A wellhead casing head

Abstract

The utility model provides a kind of wellhead casing head, comprising: the main body being configured as hollow inside, fixture being fixedly arranged in the inside of main body and being used to connect casing, and the first sliding clamping portion being connected in the lower surface of fixture, the first inner wall of main body is segmented and configured as: the first arc surface of gradually increasing inner diameter along the direction of approaching fixture, the first sliding clamping portion is configured as wedge and its side portion is in contact with the first arc surface.The utility model can improve the efficiency of oil and gas well serious well control emergency rescue emergency disposal, reduce the safety risk of operating personnel.

Description

Technical Field

[0001] This utility model belongs to the field of wellhead emergency repair technology, specifically, it relates to a wellhead casing head. Background Technology

[0002] Casing heads are typically used to fix the wellhead, connect the wellhead casing, support the technical casing and the oil layer casing, seal the annular space between different casing layers, and provide a transition connection for installing blowout preventers, tubing heads, and Christmas trees. Through the two side openings on the casing head body, drilling operations such as mud filling, monitoring, and adding balancing fluid can be performed.

[0003] When the casing head is damaged due to a blowout, the operators need to install a new wellhead casing head on site. The main devices currently used are: split-type emergency casing head, gravity self-sealing emergency device, and casing snap-in forced-blowing device. When operating the above devices or using the above methods, the operators are close to the out-of-control wellhead, which poses a great safety risk. Summary of the Invention

[0004] One objective of this invention is to provide a wellhead casing head that allows operators to stay away from the out-of-control wellhead during emergency repairs, thereby improving the efficiency of emergency response to severe well control issues in oil and gas wells and reducing the safety risks to operators.

[0005] According to this utility model, a wellhead casing head is provided, comprising: a hollow body, a clamp fixedly disposed inside the body for engaging the casing, and a first sliding engagement portion engaged with the lower surface of the clamp. The first inner wall of the body is segmented into a first arcuate surface whose inner diameter gradually increases along the direction of the clamp. The first sliding engagement portion is wedge-shaped and its side abuts against the first arcuate surface. The clamp includes: a driving mechanism and a chuck disposed in a flange hole of the casing head flange and whose lower surface engages with a wedge-shaped slip. The inner wall of the chuck is uniformly provided with a plurality of grooves along the circumference. The driving mechanism is disposed inside the grooves. The driving mechanism includes: a tooth disposed in the groove along the outer periphery of the casing, a piston rod whose first end is connected to the side of the tooth away from the casing, and a piston cylinder connected to the second end of the piston rod. The piston cylinder is connected to a grease injection mechanism for injecting grease into it.

[0006] In a preferred embodiment, the lower surface of the clamp is provided with a T-shaped groove, and the top of the first sliding engagement portion is engaged within the T-shaped groove.

[0007] In a preferred embodiment, a limit spring is provided between the lower surface of the clamp and the upper surface of the first sliding engagement portion.

[0008] In a preferred embodiment, the main body further includes: a second inner wall segment integral with the bottom end of the first inner wall segment, wherein the inner diameter of the second inner wall segment remains unchanged and is the same as the inner diameter of the bottom end of the first inner wall segment.

[0009] In a preferred embodiment, the main body further includes a third inner wall segment integral with the bottom end of the second inner wall segment, the third inner wall segment being configured as a second arcuate surface with an inner diameter that gradually increases along a direction away from the second inner wall segment, and the wellhead casing head further includes a second sliding engagement portion configured as a wedge and having its side abutting against the second arcuate surface, and a clamp support base disposed on the lower surface of the second sliding engagement portion.

[0010] In a preferred embodiment, the second inner wall segment is provided with a plurality of sealing grooves along the axial direction. The sealing grooves are connected to a grease injection pipe with its first end passing through the inside of the second inner wall segment. The second end of the grease injection pipe is located outside the wellhead casing head.

[0011] In a preferred embodiment, the first end extends into an injection pipe between two adjacent sealing grooves in the axial direction, and the second end of the injection pipe is disposed outside the wellhead casing head.

