

[0060] Exemplary embodiments of the invention will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the invention are shown in the drawings, it should be understood that the invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the invention and to fully convey the scope of the invention to those skilled in the art.

[0061] Example 1: A crack simulator with both overflow and leakage

[0062] Embodiment 1 of the present invention provides a crack simulator with both overflow and leakage, and its structure will be described in detail below with reference to the accompanying drawings.

[0063] refer to Figures 1 to 5 The crack simulator with simultaneous overflow and leakage includes a crack simulation component 1, a leakage tank 2, and an overflow tank 3.

[0064] The crack simulation component 1 includes a crack plate assembly 10, which includes a front support plate 11 and a rear guard plate 12. The rear guard plate 12 is detachably connected to the front support plate 11 to form the crack plate assembly 10. A left disk 101 and a right disk 102 are fixed to both ends of the front support plate 11 of the crack plate assembly 10, respectively. A fluid channel is provided inside the crack plate assembly 10. The fluid channel inside the crack plate assembly 10 is a crack or a permeable layer. Through holes 100 are provided on the left disk 101 and the right disk 102, respectively. The through holes 100 of the left disk 101 and the right disk 102 are respectively connected to the fluid channel inside the crack plate assembly 10.

[0065] The sides of the leak tank 2 and the overflow tank 3 are detachably connected to both ends of the seam plate assembly 10, and the through hole 100 of the left disc 101 is connected to the interior of the leak tank 2, and the through hole 100 of the right disc 102 is connected to the interior of the overflow tank 3.

[0066] The sides of the leakage tank 2 and the overflow tank 3 are parallel to each other and arranged opposite each other. The angles of the two ends of the crack simulation component 1 with the sides of the leakage tank 2 and the overflow tank 3 are adjusted so that the angle between the fluid channel in the crack plate assembly 10 of the crack simulation component 1 and the horizontal plane changes, thereby achieving the tilting of the fluid channel of the crack simulation component 1.

[0067] As a specific example of realizing the fluid channel within the seam plate assembly 10, the fluid channel inside the seam plate assembly 10 is a crack, and the angle between the crack in the crack simulation component 1 and the horizontal plane constitutes the crack inclination angle. A specific way to achieve the change of the angle between the fluid channel within the seam plate assembly 10 and the horizontal plane is as follows:

[0068] First, detach both ends of the crack simulation component 1 from the sides of the leakage tank 2 and the overflow tank 3, respectively. After rotating the crack simulation component 1, reattach both ends of the crack simulation component 1 to the sides of the leakage tank 2 and the overflow tank 3, thereby changing the crack inclination angle of the crack simulation component 1. Figure 5 As shown.

[0069] The leakage tank 2 is used to collect leaked liquid;

[0070] The overflow box 3 is used to hold the overflowing gas;

[0071] The leaked liquid and the overflowing gas mix in the crack of the crack simulation component 1 to form a gas-liquid mixture, so as to carry out a simulation experiment of leakage and coexistence under different crack inclination angles.

[0072] Since the two ends of the front support plate 11 are fixed to the left disk 101 and the right disk 102 respectively, and the rear guard plate 12 is detachably connected to the front support plate 11, in order to realize the fluid channel inside the seam plate assembly 10 as a crack, the seam plate assembly 10 also includes at least a front seam plate 13 and a rear seam plate 14.

[0073] The rear guard plate 12 is secured to the front support plate 11 by a number of bolts 120, which stack the front seam plate 13 and the rear seam plate 14 from front to back.

[0074] A gap is left between the front seam plate 13 and the rear seam plate 14 to form a crack, which serves as a fluid channel inside the seam plate assembly 10.

[0075] To simulate a rough crack cross-section, the surfaces of the front seam plate 13 corresponding to the rear seam plate 14 and the surfaces of the rear seam plate 14 corresponding to the front seam plate 13 are respectively set as rough surfaces.

