A hydraulic casing hanger and seal assembly service tool and method of use

Abstract

This invention provides a hydraulic casing hanger and sealing assembly service tool and its usage method, relating to the field of oil and gas drilling and production technology. The tool includes: a body; an upper hydraulic cylinder fitted onto the upper part of the body; a lower hydraulic cylinder fitted onto the middle part of the body, with a locking ring disposed below the lower hydraulic cylinder; and hydraulic circuitry, including: an upper hydraulic cylinder drive circuit, injecting hydraulic oil to drive the upper hydraulic cylinder to move the sealing assembly suspension ring downwards to install the sealing assembly; an upper hydraulic cylinder reset circuit, injecting hydraulic oil to drive the upper hydraulic cylinder to move the sealing assembly suspension ring upwards; a lower hydraulic cylinder drive circuit, injecting hydraulic oil to drive the lower hydraulic cylinder downwards and force the locking ring to open and lock the casing hanger; and a lower hydraulic cylinder reset circuit, injecting hydraulic oil to drive the lower hydraulic cylinder upwards to allow the locking ring to elastically return to its original shape and separate the casing hanger. This invention enables precise installation of the sealing assembly and reliable locking and separation of the casing hanger, improving operational efficiency and reducing operational risks.

Description

Technical Field

[0001] This invention relates to the field of oil and gas drilling and production technology, and in particular to a hydraulic casing hanger and sealing assembly service tool and its usage method. Background Technology

[0002] As the core equipment for deepwater oil and gas exploration and development, the subsea wellhead consists of key components such as low-pressure wellhead, high-pressure wellhead, casing hanger, and sealing assembly. It needs to be lowered from the floating drilling rig and located at the mudline, mainly undertaking the important functions of supporting the casing string and sealing the annular space between the casing strings.

[0003] In the existing technology, there are usually two ways to install the casing hanger and the sealing assembly: one is to install them in steps using a casing hanger insertion tool and a sealing assembly insertion tool respectively; the other is to install them at once using a casing hanger and sealing assembly insertion tool that integrates the functions of both tools. Depending on the power source, these integrated insertion tools can be divided into mechanical, hydraulic and hydraulically assisted types.

[0004] However, the applicant has found that the prior art has at least the following obvious defects:

[0005] On the one hand, integrated delivery tools have complex structures due to the combination of two tool functions, and are usually only compatible with subsea wellheads with a nominal inner diameter of 18-3 / 4 inches. It is difficult to meet the usage requirements of 13-5 / 8 inch subsea wellheads by simply reducing the size.

[0006] On the other hand, the metal seal between the sealing assembly and the casing hanger and high-pressure wellhead requires an initial pressure of 5-20 thousand pounds to establish an initial seal. However, in water depths of 10-50 meters, the weight of the drill pipe above the service tool cannot provide sufficient downward pressure, making it difficult for the sealing assembly to establish an effective initial seal, which seriously affects the efficiency and safety of subsea wellhead operations.

[0007] Therefore, there is an urgent need for a hydraulic sleeve hanger and sealing assembly service tool and its usage method to solve the above-mentioned technical problems. Summary of the Invention

[0008] The purpose of this invention is to provide a hydraulic casing hanger and sealing assembly service tool and its usage method. Using hydraulic power as the power source, and through precise control of the hydraulic cylinder's movement, it achieves the locking and unlocking of the 13-5 / 8 inch subsea wellhead casing hanger and the installation and separation of the sealing assembly. It also solves the problem of insufficient drill pipe weight in shallow sea operations, which prevents the initial sealing pressure of the sealing assembly from being met. Furthermore, it eliminates the need for rotating or moving tools, simplifying the drilling platform operation process. The numerous technical effects of the preferred technical solutions provided by this invention are detailed below.

[0009] To achieve the above objectives, the present invention provides the following technical solution:

[0010] This invention provides a hydraulic sleeve hanger and sealing assembly service tool, characterized in that it includes:

[0011] ontology;

[0012] An upper hydraulic cylinder is sleeved on the upper part of the body and is used to link with the suspension ring of the sealing assembly. The outer surface of the suspension ring of the sealing assembly is provided with a suspension ring groove, and a shear pin for suspending the sealing assembly is installed in the suspension ring groove.

