Wellhead under-pressure operation device

Abstract

The invention relates to the technical field of well packing, in particular to a wellhead under-pressure operation device which comprises a delivery hydraulic cylinder, the delivery hydraulic cylinder comprises a piston pipe, a cylinder body part and a connecting pipe part, the piston pipe is provided with a piston part, the lower end of the piston pipe extends out of the cylinder body part and is used for being connected with a bridge plug feeding tool, and the upper end of the cylinder body part is closed; the upper end of the piston pipe is located in an inner cavity of the cylinder part and provided with a communicating opening for communicating the piston pipe with the space, located above the piston part, of the cylinder part, and the cylinder part or the connecting pipe part is provided with a limiting structure for limiting the downward moving stroke of the piston pipe so that the bridge plug can be fed into a tool through pressure of an inner cavity of the piston pipe to achieve bridge plug setting. The delivery and setting of the bridge plug can be realized in sequence by continuously pressing the delivery hydraulic cylinder, and the piston tube does not need to upwards penetrate out of the cylinder body part for additional pressing and setting, so that the length of the piston tube can be reduced, the length of the wellhead under-pressure operation device is further reduced, the hoisting is convenient, and the operation convenience is facilitated.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of well packoff, in particular to a wellhead pressure operation device. BACKGROUND

[0002] The wellhead gas production tree is a wellhead device used for opening and closing the well, adjusting pressure, gas volume, and circulating well killing during the development of gas reservoirs. The wellhead gas production tree is connected with the gas well tubing, casing, and surface process equipment. After long-term service, due to the composition of the output gas, valve structure, and other reasons, the wellhead gas production tree may have leaks, valve operation failure, and other faults. Especially for the wellhead gas production tree of high-sulfur acid gas reservoirs, due to the sulfide and acidic substances in the gas production composition, the wellhead pressure is high, which is easy to produce wellbore impurities, corrosion products, mechanical failures, and other problems, causing the wellhead gas production tree to have faults such as the leakage of the gate valve packing, the failure of the valve rod lifting, and other problems, which further leads to the replacement of the gate valve, and even the replacement of the wellhead gas production tree.

[0003] When performing wellhead device maintenance operations, in order to avoid the ejection of well fluid, the current method is to use a plug to block the well. The plug is lowered into the well using a coiled tubing, and the plug is set by using the coiled tubing to pressurize. The plug is removed by the pressure above the plug, and the wellhead pressure is reduced to zero, which can realize pressure operation. However, the use of a connection tubing to deliver the plug requires a coiled tubing operation vehicle, which has a high use cost.

[0004] The Chinese invention patent application with application publication number CN115012863A discloses a method for replacing the wellhead of an empty wellbore of a high-pressure gas well without killing the well. The method installs a delivery hydraulic cylinder at the wellhead and uses the delivery hydraulic cylinder to deliver the setting release mechanism into the well, with low operating costs. When unclamping said control button, under the effect of the compression spring and the bubble holding vessel internal pressure that shaves, combine closely in the interior edge of valve gap and sealing load chamber, and burble goes out control valve thereby control is shaved. When unclamping said control button, under the effect of the compression spring and the bubble holding vessel internal pressure that shaves, combine closely in the interior edge of valve body and valve body, and rub against and catch cavity " rub" in valve body, and rub against and catch cavity " rub" in valve body.

[0005] The upper and lower ends of the piston tube of the above-mentioned delivery hydraulic cylinder are both passed through the cylinder body to ensure that the upper end of the piston tube can pressurize and the lower end can deliver the setting and releasing mechanism. In this way, after the piston tube descends to completely send the setting and releasing mechanism into the well, the upper end of the piston tube still needs to remain extended upward from the cylinder body, so the piston tube needs to be very long. During lifting, the part of the piston tube extending upward from the cylinder body is very long, requiring a very high lifting height, which increases the difficulty of lifting and affects the convenience of operation. Summary of the Invention

[0006] The purpose of the present invention is to provide a wellhead pressure operation device to solve the problem that when the current wellhead pressure operation device is hoisted, the piston tube of the delivery hydraulic cylinder extends too long upward from the cylinder body and is inconvenient to operate.

[0007] The technical solution of the wellhead pressure operation device of the present invention is: The wellhead pressure operation device comprises a delivery hydraulic cylinder, the delivery hydraulic cylinder comprises a piston tube, a cylinder body part and a connecting tube part connected with the cylinder body part and used for connecting the wellhead device, the piston tube has a piston part matched with the inner wall of the cylinder body part, the lower end of the piston tube extends out of the cylinder body part and is provided with a connecting structure used for connecting a bridge plug running tool when the bridge plug is delivered, the upper end of the cylinder body part is closed, the upper end of the piston tube is in the inner cavity of the cylinder body part and is provided with a communication port for communicating the inner cavity of the piston tube with the space above the piston part in the inner cavity of the cylinder body part, the cylinder body part or the connecting tube part is provided with a limiting structure for limiting the downward movement stroke of the piston tube, so that the bridge plug running tool is used to realize the bridge plug setting when the piston tube moves downward to the limiting structure and the bridge plug setting is realized by the pressure in the inner cavity of the cylinder body part and the piston tube.

[0008] Further, the lower end of the cylinder body part is provided with an inner ring table, the inner ring table has a central hole for the piston tube to pass through to extend out of the cylinder body part, the inner ring table is in sliding sealing cooperation with the piston tube, the upper side of the inner ring table on the inner wall of the cylinder body part is provided with an upward stop step, the stop step is used for stop cooperation with the piston part, and the stop step constitutes the limiting structure.

[0009] Further, the inner wall of the cylinder body part is provided with a lower liquid inlet and outlet on the part between the inner ring table and the stop step in the up-down direction, the lower liquid inlet and outlet is communicated with the space below the piston part in the inner cavity of the cylinder body part and outside the piston tube.

[0010] Further, the piston tube comprises a main tube body, the piston part comprises a piston head connected to the upper end of the main tube body, the outer wall of the piston head is provided with a sealing element, and the piston head is connected with a compression cap used for compressing the sealing element below the sealing element.