[0076] To improve the sealing performance between the front seam plate 13 and the front support plate 11 and between the rear seam plate 14 and the rear guard plate 12, and to ensure that the fluid in the seam plate assembly 10 can only flow in a directional manner along the fluid channel—the crack—in this example, the seam plate assembly 10 also includes a first pad 15 and a second pad 16. The rear guard plate 12 is secured to the front support plate 11 by a number of bolts 120, which sequentially stack the first pad 15, the front seam plate 13, the rear seam plate 14, and the second pad 16 from front to back.

[0077] To enable the leakage tank 2 to hold the liquid and discharge it in reverse, simulating the backflow of drilling fluid during drilling, one specific embodiment is that the leakage tank 2 is provided with a backflow fluid inlet 21 at the bottom and a backflow fluid outlet 22 at the top.

[0078] The inlet of the leakage tank 2 is equipped with a lower visual wellbore 23, and the bottom of the lower visual wellbore 23 is equipped with a wellbore drain pipe, and a first ball valve 24 is installed on the wellbore drain pipe;

[0079] A visual wellbore 25 is installed on the outlet of the leakage tank 2.

[0080] The upper visible wellbore 25, the leakage tank 2, and the lower visible wellbore 23 are connected sequentially from top to bottom to form an external channel for liquid flow.

[0081] A simulated drill pipe is inserted into the outer channel for liquid flow. The simulated drill pipe starts from the upper visible wellbore 25, passes through the leakage tank 2, and reaches the lower end of the lower visible wellbore 23. An annular space is formed between the outer wall of the simulated drill pipe and the outer channel for liquid flow.

[0082] The top of the upper visible wellbore 25 is provided with a flange cover 26, and the flange cover 26 is provided with a drilling fluid inlet and a return fluid outlet;

[0083] The top end of the simulated drill pipe is connected to the drilling fluid inlet, the bottom end of the simulated drill pipe is connected to the annular space, and the top end of the annular space is connected to the return fluid outlet.

[0084] The annular space is used to allow passage of simulated fluids flowing back from the formation.

[0085] When the drilling fluid enters the simulated drill pipe through the drilling fluid inlet, it flows from top to bottom along the simulated drill pipe to the lower end of the lower visualized wellbore 23. Then, it flows out from the bottom of the simulated drill pipe, enters the annular space, and returns from bottom to top within the annular space for discharge.

[0086] To collect waste liquid, a waste liquid tank 27 is provided below the first ball valve 24.

[0087] In order to enable the overflow box 3 to carry gas and deliver the gas to the crack simulation component 1 to simulate leaked gas, one specific embodiment is that the top of the overflow box 3 is provided with an injection port 31.

[0088] In order to collect drilling fluid through the fractures of the fracture simulation component 1, a liquid collection pipe 32 is provided at the bottom top of the overflow box 3. A volume scale line is provided on the pipe wall of the liquid collection pipe 32. A second ball valve 33 is provided at the bottom of the liquid collection pipe 32. A liquid collection tank 34 is provided below the second ball valve 33.

[0089] The sum of the liquid stored in the collection pipe 32 and the liquid collected in the collection bucket 34 is the total volume of drilling fluid passing through the fractures of the fracture simulation component 1.

[0090] Example 2: A crack simulation experimental device with both overflow and leakage

[0091] Embodiment 2 of the present invention provides a crack simulation experimental device with both overflow and leakage, including the crack simulator with both overflow and leakage of Embodiment 1. The structure and connection relationship of the experimental device will be described in detail below with reference to the accompanying drawings.

[0092] refer to Figure 6 The crack simulation experimental device for coexistence of overflow and leakage includes a liquid storage tank 4, a gas-liquid separation tank 40, a gas storage tank 5, and the crack simulator for coexistence of overflow and leakage provided in Example 1.

[0093] The gas-liquid separator 40 is equipped with a cover plate, and the cover plate is densely covered with exhaust holes 41;

[0094] The air storage tank 5 is equipped with an air compressor 50, and the air storage tank 5 is used to store the gas generated by the air compressor 50.

[0095] The outlet of the storage tank 4 is connected to the drilling fluid inlet of the flange cover 26 at the top of the upper visible wellbore 25 through a first pipe.