[0013] A lower hydraulic cylinder is sleeved in the middle of the body. A locking ring is provided below the lower hydraulic cylinder. The inner side of the locking ring is provided with a protrusion that matches the groove on the outer wall of the sleeve hanger. The locking connection with the sleeve hanger is achieved by the protrusion engaging with the groove.

[0014] The hydraulic circuit includes the upper hydraulic cylinder drive circuit, the upper hydraulic cylinder reset circuit, the lower hydraulic cylinder drive circuit, and the lower hydraulic cylinder reset circuit, wherein:

[0015] The upper hydraulic cylinder drive circuit is connected to the upper chamber of the upper hydraulic cylinder. Injecting hydraulic oil can drive the upper hydraulic cylinder to move the sealing assembly suspension ring down to install the sealing assembly.

[0016] The upper hydraulic cylinder reset circuit is connected to the lower chamber of the upper hydraulic cylinder. Injecting hydraulic oil can drive the upper hydraulic cylinder to move the sealing assembly suspension ring upward.

[0017] Once the sealing assembly is installed in place, the inner surface of the sealing assembly deforms and establishes a seal and lock with the sleeve hanger. Lifting the tool or pressing through the upper hydraulic cylinder reset line can cut the shearing pin, causing the sealing assembly suspension ring to separate from the sealing assembly.

[0018] The lower hydraulic cylinder drive circuit is connected to the upper chamber of the lower hydraulic cylinder. Injecting hydraulic oil can drive the lower hydraulic cylinder to move down and force the locking ring to open to lock the sleeve hanger.

[0019] The lower hydraulic cylinder reset circuit is connected to the lower chamber of the lower hydraulic cylinder. Injecting hydraulic oil can drive the lower hydraulic cylinder to move upward, so that the locking ring can elastically return to its original state to separate the sleeve hanger.

[0020] Preferably, it also includes a blowout preventer sealing suspension section, wherein a blowout preventer sealing surface is provided in the middle of the outer surface of the blowout preventer sealing suspension section, for use in conjunction with the gate blowout preventer or universal blowout preventer to construct a temporary closed space required for the sealing assembly to be sealed.

[0021] Preferably, it also includes a spur extension section, wherein the blowout preventer sealing suspension section is connected to the body via the spur extension section.

[0022] Preferably, it further includes an upper hydraulic cylinder sealing end cap and a lower hydraulic cylinder sealing end cap, wherein:

[0023] The sealing end cap of the upper hydraulic cylinder is used to connect and seal the body and the upper hydraulic cylinder;

[0024] The sealing end cap of the lower hydraulic cylinder is used to connect and seal the body and the lower hydraulic cylinder.

[0025] Preferably, it further includes a sealing gasket ring, which is disposed at the lower part of the body. The inner side of the sealing gasket ring is in sealing engagement with the body, and the outer side of the sealing gasket ring is in sealing engagement with the sleeve hanger.

[0026] Preferably, it also includes a limiting ring, which is sleeved on the outside of the body and located below the sealing gasket ring, for limiting the position of the body and the sealing gasket ring.

[0027] Preferably, the limiting ring comprises a symmetrical two-lobed structure.

[0028] Preferably, the hydraulic lines all include hydraulic hoses and connectors and hydraulic metal pipes and connectors, and the blowout preventer sealing suspension section and the body are respectively provided with a first through hole and a second through hole; the first through hole and the second through hole are respectively used to pass through the hydraulic lines so as to allow hydraulic oil to flow.

[0029] A method of using the above-mentioned hydraulic sleeve hanger and sealing assembly service tool, characterized by comprising the following steps:

[0030] S1: Before the operation begins, perform a functional test on the service tools on the deck, connect the manual pumps to the hydraulic lines respectively, and verify the pressing and resetting actions of the upper and lower hydraulic cylinders;

[0031] S2: Connect the casing string to the casing hanger, and after grouting, seat the casing string on the casing slip on the drilling platform;

[0032] S3: Connect the cementing components below the service tool, then connect the service tool to the sealing assembly and seat it on the casing hanger;

[0033] S4: Connect and secure the hydraulic hose and connector, and pressurize the line by driving the lower hydraulic cylinder to lock the service tool and the sleeve together;

[0034] S5: Lower the casing to the high-pressure wellhead to complete the cementing circulation and cementing operation;

[0035] S6: Install the sealing assembly by pressurizing the circuit driven by the upper hydraulic cylinder, and check the seal of the sealing assembly by closing the blowout preventer;

[0036] S7: Depressurization opens the blowout preventer. Pressure is applied through the upper and lower hydraulic cylinder reset lines to separate the service tool from the sealing assembly and the sleeve hanger, allowing the service tool to be recovered.

