Hydraulic fracturing experimental sample simulated wellbore sealing device and method

Abstract

The application discloses a kind of hydraulic fracturing experimental sample simulation wellbore sealing device and method, it is related to oil and gas reservoir hydraulic fracturing volume reconstruction development experimental research technical field, including rock sample, the upper side of rock sample is provided with rubber sealing mechanism, the upper side of rock sample is provided with gas sealing mechanism, rubber sealing mechanism includes rubber sealing unit, rubber sealing unit is set in the upper side of rock sample, rubber sealing unit can be rubber sealed to wellbore, rubber sealing mechanism also includes limiting unit, limiting unit is set in the upper side of rock sample, limiting unit cooperates with rubber sealing unit, limiting unit can make rubber sealing unit more stable inside wellbore, this hydraulic fracturing experimental sample simulation wellbore sealing device and method, by being provided with rubber sealing unit, limiting unit and gas sealing mechanism, can effectively avoid equipment when using, the problem that sealing effect is not good and leads to water leakage.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of experimental research on hydraulic fracturing volume reconstruction development of oil and gas reservoirs, in particular to a hydraulic fracturing experimental sample simulated wellbore sealing device and method. BACKGROUND

[0002] The experimental research project on hydraulic fracturing volume reconstruction development of oil and gas reservoirs is an effective means for studying the volume reconstruction of oil and gas reservoirs at present. Various samples and wellbore sealing equipment are used in the hydraulic fracturing experiment.

[0003] The existing wellbore sealing equipment only uses epoxy resin as a sealing agent when in use, the sealing form is single, and there are a large number of bubbles between the epoxy resin and the sample wall, which reduces the contact area between the epoxy resin and the sample wall, causes the bearing capacity to be reduced, and easily causes the problem of liquid leakage in the experimental process.

[0004] In combination with the above problems, it will be found that the existing hydraulic fracturing experimental sample simulated wellbore sealing device in the market is difficult to avoid the above-mentioned problems at the same time when in use, and even if it can be solved, it needs to be solved by external tools, so that the desired effect cannot be achieved. Therefore, we propose a hydraulic fracturing experimental sample simulated wellbore sealing device and method. SUMMARY

[0005] The purpose of the present application is to provide a hydraulic fracturing experimental sample simulated wellbore sealing device and method to solve the problems raised in the background.

[0006] To achieve the above purpose, the present application provides the following technical scheme: a hydraulic fracturing experimental sample simulated wellbore sealing device, comprising a rock sample, a rubber sealing mechanism is arranged above the rock sample, and a gas sealing mechanism is arranged above the rock sample.

[0007] The rubber sealing mechanism comprises a rubber sealing unit, the rubber sealing unit is arranged above the rock sample, and the rubber sealing unit can rubber seal the wellbore.

[0008] The rubber sealing mechanism further comprises a limiting unit, the limiting unit is arranged above the rock sample, and the limiting unit cooperates with the rubber sealing unit, and the limiting unit can make the rubber sealing unit more stable in the inside of the wellbore.

[0009] The gas sealing mechanism is arranged above the rock sample, the gas sealing mechanism cooperates with the rubber sealing mechanism, and the gas sealing mechanism can perform gas sealing treatment on the wellbore.

[0010] Preferably, the rubber sealing unit comprises a first opening pad, the outer surface of the first opening pad is fixedly connected with a rolling bearing, the outer ring of the rolling bearing is fixedly connected with a second opening pad, the upper surface of the second opening pad is fixedly connected with a connecting plate, the upper surface of the connecting plate is fixedly connected with a stud, the outer surface of the stud is threadedly connected with a lifting block, the inside of the stud, the connecting plate, the first opening pad and the second opening pad are jointly and slidably connected with a circular shaft, the outer surface of the circular shaft is threadedly connected with a circular ring, the bottom end of the circular shaft is fixedly connected with a tapered expander, and the outer side of the circular shaft is provided with a rubber ring.

[0011] Preferably, the upper surface of the first opening pad is fixedly connected with a positioning shaft, the inside of the lifting block is slidably connected to the outer surface of the positioning shaft, the bottom surface of the first opening pad is in contact with the upper surface of the rock sample, the outer surface of the first opening pad is fixedly connected to the inner ring of the rolling bearing, the bottom end of the rubber ring is in contact with the outer surface of the tapered expander, and the rubber ring and the tapered expander are both arranged in the inner cavity of the rock sample.

[0012] Preferably, the limiting unit comprises a circular cylinder, the inside of the circular cylinder is clamped with two clamping plates, the inside of the circular cylinder is slidably connected with two groups of pressure blocks, the outer surface of the first opening pad is provided with two sliding grooves, the inside of each sliding groove is slidably connected with a sliding shaft, the outer surfaces of the two sliding shafts are jointly and fixedly connected with a connecting ring, the outer surfaces of the two sliding shafts are jointly and fixedly connected with a first extrusion block, the first extrusion block and the circular shaft are both arranged in the inner cavity of the circular cylinder, the outer surface of the circular shaft is fixedly connected with a second extrusion block, and the second extrusion block is arranged in the inner cavity of the circular cylinder.

[0013] Preferably, the inner wall of the first opening pad is fixedly connected with two first fixed cylinders, the two first fixed cylinders are distributed in the center of the circular cylinder in a symmetrical manner, the inner wall of each first fixed cylinder is fixedly connected with a first force spring, and the ends of the two first force springs away from each other are both fixedly connected with a first clamping block.