[0096] The return fluid outlet of the flange cover 26 at the top of the upper visible wellbore 25 is connected to the inlet of the gas-liquid separator 40 through a second pipe, and the outlet of the gas-liquid separator 40 is connected to the return port of the storage tank 4 through a third pipe.

[0097] The outlet of the gas storage tank 5 is connected to the inlet of the overflow tank 3 through a fourth pipe.

[0098] Example 3: A simulation experiment method for cracks with both overflow and leakage

[0099] Embodiment 3 of the present invention provides a method for simulating fractures with both overflow and leakage. Using the fracture simulation apparatus for both overflow and leakage provided in Embodiment 2, a simulation experiment of the phenomenon of both overflow and leakage in fractured formation drilling is conducted. Before conducting the experiment, the air compressor 50 is started, and the gas generated by the air compressor 50 is stored in the air storage tank 5. Drilling fluid is pre-stored in the liquid storage tank 4. The experimental method includes the following steps:

[0100] The drilling fluid pre-stored in the storage tank 4 enters the drilling fluid inlet of the flange cover 26 at the top of the upper visualized wellbore 25 through the first pipe. The drilling fluid flows down the simulated drill pipe to the bottom of the simulated drill pipe, enters the annular space, and returns from bottom to top within the annular space to be discharged.

[0101] At the same time, the gas stored in the gas storage tank 5 enters the overflow box 3 through the fourth pipe, and then reaches the leakage box 2 through the crack of the inclined crack simulator where overflow and leakage coexist.

[0102] The liquid returning through the annular space mixes with the gas in the leak tank 2 to form a gas-liquid mixture.

[0103] The gas-liquid mixture flows upward along the annular space to the return fluid outlet, then flows out from the return fluid outlet and enters the gas-liquid separator 40 through the second pipe;

[0104] The gas-liquid separator 40 separates the gas and liquid in the gas-liquid mixture. The separated liquid flows back to the storage tank 4 through the third pipe, and the separated gas is discharged to the atmosphere through the exhaust port 41 of the gas-liquid separator 40.

[0105] When simulating the coexistence of overflow and leakage under different crack inclination angles, if it is necessary to change the crack inclination angle of the crack simulation component 1, first remove both ends of the crack simulation component 1 from the sides of the leakage tank 2 and the overflow tank 3 respectively, rotate the crack simulation component 1, and then install both ends of the crack simulation component 1 on the sides of the leakage tank 2 and the overflow tank 3 respectively, so that the crack inclination angle of the crack simulation component 1 is changed.

[0106] Example 4: Application of a fracture simulator with both overflow and leakage in drilling simulation of permeable formations

[0107] Embodiment 4 of the present invention provides an application of a fracture simulator with both overflow and leakage in drilling simulation of permeable formations. It uses the fracture simulator with both overflow and leakage from Embodiment 1 as another specific example to realize fluid channels within the fracture-plate assembly 10. The fluid channels within the fracture-plate assembly 10 are permeable layers, replacing the fractures used as fluid channels within the fracture-plate assembly 10 in Embodiment 1.

[0108] Before application, the first padding layer 15, the front seam board 13, the rear seam board 14, and the second padding layer 16 inside the seam board assembly 10 are omitted. A permeable layer is then created inside the seam board assembly 10. The method for creating the permeable layer is as follows:

[0109] The rear guard plate 12 is fastened to the front support plate 11 by several bolts, and a sand storage cavity is formed between the rear guard plate 12 and the front support plate 11 to store sand and gravel simulating the sand and gravel layer to simulate the permeable layer.

[0110] The top wall of the front support plate 11 is provided with several sand filling ports 60 for receiving sand and gravel from the simulated sand and gravel layer.

[0111] A drilling simulation experiment of permeable formations with both overflow and leakage was carried out according to the method in Example 3.

[0112] Until the fracture simulator with both overflow and leakage is completed, it will be able to carry out permeable formation drilling simulation experiments.