[0037] Preferably, in step S5, the casing is lowered to the high-pressure wellhead using the drill pipe.

[0038] This invention provides a hydraulic casing hanger and sealing assembly service tool and its usage method. Through the combination of upper and lower hydraulic cylinders and a suitable hydraulic circuit, it enables precise installation of the sealing assembly and reliable locking and disengagement of the casing hanger, meeting the installation requirements for 13-5 / 8 inch subsea wellheads in a single drilling run. No tool changes are required, significantly improving operational efficiency. The multiple sealing structures of the upper and lower hydraulic cylinders, along with the high-pressure-resistant and corrosion-resistant hydraulic pipeline materials, effectively prevent hydraulic oil leakage, ensuring stable operation of the tool in marine environments with water depths of 10-50 meters and reducing the risk of operational failure. Attached Figure Description

[0039] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0040] Figure 1 This is a schematic diagram of a service tool for a hydraulic sleeve hanger and sealing assembly according to an embodiment of the present invention.

[0041] In the diagram: 1. Blowout preventer sealing suspension section; 2. Body; 3. Upper hydraulic cylinder sealing end cap; 4. Upper hydraulic cylinder; 5. Sealing assembly suspension ring; 501. Shear pin; 502. Suspension ring groove; 6. Lower hydraulic cylinder sealing end cap; 7. Lower hydraulic cylinder; 8. Locking ring; 9. Sealing gasket ring; 10. Limiting ring; 11. Hydraulic hose and connector; 12. Hydraulic metal pipe and connector; 13. Extension section; 101. First through hole; 102. Sealing surface; 201. Second through hole; E1. Drill rod; E2. Sealing assembly; E3. Casing hanger; L1. Upper hydraulic cylinder drive circuit; L2. Upper hydraulic cylinder reset circuit; L3. Lower hydraulic cylinder drive circuit; L4. Lower hydraulic cylinder reset circuit. Detailed Implementation

[0042] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0043] In the description of this invention, it should be understood that the terms "center," "side," "length," "width," "height," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," and "side," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0044] In the description of this invention, it should also be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0045] Figure 1 This is a structural schematic diagram of this embodiment, as shown below. Figure 1 As shown, this embodiment provides a hydraulic sleeve hanger and sealing assembly service tool, including a blowout preventer seal suspension stub 1, a body 2, an upper hydraulic cylinder sealing end cap 3, an upper hydraulic cylinder 4, a sealing assembly suspension ring 5, a lower hydraulic cylinder sealing end cap 6, a lower hydraulic cylinder 7, a locking ring 8, a sealing gasket ring 9, a limit ring 10, a hydraulic hose and connector 11, a hydraulic metal pipe and connector 12, a lengthening stub 13, and hydraulic lines.

[0046] The main body 2 has a second through hole 201, which is adapted to the hydraulic metal pipe and connector 12 for passing through the hydraulic line and providing a channel for the hydraulic oil to flow between the upper hydraulic cylinder 4 and the lower hydraulic cylinder 7. In this embodiment, the main body 2 is made of high-strength alloy material to ensure that it is not easily deformed when bearing the weight of the casing string, hydraulic pressure and other loads, and to meet the strength requirements of underwater wellhead operation.

[0047] The upper hydraulic cylinder 4 is sleeved on the upper part of the main body 2 and is used to link with the sealing assembly suspension ring 5. In this embodiment, the upper hydraulic cylinder 4 includes a cylinder barrel, a piston, and a piston rod. The lower end of the piston rod is connected to the sealing assembly suspension ring 5 by a thread to ensure the stability of the linkage. The inner wall of the cylinder barrel is provided with a precision sealing groove and a built-in high temperature and high pressure resistant sealing ring to prevent hydraulic oil leakage and ensure that the upper hydraulic cylinder 4 works normally within the hydraulic drive pressure range required for operation.