[0012] In a preferred embodiment, the wellhead casing head further includes: a pressure pipe with a first end extending to the second inner wall segment, the second end of the pressure pipe being disposed outside the wellhead casing head, and a pressure gauge being disposed thereon.

[0013] In a preferred embodiment, the main body includes: a sleeve head body and a sleeve head flange fixedly disposed on the top of the sleeve head body.

[0014] In a preferred embodiment, the casing head flange is connected to the bottom flange of the drilling crossover, and the top flange of the drilling crossover is connected to the lower flange of the gate blowout preventer.

[0015] This utility model has at least the following technical effects: According to the wellhead casing head described in this utility model, the outer surface of the casing is secured by the jaws of a remotely driven clamp. Since the clamp engages with the casing and the first sliding engagement part engages with the lower surface of the clamp, the first sliding engagement part is restricted by the clamp and cannot move upwards. Furthermore, because the first inner wall of the main body is segmented into a first arc-shaped surface with an inner diameter gradually increasing towards the clamp direction, the first sliding engagement part is constructed as a wedge, with its side abutting against the first arc-shaped surface. During the upward movement of the wellhead casing head, the first sliding engagement part moves towards the casing with a lateral force and engages the casing. The greater the upward lifting force applied by the rotary drilling rig, the greater the engaging force applied by the first sliding engagement part to the casing, further restricting the upward movement of the wellhead casing head. Throughout the process, rescue personnel remain away from the out-of-control wellhead, improving the efficiency of emergency response to severe well control issues in oil and gas wells and reducing the safety risks to personnel. Attached Figure Description

[0016] Figure 1 A schematic diagram of the overall structure of a wellhead casing head according to an embodiment of the present invention is shown. Figure 2 A schematic diagram of the structure of a wellhead casing head chuck according to an embodiment of the present invention is shown. Figure 3 A schematic diagram of a grease injection mechanism according to an embodiment of the present invention is shown. Figure 4 A schematic diagram of a chuck anti-fall mechanism for a wellhead casing head according to an embodiment of the present invention is shown.

[0017] In this application, all the accompanying drawings are schematic drawings, used only to illustrate the principle of the present invention, and are not drawn to scale. Detailed Implementation

[0018] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0019] In the description of the utility model, it should be understood that the terms "inner" and "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the utility model 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 the utility model.

[0020] In this utility model, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral part; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0021] like Figures 1 to 2 As shown, this utility model provides a wellhead casing head 100, which is disposed on the outer periphery of the casing. It includes: a main body 1 with a hollow interior, a clamp 3 fixedly disposed inside the main body 1 for clamping the casing, and a first sliding engagement part 2 that is clamped to the lower surface of the clamp 3. The first inner wall of the main body 1 is segmented into a first arc-shaped surface with an inner diameter that gradually increases in the direction approaching the clamp 3. The first sliding engagement part 2 is constructed in a wedge shape and its side abuts against the first arc-shaped surface.

[0022] In one or more embodiments, the clamp 3 includes: a drive mechanism and a chuck a disposed in a flange hole of the sleeve head flange c. The lower surface of the chuck a engages with a first sliding engagement portion 2. The inner wall of the chuck a has a plurality of grooves b evenly distributed circumferentially. The drive mechanism is disposed inside the grooves b. The drive mechanism includes: a chuck d disposed in the groove b along the outer periphery of the sleeve; a piston rod e whose first end is connected to the side of the chuck d away from the sleeve; and a piston cylinder f connected to the second end of the piston rod e. The piston cylinder f is connected to an external grease injection mechanism for injecting grease into it. Optionally, the chuck a is constructed as an annular ring.

