Christmas tree cap running tool

Abstract

The application discloses a Christmas tree cap feeding tool, which comprises a tool body, characterized in that the tool body comprises a bearing body, a limiting ring, a driving ring and a burst ring; the bearing body is sequentially sleeved with the limiting ring, the driving ring and the burst ring from top to bottom; the top of the bearing body is provided with hydraulic interfaces which are in one-to-one correspondence with locking cavities and unlocking cavities; when the driving ring pushes the burst ring to be in a cylindrical surface and the lower end of the burst ring abuts against the step for the burst ring, the radial outer end of the burst ring protrudes outside the step for the burst ring and forms a locking tooth for being clamped into a connecting clamping groove of the Christmas tree cap. The application has the advantages that the lowering, installation and recovery operations of the Christmas tree cap can be better ensured to be smoothly carried out, and the application has better use effect.

Description

Technical Field

[0001] This invention belongs to the field of oil well caps, specifically relating to an oil well cap delivery tool. Background Technology

[0002] Subsea wellheads are crucial equipment in subsea oil and gas production systems. They are mainly classified into two categories based on their installation method: vertical subsea wellheads and horizontal subsea wellheads. Because of these differences, the wellhead caps also differ. In this technical solution, the wellhead cap refers to the cap of a vertical wellhead.

[0003] The well cap is an important component located at the very top of the subsea well. It plays a reliable role in sealing the production borehole and annulus. At the same time, the hydraulic circuit on the well cap is connected to the hydraulic circuit of the subsea well, which plays an important role in the control and efficiency of the entire oil / gas extraction process.

[0004] The submersible tree cap delivery tool is one of the supporting tools for the submersible tree. The delivery tool is crucial to the smooth operation of the lowering, installation and retrieval of the tree cap.

[0005] The prior art, publication number CN213269820U, discloses an underwater oil production tree cap retrieval tool. However, this tool still has the following shortcomings:

[0006] The tool lacks a hoisting structure, making it inconvenient to lower and retrieve. In actual use, it is disassembled via a turntable. However, the turntable has a low torque and is cumbersome and time-consuming to operate underwater, making it difficult to use. This negatively impacts the delivery and retrieval of the oilfield tree cap.

[0007] Based on this, the applicant is considering designing an oil well cap delivery tool that can better facilitate the smooth operation of oil well cap lowering, installation and retrieval. Summary of the Invention

[0008] In view of the shortcomings of the prior art, the technical problem to be solved by the present invention is: how to provide an oilfield tree cap delivery tool that can better facilitate the smooth operation of oilfield tree cap lowering, installation and retrieval.

[0009] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0010] An oil well cap delivery tool, comprising a tool body, characterized in that:

[0011] The tool body includes a bearing body, a limiting ring, a driving ring, and a bursting ring;

[0012] The main body of the support is cylindrical in shape, and the top surface has an upwardly protruding hoisting connection joint for connecting with the drill pipe; the outer side of the main body is provided with a series of steps for limiting rings, driving rings and expansion rings with gradually increasing outer diameters from top to bottom;

[0013] The supporting body is fitted with the limiting ring, the driving ring and the expansion ring in sequence from top to bottom;

[0014] The limiting ring and the supporting body are fixedly connected; the lower end face of the limiting ring abuts against and limits the limiting ring with a step;

[0015] The drive ring has an inwardly convex pushing shoulder at the midpoint of its inner height direction. The pushing shoulder is slidably connected to the outer side of the support body located between the step of the limiting ring and the step of the drive ring. The upper annular sealing cavity of the pushing shoulder constitutes a locking cavity for driving the pushing shoulder downward, and the lower annular sealing cavity of the pushing shoulder constitutes an unlocking cavity for driving the pushing shoulder upward. The top of the support body has a hydraulic interface that is connected to the locking cavity and the unlocking cavity one by one.