[0011] Further, the inner wall of the cylinder body part is further provided with an upper stop structure used for limiting the upward movement stroke of the piston part, the upper side of the upper stop structure on the inner wall of the cylinder body part is provided with an upper liquid inlet and outlet, and the upper liquid inlet and outlet is communicated with the space above the piston part in the inner cavity of the cylinder body part.

[0012] Further, the upper end of the cylinder body part is provided with a hoisting cooperation structure.

[0013] Further, the wellhead pressure operation device comprises a bridge plug running tool, the bridge plug running tool has a central inner cavity communicated with the inner cavity of the piston tube, and the cavity bottom of the central inner cavity is provided with a blind plate structure.

[0014] Further, the bridge plug running tool comprises a setting hydraulic cylinder, the setting hydraulic cylinder comprises a setting piston and a setting cylinder body, the setting piston is connected with the lower end of the piston tube, the setting piston has a central hole communicated with the inner cavity of the piston tube, the central inner cavity comprises the central hole of the setting piston, the setting piston and the setting cylinder body enclose a pressure setting cavity, the hole wall of the central hole of the setting piston is provided with a pressure transmission hole communicated with the pressure setting cavity and the central hole of the setting piston for transmitting pressure to the pressure setting cavity to make the setting cylinder body move downward relative to the setting piston.

[0015] Further, the bridge plug running tool further comprises a retaining outer tube, the retaining outer tube is sleeved outside the setting cylinder, and the retaining outer tube is connected to the setting piston at the upper end of the retaining outer tube.

[0016] Further, the wellhead pressure operation device comprises a fishing tool, and the fishing tool is provided with a connecting matching structure for being connected with the connecting structure of the piston tube when the bridge plug is fished.

[0017] Beneficial effects: the wellhead pressure operation device of the present application is improved on the basis of the prior art, the upper end of the cylinder part of the delivery hydraulic cylinder of the wellhead pressure operation device is provided as a closed structure, the upper end of the piston tube is located in the inner cavity of the cylinder part, and the inner cavity of the piston tube is in communication with the space above the piston part in the inner cavity of the cylinder part, so that after the wellhead pressure operation device is fixed on the wellhead device by using the connecting pipe part, the lower end of the piston tube is blocked by the bridge plug running tool by pressing the space above the piston part in the inner cavity of the cylinder part, and thus under the action of pressure, the piston part slides downward relative to the inner wall of the cylinder part, the piston tube moves downward with the bridge plug running tool and the bridge plug, and when the piston tube moves to the limiting structure, the bridge plug is sent to the predetermined position in the well, and the piston tube is limited and no longer moves downward, so that by continuing to press the space above the piston part in the inner cavity of the cylinder part, the pressure in the inner cavity of the cylinder part and the piston tube is transmitted to the inside of the bridge plug running tool, and then the bridge plug is set, so that the delivery and setting of the bridge plug can be sequentially realized by continuously pressing the delivery hydraulic cylinder, the piston tube does not need to be pulled out of the cylinder part to be pressed and set, the length of the piston tube can be reduced, and thus the length of the wellhead pressure operation device can be reduced, hoisting is facilitated, and the operation convenience is improved. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 A schematic view of the wellhead pressure operation device of the embodiment of the present application installed on a Christmas tree; Figure 2 A schematic view of the delivery hydraulic cylinder of the wellhead pressure operation device in the embodiment of the present application; Figure 1 A schematic view of the delivery hydraulic cylinder connecting the bridge plug running tool and the bridge plug of the wellhead pressure operation device in the embodiment of the present application; Figure 3 A structural schematic view of the delivery hydraulic cylinder in the embodiment of the present application; Figure 2 A structural schematic view of the delivery hydraulic cylinder in the embodiment of the present application; Figure 4 A structural schematic view of the delivery hydraulic cylinder and the bridge plug running tool connecting structure in the embodiment of the present application; Figure 2 A structural schematic view of the bridge plug running tool in the embodiment of the present application; Figure 5 Figure 2 A structural schematic view of the bridge plug in the embodiment of the present application; Figure 6 A structural schematic view of the bridge plug in the embodiment of the present application; Figure 2 A structural schematic view of the bridge plug in the embodiment of the present application; Figure 7 ​Fig. 1 is a schematic view of a wellhead pressure operation device of an embodiment of the present application.

[0019] Fig. 1 is a schematic view of a wellhead pressure operation device of an embodiment of the present application. Fig. 1 is a schematic view of a wellhead pressure operation device of an embodiment of the present application. Fig. 1 is a schematic view of a wellhead pressure operation device of an embodiment of the present application. Fig. 1 is a schematic view of a wellhead pressure operation device of an embodiment of the present application. Fig. 1 is a schematic view of a wellhead pressure operation device of an embodiment of the present application. Fig. 1 is a schematic view of a wellhead pressure operation device of an embodiment of the present application. Fig. 1 is a schematic view of a wellhead pressure operation device of an embodiment of the present application. Fig. 1 is a schematic view of a wellhead pressure operation device of an embodiment of the present application. Fig. 1 is a schematic view of a wellhead pressure operation device of an embodiment of the present application. Fig. 1 is a schematic view of a wellhead pressure operation device of an embodiment of the present application. DETAILED DESCRIPTION

[0020] The upper end of the cylinder part of the delivery hydraulic cylinder of the wellhead pressure operation device of the present application is provided as a closed structure, so that the upper end of the piston tube is in the inner cavity of the cylinder part, and the inner cavity of the piston tube communicates with the space above the piston part in the inner cavity of the cylinder part. After the wellhead pressure operation device is fixed on the wellhead device by the connecting pipe part, the lower end of the piston tube is blocked by the bridge plug running tool by pressing the space above the piston part in the inner cavity of the cylinder part. Thus, under the action of pressure, the piston part slides downward relative to the inner wall of the cylinder part, and the piston tube moves downward with the bridge plug running tool and the bridge plug. When the piston tube moves to the limiting structure, the bridge plug is sent to the predetermined position downhole, and the piston tube is limited and no longer moves downward. Thus, by continuing to press the space above the piston part in the inner cavity of the cylinder part, the pressure in the inner cavity of the cylinder part and the piston tube is transmitted to the inside of the bridge plug running tool, and the bridge plug is set. Thus, only the delivery hydraulic cylinder needs to be continuously pressed to sequentially realize the delivery and setting of the bridge plug, and the piston tube does not need to be pressed to set by penetrating upward out of the cylinder part. The length of the piston tube can be reduced, and the length of the wellhead pressure operation device can be reduced, which facilitates hoisting and improves the convenience of operation.