[0048] The outer surface of the suspension ring 5 of the sealing assembly is provided with a suspension ring groove. The sealing assembly E2 is provided with a ring of shear pin mounting threaded holes. The shear pin 501 is installed in the suspension ring groove to suspend the sealing assembly. The shear pin 501 has a shear value of approximately 3.5 tons per shear pin, and there are 4 of them to prevent them from falling off during the installation of the sealing assembly E2.

[0049] The lower hydraulic cylinder 7 is sleeved in the middle of the body 2, and a locking ring 8 is provided below the lower hydraulic cylinder 7. In this embodiment, the structure of the lower hydraulic cylinder 7 is the same as that of the upper hydraulic cylinder 4, which also includes a cylinder barrel, a piston, and a piston rod. The contact part between the lower end of the piston rod and the locking ring 8 adopts an arc transition design to ensure that the lower hydraulic cylinder 7 can smoothly push the locking ring 8 open when it moves down. A multi-seal structure is provided at the joint between the cylinder barrel and the body 2 to further improve the sealing performance and prevent hydraulic oil leakage from affecting the operating accuracy of the lower hydraulic cylinder 7.

[0050] The locking ring 8 is made of a highly elastic alloy material. Its inner side has a protrusion that matches the groove on the outer wall of the sleeve hanger E3. The surface of the protrusion is hardened to improve wear resistance. The locking ring 8 is initially in a contracted state. When the lower hydraulic cylinder 7 moves downward and compresses, it can evenly open and lock tightly with the sleeve hanger E3. After the pressure from the lower hydraulic cylinder 7 is lost, it quickly returns to its contracted state due to its own elasticity, achieving separation from the sleeve hanger E3. By using a highly elastic alloy material and hardening it, the locking ring 8 not only achieves a firm lock with the sleeve hanger E3 but also quickly returns to its original shape upon reset, ensuring smooth separation, reducing damage to the sleeve hanger E3, and extending its service life.

[0051] The hydraulic circuit includes an upper hydraulic cylinder drive circuit L1, an upper hydraulic cylinder reset circuit L2, a lower hydraulic cylinder drive circuit L3, and a lower hydraulic cylinder reset circuit L4. Specifically: the upper hydraulic cylinder drive circuit L1 is connected to the upper chamber of the upper hydraulic cylinder 4; injecting hydraulic oil drives the upper hydraulic cylinder 4 to move the sealing assembly suspension ring 5 downwards to install the sealing assembly E2; the upper hydraulic cylinder reset circuit L2 is connected to the lower chamber of the upper hydraulic cylinder 4; injecting hydraulic oil drives the upper hydraulic cylinder 4 to move the sealing assembly suspension ring 5 upwards; the lower hydraulic cylinder drive circuit L3 is connected to the upper chamber of the lower hydraulic cylinder 7; injecting hydraulic oil drives the lower hydraulic cylinder 7 downwards and forces the locking ring 8 to open, thus locking the sleeve hanging E3; the lower hydraulic cylinder reset circuit L4 is connected to the lower chamber of the lower hydraulic cylinder 7; injecting hydraulic oil drives the lower hydraulic cylinder 7 upwards, allowing the locking ring 8 to elastically return to its original shape, thus separating the sleeve hanging E3. Once the sealing assembly E2 is installed in place, the inner surface of the sealing assembly E2 deforms and establishes a seal and lock with the sleeve hanger E3. The tool is lifted or the pressure is applied through the upper hydraulic cylinder reset line L2 to cut the shear pin, thereby separating the sealing assembly suspension ring 5 from the sealing assembly.

[0052] In this embodiment, the hydraulic circuits all include hydraulic hoses and connectors 11 and hydraulic metal pipes and connectors 12. The hydraulic hoses and connectors 11 are made of rubber material that is resistant to high pressure and seawater corrosion. Anti-loosening buckles are provided at the connectors to prevent the connectors from falling off due to vibration during operation. The hydraulic metal pipes and connectors 12 are made of stainless steel, which has good pressure resistance and corrosion resistance. The diameter of the metal pipe is precisely designed according to the hydraulic oil flow requirements to ensure smooth hydraulic oil flow and no significant pressure loss.