[0016] The outer surface of the load-bearing body between the step of the drive ring and the step of the fracturing ring is a fracturing profile, and the outer diameter of the lower section of the fracturing profile is larger than that of the upper section, and the lower section is a conical profile and a cylindrical profile from top to bottom; the fracturing ring is slidably fitted on the fracturing profile, and the lower end face of the drive ring abuts against the upper end face of the fracturing ring; and when the drive ring pushes the fracturing ring onto the cylindrical profile and the lower end of the fracturing ring abuts against the step of the fracturing ring, the radial outer end of the fracturing ring protrudes outside the step of the fracturing ring and forms a locking tooth for engaging in the groove of the oil well cap connection.

[0017] The process of using the oilfield tree cap delivery tool in this technical solution is as follows:

[0018] After the drill pipe is used to support the main body and the hoisting connection is fastened together, it can be hoisted, lowered or retrieved.

[0019] After the oil well cap tool is connected to the oil well cap, pressure is applied to the locking cavity of the drive ring through the hydraulic connector. Under the action of hydraulic pressure, the drive ring drives the fracturing ring downward to move towards the conical surface. Under the action of the conical surface, the fracturing ring expands radially outward, so that the outer edge of the fracturing ring enters the connecting groove of the oil well cap, thereby connecting the oil well cap and the tool together.

[0020] When installation is complete and unlocking is required, pressure is applied to the unlocking chamber through the hydraulic connector. The drive ring moves upward under the action of hydraulic pressure (usually 3000 psi), and at the same time, the fracturing ring exits from the groove of the tree cap, thus unlocking the tree cap from the tool.

[0021] In summary, compared with existing technologies, the advantages of the oilfield tree cap delivery tool in this technical solution are:

[0022] The drill pipe is used for connection and hoisting, and the hydraulic system drives the drive ring to move up and down to expand or retract the fracturing ring. This allows for easy locking and unlocking with the Christmas tree, thus ensuring the smooth lowering, installation and recovery of the Christmas tree cap and providing better performance. Attached Figure Description

[0023] Figure 1 Top view of the oil well tree

[0024] Figure 2 A cross-sectional view of the oil well cap.

[0025] Figure 3 This is a schematic diagram of the structure of the oilfield tree cap delivery tool of the present invention, which carries and lowers the oilfield tree cap.

[0026] Figure 4 This is a schematic diagram of the structure of the oil well cap delivery tool of the present invention, which installs the oil well cap onto the oil well tree.

[0027] Figure 5 This is a schematic diagram of the retraction structure of the oil well cap feeding tool of the present invention.

[0028] Figure 6 A schematic diagram of the structure of an oil wellhead equipped with an oil wellhead cap.

[0029] Figure 7 This is a top view of the oil well cap feeding tool (equipped with a guide frame) of the present invention.

[0030] Figure 8 This is a cross-sectional view of the oil well cap feeding tool (equipped with a guide frame) of the present invention.

[0031] Figure 9 This is a cross-sectional view of the oil well cap feeding tool (without guide frame) of the present invention.

[0032] The diagram is marked as follows:

[0033] A seabed

[0034] Base B

[0035] C-type wellhead: C1 production borehole, C2 hydraulic connector

[0036] D drill pipe

[0037] E1 adapter short section, E2 drill pipe joint

[0038] F-type oil production tree cap; F1-type position indicator; F2-type hydraulic connector; F3-type production hole sealing mandrel; F4-type annular sealing mandrel.