[0021] Embodiment of wellhead operation device with pressure of the application: As Figure 1 , Figure 2 shown, the wellhead operation device with pressure includes a delivery hydraulic cylinder 100, a setting and releasing tool 200, the setting and releasing tool 200 includes a bridge plug delivery tool 2001 and a bridge plug 2002. By fixing the delivery hydraulic cylinder 100 on the top flange of the Christmas tree 400, the bridge plug delivery tool 2001 and the bridge plug 2002 are sent into the downhole completion tubing 500 by the delivery hydraulic cylinder 100, and the pressure is transmitted to the bridge plug delivery tool 2001 by the delivery hydraulic cylinder 100 to make the bridge plug 2002 set in the completion tubing 500, and the completion tubing 500 is blocked near the wellhead by the bridge plug 2002, and then the wellhead operation with pressure can be carried out.

[0022] In combination Figure 1 , Figure 2 , Figure 3 , Figure 4 The structure of the delivery hydraulic cylinder 100 is described, the delivery hydraulic cylinder 100 includes a hanging ring 101, a fixed outer pipe, an upper transmission pressure pipe joint 103, a lower transmission pressure pipe joint 110 and a piston pipe, the fixed outer pipe includes an upper end cap 102, a cylinder sleeve 107, a lower end cap 109, an extension pipe 111 and a flange joint 112 which are sequentially threadedly sealed and connected from top to bottom, the upper end cap 102, the cylinder sleeve 107 and the lower end cap 109 jointly constitute a cylinder body part of the delivery hydraulic cylinder 100, the extension pipe 111 and the flange joint 112 jointly constitute a connecting pipe part which is connected with the cylinder body part and used for connecting the wellhead device, and the wellhead device is the Christmas tree 400. The piston pipe includes a main pipe body and a piston part, the main pipe body is an inner connecting pipe 108, the piston part includes a piston head 104, the inner wall of the lower end of the piston head 104 is threadedly sealed and connected with the upper end of the inner connecting pipe 108, the outer wall of the lower end of the piston head 104 is threadedly connected with a compression cap 106, the upper end of the piston head 104 is provided with a downward compression matching surface, a combined sealing element 105 is sleeved on the outer wall of the piston head 104 between the compression matching surface and the compression cap 106, the combined sealing element 105 realizes the sliding sealing of the piston part and the inner wall of the cylinder sleeve 107, and the compression cap 106 is used for compressing the combined sealing element 105 to ensure reliable sealing.

[0023] The upper portion of the lifting ring 101 is provided with a circular ring, and the lower portion is threadedly connected to the upward connecting hole of the upper end cap 102. The upward connecting hole is a blind hole. The lifting ring 101 constitutes a lifting and matching structure provided at the upper end of the cylinder body, which is convenient for cooperating with a crane for hooking operations. The lower end of the upper end cap 102 has a downward inner cavity, and the inner cavity has a downward cavity bottom, so that the upper end of the cylinder body is closed and the sealing is ensured. The cavity wall of the downward inner cavity of the upper end cap 102 is provided with a radially penetrating upper liquid inlet and outlet, and the upper liquid inlet and outlet are sealed with an upper pressure pipe joint 103. The upper end cap 102 is provided with an internal thread below the upper pressure pipe joint 103 for threaded connection with the upper end of the cylinder sleeve 107. The piston head 104 and the clamping cap 106 are installed in the inner cavity of the cylinder sleeve 107 and form a sliding seal through the combined seal 105. The combined seal 105 includes multiple sealing rings. The internal thread at the upper end of the lower end cap 109 is threadedly connected to the external thread at the lower end of the cylinder sleeve 107. The lower end cap 109 is provided with a radially extending lower liquid inlet and outlet below the internal thread at its upper end. The lower liquid inlet and outlet are sealed with a lower pressure transmission pipe joint 110. The upper end of the inner connecting pipe 108 extends into the inner cavity of the cylinder body. The lower end cap 109 has an inner cavity that passes through from top to bottom. The middle part of the inner wall of the lower end cap 109 is provided with an inner ring platform, which constitutes the inner ring platform provided at the lower end of the cylinder body. The inner ring platform has a central hole for the inner connecting pipe 108 to pass through and extend out of the cylinder body. The hole wall of the central hole of the inner ring platform is provided with a sealing ring that seals with the outer wall of the inner connecting pipe 108, so that when the piston tube moves up and down, the lower end cap 109 and the inner connecting pipe 108 form a sliding sealing fit.