[0014] Preferably, the inner wall of the circular cylinder is fixedly connected with two second fixed cylinders, the inner wall of each second fixed cylinder is fixedly connected with a second force spring, the ends of the two second force springs close to each other are jointly and fixedly connected with a second clamping block, the outer surface of each second clamping block is fixedly connected with a rectangular plate, the outer surface of each rectangular plate is slidably connected to the inside of the second fixed cylinder, and the outer surface of the circular shaft is provided with two clamping grooves.

[0015] Preferably, the two second clamping blocks are fixedly connected with bull-eye bearings at their ends close to each other, the outer surfaces of the bull-eye bearings are in contact with the outer surface of the circular shaft, the circular cylinder is arranged in the inner cavity of the rock sample, the upper surfaces of the clamping plates are fixedly connected to the bottom surface of the first open pad, the upper surface of the circular cylinder is in contact with the bottom surface of the first open pad, the number of each group of pressure blocks is two, and the two groups of pressure blocks are uniformly distributed around the center of the circular cylinder.

[0016] Preferably, the air-tight sealing mechanism comprises a limiting cylinder, a plurality of same communication openings are arranged on the outer surface of the limiting cylinder, a plurality of same gas conveying openings are arranged on the outer surface of the circular shaft, the outer surface of the limiting cylinder is fixedly connected with an air bag, the inner part of the circular shaft is slidably connected with an elongated shaft, the bottom end of the elongated shaft is fixedly connected with a circular plate, the bottom surface of the circular plate is fixedly connected with a first fixed rubber pad, the outer surface of the first fixed rubber pad is fixedly connected with a first folded rubber pad, the upper surface of the circular plate is provided with a first circular opening, the inner top wall of the circular shaft is fixedly connected with a second fixed rubber pad, the outer surface of the second fixed rubber pad is fixedly connected with a second folded rubber pad, and the top end of the circular shaft is provided with a second circular opening.

[0017] Preferably, the outer surface of the circular shaft is fixedly connected with a rubber sealing plate, the outer surface of the rubber sealing plate is in contact with the inner wall of the limiting cylinder, the top end of the elongated shaft penetrates through the circular shaft and extends above the circular shaft, the top end of the elongated shaft is fixedly connected with a stress plate, the top end of the limiting cylinder is in contact with the bottom end of the circular cylinder, the bottom end of the limiting cylinder is in contact with the top end of the rubber ring, the upper surface of the first folded rubber pad is in contact with the bottom surface of the circular plate, and the upper surface of the second folded rubber pad is in contact with the inner top wall of the circular shaft.

[0018] A method for simulating a wellbore sealing device of a hydraulic fracturing experiment sample, comprising the following steps:

[0019] S1: the first open pad is placed on the upper surface of the rock sample, then the rotating power is applied to the second open pad, driving the second open pad, the fixed connecting plate above and the stud to rotate, the stud pushes the lifting block to move upward by the threaded connection relationship when rotating, and finally the lifting block is in contact with the bottom surface of the circular ring, thereby driving the circular ring and the circular shaft to move upward, so that the expansion cone moves upward synchronously when the circular shaft moves upward, so that the expansion cone is squeezed into the inner part of the rubber ring, so that the rubber ring is expanded and tightly contacted with the inner wall of the rock sample, to achieve the purpose of sealing;

[0020] S2: When the limiting unit needs to be used, the connecting ring can be pressed downward, and the two sliding shafts are driven to slide along the inside of the sliding groove when the connecting ring moves downward, so that the first extrusion block fixed on the surface of the sliding shaft can slide to the direction of the pressure block, and when the first extrusion block contacts the pressure block, the first extrusion block can drive the pressure block to move to the rock sample, and finally the surface of the pressure block can contact the inner wall of the rock sample, so that the circular barrel and the first opening pad can be limited;

[0021] S3: The stress plate can be pulled to move upward, and the long shaft and the circular plate fixed at the bottom of the long shaft are synchronously moved upward when the stress plate moves upward, so that the air in the space above the circular plate is pressed into the space below the circular plate, and when the circular plate moves upward to the top position close to the circular shaft, the stress plate is pushed to move the long shaft and the circular plate downward, so that the air moves downward until the air enters the inside of the air bag, the air bag is inflated, and the purpose of inflation sealing is achieved.

[0022] Compared with the prior art, the beneficial effects of the present application are:

[0023] 1、The rubber sealing unit is arranged, the rubber ring and the expansion cone structure in the rubber sealing unit are used, the expansion cone is moved upward to push the rubber ring to expand, the inside of the wellbore can be sealed, and the occurrence of leakage in the inside of the wellbore can be reduced.

[0024] 2、The limiting unit is arranged, the first opening pad can be temporarily fixed above the rock sample by the limiting unit, and the circular shaft can be fixed in the inside of the rock sample for a long time, so that the stability of the circular shaft and the rubber sealing unit in the inside of the rock sample is increased.