[0113] To prevent sand and fluid from overflowing from the permeable layer, each sand filling port 60 is equipped with a sand filling port plug 61.

[0114] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A crack simulator with both overflow and leakage, characterized in that, include A crack simulation component (1) includes a crack plate assembly (10), which includes a front support plate (11) and a rear guard plate (12). The rear guard plate (12) is detachably connected to the front support plate (11) to form the crack plate assembly (10). A left disc (101) and a right disc (102) are fixed at both ends of the front support plate (11) of the crack plate assembly (10). A fluid channel is provided inside the crack plate assembly (10). The fluid channel inside the crack plate assembly (10) is a crack or a permeable layer. Through holes (100) are provided on the left disc (101) and the right disc (102). The through holes (100) of the left disc (101) and the right disc (102) are connected to the fluid channel inside the crack plate assembly (10). The leak tank (2) and the overflow tank (3) are detachably connected to the two ends of the seam plate assembly (10) on their sides, and the through hole (100) of the left disc (101) is connected to the interior of the leak tank (2), and the through hole (100) of the right disc (102) is connected to the interior of the overflow tank (3). The sides of the leak tank (2) and the overflow tank (3) are parallel to each other and opposite to each other. The angles of the two ends of the crack simulation component (1) with the sides of the leak tank (2) and the overflow tank (3) are adjusted so that the angle between the fluid channel in the crack plate assembly (10) of the crack simulation component (1) and the horizontal plane changes, thereby achieving the inclination of the fluid channel of the crack simulation component (1). The fluid channel inside the seam plate assembly (10) is a crack. The angle between the crack of the crack simulation component (1) and the horizontal plane constitutes the crack inclination angle. First, the two ends of the crack simulation component (1) are removed from the sides of the leak tank (2) and the overflow tank (3) respectively. After rotating the crack simulation component (1), the two ends of the crack simulation component (1) are installed on the sides of the leak tank (2) and the overflow tank (3) respectively, so that the crack inclination angle of the crack simulation component (1) changes. The leak tank (2) is used to carry the leaked liquid. The overflow tank (3) is used to carry the overflowed gas. The leaked liquid and the overflowed gas mix in the crack of the crack simulation component (1) to form a gas-liquid mixture, so as to carry out the overflow and leakage coexistence simulation experiment under different crack inclination angles. The bottom of the leak tank (2) is provided with a return liquid inlet (21) and the top is provided with a return liquid outlet (22). A lower visual wellbore (23) is provided on the inlet of the leak tank (2). A wellbore drain pipe is provided at the bottom of the lower visual wellbore (23). A first ball valve (24) is provided on the wellbore drain pipe. A waste liquid tank (27) is provided below the first ball valve (24). An upper visual wellbore (25) is provided on the outlet of the leak tank (2). The upper visual wellbore (25), the leak tank (2) and the lower visual wellbore (23) are connected from top to bottom to form an outer channel for liquid flow. A simulated drill rod is inserted in the outer channel for liquid flow. The simulated drill rod starts from the upper visual wellbore (25), passes through the leak tank (2) and reaches the lower end of the lower visual wellbore (23). An annular space is formed between the outer wall of the simulated drill rod and the outer channel for liquid flow. The top of the overflow box (3) is provided with an air inlet (31).

2. The crack simulator with simultaneous overflow and leakage according to claim 1, characterized in that, The seam panel assembly (10) also includes a front seam panel (13) and a rear seam panel (14). The rear guard plate (12) is secured to the front support plate (11) by a number of bolts (120) stacking the front seam plate (13) and the rear seam plate (14) from front to back. A gap is left between the front seam plate (13) and the rear seam plate (14) to form a crack, which serves as a fluid channel inside the seam plate assembly (10).

3. The crack simulator with simultaneous overflow and leakage according to claim 2, characterized in that, The surfaces of the front seam plate (13) corresponding to the rear seam plate (14) and the surfaces of the rear seam plate (14) corresponding to the front seam plate (13) are respectively set as rough surfaces to simulate rough crack cross sections.