[0023] The following is a brief description of the usage process of the wellhead casing head 100 described in this utility model. After the wellhead casing head 100 is aligned with the casing inside the well and lowered to the designated position by a rotary drilling rig, the jaws d of the remote-driven clamp 3 are used to clamp the outer surface of the casing. Then, the rotary drilling rig drives the drilling cross-connector and the gate blowout preventer to be lifted. The wellhead casing head 100 moves upward a short distance along with the drilling cross-connector. Since the clamp 3 is engaged with the casing and the first sliding engagement part 2 is engaged with the lower surface of the clamp 3, the first sliding engagement part 2 is restricted by the clamp 3 and cannot move upward. Furthermore, since the first inner wall of the main body 1 is segmented into a first arc-shaped surface with an inner diameter that gradually increases along the direction approaching the clamp 3, the first sliding engagement part 2 is constructed as a wedge shape and its side abuts against the first arc-shaped surface. During the upward movement of the wellhead casing head 100, the first sliding engagement part 2 moves towards the casing with a lateral force and clamps the casing. The greater the upward force applied by the rotary drilling rig, the greater the clamping force applied to the casing by the first sliding engagement part 2, and the more it restricts the casing head 100 from continuing to move upward.

[0024] like Figure 3As shown, for example, the grease injection mechanism includes: a hydraulic cylinder assembly 40 and a grease injection chamber 49 connected to the output end of the hydraulic cylinder assembly 40. The grease injection chamber 49 is connected to the inlet end of 48 via a first hose 42, and the outlet end of 48 is connected to the piston cylinder f via a piping assembly. A connecting groove is provided inside the casing head flange. The piping assembly includes: a grease injection hose 46 disposed on the outer periphery of the wellhead casing head; a rigid tube 44 disposed within the connecting groove and connected at its first end to the grease injection hose 46; and a second hose 43 whose first end is connected to the second end of the rigid tube 44. The second end of the second hose 43 is connected to the piston cylinder f. The grease injection hose 46 is circular, with a connecting four-way connector 47 and multiple connecting three-way connectors 45 evenly arranged on it. One port of each connecting four-way connector 47 and connecting three-way connectors 45 is connected to the rigid tube 44 within the disc. One port of the connecting four-way connector 47 is connected to the grease injection mechanism via 48.

[0025] like Figure 1 As shown, in one or more embodiments, a T-slot 8 is formed on the lower surface of the clamp 3, and the top of the first sliding engagement portion 2 is configured as a snap-fit ​​portion, which is snap-fitted into the T-slot 8. Optionally, the snap-fit ​​portion is configured as a T-shape. Optionally, a limiting spring 9 is provided between the lower surface of the clamp 3 and the upper surface of the first sliding engagement portion 2, with both ends of the limiting spring 9 contacting the lower surface of the clamp 3 and the upper surface of the first sliding engagement portion 2, respectively, to restrict the movement of the first sliding engagement portion 2 toward the sleeve during initial assembly and to prevent it from contacting the sleeve.

[0026] In one or more embodiments, the main body 1 further includes: a second inner wall segment integral with the bottom end of the first inner wall segment, the inner diameter of the second inner wall segment remaining unchanged and being the same as the inner diameter of the bottom end of the first inner wall segment.

[0027] In one or more embodiments, the second inner wall segment has a plurality of BT sealing grooves 10 formed along the axial direction. Optionally, the BT sealing grooves 10 are constructed as annular. The BT sealing grooves 10 are connected to a grease injection pipe 31 with its first end passing through the interior of the second inner wall segment. The second end of the grease injection pipe 31 is located outside the wellhead casing head 100 and serves as a BT sealing grease injection hole.

[0028] In one or more embodiments, the wellhead casing head 100 of the present invention further includes: a pressure pipe 32 with its first end extending to a second inner wall segment, the second end of the pressure pipe 32 being disposed outside the wellhead casing head 100, and a pressure gauge 11 being disposed thereon.

[0029] In one or more embodiments, the wellhead casing head 100 of the present invention further includes: an injection pipe 33 with its first end extending between two adjacent BT sealing grooves 10 in the axial direction, and the second end of the injection pipe 33 being disposed outside the wellhead casing head 100 and used as a sealant injection port.

[0030] Once the lifting force of the rotary drilling rig reaches a certain value, grease is injected into the BT sealing groove 10 through the grease injection pipe 31, and the BT sealing effect is observed through the pressure gauge 11. If leakage occurs, sealant can be injected between two adjacent BT sealing grooves 10 in the axial direction through the injection pipe 33 to improve the sealing effect between the wellhead casing head 100 and the casing.