[0053] This hydraulic casing hanger and sealing assembly service tool, through the combination of upper hydraulic cylinder 4 and lower hydraulic cylinder 7 and a suitable hydraulic circuit, can accurately install the sealing assembly E2 and reliably lock and release the casing hanger E3, meeting the installation requirements for 13-5 / 8 inch subsea wellheads in a single drilling run. No tool changes are required, significantly improving operational efficiency. Furthermore, the tool does not require rotation or movement during use, facilitating the installation and layout of cementing hydraulic lines on the drilling rig. The multiple sealing structures of upper hydraulic cylinder 4 and lower hydraulic cylinder 7, along with the high-pressure-resistant and corrosion-resistant hydraulic line materials, effectively prevent hydraulic oil leakage, ensuring stable operation in marine environments with water depths of 10-50 meters and reducing the risk of operational failure.

[0054] Specifically, a first through hole 101 is provided inside the blowout preventer sealing suspension section 1 for the passage of hydraulic lines, providing a channel for the flow of hydraulic oil between the upper hydraulic cylinder 4 and the lower hydraulic cylinder 7. The number of first through holes 101 corresponds to the number of hydraulic lines; in this embodiment, there are four. The diameter of the first through holes 101 is adapted to the outer diameter of the hydraulic hose and connector 11, ensuring that the hydraulic hose can pass through smoothly. Simultaneously, the inner wall of the first through hole 101 is smoothed to reduce wear on the hydraulic hose during installation and use.

[0055] The outer surface of the blowout preventer sealing suspension section 1 is provided with a blowout preventer sealing surface 102, which is used to cooperate with the blowout preventer gate blowout preventer or universal blowout preventer to construct the temporary closed space required for the sealing assembly E2 to be sealed. No additional sealing structure is required, which simplifies the sealing process and shortens the operation time.

[0056] When the blowout preventer (BOP) is closed, the gate of the gate BOP or the rubber core of the universal BOP can tightly wrap the BOP sealing surface 102 of the BOP sealing suspension section 1. The gate or rubber core is made of high-pressure resistant and wear-resistant rubber or alloy material, and the shape of the part in contact with the sealing surface 102 is completely matched with the contour of the sealing surface 102 to ensure a gapless seal. It can withstand the pressure required for sealing verification, avoid safety hazards in subsequent wellhead operations due to poor sealing, and improve the safety of underwater wellhead operations.

[0057] In this embodiment, the blowout preventer (BOP) sealing suspension section 1 is connected to the body 2 via an extension section 13. The length of the extension section 13 can be customized according to the actual installation distance between the BOP sealing suspension section 1 and the body 2 to meet the installation size requirements under different operating scenarios. Preferably, the extension section 13 is threadedly connected to the BOP sealing suspension section 1 and the body 2. A metal sealing ring or a high-strength rubber sealing ring is provided at the threaded connection between the extension section 13 and the BOP sealing suspension section 1 and the body 2. The cross-sectional shape of the sealing ring or sealing ring is designed according to the thread sealing requirements and can be V-shaped, O-shaped, etc., to ensure the sealing performance of the connection, prevent drilling fluid or seawater from entering the connection gap, corroding the threads, affecting the connection strength and tool life, reducing maintenance costs, and ensuring the overall stability of the tool during operation to avoid operational accidents caused by connection problems.

[0058] In this embodiment, the upper hydraulic cylinder sealing end cap 3 is used to connect and seal the body 2 and the upper hydraulic cylinder 4; the lower hydraulic cylinder sealing end cap 6 is used to connect and seal the body 2 and the lower hydraulic cylinder 7.