[0024] The outer diameter of the compression cap 106 is greater than the inner diameter of the portion of the lower end cap 109 corresponding to the installation of the lower pressure transmission pipe joint 110. An upward stop step 113 is arranged on the upper inner wall of the lower end cap 109 below the upper end internal thread. The upward stop step 113 constitutes a stop step on the inner wall of the cylinder part above the inner ring table and faces upward. The upward stop step 113 is used for stop cooperation with the piston part. When the piston part moves downward to a certain position, the lower end surface of the compression cap 106 abuts against the upward stop step 113. The stop step constitutes a limiting structure of the cylinder part for limiting the downward movement stroke of the piston pipe. The movement of the piston pipe is limited by the upward stop step 113, which is simple and reliable in structure. The inner diameter of the portion of the lower end cap 109 where the stop step is arranged is smaller than the inner diameter of the portion where the inner ring table is arranged. The lower liquid inlet and outlet is arranged on the portion of the inner wall of the lower end cap 109 between the inner ring table and the upward stop step 113 in the upward and downward direction, which facilitates the opening of the lower liquid inlet and outlet. The lower liquid inlet and outlet is in communication with the space in the inner cavity of the cylinder part below the piston part, above the inner ring table and outside the piston pipe, so as to realize the liquid inlet and outlet of the space by the lower pressure transmission pipe joint 110. The outer diameter of the piston head 104 is greater than the inner diameter of the portion of the upper end cap 102 corresponding to the installation of the upper pressure transmission pipe joint 103. An downward stop step 114 is arranged on the inner wall of the upper end cap 102 below the upper liquid inlet and outlet. The upper liquid inlet and outlet is in communication with the space in the inner cavity of the cylinder part above the piston part, which includes the downward inner cavity of the upper end cap 102. The downward stop step 114 is above the cylinder sleeve 107 and constitutes an upper stop structure on the inner wall of the cylinder part for limiting the upward movement stroke of the piston part. When the piston pipe moves upward to a certain position, the upper end surface of the piston head 104 abuts against the downward stop step 114, thereby avoiding the piston part from blocking the upper liquid inlet and outlet.

[0025] The upper part of the flange joint 112 is provided with a long neck and the upper end inner wall is threadedly connected with the lower end of the lengthened pipe 111. The lower end flange of the flange joint 112 is provided with a connecting hole matched with the top flange of the gas production tree 400, so as to fixedly connect the flange joint 112 with the gas production tree 400 by bolts. The flange joint 112, the lengthened pipe 111, the lower end cap 109, the cylinder sleeve 107 and the upper end cap 102 form a sealed inner cavity, thereby avoiding the leakage of well gas when the valve of the gas production tree 400 is opened.

[0026] The piston head 104 and the inner connecting pipe 108 are both provided with a through central hole, the piston head 104 is located at the upper end of the piston pipe, the upper hole of the central hole of the piston head 104 constitutes a communication port for connecting the inner cavity of the piston pipe with the space above the piston part in the inner cavity of the cylinder part, the inner connecting pipe 108 extends out of the lower end of the inner cavity of the cylinder part to connect the bridge plug setting tool 2001, and the lower end of the bridge plug setting tool 2001 connects the bridge plug 2002. When the space above the piston part in the inner cavity of the cylinder part is pressed through the upper transmission pipe joint 103, the hydraulic pressure will act on the bridge plug setting tool 2001 through the piston pipe, and then drive the piston pipe, the bridge plug setting tool 2001 and the bridge plug 2002 to move downward as a whole, when the compression cap 106 moves downward to the upward blocking step 113, the bridge plug setting tool 2001 is driven to move by the continuous pressure of the inner cavity of the cylinder part and the piston pipe, so as to realize the setting of the bridge plug 2002. In this way, only the continuous pressing of the delivery hydraulic cylinder 100 is needed to realize the delivery and setting of the bridge plug 2002 in sequence, and the piston pipe does not need to be pressed to set the bridge plug 2002 by penetrating the cylinder part upward, which can reduce the length of the piston pipe, and then reduce the length of the wellhead pressurized operation device, facilitate hoisting, and be beneficial to improve the operation convenience.

[0027] In combination Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5The structure of the bridge plug running tool 2001 is described as follows. The bridge plug running tool 2001 comprises a piston assembly formed by a first-stage piston 201, a second-stage piston 204 and a third-stage piston 206 connected in sequence from top to bottom by thread sealing. The piston assembly is sleeved with a cylinder assembly formed by a first-stage cylinder 203, a second-stage cylinder 205 and a third-stage cylinder 207 connected in sequence from top to bottom by thread sealing. A sealing ring is arranged on the contact surface of the piston assembly and the cylinder assembly. The piston assembly and the cylinder assembly are used together to form a setting hydraulic cylinder. The piston assembly is used to form a setting piston, and the cylinder assembly is used to form a setting cylinder. The setting piston is connected with the lower end of the piston tube. The setting piston has a central hole communicating with the inner cavity of the piston tube. The central hole of the setting piston is formed by the central holes of the first-stage piston 201, the second-stage piston 204 and the third-stage piston 206. The upper end of the first-stage piston 201 is threadedly connected with the lower end of the inner connecting pipe 108. The lower end of the third-stage piston 206 is threadedly connected with a plugging connector 208. The upper part of the plugging connector 208 is provided with an inner cavity with an upward opening, and the lower part of the plugging connector 208 is provided with an inner cavity with a downward opening. The part of the plugging connector 208 between the upper inner cavity and the lower inner cavity is used to form a cavity bottom and constitutes a blind plate structure. The upward inner cavity of the plugging connector 208 and the central hole of the setting piston together form a central inner cavity of the bridge plug running tool 2001 communicating with the inner cavity of the piston tube. The blind plate structure of the plugging connector 208 forms a closed cavity bottom 2011 of the central inner cavity, so that when the pressure is applied through the upper pressure pipe connector 103, the pressure acts on the closed cavity bottom 2011 to drive the piston tube, the bridge plug running tool 2001 and the bridge plug 2002 to move downward as a whole.