[0031] In one or more embodiments, the main body 1 includes: a casing head body 111 and a casing head flange 112 fixedly disposed on the top of the casing head body 111. Optionally, the casing head body 111 and the casing head flange 112 are fixedly connected by flange bolts 7. A clamp 3 is disposed in the flange hole of the casing head flange, and a sealing ring groove 6 is formed on the upper surface of the casing head flange 112. Optionally, the sealing ring groove is configured as an annular groove. The casing head flange 112 is connected to the bottom flange of a drilling crossover (shown in the figure). The top flange of the drilling crossover is connected to the lower flange of a gate blowout preventer (shown in the figure).

[0032] like Figure 4 As shown, in one or more embodiments, the chuck a and the sleeve head flange c are connected by a chuck anti-drop mechanism. The chuck anti-drop mechanism includes: a fixed pressure plate 24 disposed on the upper surface of the chuck a, a pressure rod 25 vertically passing through the fixed pressure plate 24 and entering the receiving space of the chuck a, and an elastic element 22 sleeved on the outer periphery of the pressure rod 25. The fixed pressure plate 24 is fixedly connected to the sleeve head flange c. Optionally, the fixed pressure plate 24 is fixedly connected to the sleeve head flange through a pressure plate screw hole 26.

[0033] According to this utility model, a fixed pressure plate 24 is provided on the upper surface of the chuck a, a pressure rod 25 is provided that passes vertically through the fixed pressure plate 24 and enters the accommodating space of the chuck a, and an elastic element 22 is provided that is sleeved on the outer periphery of the pressure rod 25. Since the fixed pressure plate 24 is fixedly connected to the casing head flange c, when the casing head flange c moves upward with the casing head (a very small distance, for example, 0.5-1mm) under the action of the pressure inside the well, the chuck anti-fall mechanism can keep the chuck a stationary through the elastic element 22 and the pressure rod 25, so as not to affect the working state of the clamp 100.

[0034] In one or more embodiments, the elastic member 22 is disposed within the accommodating space, and the bottom end of the elastic member 22 is connected to the bottom end of the pressure rod 25, and the top end of the elastic member 22 is connected to the top inner wall of the accommodating space formed by the chuck a.

[0035] In one or more embodiments, the accommodating space extends vertically from the lower surface of chuck a into the interior of chuck a, and the chuck stopping mechanism further includes an elastic pressure plate 23 fixedly disposed on the lower surface of chuck a and closing the bottom of the accommodating space.

[0036] In one or more embodiments, the pressure rod 25 is configured as a T-shape, with the area of ​​its bottom end being larger than the area of ​​its top end. The bottom end of the pressure rod 25 is disposed within the accommodating space and contacts the elastic pressure plate 23. The top end of the pressure rod 25 is fixedly connected to the fixed pressure plate 24. Optionally, the top end of the pressure rod 25 is fixedly connected to the fixed pressure plate 24 by a fixing nut. Optionally, the elastic element 22 is a spring.

[0037] In one or more embodiments, the main body 1 further includes a third inner wall segment integral with the bottom end of the second inner wall segment, the third inner wall segment being configured as a second arcuate surface with an inner diameter that gradually increases along a direction away from the second inner wall segment. The wellhead casing head 100 of this utility model further includes a second sliding engagement portion 12 configured in a wedge shape with its side abutting against the second arcuate surface, and a clamping support base 13 disposed on the lower surface of the second sliding engagement portion 12.

[0038] If the aforementioned clamp 3 is used to remotely inject grease so that the clamp 3 is engaged with the casing, after the casing head is installed, if the rotary drilling rig disengages and withdraws, the gate blowout preventer, drilling crossbar, and wellhead casing head 100 will sink along the casing, causing leakage in the wellhead casing head 100 and the clamp 3 will fail.