[0025] 3、The air sealing mechanism is arranged, the inside of the air bag can be inflated by the air sealing mechanism, the surface of the air bag contacts the inner wall of the rock sample, the sealing effect is increased, the rubber sealing unit, the limiting unit and the air sealing mechanism are arranged, and the problem of poor sealing effect leading to water leakage during use of the equipment can be effectively avoided. DETAILED DESCRIPTION

[0026] Figure 1 It is a structure schematic view of the whole application;

[0027] Figure 2 It is a structure schematic view of the expansion cone of the application;

[0028] Figure 3 It is a structure schematic view of the long shaft of the application;

[0029] Figure 4 It is a structure schematic view of the connecting plate of the application;

[0030] Figure 5Structure diagram of the second folded rubber pad of the present application;

[0031] Figure 6 Structure diagram of the first folded rubber pad of the present application;

[0032] Figure 7 Structure diagram of the air bag of the present application;

[0033] Figure 8 Structure diagram of the first fixing cylinder of the present application;

[0034] Figure 9 Structure diagram of the first force spring of the present application;

[0035] Figure 10 Structure diagram of the extrusion block of the present application;

[0036] Figure 11 Left view structure diagram of the second fixing cylinder of the present application;

[0037] Figure 12 Left view structure diagram of the second force spring of the present application;

[0038] Figure 13 Structure diagram of the rubber ring of the present application.

[0039] In the figure: 1, rock sample; 2, rubber sealing mechanism; 21, rubber sealing unit; 2101, round shaft; 2102, round ring; 2103, positioning shaft; 2104, stud; 2105, lifting block; 2106, connecting plate; 2107, second open pad; 2108, first open pad; 2109, expansion cone; 2110, rubber ring; 2111, rolling bearing; 22, limiting unit; 2201, connecting ring; 2202, first clamping block; 2203, round cylinder; 2204, pressure receiving block; 2205, clamping groove; 2206, sliding groove; 2207, sliding shaft; 2208, first extrusion block; 2209, clamping plate; 2210, first fixing cylinder; 2211, first force spring; 2212, second extrusion block; 2213, second fixing cylinder; 2214, bull's eye bearing; 2215, rectangular plate; 2216, second clamping block; 2217, second force spring; 3, air sealing mechanism; 301, force plate; 302, air bag; 303, limiting cylinder; 304, communication port; 305, round plate; 306, long shaft; 307, gas inlet; 308, second round port; 309, second folded rubber pad; 310, second fixed rubber pad; 311, first fixed rubber pad; 312, first folded rubber pad; 313, first round port; 314, rubber sealing plate. DETAILED DESCRIPTION

[0040] With reference to the drawings of the embodiments of the present application, the technical solutions in the embodiments of the present application will be described clearly and completely. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0041] Embodiment 1: refer to Figures 1-4 , Figure 7 and Figure 8 , the present application provides a technical solution: a hydraulic fracturing experimental sample simulation wellbore sealing device, the present application is corresponding to the technical problems mentioned in the background art, including rock sample 1, the upper side of the rock sample 1 is provided with a rubber sealing mechanism 2, the upper side of the rock sample 1 is provided with a gas sealing mechanism 3.

[0042] The rubber sealing mechanism 2 includes a rubber sealing unit 21, which is arranged above the rock sample 1, and the rubber sealing unit 21 can seal the wellbore with rubber.

[0043] As a further limitation of the rubber sealing mechanism 2 of the present application, the rubber sealing unit 21 includes a first opening pad 2108, the outer surface of the first opening pad 2108 is fixedly connected with a rolling bearing 2111, the outer ring of the rolling bearing 2111 is fixedly connected with a second opening pad 2107, the upper surface of the second opening pad 2107 is fixedly connected with a connecting plate 2106, the upper surface of the connecting plate 2106 is fixedly connected with a stud 2104, the outer surface of the stud 2104 is threadedly connected with a lifting block 2105, the inside of the stud 2104, the connecting plate 2106, the first opening pad 2108 and the second opening pad 2107 are jointly and slidingly connected with a circular shaft 2101, the outer surface of the circular shaft 2101 is threadedly connected with a circular ring 2102, the bottom end of the circular shaft 2101 is fixedly connected with a tapered expansion 2109, the outer side of the circular shaft 2101 is provided with a rubber ring 2110, by setting the rubber sealing unit 21, using the rubber ring 2110 and the tapered expansion 2109 structure in the rubber sealing unit 21, the tapered expansion 2109 moves upward to push the rubber ring 2110 to expand, which can seal the inside of the wellbore, thereby reducing the occurrence of leakage problem in the wellbore.

[0044] Please refer to Figure 1 and Figure 2The upper surface of the first open pad 2108 is fixedly connected with a positioning shaft 2103, the inside of the lifting block 2105 is slidably connected to the outer surface of the positioning shaft 2103, the bottom surface of the first open pad 2108 is in contact with the upper surface of the rock sample 1, the outer surface of the first open pad 2108 is fixedly connected with the inner ring of the rolling bearing 2111, the bottom end of the rubber ring 2110 is in contact with the outer surface of the expansion cone 2109, and the rubber ring 2110 and the expansion cone 2109 are arranged in the inner cavity of the rock sample 1. By arranging the positioning shaft 2103, the movement position of the lifting block 2105 can be limited by the positioning shaft 2103, so that the lifting block 2105 only moves in the up-down direction.