[0028] The cylinder assembly is sleeved with a retaining outer tube 202, an inner wall of an upper end of the retaining outer tube 202 is threadedly and sealingly connected with an upper outer wall of the first-stage piston 201, the retaining outer tube 202 comprises an upper cylinder segment and a lower cylinder segment which are arranged separately, the upper cylinder segment is fixedly connected with the first-stage piston 201, the lower cylinder segment is supported on a step on an outer wall of the third-stage cylinder 207, an inner wall of the retaining outer tube 202 is in sliding contact with the cylinders of the stages, which is favorable for reliable assembly of the cylinders of the stages. The three-stage pistons are sequentially connected end to end, and the three-stage cylinders are sequentially connected end to end. The first-stage piston 201 is provided with a downward step face on an upper portion thereof and the step face is opposite to an upper end face of the second-stage piston 204, the first-stage cylinder 203 has a sliding portion which is slidingly arranged between the downward step face on the upper portion of the first-stage piston 201 and the upper end face of the second-stage piston 204, a first press and setting cavity is formed between an upper side face of the sliding portion of the first-stage cylinder 203 and the downward step face on the upper portion of the first-stage piston 201, and the first press and setting cavity is surrounded by the first-stage piston 201, the first-stage cylinder 203 and the retaining outer tube 202. The second-stage piston 204 is provided with a downward step face on an upper portion thereof and the step face is opposite to an upper end face of the third-stage piston 206, the second-stage cylinder 205 has a sliding portion which is slidingly arranged between the downward step face on the upper portion of the second-stage piston 204 and the upper end face of the third-stage piston 206, a second press and setting cavity is formed between an upper side face of the sliding portion of the second-stage cylinder 205 and the downward step face on the upper portion of the second-stage piston 204, and the second press and setting cavity is surrounded by the second-stage piston 204, the second-stage cylinder 205 and the first-stage cylinder 203. The third-stage piston 206 is provided with a downward step face on an upper portion thereof and the step face is opposite to an upper end face of the plugging connector 208, the third-stage cylinder 207 has a sliding portion which is slidingly arranged between the downward step face on the upper portion of the third-stage piston 206 and the upper end face of the plugging connector 208, a third press and setting cavity is formed between an upper side face of the sliding portion of the third-stage cylinder 207 and the downward step face on the upper portion of the third-stage piston 206, and the third press and setting cavity is surrounded by the third-stage piston 206, the third-stage cylinder 207 and the second-stage cylinder 205. A pressure transmission hole 2010 which communicates the press and setting cavities with the central hole of the setting piston is arranged on a hole wall of the central hole of the setting piston, and the first-stage piston 201, the second-stage piston 204 and the third-stage piston 206 are each provided with a radial pressure transmission hole 2010 above the first-stage cylinder 203, the second-stage cylinder 205 and the third-stage cylinder 207, respectively, so that pressure is transmitted to the press and setting cavities and the setting cylinders are moved downward relative to the setting piston.

[0029] The upper end portion of the first stage cylinder 203, the second stage cylinder 205 and the third stage cylinder 207 has a smaller inner diameter than the portion below the upper end portion. Each stage cylinder is provided with a pressure relief hole below the upper end portion and adjacent to the upper end portion. The holding outer tube 202 is also provided with a pressure relief hole. The pressure in the cavity below the sliding portion of the corresponding cylinder can be released through the pressure relief hole, thereby ensuring smooth downward movement of the cylinder assembly relative to the piston assembly. The distance between the pressure relief hole on the holding outer tube 202 and the lowermost sealing ring on the outer wall of the upper end portion of the first stage cylinder 203 is slightly greater than the maximum displacement of the cylinder assembly relative to the piston assembly in the axial direction, thereby ensuring the sealing effect.

[0030] The lower inner cavity of the plugging connector 208 is provided with a thread connected to the pull rod 210. The third stage cylinder 207 of the cylinder assembly is provided with a force transmission pressure cap 209 threaded on the outer wall of the lower end. The pull rod 210 is connected to the bridge plug 2002. The force transmission pressure cap 209 is used to apply downward pressure to the bridge plug 2002, thereby achieving setting and releasing of the bridge plug 2002.

[0031] In combination Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6The structure of the bridge plug 2002 is described as follows. The bridge plug 2002 comprises, from top to bottom, a locking sleeve 211, a setting sleeve 214, a setting outer tube assembly formed by a rubber sleeve pressing cap 219, and a center rod assembly formed by an upper center rod 213 and a lower center rod 218 connected in sequence from top to bottom. An annulus is formed between the setting outer tube assembly and the center rod assembly. A fishing head 212, a locking ring seat 216, and a locking ring 217 connected to the outer wall of the lower end of the locking ring seat 216 are arranged above the lower center rod 218 in the annulus. The lower end of the fishing head 212 is crimped to the outside of a locking block 215 at the upper end of the locking ring seat 216. The upper end of the locking ring seat 216 is provided with a plurality of through holes in the circumferential direction, and the locking block 215 is arranged in the through holes. The outer end of the locking block 215 abuts against the inner wall of the fishing head 212, and the inner end of the locking block 215 is installed in a groove at the corresponding position of the upper center rod 213. The fishing head 212 can limit the locking block 215 to maintain the relative position of the locking ring seat 216 and the upper center rod 213. The upper part of the lower center rod 218 is provided with a downward stepped surface. An outer center tube 220 is sleeved outside the lower side of the stepped surface of the lower center rod 218. The upper part of the outer center tube 220 is hung on the lower end boss in the inner cavity of the rubber sleeve pressing cap 219. The upper end inner wall of the outer center tube 220 is provided with a sealing ring that seals the lower center rod 218. The outer center tube 220 is sleeved outside the lower part of the rubber sleeve pressing cap 219 to form a rubber sleeve assembly formed by an end rubber sleeve 221, a spacer ring 222, and a middle rubber sleeve 223. A slip seat 224 is threadedly connected to the outer center tube 220 below the rubber sleeve assembly. The lower end of the slip seat 224 is provided with an inclined dovetail groove. A slip 227 is inserted into the dovetail groove. The inner end of the slip 227 is installed in the dovetail groove. The outer end of the slip 227 is inclined and arranged in the corresponding window of a slip sleeve 226. The upper end of the slip sleeve 226 is threadedly connected to an upper connecting cap 225, which is hung on the boss at the lower end of the slip seat 224. The lower end inner wall of the slip sleeve 226 is threadedly connected to a lower connecting cap 228. The bottom of the lower connecting cap 228 is closed and has an upward inner cavity. The inner cavity of the lower connecting cap 228 is provided with an internal thread and is threadedly connected to the lower end of the lower center rod 218.