[0039] G Oilfield Tree Cap Feeding Tool (equipped with a guide frame)

[0040] H guide rope

[0041] 10. Supporting Body: 101. Step for Limiting Ring; 102. Step for Drive Ring; 103. Step for Expansion Ring; 104. Expansion Profile; 105. Joint for Lifting Connection; 106. Step for Support and Limitation; 107. Locking Cavity; 108. Unlocking Cavity

[0042] 20 limit rings

[0043] 30 drive ring: 301 annular groove

[0044] 40 rupture ring

[0045] 50 preload spring

[0046] 60 guide limit pin

[0047] Safety withdrawal mechanism: 71 Reset compression spring, 72 Central sleeve, 73 Piston

[0048] 80 Guide frame: 81 Center mounting cylinder, 82 Cantilever, 83 Guide funnel, 84 Level, 85 Lifting lug, 86 Bearing plate

[0049] 90 spear shaft Detailed Implementation

[0050] The present invention will now be described in further detail with reference to the accompanying drawings.

[0051] In practical implementation: such as Figures 3 to 9 As shown,

[0052] The oil well cap feeding tool includes a tool body, which includes a bearing body, a limiting ring, a driving ring, and a fracturing ring;

[0053] The main body of the support is cylindrical in shape, and the top surface has an upwardly protruding hoisting connection joint for connecting with the drill pipe; the outer side of the main body is provided with a series of steps for limiting rings, driving rings and expansion rings with gradually increasing outer diameters from top to bottom;

[0054] The supporting body is fitted with the limiting ring, the driving ring and the expansion ring in sequence from top to bottom;

[0055] The limiting ring and the supporting body are fixedly connected; the lower end face of the limiting ring abuts against and limits the limiting ring with a step;

[0056] The drive ring has an inwardly convex pushing shoulder at the midpoint of its inner height direction. The pushing shoulder is slidably connected to the outer side of the support body located between the step of the limiting ring and the step of the drive ring. The upper annular sealing cavity of the pushing shoulder constitutes a locking cavity for driving the pushing shoulder downward, and the lower annular sealing cavity of the pushing shoulder constitutes an unlocking cavity for driving the pushing shoulder upward. The top of the support body has a hydraulic interface that is connected to the locking cavity and the unlocking cavity one by one.

[0057] The outer surface of the load-bearing body between the step of the drive ring and the step of the fracturing ring is a fracturing profile, and the outer diameter of the lower section of the fracturing profile is larger than that of the upper section, and the lower section is a conical profile and a cylindrical profile from top to bottom; the fracturing ring is slidably fitted on the fracturing profile, and the lower end face of the drive ring abuts against the upper end face of the fracturing ring; and when the drive ring pushes the fracturing ring onto the cylindrical profile and the lower end of the fracturing ring abuts against the step of the fracturing ring, the radial outer end of the fracturing ring protrudes outside the step of the fracturing ring and forms a locking tooth for engaging in the groove of the oil well cap connection.

[0058] When implementing, such as Figures 3 to 5 As shown, the hoisting connection joint achieves a coaxial, detachable, and fixed connection with the drill pipe through a conversion short section.

[0059] In practice, the sealing structure for the locking and unlocking cavities consists of sealing grooves filled with sealing rings on the two mating surfaces of their respective cavities. Sealing of the hydraulic cavity is existing technology and will not be elaborated upon here.

[0060] The oil well cap feeding tool also includes a preload spring and a guide limit pin;

[0061] A spring mounting groove for placing the preload spring is provided on the end face directly opposite to the drive ring and the limiting ring.

[0062] The guide pin is fixedly installed on the upper end face of the drive ring, and the upper section of the guide pin is slidably inserted into the guide hole correspondingly provided on the limit ring.

[0063] The use of the above preload spring can apply downward pressure to the drive ring, thereby better maintaining the expansion and locking state of the expansion ring and ensuring the reliability of the locking connection.

[0064] By adopting the above structure of guide limit pin and guide hole, the drive ring can be prevented from rotating in the circumferential direction, the wear of the seal ring caused by rotation can be reduced, and the preload spring can be prevented from deforming and failing due to torque, thus ensuring the reliability of the structure for long-term use.