[0045] The specific implementation of the embodiment is that when the device needs to be used, the first open pad 2108 is placed on the upper surface of the rock sample 1, and the bottom surface of the first open pad 2108 is covered with a layer of rubber. The large friction coefficient of the rubber can increase the friction between the first open pad 2108 and the rock sample 1. The equipment below the first open pad 2108 needs to be inside the rock sample 1. Then the equipment is fixed on the rock sample 1 by the limiting unit 22, and then the rotating power is applied to the second open pad 2107 to drive the second open pad 2107, the fixed connecting plate 2106 above and the stud 2104 to rotate. The stud 2104 will push the lifting block 2105 to move upward by the threaded connection relationship. It should be understood that the lifting block 2105 slides on the surface of the positioning shaft 2103, so that the lifting block 2105 can only move in the up-down direction. With the continuous rotation of the second open pad 2107, the lifting block 2105 will finally contact the bottom surface of the circular ring 2102, thereby pushing the circular ring 2102 and the circular shaft 2101 to move upward. The circular shaft 2101 will drive the expansion cone 2109 to move upward synchronously when moving upward, so that the expansion cone 2109 will be squeezed into the inside of the rubber ring 2110, so that the rubber ring 2110 expands and tightly contacts the inner wall of the rock sample 1 to achieve the purpose of sealing. It should be understood that the top end of the rubber ring 2110 is in contact with the bottom end of the limiting cylinder 303, the top end of the limiting cylinder 303 is fixed with the bottom end of the circular cylinder 2203, and the top end of the circular cylinder 2203 is in contact with the first open pad 2108. Therefore, when the expansion cone 2109 enters the inside of the rubber ring 2110, it will not push the rubber ring 2110 to move upward.

[0046] Embodiment 2: please refer to Figures 1-4 and Figures 8-13The application provides a technical scheme: a hydraulic fracturing experiment sample simulation wellbore sealing device, and the rubber sealing mechanism 2 further comprises a limiting unit 22, the limiting unit 22 is arranged above the rock sample 1, the limiting unit 22 cooperates with the rubber sealing unit 21, and the limiting unit 22 can make the rubber sealing unit 21 more stable inside the wellbore.

[0047] As a further limitation of the rubber sealing mechanism 2 of the application, the limiting unit 22 comprises a circular cylinder 2203, two clamping plates 2209 are clamped in the circular cylinder 2203, two groups of pressure blocks 2204 are slidably connected in the circular cylinder 2203, two sliding grooves 2206 are formed in the outer surface of the first opening pad 2108, a sliding shaft 2207 is slidably connected in each sliding groove 2206, a connecting ring 2201 is fixedly connected to the outer surfaces of the two sliding shafts 2207, a first extrusion block 2208 is fixedly connected to the outer surfaces of the two sliding shafts 2207, the first extrusion block 2208 and the circular shaft 2101 are arranged in the inner cavity of the circular cylinder 2203, a second extrusion block 2212 is fixedly connected to the outer surface of the circular shaft 2101, and the second extrusion block 2212 is arranged in the inner cavity of the circular cylinder 2203. By arranging the limiting unit 22, the first opening pad 2108 can be temporarily fixed above the rock sample 1, and the circular shaft 2101 can be fixed in the rock sample 1 for a long time, so that the stability of the circular shaft 2101 and the rubber sealing unit 21 in the rock sample 1 is increased.

[0048] Please refer to Figure 9 The inner wall of the first opening pad 2108 is fixedly connected with two first fixed cylinders 2210, the two first fixed cylinders 2210 are distributed in the center of the circular cylinder 2203 in a circular manner, the inner wall of each first fixed cylinder 2210 is fixedly connected with a first force spring 2211, and the ends, away from each other, of the two first force springs 2211 are fixedly connected with first clamping blocks 2202. By arranging the first fixed cylinder 2210, the first force spring 2211 and the first clamping block 2202, the first force spring 2211 can push the first clamping block 2202 to limit the connecting ring 2201.

[0049] Please refer to Figure 11 and Figure 12The inner wall of the circular cylinder 2203 is fixedly connected with two second fixing cylinders 2213. The inner wall of each second fixing cylinder 2213 is fixedly connected with a second stress spring 2217. The two second stress springs 2217 are commonly fixedly connected at one end close to each other with a second clamping block 2216. The outer surface of each second clamping block 2216 is fixedly connected with a rectangular plate 2215. The outer surface of each rectangular plate 2215 is slidingly connected in the interior of the second fixing cylinder 2213. The outer surface of the circular shaft 2101 is provided with two clamping grooves 2205. By being provided with the second stress spring 2217 and the second clamping block 2216, the second clamping block 2216 can be pushed into the interior of the clamping groove 2205, and the connection purpose of the circular shaft 2101 and the circular cylinder 2203 is achieved.

[0050] Please refer to Figure 11 and Figure 12 One end close to each other of the two second clamping blocks 2216 is fixedly connected with a bull's eye bearing 2214. The outer surface of each bull's eye bearing 2214 is in contact with the outer surface of the circular shaft 2101. The circular cylinder 2203 is arranged in the inner cavity of the rock sample 1. The upper surface of each clamping plate 2209 is fixedly connected to the bottom surface of the first opening pad 2108. The upper surface of the circular cylinder 2203 is in contact with the bottom surface of the first opening pad 2108. The number of each set of pressure blocks 2204 is two. The two sets of pressure blocks 2204 are evenly distributed around the center of the circular cylinder 2203. By being provided with the bull's eye bearing 2214, the friction generated when the circular shaft 2101 moves upward can be reduced by the sliding characteristics of the bull's eye bearing 2214.