[0032] The force transmission pressure cap 209 of the bridge plug running tool 2001 is pressed on the upward step on the upper end of the locking sleeve 211, the locking sleeve 211 is overlapped with the force transmission pressure cap 209, the locking sleeve 211 is uniformly distributed with the setting shear pins of the fishing head 212 above the upward step in the circumferential direction, the force transmission pressure cap 209 is provided with a slot corresponding to the position of the setting shear pins, so as to facilitate the installation of the setting shear pins. The inner wall of the lower part of the locking sleeve 211 is provided with locking threads matched with the locking ring 217. The upper end inner cavity of the upper central rod 213 is provided with threads connected with the lower end of the pull-off rod 210. The part between the upper end inner cavity and the lower end inner cavity of the upper central rod 213 forms a blind plate structure. The lower central rod 218 has an upward inner cavity, and the upper end of the lower central rod 218 is threadedly connected with the lower end of the upper central rod 213. The cavity wall of the lower end inner cavity of the upper central rod 213 is provided with a pressure relief hole, and the cavity wall of the upper end inner cavity of the lower central rod 218 is provided with a pressure relief hole. The outer wall of the upper central rod 213 is provided with sealing rings on the upper and lower sides of the pressure relief hole thereof, so that when the fishing head 212 is moved upward to a certain position relative to the upper central rod 213, the cavity surrounded by the upper central rod 213 and the lower central rod 218 is communicated with the space outside the bridge plug 2002, and the gas pressure is balanced. The total length of the setting releasing tool 200 is not greater than the distance from the lower end surface of the inner connecting pipe 108 of the delivery hydraulic cylinder 100 to the lower end surface of the flange joint 112, so as to facilitate the accommodation of the setting releasing tool 200 in the lengthened pipe 111 and the flange joint 112 before the setting releasing tool 200 is lowered. The distance from the lower end surface of the compression cap 106 of the delivery hydraulic cylinder 100 to the upward stop step 113 of the lower end cap 109 is at least 0.5 meters longer than the distance from the upper end surface of the fishing head 212 to the upper end surface of the completion tubing 500 below the gas production tree 400, so as to ensure the depth of the bridge plug 2002 lowered into the completion tubing 500.

[0033] Under the pushing action of the force transmission pressure cap 209 of the bridge plug running tool 2001, the setting outer pipe assembly is lowered relative to the central rod assembly, the bridge plug 2002 is set, the pull-off rod 210 is pulled off under the action of pressure, the releasing is realized, and after the bridge plug running tool 2001 is taken out, the fishing head 212 is exposed in the completion tubing 500, so as to facilitate the fishing of the bridge plug 2002 out of the well with the fishing tool 300.

[0034] In combination Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 5 , Figure 6 , Figure 7The structure of the fishing tool 300 is described, the fishing tool 300 comprises a fishing connector 301, a fishing barrel 302 and a fishing claw 303, the upper end of the fishing connector 301 is provided with a sealing pipe thread for thread sealing connection with the lower end of the inner connecting pipe 108 of the delivery hydraulic cylinder 100, the outer thread of the lower end of the inner connecting pipe 108 constitutes the connecting structure thereof, and the inner thread of the upper end of the fishing connector 301 constitutes the connecting matching structure thereof. The inner cavity of the fishing connector 301 is provided with a blind plate structure, the outer wall of the lower end of the fishing connector 301 is threadedly connected with the inner wall of the upper end of the fishing barrel 302, and a stabilizing nail is arranged between the outer wall of the lower end of the fishing connector 301 and the inner wall of the upper end of the fishing barrel 302. The fishing claw 303 is inserted and assembled in the inner cavity of the fishing barrel 302, and the fishing claw 303 is used for grabbing the fishing head 212 of the setting and releasing tool structure 200. The length of the fishing connector 301 is greater than the length of the bridge plug running tool 2001 of the setting and releasing tool structure 200, so that the fishing head 212 can be grabbed when the piston pipe of the delivery hydraulic cylinder 100 moves downward.

[0035] When the gas production tree 400 is maintained under pressure using the wellhead pressure operation device, the process is as follows: 1) Close the wellhead safety valve 401 of the gas production tree 400, and release and vent the pressure in the inner cavity of the gas production tree 400 above the wellhead installation valve; close the test valve 402 of the gas production tree 400.

[0036] 2) Hoist the delivery hydraulic cylinder 100 and the setting and releasing tool structure 200: install the setting and releasing tool structure 200 into the inner cavity of the connecting pipe part of the delivery hydraulic cylinder 100 on the ground, thread sealingly connect the upper end of the first stage piston 201 of the setting and releasing tool structure 200 with the lower end of the inner connecting pipe 108 of the delivery hydraulic cylinder 100, connect the transmission pressure pipe joint 103 with the pressure transmission pipeline, connect the pressure release pipe joint 110 with the pressure release pipeline, and hoist the delivery hydraulic cylinder 100 and the setting and releasing tool structure 200 to the upper side of the gas production tree 400 by the lifting ring 101, align the lower end face of the flange joint 112 of the delivery hydraulic cylinder 100 with the upper end flange face of the wellhead safety valve 401, and tighten the fixing bolts.

[0037] 3) Delivery, setting, releasing and setting the setting and releasing tool structure 200: ① Delivery: open the wellhead safety valve 401 and the test valve 402 of the gas production tree 400 in sequence, transmit the hydraulic pressure from the pressure transmission pipeline to the cavity above the piston head 104 of the delivery hydraulic cylinder 100 through the transmission pressure pipe joint 103, act the hydraulic pressure on the closed cavity bottom 2011, push the piston head 104 and the combined sealing member 105, the pressure tight cap 106 downward, and make the inner connecting pipe 108 and the setting and releasing tool structure 200 descend, when the lower end face of the pressure tight cap 106 falls on the upward blocking step 113 of the lower end cap 109, the bridge plug 2002 of the setting and releasing tool structure 200 is placed in the well completion tubing 500 below the gas production tree 400.