[0059] The upper hydraulic cylinder sealing end cap 3 has an annular structure, with its inner diameter matching the outer diameter of the body 2 and its outer diameter matching the inner diameter of the upper hydraulic cylinder 4. Sealing grooves are provided at the contact points between the upper hydraulic cylinder sealing end cap 3 and the body 2 and the upper hydraulic cylinder 4, respectively, and a high-pressure, high-temperature resistant combined sealing ring is installed inside. The lower hydraulic cylinder sealing end cap 6 also has an annular structure, with its inner diameter matching the outer diameter of the body 2 and its outer diameter matching the inner diameter of the lower hydraulic cylinder 7. Sealing grooves are provided at the contact points between the lower hydraulic cylinder sealing end cap 6 and the body 2 and the lower hydraulic cylinder 7, respectively, and a high-pressure, high-temperature resistant combined sealing ring is installed inside.

[0060] By installing an upper hydraulic cylinder sealing end cap 3 to connect and seal the body 2 and the upper hydraulic cylinder 4, and a lower hydraulic cylinder sealing end cap 6 to connect and seal the body 2 and the lower hydraulic cylinder 7, hydraulic oil leakage from the connection points is prevented during hydraulic cylinder operation. This ensures the normal operating pressure of the hydraulic cylinders and guarantees the accuracy and reliability of the sealing assembly E2 installation and the sleeve locking action E3. This reduces tool repair frequency and downtime caused by sealing end cap damage or seal failure, lowers operating costs, and improves overall operating efficiency.

[0061] In this embodiment, the sealing gasket 9 is located at the lower part of the body 2. The inner side of the sealing gasket 9 is sealed to the body 2, and the outer side of the sealing gasket 9 is sealed to the casing hanger E3. Specifically, the sealing gasket 9, the body 2, and the casing hanger E3 all adopt an interference fit, which can effectively construct the temporary closed space required for the sealing assembly E2 to be tested. Moreover, the sealing performance of the closed space is excellent, with no leakage under the test pressure, ensuring the accuracy of the test results and providing a guarantee for the safe conduct of subsequent wellhead operations.

[0062] The limiting ring 10 is sleeved on the outside of the body 2 and located below the sealing gasket 9, and is used to limit the movement of the body 2 and the sealing gasket 9. In this embodiment, the limiting ring 10 includes a symmetrical two-lobed structure, both lobes being semi-circular. Each lobed limiting ring has connecting ear plates at both ends, with bolt holes on the ear plates for fixed connection by bolts.

[0063] During installation, after the limiting ring 10 is fitted onto the outside of the main body 2, the connecting ear plates of the two halves of the structure are fastened together by high-strength bolts. The preload of the bolts is precisely controlled according to the design requirements to ensure the overall structural integrity of the limiting ring. The installation position of the limiting ring on the main body 2 is precisely positioned by a scale or positioning mark to ensure that it can accurately limit the main body 2 and the sealing ring 9, preventing the main body 2 from moving down excessively or the sealing ring 9 from shifting during operation.

[0064] A method of using the above-mentioned hydraulic sleeve hanger and sealing assembly service tool includes the following steps:

[0065] S1: Before the operation begins, perform a functional test on the service tools on the deck, connect the manual pumps to the hydraulic lines respectively, and verify the pressing and resetting actions of the upper hydraulic cylinder 4 and the lower hydraulic cylinder 7.

[0066] First, before the operation begins, the service tool is functionally tested on the deck. A manual pump is connected to the upper hydraulic cylinder drive line L1, the upper hydraulic cylinder reset line L2, the lower hydraulic cylinder drive line L3, and the lower hydraulic cylinder reset line L4 respectively. The hydraulic cylinders are controlled by the manual pump. The state of the hydraulic cylinders can be accurately determined by the pumped liquid pressure and volume. The pressing down and resetting of the upper hydraulic cylinder 4 and the lower hydraulic cylinder 7 of the service tool can be verified in sequence.

[0067] S2: Connect the casing string to the casing hanger E3, and after grouting, sit the casing string on the casing slip on the drilling platform.

[0068] After the test is completed, in accordance with the operation requirements, connect the lowered casing string and casing hanger E3 and grout regularly. The casing string is then placed on the casing slip on the drilling platform.

[0069] S3: Connect the cementing components below the service tool, then connect the service tool to the sealing assembly E2 and sit on the casing hanger E3;

[0070] During construction, the service tool is transported to the drilling platform, and the cementing inner string or cementing plug is connected and lowered below the service tool. The service tool is then connected to the sealing assembly E2, and the service tool is seated on the casing and hung on E3.