[0051] The specific implementation of the embodiment is that when the limiting unit 22 needs to be used, the triggering step of the limiting unit 22 needs to be in front of the rubber sealing unit 21, and after the first opening pad 2108 is in contact with the upper surface of the rock sample 1, the connecting ring 2201 can be pressed downward, the connecting ring 2201 drives the two sliding shafts 2207 to slide along the inside of the sliding groove 2206 when moving downward, so that the first extrusion block 2208 fixed on the surface of the sliding shaft 2207 can slide to the direction of the pressure block 2204, and after the first extrusion block 2208 is in contact with the pressure block 2204, the first extrusion block 2208 can drive the pressure block 2204 to move to the rock sample 1, and finally the surface of the pressure block 2204 is in contact with the inner wall of the rock sample 1, and the surface of the pressure block 2204 is also covered with a layer of rubber, and the large friction coefficient of the rubber can increase the friction between the pressure block 2204 and the rock sample 1, so that the circular cylinder 2203 and the first opening pad 2108 can be limited, and the first opening pad 2108 is indirectly fixed above the rock sample 1, when the connecting ring 2201 is pushed downward, the connecting ring 2201 can extrude the first clamping block 2202 in the first fixed cylinder 2210, so that the first clamping block 2202 is extruded to the inside of the first fixed cylinder 2210, so that the first stress spring 2211 is contracted, when the connecting ring 2201 moves to the gap in the first clamping block 2202, the first stress spring 2211 can drive the first clamping block 2202 to reset quickly, so as to limit the connecting ring 2201, prevent the connecting ring 2201 from moving upward, and further prevent the sliding shaft 2207 and the first extrusion block 2208 from moving upward, so that the first extrusion block 2208 can stably provide pressure to the pressure block 2204, when the user applies a rotating force to the second opening pad 2107, the user does not need to use the other hand to limit the first opening pad 2108, then the user can apply a rotating force to the second opening pad 2107 to drive the circular shaft 2101 and the expanding cone 2109 in the rubber sealing unit 21 to move upward, so as to make the rubber ring 2110 expand, and the purpose of rubber sealing is achieved, and when the circular shaft 2101 moves upward, the clamping groove 2205 on the surface of the circular shaft 2101 can move to the position of the two bull's eye bearings 2214, the bull's eye bearings 2214 and the second clamping block 2216 can enter the inside of the clamping groove 2205 under the pushing force of the second stress spring 2217, so as to limit the circular shaft 2101, and the circular cylinder 2203 and the circular shaft 2101 are connected together, it can be understood that the bull's eye bearings 2214 and the second clamping block 2216 are always extruded by the elastic force of the second stress spring 2217, so the bull's eye bearings 2214 are always in contact with the surface of the circular shaft 2101,Subsequently, the circular ring 2102 can be unscrewed from the circular shaft 2101, and then the first open pad 2108 is pulled upward with force, and the fixed clamping plate 2209 at the bottom of the first open pad 2108 is separated from the clamping relationship with the circular cylinder 2203, at this time, the connecting ring 2201, the sliding shaft 2207, the first extrusion block 2208, the first open pad 2108 and the structure above the first open pad 2108 can be removed, and the circular shaft 2101, the circular cylinder 2203, the pressure block 2204, the second extrusion block 2212, the expansion cone 2109, the limiting cylinder 303 and the rubber ring 2110 still remain in the interior of the rock sample 1, and the limiting effect of the rubber sealing unit 21 is completed.

[0052] Embodiment 3: see Figures 1-8 、 Figure 10 、 Figure 11 and Figure 13 The present application provides a technical solution: a hydraulic fracturing experimental sample simulation wellbore sealing device, which improves the technical problems mentioned in the background art. The gas sealing mechanism 3 is arranged above the rock sample 1, and the gas sealing mechanism 3 and the rubber sealing mechanism 2 cooperate with each other, and the gas sealing mechanism 3 can perform gas sealing treatment on the wellbore.

[0053] As a further limitation of the gas sealing mechanism 3 of the present application, the gas sealing mechanism 3 comprises a limiting cylinder 303, the outer surface of the limiting cylinder 303 is provided with a plurality of same communication openings 304, the outer surface of the circular shaft 2101 is provided with a plurality of same gas conveying openings 307, the outer surface of the limiting cylinder 303 is fixedly connected with a gas bag 302, the inside of the circular shaft 2101 is slidably connected with a long shaft 306, the bottom end of the long shaft 306 is fixedly connected with a circular plate 305, the bottom surface of the circular plate 305 is fixedly connected with a first fixed rubber pad 311, the outer surface of the first fixed rubber pad 311 is fixedly connected with a first folded rubber pad 312, the upper surface of the circular plate 305 is provided with a first circular opening 313, the inner top wall of the circular shaft 2101 is fixedly connected with a second fixed rubber pad 310, the outer surface of the second fixed rubber pad 310 is fixedly connected with a second folded rubber pad 309, and the top end of the circular shaft 2101 is provided with a second circular opening 308. By setting the gas sealing mechanism 3, the gas sealing mechanism 3 can be inflated into the gas bag 302, so that the surface of the gas bag 302 is in contact with the inner wall of the rock sample 1, and the sealing effect is increased. By setting the rubber sealing unit 21, the limiting unit 22 and the gas sealing mechanism 3, the problem of water leakage caused by poor sealing effect during use of the equipment can be effectively avoided.