[0038] ② Setting and releasing: continue to pressurize, the hydraulic pressure is transmitted to the bridge plug running tool 2001 of the setting and releasing tool 200 through the inner cavity of the piston head 104 and the inner connecting pipe 108, and the pressure is transmitted to the setting and releasing cavity through the pressure transmission holes 2010 of the first-stage piston 201, the second-stage piston 204 and the third-stage piston 206, and the pressure is transmitted to the cylinder assembly of the bridge plug running tool 2001, and the cylinder assembly is driven to move downward relative to the piston assembly, and the pressure of the cylinder assembly is transmitted to the locking sleeve 211 through the force transmission pressure cap 209, and the piston tube is no longer moved downward due to the limitation, and thus the piston assembly of the bridge plug running tool 2001, the blocking connector 208, the pull-off rod 210, the upper central rod 213, the lower central rod 218, the lower connecting cap 228, the slip sleeve 226 and the upper connecting cap 225 connected below the piston tube are no longer moved downward, the fishing head 212 is connected with the upper central rod 213 through the shear pin and is limited by the lock ring seat 216, the lock ring seat 216 is limited by the lock block 215 and the lower central rod 218, and thus the hydraulic driving force is transmitted to the locking sleeve 211 to drive the locking sleeve 211 to move downward relative to the fishing head 212 to shear the setting shear pin arranged therebetween; the locking sleeve 211 drives the setting sleeve 214, the rubber sleeve pressure cap 219, the outer central pipe 220 and the slip seat 224 to move downward, and the slip seat 224 moves downward relative to the slip sleeve 226 to drive the slips 227 to move along the inclined window on the slip sleeve 226 and the inclined dovetail groove on the slip seat 224, extend outward and be clamped to the inner wall of the completion tubing 500; the locking sleeve 211, the setting sleeve 214 and the rubber sleeve pressure cap 219 are continuously driven by the hydraulic pressure to move downward, and the rubber sleeve assembly is axially compressed to expand radially and be sealed to the inner wall of the completion tubing 500, at this time, the locking sleeve 211 is locked to the lock ring 217 to be fixed, the bridge plug 2002 is kept in the setting state, and the clamping and setting of the bridge plug 2002 of the setting and releasing tool 200 are completed. The pressure is continuously increased, and after the pull-off force of the pull-off rod 210 is exceeded, the weak part of the pull-off rod 210 is broken under the action of the bridge plug running tool 2001 of the setting and releasing tool 200, the bridge plug 2002 is released in the completion tubing 500, and then the pressure is released.

[0039] 4) Take out the bridge plug delivery tool 2001 of the setting and releasing tool 200: switch the pipeline, the uploading pressure pipe joint 103 connects the pressure relief pipeline, the downward pressure pipe joint 110 connects the pressure pipeline, the pressure pushing piston head 104, the combined sealing element 105, the compression cap 106 go up, and then the inner connecting pipe 108 and the bridge plug delivery tool 2001 of the setting and releasing tool 200 go up, the force transmission compression cap 209 of the bridge plug delivery tool 2001 is separated from the locking sleeve 211, the upper half of the broken rod 210 is pulled up with the blocking connector 208, the bridge plug delivery tool 2001 goes up to the inner cavity of the connecting pipe part of the delivery hydraulic cylinder 100. Remove the bolts connecting the delivery hydraulic cylinder 100 and the gas tree 400, hoist the delivery hydraulic cylinder 100 together with the bridge plug delivery tool 2001 in its inner cavity, and place it on the ground at the designated position.

[0040] 5) Maintenance and even replacement of new gas trees 400 according to the needs of the gas tree 400.

[0041] 6) Take out the bridge plug 2002 of the setting and releasing tool 200 in the completion tubing 500: ① Hoist the delivery hydraulic cylinder 100 and the fishing tool 300: install the fishing tool 300 into the inner cavity of the connecting pipe part of the delivery hydraulic cylinder 100 on the ground, the upper end of the fishing connector 301 of the fishing tool 300 is threadedly sealed with the lower end of the inner connecting pipe 108 of the delivery hydraulic cylinder 100, the uploading pressure pipe joint 103 connects the pressure pipeline, the downward pressure pipe joint 110 connects the pressure relief pipeline, the crane lifts the delivery hydraulic cylinder 100 and the fishing tool 300 by the lifting ring 101 to the upper part of the gas tree 400, and the flange joint 112 of the delivery hydraulic cylinder 100 is fixed on the gas tree 400.

[0042] ② Fishing: through the uploading pressure pipe joint 103, the pressure pushing piston head 104, the combined sealing element 105, the compression cap 106, the inner connecting pipe 108, and the fishing tool 300 go down, and the fishing claw 303 of the fishing tool 300 grabs the upper part of the fishing head 212 of the bridge plug 2002.

[0043] ③Unblocking, pulling out the bridge plug 2002: switching the pipeline, uploading the pressure pipe joint 103 connecting the pressure relief pipeline, the lower transmission pressure pipe joint 110 connecting the pressure pipeline, the pressure pushing the piston head 104, the combined sealing element 105, the compression cap 106, the inner connecting pipe 108 up, driving the fishing tool 300 fishing connector 301, fishing barrel 302 up, fishing barrel 302 relative to the fishing claw 303 up, the fishing claw 303 is guided by the lower end of the fishing barrel 302. The slope locks the fishing head 212; then under the action of the upward force, the fishing head 212 is relative to the upper center rod 213 and cuts the unblocking shear pin provided between them, the fishing head 212 continues to go up, the locking block 215 is released, and the positioning connection of the upper center rod 213 and the lock ring seat 216 is released; the fishing head 212 goes up, driving the locking sleeve 211 and the lock ring seat 216 threaded with the lock ring 217 up; the locking sleeve 211 drives the setting sleeve 214 and the rubber tube compression cap 219 up, the rubber tube assembly rebounds and shrinks, the rubber tube compression cap 219 hangs the outer center pipe 220 and continues to go up, the outer center pipe 220 drives the slip seat 224 up, under the action of the dovetail groove of the slip seat 224 and the oblique window of the slip sleeve 226, the slip 227 is retracted into the window of the slip sleeve 226, and the bridge plug 2002 is unblocked. Continue to press, drive the fishing tool 300, bridge plug 2002 up and retract into the connecting pipe inner cavity of the delivery hydraulic cylinder 100.