[0071] S4: Connect and secure the hydraulic hose and connector 11, and use the lower hydraulic cylinder to drive the circuit L3 to pressurize and lock the service tool and the sleeve to E3.

[0072] In this embodiment, firstly, the four hydraulic hoses and connectors 11 of the service tool are connected and secured on the drill rod E1 with clamps or hemp rope; then, the manual pump is connected to the lower hydraulic cylinder drive line L3, and pressure is applied to lock the service tool and casing E3 together.

[0073] S5: Lower the casing and hang E3 to the high-pressure wellhead to complete the cementing circulation and cementing operation;

[0074] Specifically, the casing hanger E3 is lowered to the high-pressure wellhead via drill pipe E1, and the casing is then placed at the high-pressure wellhead.

[0075] S6: Pressurize and install sealing assembly E2 by driving line L1 with upper hydraulic cylinder, and close the blowout preventer to verify the seal of sealing assembly E2;

[0076] This includes: before the cement hardens, connecting the manual pump to the upper hydraulic cylinder drive line L1, pressurizing and installing the sealing assembly, and establishing an initial seal; closing the blowout preventer, making the blowout preventer seal suspension section 1 seal with the universal blowout preventer or gate blowout preventer, and verifying the seal assembly through the blowout preventer test pressure line.

[0077] S7: Depressurize and open the blowout preventer. Pressurize via the upper hydraulic cylinder reset line L2 and the lower hydraulic cylinder reset line L4 to separate the service tool from the sealing assembly E2 and the sleeve hanger E3, and recover the service tool.

[0078] The specific operating procedure is as follows: depressurize, open the blowout preventer, connect the manual pump to the upper hydraulic cylinder reset line L2, pressurize to separate the service tool from the sealing assembly; then, connect the manual pump to the lower hydraulic cylinder reset line L4, pressurize to separate the service tool from the casing hanger, and retrieve the service tool.

[0079] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A hydraulic casing hanger and seal assembly servicing tool, suitable for 13-5 / 8 inch subsea wellheads operating in a water depth of 10-50 meters, characterized in that, Comprise: The body (2); Upper hydraulic cylinder (4), set in the upper part of the body (2), used for linkage with sealing assembly suspension ring (5), the outer surface of sealing assembly suspension ring (5) is provided with suspension ring groove (502), the shear pin (501) for suspending sealing assembly (E2) is installed in the suspension ring groove (502); Lower hydraulic cylinder (7), set in the middle part of the body (2), the lower part of the lower hydraulic cylinder (7) is provided with a lock ring (8), the inner side of the lock ring (8) is provided with a protrusion matched with the outer wall of the sleeve hanger (E3) clamping groove, the sleeve hanger (E3) is locked and connected by the protrusion and the clamping groove. Hydraulic circuit, including upper hydraulic cylinder drive circuit (L1), upper hydraulic cylinder reset circuit (L2), lower hydraulic cylinder drive circuit (L3), lower hydraulic cylinder reset circuit (L4), wherein: The upper hydraulic cylinder drive circuit (L1) is communicated with the upper part of the upper hydraulic cylinder (4) chamber, and the injection of hydraulic oil can drive the upper hydraulic cylinder (4) to drive the sealing assembly suspension ring (5) to move down and install the sealing assembly (E2); The upper hydraulic cylinder reset circuit (L2) is communicated with the lower part of the upper hydraulic cylinder (4) chamber, and the injection of hydraulic oil can drive the upper hydraulic cylinder (4) to drive the sealing assembly suspension ring (5) to move up; When the sealing assembly (E2) is installed in place, the inner surface of the sealing assembly (E2) is deformed to establish sealing and locking with the sleeve hanger (E3), the upper lifting tool or through the upper hydraulic cylinder reset circuit (L2) is pressed, the shear pin (501) can be cut off, so that the sealing assembly suspension ring (5) is separated from the sealing assembly (E2); The lower hydraulic cylinder drive circuit (L3) is communicated with the upper part of the lower hydraulic cylinder (7) chamber, and the injection of hydraulic oil can drive the lower hydraulic cylinder (7) to move down and force the lock ring (8) to open to lock the sleeve hanger (E3); The lower hydraulic cylinder reset circuit (L4) is communicated with the lower part of the lower hydraulic cylinder (7) chamber, and the injection of hydraulic oil can drive the lower hydraulic cylinder (7) to move up, so that the lock ring (8) restores to the original state by elasticity to separate the sleeve hanger (E3).