4. The crack simulator with simultaneous overflow and leakage according to claim 2, characterized in that, The seam panel assembly (10) also includes a first padding layer (15) and a second padding layer (16). The rear guard plate (12) is secured to the front support plate (11) by a number of bolts (120) stacking the first pad (15), the front seam plate (13), the rear seam plate (14) and the second pad (16) from front to back.

5. The crack simulator with simultaneous overflow and leakage according to claim 1, characterized in that, The top of the upper visible wellbore (25) is provided with a flange cover (26), and the flange cover (26) is provided with a drilling fluid inlet and a return fluid outlet; The top end of the simulated drill pipe is connected to the drilling fluid inlet, the bottom end of the simulated drill pipe is connected to the annular space, and the top end of the annular space is connected to the return fluid outlet.

6. The crack simulator with simultaneous overflow and leakage according to claim 5, characterized in that, The top of the overflow box (3) is provided with a liquid collection pipe (32), the wall of the liquid collection pipe (32) is provided with a volume scale line, the bottom of the liquid collection pipe (32) is provided with a second ball valve (33), and a liquid collection bucket (34) is provided below the second ball valve (33).

7. A crack simulation experimental device for simultaneous overflow and leakage, characterized in that, Includes a liquid storage tank (4), a gas-liquid separator (40), a gas storage tank (5), and a crack simulator with both overflow and leakage as described in claim 6. The gas-liquid separator (40) is equipped with a cover plate, and the cover plate is densely covered with exhaust holes (41). The gas storage tank (5) is equipped with an air compressor (50), and the gas storage tank (5) is used to store the gas generated by the air compressor (50); The outlet of the storage tank (4) is connected to the drilling fluid inlet of the flange cover (26) at the top of the upper visible wellbore (25) through a first pipe; The return fluid outlet of the flange cover (26) at the top of the upper visible wellbore (25) is connected to the inlet of the gas-liquid separator (40) through a second pipe, and the outlet of the gas-liquid separator (40) is connected to the return port of the storage tank (4) through a third pipe. The outlet of the gas storage tank (5) is connected to the inlet of the overflow box (3) through a fourth pipe.

8. A method for simulating fractures with both overflow and leakage, using the fracture simulation apparatus for both overflow and leakage as described in claim 7, wherein before conducting the experiment, the air compressor (50) is started, and the gas generated by the air compressor (50) is stored in the air storage tank (5), and drilling fluid is pre-stored in the liquid storage tank (4), characterized in that, include The drilling fluid pre-stored in the storage tank (4) enters the drilling fluid inlet of the flange cover (26) at the top of the upper visualized wellbore (25) through the first pipe. The drilling fluid flows down the simulated drill pipe to the bottom of the simulated drill pipe, enters the annular space, and returns from bottom to top within the annular space. At the same time, the gas stored in the gas storage tank (5) enters the overflow tank (3) through the fourth pipe, and then reaches the leakage tank (2) through the crack of the inclined crack simulator where overflow and leakage coexist. The liquid returning through the annular space mixes with the gas in the leak tank (2) to form a gas-liquid mixture; The gas-liquid mixture flows upward along the annular space to the return fluid outlet, then flows out from the return fluid outlet and enters the gas-liquid separator (40) through the second pipe; The gas-liquid separator (40) separates the gas and liquid in the gas-liquid mixture. The separated liquid flows back to the storage tank (4) through the third pipe, and the separated gas is discharged to the atmosphere through the exhaust port (41) of the gas-liquid separator (40). When simulating the coexistence of overflow and leakage under different crack inclination angles, when it is necessary to change the crack inclination angle of the crack simulation component (1), first remove both ends of the crack simulation component (1) from the sides of the leakage tank (2) and the overflow tank (3) respectively, rotate the crack simulation component (1), and then install both ends of the crack simulation component (1) on the sides of the leakage tank (2) and the overflow tank (3) respectively, so that the crack inclination angle of the crack simulation component (1) changes.

9. The application of the fracture simulator with both overflow and leakage as described in claim 1 in drilling simulation of permeable formations.

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