[0065] On the outer side of the bearing body, at the midpoint of the height direction between the step for the drive ring and the step for the expansion ring, a support and limiting step is provided. The outer diameter of the support and limiting step is larger than the outer diameter of the step for the drive ring and smaller than the outer diameter of the step for the expansion ring.

[0066] The inner side of the drive ring, located below the push shoulder, has an annular groove for engaging with the support and limiting step.

[0067] After the support and limiting steps on the main body are fitted with the annular groove between the support and the drive ring, the contact surface of the drive ring can be increased, which can better prevent the drive ring from deforming due to local stress concentration during the locking process, better ensure the reliability of the drive ring structure, and thus better ensure the smooth realization of the locking and unlocking action.

[0068] The oil well cap delivery tool also includes a safety withdrawal mechanism, which includes a reset compression spring, a central sleeve, and a piston.

[0069] The lower section of the supporting body has an inner cavity with an opening at the lower end, and the central sleeve is inserted and fixed in the mounting hole on the top wall of the inner cavity; the lower end of the central sleeve is located inside the inner cavity and has a circumferentially protruding flange.

[0070] The piston is a cylindrical structure fitted outside the central sleeve, and the top radial inner side of the piston is sealed and slidably connected to the central sleeve, and the top radial outer side of the piston is sealed and slidably connected to the inner cavity sidewall; the top of the piston, the central sleeve and the inner cavity together form an ejection hydraulic cavity, and the top of the supporting body has a hydraulic interface corresponding to and connected to the ejection hydraulic cavity.

[0071] The reset compression spring is fitted outside the central sleeve located inside the piston, with its two ends abutting between the top end plate of the piston and the flange at the bottom of the central sleeve.

[0072] like Figure 1 and Figure 2 As shown, the top of the wellhead is equipped with multiple hydraulic joints that mate with the wellhead cap. This necessitates more precise installation and removal of the wellhead cap from the wellhead to ensure the reliability of each connection. If the tool shakes during lifting, it may damage the structural shape of a connection point, thereby affecting the controllability and efficiency of subsequent oil and gas extraction.

[0073] Therefore, this technical solution incorporates the aforementioned safe withdrawal mechanism. After the wellhead cap is installed on the wellhead, the piston can be driven by hydraulic pressure to slowly and precisely rise, ensuring reliable withdrawal of the tool from the wellhead cap, thus enabling rapid subsequent recovery.

[0074] At the same time, the safety exit mechanism is located inside the load-bearing body, which makes full use of the internal space of the load-bearing body, making the overall structure of the load-bearing body more compact and also helping to reduce the weight of the load-bearing body.

[0075] The oil well cap feeding tool also includes a guide frame, which includes a central mounting cylinder, a cantilever, and a guide funnel;

[0076] The central mounting cylinder is detachably mounted and fixed to the upper exterior of the supporting body;

[0077] At least one pair of cantilever arms are evenly spaced on the outer side of the central mounting cylinder in the circumferential direction. Each cantilever arm has a guide funnel fixedly installed at its outer end, with its axis parallel to the axis of the central mounting cylinder. The upper section of the guide funnel is cylindrical, and the lower section is a funnel-shaped structure with a gradually increasing opening.

[0078] The guide frame supports the tool and the oil well cap, and guides the retrieval below, ensuring the safety of the entire tool during operation;

[0079] The guide funnel serves two main guiding functions: firstly, when the tool is fed in, a guide rope connected to the tree trunk is inserted through the middle of the funnel, and the tool is guided with the assistance of the guide rope; secondly, when the tree trunk cap is connected to the tool and needs to be placed on a transport frame (such as an LRP transport frame), the guide funnel and the guide rod on the transport frame are used to guide and fix the tool.

[0080] In practice, the top edge of the supporting body has a ring of upward-convex connecting protrusions, which are fixedly connected to the central mounting cylinder by a connector.

[0081] The oil well cap delivery tool also includes a level fixedly mounted on the cantilever.

[0082] In practice, it is preferable to fix a crossbeam between two adjacent cantilever arms, and fix the level on the crossbeam.