2. The hydraulic casing hanger and seal assembly service tool of claim 1, wherein: It also includes a blowout preventer sealing suspension nipple (1), the outer surface of the blowout preventer sealing suspension nipple (1) is provided with a blowout preventer sealing surface (102) in the middle, which is used for cooperation with the gate blowout preventer or universal blowout preventer of the blowout preventer, so as to build the temporary closed space required for sealing assembly (E2) sealing test.

3. The hydraulic casing hanger and seal assembly service tool of claim 2, wherein: It also includes a length matching nipple (13), the blowout preventer sealing suspension nipple (1) is connected with the body (2) through the length matching nipple (13).

4. The hydraulic casing hanger and packoff assembly service tool of any one of claims 1-3, wherein, It also includes upper hydraulic cylinder sealing end cover (3) and lower hydraulic cylinder sealing end cover (6), wherein: The upper hydraulic cylinder sealing end cover (3) is used for connecting and sealing the body (2) and the upper hydraulic cylinder (4); The lower hydraulic cylinder sealing end cover (6) is used for connecting and sealing the body (2) and the lower hydraulic cylinder (7).

5. The hydraulic casing hanger and packoff assembly service tool of any of claims 1-3, wherein: It also includes a sealing gasket ring (9), which is arranged in the lower part of the body (2), the inner side of the sealing gasket ring (9) is sealingly matched with the body (2), and the outer side of the sealing gasket ring (9) is sealingly matched with the sleeve hanger (E3).

6. The hydraulic casing hanger and seal assembly service tool of claim 5, wherein: The limiting ring (10) is sleeved outside the body (2) and is located at the lower part of the sealing gasket ring (9) to limit the body (2) and the sealing gasket ring (9).

7. The hydraulic casing hanger and seal assembly service tool of claim 6, wherein: The limiting ring (10) comprises a symmetrical two-limb structure.

8. The hydraulic casing hanger and packoff assembly service tool of claim 1, wherein: The hydraulic circuit comprises a hydraulic hose and joint (11) and a hydraulic metal pipe and joint (12), and the blowout preventer sealing suspension short section (1) and the body (2) are respectively provided with a first through hole (101) and a second through hole (201); the first through hole (101) and the second through hole (201) are respectively used for penetrating the hydraulic circuit to make the hydraulic oil flow.

9. A method of using a hydraulic casing hanger and packoff assembly service tool according to any of claims 1-8, wherein, The method comprises the following steps: S1: Before starting the operation, the function of the service tool is tested on the deck, the manual pump is connected to the hydraulic circuit, and the pressing and resetting actions of the upper hydraulic cylinder (4) and the lower hydraulic cylinder (7) are verified; S2: The casing string is connected with the casing hanger (E3), and after grouting, the casing string is seated on the drilling platform casing slip; S3: The service tool is connected with the cementing component below the service tool, and then the service tool is connected with the sealing assembly (E2) and is seated on the casing hanger (E3); S4: The hydraulic hose and joint (11) are connected and fixed, the service tool is locked with the casing hanger (E3) by pressing the lower hydraulic cylinder driving line (L3); S5: The casing hanger (E3) is lowered to the high-pressure well mouth, and the cementing cycle and the cement injection operation are completed; S6: The sealing assembly (E2) is installed by pressing the upper hydraulic cylinder driving line (L1), and the sealing assembly (E2) is sealed by closing the blowout preventer; S7: The blowout preventer is opened, the service tool is separated from the sealing assembly (E2) and the casing hanger (E3) by pressing the upper hydraulic cylinder resetting line (L2) and the lower hydraulic cylinder resetting line (L4), and the service tool is recovered.

10. The method of using a hydraulic casing hanger and packoff assembly service tool of claim 9, wherein: In step S5, the casing hanger (E3) is lowered to the high-pressure well mouth through the drill pipe (E1).

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