[0054] see Figure 3 and Figure 13The outer surface of the circular shaft 2101 is fixedly connected with a rubber sealing plate 314, the outer surface of the rubber sealing plate 314 is in contact with the inner wall of the limiting cylinder 303, the top end of the long shaft 306 penetrates through the circular shaft 2101 and extends above the circular shaft 2101, the top end of the long shaft 306 is fixedly connected with a stress plate 301, the top end of the limiting cylinder 303 is in contact with the bottom end of the circular cylinder 2203, the bottom end of the limiting cylinder 303 is in contact with the top end of the rubber ring 2110, the upper surface of the first folded rubber pad 312 is in contact with the bottom surface of the circular plate 305, the upper surface of the second folded rubber pad 309 is in contact with the inner top wall of the circular shaft 2101, by being provided with the rubber sealing plate 314, the rubber sealing plate 314 can ensure that the gas only enters the inside of the air bag 302, and when the rubber sealing plate 314 moves downward below the gas outlet 307, the gas in the air bag 302 can be guided to flow out to the outside, in addition, the existence of the stress plate 301 can facilitate the power to be applied to the circular shaft 1, so as to drive the circular shaft 1 to move upward or downward.

[0055] The specific implementation of the embodiment is: when the connecting ring 2201, the sliding shaft 2207, the first extrusion block 2208, the first opening pad 2108 and the structure above the first opening pad 2108 are removed, the stressed plate 301 can be pulled to move upward, and when the stressed plate 301 moves upward, the long shaft 306 and the circular plate 305 fixed at the bottom end of the long shaft 306 are synchronously moved upward, so that the air in the space above the circular plate 305 is extruded, the pressure in the space above the circular plate 305 is increased, and the size of the second folded rubber pad 309 is greater than that of the second circular port 308, so that the air pressure pushes the second folded rubber pad 309 to tightly adhere to the inner top wall of the circular shaft 2101, and the first folded rubber pad 312 below the circular plate 305 is unfolded downward under the action of the air pressure, so that the gas in the space above the circular plate 305 enters the space below the circular plate 305, when the circular plate 305 moves upward to the top position of the circular shaft 2101, the long shaft 306 and the circular plate 305 are pushed to move downward, and in the process of moving downward, a large amount of air is stored in the space below the circular plate 305, so that the downward moving gas extrudes the first folded rubber pad 312 below the circular plate 305 to tightly adhere to the bottom surface of the circular plate 305, prevents the gas from flowing to the space above the circular plate 305 through the second circular port 308, promotes the downward movement of the air, and until the air enters the inside of the air bag 302, the air bag 302 is inflated, the purpose of inflation sealing is achieved, and when the circular plate 305 moves downward, the gas content in the space above the circular plate 305 is small, so that a negative pressure state is formed, so that the second folded rubber pad 310 can be pulled downward by suction, at this time, the air outside can enter the space above the circular plate 305, and the cycle is repeated to achieve the purpose of inflating the air bag 302, and when it is necessary to remove the circular shaft 2101, the circular cylinder 2203, the stressed block 2204, the second extrusion block 2212, the expansion cone 2109, the limiting cylinder 303 and the rubber ring 2110 from the inside of the rock sample 1, the two rectangular plates 2215 are pushed, the second clamping block 2216 and the bull's eye bearing 2214 fixed on the surface of the rectangular plate 2215 extrude the second stressed spring 2217, the bull's eye bearing 2214 stops the clamping relationship with the clamping groove 2205, and then the circular shaft 2101 is pressed downward, so that the expansion cone 2109 and the rubber sealing plate 314 are moved downward, the expansion cone 2109 stops extruding the rubber ring 2110, and the rubber sealing plate 314 moves to below the communication port 304 on the surface of the limiting cylinder 303, at this time, the gas in the air bag 302 is discharged outward through the communication port 304, so that the air bag 302 is no longer filled, and then the device is removed.

[0056] A method for simulating a wellbore sealing device of a hydraulic fracturing experimental sample, comprising the following steps:

[0057] S1: the first opening pad 2108 is placed on the upper surface of the rock sample 1, and then the rotating power is applied to the second opening pad 2107, so as to drive the second opening pad 2107, the fixed connecting plate 2106 above and the stud 2104 to rotate, the stud 2104 pushes the lifting block 2105 to move upwards by the threaded connection relationship during rotation, and finally the lifting block 2105 is in contact with the bottom surface of the circular ring 2102, so as to push the circular ring 2102 and the circular shaft 2101 to move upwards, the circular shaft 2101 drives the expansion cone 2109 to move upwards synchronously, so that the expansion cone 2109 is squeezed into the inside of the rubber ring 2110, and the rubber ring 2110 is inflated to be in close contact with the inner wall of the rock sample 1;

[0058] S2: when the limiting unit 22 needs to be used, the connecting ring 2201 can be pressed downwards, the connecting ring 2201 drives the two sliding shafts 2207 to slide along the inside of the sliding groove 2206 when moving downwards, so as to push the first extrusion block 2208 fixed on the surface of the sliding shaft 2207 to slide to the direction of the pressure receiving block 2204, when the first extrusion block 2208 is in contact with the pressure receiving block 2204, the first extrusion block 2208 pushes the pressure receiving block 2204 to move to the rock sample 1, and finally the surface of the pressure receiving block 2204 is in contact with the inner wall of the rock sample 1, so as to limit the circular cylinder 2203 and the first opening pad 2108;