[0039] According to this utility model, the main body 1 includes a third inner wall segment integral with the bottom end of the second inner wall segment. The third inner wall segment is constructed as a second arc-shaped surface with an inner diameter that gradually increases along the direction away from the second inner wall segment. Furthermore, the wellhead casing head 100 of this utility model also includes a second sliding engagement part 12 constructed in a wedge shape with its side abutting against the second arc-shaped surface, and a clamping support base 13 disposed on the lower surface of the second sliding engagement part 12. After the casing head is installed, during the process of the rotary drilling rig disengaging and withdrawing, the operator installs the second sliding engagement part 12 until it abuts against the second arc-shaped surface. The second sliding engagement part 12, together with the clamping support base, applies a radially outward force to the wellhead casing head 100, thereby preventing the blowout preventer, drilling cross-connector, and wellhead casing head 100 from sinking along the casing after the rotary drilling rig is disengaged, thus avoiding leakage of the wellhead casing head 100 and ensuring a stable engagement of the clamping device 3.

[0040] Although the present invention has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A wellhead casing head provided on the outer periphery of a casing, characterized by include: The body is internally constructed as a hollow main body, a clamp fixedly disposed inside the main body for engaging the sleeve, and a first sliding engagement portion engaging the lower surface of the clamp. The first inner wall of the main body is segmented into a first arc-shaped surface that gradually increases in diameter along the direction of the clamp. The first sliding engagement portion is constructed as a wedge and its side abuts against the first arc-shaped surface. The clamp includes: a driving mechanism and a chuck disposed in the flange hole of the sleeve head flange and whose lower surface engages with a wedge-shaped slip. The inner wall of the chuck is provided with a plurality of grooves evenly distributed circumferentially. The driving mechanism is disposed inside the grooves. The driving mechanism includes: a cleaver disposed in the groove along the outer periphery of the sleeve, a piston rod whose first end is connected to the side of the cleaver away from the sleeve, and a piston cylinder connected to the second end of the piston rod. The piston cylinder is connected to a grease injection mechanism for injecting grease into it.

2. The wellhead casing head according to claim 1, characterized in that, The lower surface of the clamp is provided with a T-shaped groove, and the top of the first sliding engagement part is engaged in the T-shaped groove.

3. The wellhead housing of claim 2, wherein, A limit spring is provided between the lower surface of the clamp and the upper surface of the first sliding engagement part.

4. A wellhead spool as claimed in any one of claims 1 to 3, characterised in that, The main body further includes: a second inner wall segment integral with the bottom end of the first inner wall segment, wherein the inner diameter of the second inner wall segment remains unchanged and is the same as the inner diameter of the bottom end of the first inner wall segment.

5. The wellhead housing of claim 4, wherein, The main body further includes a third inner wall segment integral with the bottom end of the second inner wall segment, the third inner wall segment being configured as a second arc-shaped surface with an inner diameter that gradually increases along the direction away from the second inner wall segment, and the wellhead casing head further includes a second sliding engagement portion configured as a wedge and having its side abutting against the second arc-shaped surface and a clamp support base disposed on the lower surface of the second sliding engagement portion.

6. The wellhead housing of claim 4, wherein, The second inner wall segment has multiple sealing grooves along the axial direction. The sealing grooves are connected to the grease injection pipe whose first end passes through the inside of the second inner wall segment. The second end of the grease injection pipe is located outside the wellhead casing head.

7. The wellhead housing of claim 6, wherein, The first end is inserted into the injection pipe between two adjacent sealing grooves in the axial direction, and the second end of the injection pipe is located outside the wellhead casing head.

8. A wellhead spool as claimed in any one of claims 4 to 7, characterised in that, Also includes: The first end of the pressure pipe extends into the second inner wall segment, and the second end of the pressure pipe is located outside the wellhead casing head, on which a pressure gauge is installed.

9. The wellhead housing of claim 1, wherein, The main body includes: a sleeve head body and a sleeve head flange fixedly disposed on the top of the sleeve head body.

10. The wellhead housing of claim 9, wherein, The casing head flange is connected to the bottom flange of the drilling cross, and the top flange of the drilling cross is connected to the lower flange of the gate blowout preventer.

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