[0083] The level plays a role in leveling the entire system during the tool lowering process.

[0084] The number of cantilever arms is two pairs. Each cantilever arm has a reinforcing rib fixedly connected to its outer side near the guide funnel. The reinforcing rib has a lifting hole and forms a lifting lug.

[0085] In this way, during operation, the corresponding cantilever can be raised and lowered according to the deviation of the ball on the horizontal instrument panel until the tool is leveled, thereby ensuring precise docking and installation between the tree cap and the tree.

[0086] A horizontally oriented load-bearing plate is fixedly connected between two adjacent cantilever arms near the central mounting cylinder.

[0087] The above-mentioned support plate not only enhances the strength of the entire guide frame structure, but also facilitates standing for the user, making it easier for personnel to align and quickly connect the drill rod and tools.

[0088] During implementation, the load-bearing plate is made of metal mesh.

[0089] In practice, it also includes a spear rod inserted into the bearing body, the lower section of which is confined within the bearing body by a conical surface, and the lower end of the spear rod is sealed and inserted into the central sleeve.

[0090] After setting up the above spear shaft structure, pressure testing can be performed below the wellhead cap before the wellhead cap is recovered. The specific testing steps are as follows:

[0091] 1) Connect the pipeline to the TC CONECTOR BORES TEST port, open the test needle valve, and close the vent needle valve;

[0092] 2) Close the TCT valve and perform a pressure test to confirm the sealing of the interface between the TCRT piston and the TC spear rod. The test pressure is 7500 psi, held for 15 minutes, and then reduced to 200 psi.

[0093] 3) Open the TCT needle valve for 5 minutes and check the pressure leakage of the tree cap dewaxing valve and the tree dewaxing valve;

[0094] 4) Vent the TC CONNECTOR BORES TEST, close the valve to check for leaks in the production tree cap, then open the valve to vent and record the results (error messages should also be recorded).

[0095] 5) After releasing all pressure, turn on the TCV with the ROV.

[0096] The above is a preferred embodiment of the oil well cap delivery tool:

[0097] The oilfield tree cap delivery tool in this technical solution uses hydraulic power to drive the mechanical locking mechanism. There are four hydraulic joints on the upper surface of the supporting body, which serve the functions of locking, unlocking, disconnecting, and testing, respectively.

[0098] The main steps for installing the oil well cap are: connecting the oil well cap to the tool and lowering it → connecting the oil well cap to the oil well → testing the oil well cap and the dewaxing valve of the oil well → disconnecting the tool from the oil well cap and retrieving it.

[0099] The main steps for recovering the tree cap are: connecting the tool to the drill pipe and lowering it → connecting the tool to the tree cap → testing the pressure below the tree cap → disconnecting the tree cap from the tree and recovering it.

[0100] The above are merely preferred embodiments of the present invention. It should be noted that any modifications and improvements made by those skilled in the art without departing from the present technical solution should also be considered to fall within the scope of protection claimed in this claim.