[0059] S3: the stress plate 301 can be pulled to move upwards, the stress plate 301 drives the long shaft 306 and the circular plate 305 fixed at the bottom end of the long shaft 306 to move upwards synchronously when moving upwards, so as to squeeze the air in the space above the circular plate 305 into the space below the circular plate 305, when the circular plate 305 moves upwards to the top position close to the circular shaft 2101, the stress plate 301 is pushed to move the long shaft 306 and the circular plate 305 downwards, so as to move the air downwards, until the air enters the inside of the air bag 302 to inflate the air bag 302.

[0060] It should be noted that, in the present text, the relationship terms such as first and second are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or includes the elements inherent to such process, method, article or equipment.

[0061] While embodiments of the application have been shown and described, it is to be understood that the embodiments described are merely exemplary of the principles and application of the present application. Numerous modifications and adaptions can be effected without departing from the spirit and scope of the present application, which is not limited to the exact construction and arrangement described. It is intended, therefore, to cover all modifications and adaptions that fall within the scope of the claims and their equivalents.

Claims

1. A hydraulic fracturing experimental sample analog wellbore sealing device, comprising a rock sample (1), characterized in that: The upper side of the rock sample (1) is provided with a rubber sealing mechanism (2), and the upper side of the rock sample (1) is provided with a gas sealing mechanism (3); The rubber sealing mechanism (2) comprises a rubber sealing unit (21), which is arranged above the rock sample (1), and the rubber sealing unit (21) can be used for rubber sealing of the wellbore; The rubber sealing mechanism (2) further comprises a limiting unit (22), which is arranged above the rock sample (1), and the limiting unit (22) cooperates with the rubber sealing unit (21), and the limiting unit (22) can make the rubber sealing unit (21) more stable in the wellbore; The gas sealing mechanism (3) is arranged above the rock sample (1), and the gas sealing mechanism (3) cooperates with the rubber sealing mechanism (2), and the gas sealing mechanism (3) can be used for gas sealing treatment of the wellbore; The rubber sealing unit (21) comprises a first opening pad (2108), the outer surface of the first opening pad (2108) is fixedly connected with a rolling bearing (2111), the outer ring of the rolling bearing (2111) is fixedly connected with a second opening pad (2107), the upper surface of the second opening pad (2107) is fixedly connected with a connecting plate (2106), the upper surface of the connecting plate (2106) is fixedly connected with a stud (2104), the outer surface of the stud (2104) is threadedly connected with a lifting block (2105), the inside of the stud (2104), the connecting plate (2106), the first opening pad (2108) and the second opening pad (2107) are jointly and slidably connected with a circular shaft (2101), the outer surface of the circular shaft (2101) is threadedly connected with a circular ring (2102), the bottom end of the circular shaft (2101) is fixedly connected with a tapered expansion (2109), and the outer side of the circular shaft (2101) is provided with a rubber ring (2110); The limiting unit (22) comprises a circular cylinder (2203), two clamping plates (2209) are clamped in the inside of the circular cylinder (2203), two groups of pressure receiving blocks (2204) are slidably connected in the inside of the circular cylinder (2203), the outer surface of the first opening pad (2108) is provided with two sliding grooves (2206), each sliding groove (2206) is slidably connected with a sliding shaft (2207), the outer surfaces of the two sliding shafts (2207) are jointly and fixedly connected with a connecting ring (2201), the outer surfaces of the two sliding shafts (2207) are jointly and fixedly connected with a first extrusion block (2208), the first extrusion block (2208) and the circular shaft (2101) are arranged in the inner cavity of the circular cylinder (2203), the outer surface of the circular shaft (2101) is fixedly connected with a second extrusion block (2212), and the second extrusion block (2212) is arranged in the inner cavity of the circular cylinder (2203). The air-tight mechanism (3) comprises a limiting cylinder (303), the outer surface of the limiting cylinder (303) is provided with a plurality of same communication openings (304), the outer surface of the circular shaft (2101) is provided with a plurality of same gas conveying openings (307), the outer surface of the limiting cylinder (303) is fixedly connected with an air bag (302) in communication, the inside of the circular shaft (2101) is slidably connected with an elongated shaft (306), the bottom end of the elongated shaft (306) is fixedly connected with a circular plate (305), the bottom surface of the circular plate (305) is fixedly connected with a first fixed rubber pad (311), the outer surface of the first fixed rubber pad (311) is fixedly connected with a first folded rubber pad (312), the upper surface of the circular plate (305) is provided with a first circular opening (313), the inner top wall of the circular shaft (2101) is fixedly connected with a second fixed rubber pad (310), the outer surface of the second fixed rubber pad (310) is fixedly connected with a second folded rubber pad (309), and the top end of the circular shaft (2101) is provided with a second circular opening (308).