[0044] ④Close the test valve 402, depressurize the inner cavity of the test valve 402 above the gas tree 400 and the connecting pipe inner cavity of the wellhead operating device with pressure to zero through the well site process, close the wellhead safety valve 401; remove the delivery hydraulic cylinder 100, lift the delivery hydraulic cylinder 100 together with the fishing tool 300 and the bridge plug 2002 in it away from the gas tree 400 and place it on the ground at the designated position.

[0045] 7) The gas tree 400 opens the gate according to the standard requirements, and produces normally.

[0046] The wellhead operating device with pressure can realize the delivery, setting, releasing and fishing of the bridge plug 2002 through a set of pressure pipeline. The upper end of the piston pipe of the delivery hydraulic cylinder 100 remains in the inner cavity of the cylinder body, avoiding the length of the piston pipe being too long to affect lifting, and the upper end of the inner cavity of the cylinder body is closed to effectively ensure the sealing performance. It is simple to operate, safe and reliable, and can effectively save operation time and operation cost.

[0047] In other embodiments, a limiting structure can also be provided on the connecting pipe, an outer ring table is provided on the inner connecting pipe, and an upward stop surface is provided on the upper end of the flange joint, which constitutes the limiting structure. The outer ring table of the inner connecting pipe can form a stop cooperation with the upward stop surface to limit the downward movement stroke of the piston pipe.

[0048] In other embodiments, the upward side of the inner ring table can form a limiting structure, and the lower liquid inlet and outlet can be arranged on the upward side of the inner ring table to facilitate liquid entering.

[0049] In other embodiments, the piston head and the inner connecting pipe can be integrally arranged.

[0050] In other embodiments, the connecting pipe part can also be an integral structure, and the extension pipe and the flange joint are integrally machined and formed.

[0051] In other embodiments, the setting hydraulic cylinder of the bridge plug running tool can only have a primary piston and a primary cylinder body, and can meet the pressure transmission to the bridge plug.

[0052] Finally, it should be noted that the above description is only for the preferred embodiments of the present application, and is not intended to limit the present application. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments without creative labor, or replace some technical features with equivalent ones. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A wellhead pressure operation device, comprising a delivery hydraulic cylinder, the delivery hydraulic cylinder comprising a piston tube, a cylinder body, and a connecting pipe portion connected to the cylinder body and used to connect to the wellhead device, the piston tube having a piston portion that cooperates with the inner wall of the cylinder body, the lower end of the piston tube extending out of the cylinder body and provided with a connecting structure for connecting to a bridge plug delivery tool when delivering a bridge plug, characterized in that: The upper end of the cylinder body is closed, the upper end of the piston tube is in the inner cavity of the cylinder body and is provided with a connecting port that connects the inner cavity of the piston tube with the space above the piston part in the inner cavity of the cylinder body. The cylinder body or the connecting tube is provided with a limiting structure for limiting the downward movement stroke of the piston tube so that when the piston tube moves down to the limiting structure, the bridge plug delivery tool can realize the bridge plug sealing through the pressure in the inner cavity of the cylinder body and the piston tube.

2. The wellhead pressure operation device according to claim 1, characterized in that: An inner ring platform is provided at the lower end of the cylinder body, and the inner ring platform has a central hole for the piston tube to pass through to extend out of the cylinder body. The inner ring platform and the piston tube are slidingly and sealed together. An upward stopping step is provided on the inner wall of the cylinder body above the inner ring platform. The stopping step is used to stop and cooperate with the piston part, and the stopping step constitutes the above-mentioned limiting structure.

3. The wellhead pressure operation device according to claim 2, characterized in that: A lower liquid inlet and outlet is provided on the inner wall of the cylinder body between the inner ring platform and the stop step in the vertical direction. The lower liquid inlet and outlet are connected to the space in the inner cavity of the cylinder body below the piston part and outside the piston tube.

4. The wellhead pressure operation device according to claim 1, 2 or 3, characterized in that: The piston tube includes a main body, and the piston part includes a piston head connected to the upper end of the main body. A sealing member is provided on the outer wall of the piston head, and a compression cap for compressing the sealing member is connected to the lower side of the sealing member on the piston head.

5. The wellhead pressure operation device according to claim 1, 2 or 3, characterized in that: An upper stop structure is also provided on the inner wall of the cylinder body for limiting the upward movement of the piston part. An upper liquid inlet and outlet are provided on the inner wall of the cylinder body on the upper side of the upper stop structure. The upper liquid inlet and outlet are connected to the space in the inner cavity of the cylinder body located above the piston part.

6. The wellhead pressure operation device according to claim 1, 2 or 3, characterized in that: The upper end of the cylinder body is provided with a hoisting matching structure.

7. The wellhead pressure operation device according to claim 1, 2 or 3, characterized in that: The wellhead pressure operation device includes a bridge plug running tool, which has a central inner cavity communicating with the inner cavity of the piston tube, and a blind plate structure is provided at the bottom of the central inner cavity.

8. The wellhead pressure operation device according to claim 7, characterized in that: The bridge plug delivery tool includes a sealing hydraulic cylinder, which includes a sealing piston and a sealing cylinder body. The sealing piston is connected to the lower end of the piston tube. The sealing piston has a center hole that passes through the inner cavity of the piston tube. The central inner cavity includes the center hole of the sealing piston. The sealing piston and the sealing cylinder body form a pressure sealing cavity. The wall of the center hole of the sealing piston is provided with a pressure transmission hole that connects the pressure sealing cavity with the center hole of the sealing piston so that pressure is transmitted to the pressure sealing cavity to cause the sealing cylinder body to move downward relative to the sealing piston.

9. The wellhead pressure operation device according to claim 8, characterized in that: The bridge plug running tool further comprises a retaining outer tube, which is sleeved outside the setting cylinder and the upper end of which is connected to the setting piston.

10. The wellhead pressure operation device according to claim 1, 2 or 3, characterized in that: The wellhead pressure operation device comprises a fishing tool, which is provided with a connecting and matching structure for connecting with the connecting structure of the piston tube when fishing the bridge plug.

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