Claims

1. An oil well cap feeding tool, comprising a tool body, characterized in that: The tool body includes a bearing body, a limiting ring, a driving ring, and a bursting ring; The main body of the support is cylindrical in shape, and the top surface has an upwardly protruding hoisting connection joint for connecting with the drill pipe; the outer side of the main body is provided with a series of steps for limiting rings, driving rings and expansion rings with gradually increasing outer diameters from top to bottom; The supporting body is fitted with the limiting ring, the driving ring and the expansion ring in sequence from top to bottom; The limiting ring is fixedly connected to the supporting body; the lower end face of the limiting ring abuts against and limits the limiting ring with a step; The drive ring has an inwardly convex pushing shoulder at the middle of its inner height direction. The pushing shoulder is slidably connected to the outer side of the bearing body located between the step of the limiting ring and the step of the drive ring. The upper annular sealing cavity of the pushing shoulder constitutes a locking cavity for driving the pushing shoulder to move downward, and the lower annular sealing cavity of the pushing shoulder constitutes an unlocking cavity for driving the pushing shoulder to move upward. The top of the supporting body has a hydraulic interface that is connected to the locking cavity and the unlocking cavity one by one; The outer surface of the load-bearing body between the step of the drive ring and the step of the fracturing ring is a fracturing profile, and the outer diameter of the lower section of the fracturing profile is larger than that of the upper section, and the lower section is a conical profile and a cylindrical profile from top to bottom; the fracturing ring is slidably fitted on the fracturing profile, and the lower end face of the drive ring abuts against the upper end face of the fracturing ring; and when the drive ring pushes the fracturing ring onto the cylindrical profile and the lower end of the fracturing ring abuts against the step of the fracturing ring, the radial outer end of the fracturing ring protrudes outside the step of the fracturing ring and forms a locking tooth for engaging in the groove of the oil well cap connection; It also includes a safety exit mechanism, which comprises a reset compression spring, a central sleeve, and a piston; The lower section of the supporting body has an inner cavity with an opening at the lower end, and the central sleeve is inserted and fixed in the mounting hole on the top wall of the inner cavity; the lower end of the central sleeve is located inside the inner cavity and has a circumferentially protruding flange. The piston is a cylindrical structure fitted outside the central sleeve, and the top radial inner side of the piston is sealed and slidably connected to the central sleeve, and the top radial outer side of the piston is sealed and slidably connected to the inner cavity sidewall; the top of the piston, the central sleeve and the inner cavity together form an ejection hydraulic cavity, and the top of the supporting body has a hydraulic interface corresponding to and connected to the ejection hydraulic cavity. The reset compression spring is fitted outside the central sleeve located inside the piston, with its two ends abutting between the top end plate of the piston and the flange at the bottom of the central sleeve.

2. The Christmas tree cap installation tool of claim 1, wherein: It also includes a preload spring and a guide pin; A spring mounting groove for placing the preload spring is provided on the end face directly opposite to the drive ring and the limiting ring. The guide pin is fixedly installed on the upper end face of the drive ring, and the upper section of the guide pin is slidably inserted into the guide hole correspondingly provided on the limit ring.

3. The Christmas tree cap installation tool of claim 1, wherein: On the outer side of the bearing body, at the midpoint of the height direction between the step for the drive ring and the step for the expansion ring, a support and limiting step is provided. The outer diameter of the support and limiting step is larger than the outer diameter of the step for the drive ring and smaller than the outer diameter of the step for the expansion ring. The inner side of the drive ring, located below the push shoulder, has an annular groove for engaging with the support and limiting step.

4. The Christmas tree cap installation tool of claim 1, wherein: It also includes a guide frame, which comprises a central mounting cylinder, a cantilever, and a guide funnel; The central mounting cylinder is detachably mounted and fixed to the upper exterior of the supporting body; At least one pair of cantilever arms are evenly spaced on the outer side of the central mounting cylinder in the circumferential direction. Each cantilever arm has a guide funnel fixedly installed at its outer end, with its axis parallel to the axis of the central mounting cylinder. The upper section of the guide funnel is cylindrical, and the lower section is a funnel-shaped structure with a gradually increasing opening.

5. The Christmas tree cap installation tool of claim 4, wherein: It also includes a level that is fixedly installed on the cantilever.

6. The Christmas tree cap installation tool of claim 4 or 5, characterized in that: The number of cantilever arms is two pairs. Each cantilever arm has a reinforcing rib fixedly connected to its outer side near the guide funnel. The reinforcing rib has a lifting hole and forms a lifting lug.

7. The Christmas tree cap installation tool of claim 4 or 5, characterized in that: A horizontally oriented load-bearing plate is fixedly connected between two adjacent cantilever arms near the central mounting cylinder.

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