2. A hydraulic fracturing experimental sample simulation wellbore sealing device according to claim 1, characterized in that: The upper surface of the first opening pad (2108) is fixedly connected with a positioning shaft (2103), the inside of the lifting block (2105) is slidably connected to the outer surface of the positioning shaft (2103), the bottom surface of the first opening pad (2108) is in contact with the upper surface of the rock sample (1), the outer surface of the first opening pad (2108) is fixedly connected to the inner ring of the rolling bearing (2111), the bottom end of the rubber ring (2110) is in contact with the outer surface of the expansion cone (2109), and the rubber ring (2110) and the expansion cone (2109) are arranged in the inner cavity of the rock sample (1).

3. A simulated wellbore seal apparatus for hydraulic fracturing experiments according to claim 1, wherein: The inner wall of the first opening pad (2108) is fixedly connected with two first fixed cylinders (2210), the two first fixed cylinders (2210) are distributed in the center of the circular cylinder (2203) in a circular manner, the inner wall of each first fixed cylinder (2210) is fixedly connected with a first stress spring (2211), and the ends of the two first stress springs (2211) away from each other are fixedly connected with a first clamping block (2202).

4. The simulated wellbore seal apparatus for hydraulic fracturing experiments of claim 1, wherein: The inner wall of the circular cylinder (2203) is fixedly connected with two second fixed cylinders (2213), the inner wall of each second fixed cylinder (2213) is fixedly connected with a second stress spring (2217), the ends of the two second stress springs (2217) close to each other are fixedly connected with a second clamping block (2216), the outer surface of each second clamping block (2216) is fixedly connected with a rectangular plate (2215), the outer surface of each rectangular plate (2215) is slidably connected to the inside of the second fixed cylinder (2213), and the outer surface of the circular shaft (2101) is provided with two clamping grooves (2205).

5. A simulated wellbore seal apparatus for hydraulic fracturing experiments of claim 4, wherein: Two second clamping blocks (2216) are fixedly connected with eye shaft bearings (2214) at one end close to each other, the outer surfaces of the eye shaft bearings (2214) are in contact with the outer surface of the circular shaft (2101), the circular cylinder (2203) is arranged in the inner cavity of the rock sample (1), the upper surfaces of the clamping plates (2209) are fixedly connected to the bottom surface of the first opening pad (2108), the upper surface of the circular cylinder (2203) is in contact with the bottom surface of the first opening pad (2108), the number of each group of pressure blocks (2204) is two, and the two groups of pressure blocks (2204) are uniformly distributed around the center of the circular cylinder (2203).

6. A simulated wellbore seal apparatus for hydraulic fracturing experiments of claim 1, wherein: The outer surface of the circular shaft (2101) is fixedly connected with a rubber sealing plate (314), the outer surface of the rubber sealing plate (314) is in contact with the inner wall of the limiting cylinder (303), the top end of the long shaft (306) penetrates through the circular shaft (2101) and extends above the circular shaft (2101), the top end of the long shaft (306) is fixedly connected with a stress plate (301), the top end of the limiting cylinder (303) is in contact with the bottom end of the circular cylinder (2203), the bottom end of the limiting cylinder (303) is in contact with the top end of the rubber ring (2110), the upper surface of the first folded rubber pad (312) is in contact with the bottom surface of the circular plate (305), and the upper surface of the second folded rubber pad (309) is in contact with the inner top wall of the circular shaft (2101).

7. The method of modeling a wellbore seal for a hydraulic fracturing experiment sample of any one of claims 1-6, wherein: Specifically comprising the following steps: S1: place the first opening pad (2108) on the upper surface of the rock sample (1), then apply a rotating power to the second opening pad (2107), which drives the second opening pad (2107), the fixed connecting plate (2106) above and the stud (2104) to rotate, the stud (2104) pushes the lifting block (2105) to move upward by the threaded connection relationship when rotating, and finally pushes the lifting block (2105) to contact the bottom surface of the circular ring (2102) with the continuous rotation of the second opening pad (2107), thereby pushing the circular ring (2102) and the circular shaft (2101) to move upward, the circular shaft (2101) drives the expansion cone (2109) to move upward at the same time when moving upward, so that the expansion cone (2109) is squeezed into the inside of the rubber ring (2110), and the rubber ring (2110) is inflated to be in close contact with the inner wall of the rock sample (1), to achieve the purpose of sealing; S2: When it is necessary to use the limiting unit (22), the connecting ring (2201) can be pressed downward, and the two sliding shafts (2207) will slide along the inside of the sliding groove (2206) when the connecting ring (2201) moves downward, so as to push the first extrusion block (2208) fixed on the surface of the sliding shaft (2207) to slide in the direction of the pressure block (2204). When the first extrusion block (2208) contacts the pressure block (2204), the first extrusion block (2208) will push the pressure block (2204) to move to the rock sample (1), and finally the surface of the pressure block (2204) will contact the inner wall of the rock sample (1), so as to limit the circular cylinder (2203) and the first opening pad (2108); S3: The stress plate (301) can be pulled to move upward, and the stress plate (301) will move upward synchronously with the long shaft (306) and the circular plate (305) fixed at the bottom of the long shaft (306), so as to extrude the air in the space above the circular plate (305) into the space below the circular plate (305). When the circular plate (305) moves upward to the top position close to the circular shaft (2101), the stress plate (301) can be pushed to make the long shaft (306) and the circular plate (305) move downward, so as to make the air move downward, until the air enters the inside of the air bag (302), inflates the air bag (302), and achieves the purpose of inflation sealing.

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