Casing head device with variable inner cavity step

Abstract

The utility model discloses a casing head device with a variable inner cavity step. The casing head device comprises a casing head body, a plurality of sets of jackscrew assemblies and a plurality of sets of slip assemblies. A casing inner cavity and a mounting hole are formed in the casing head main body; the mounting holes are circumferentially arranged at intervals along the axis perpendicular to the inner cavity of the sleeve; each jackscrew assembly is movably connected with the corresponding mounting hole, and the axis of each jackscrew assembly is perpendicular to the axis of the inner cavity of the sleeve; the slip assembly comprises a plurality of slips, each slip is installed on the corresponding jackscrew assembly, so that the plurality of slips form a circular ring, each jackscrew assembly drives each slip to move in the direction perpendicular to the axis of the inner cavity of the casing pipe, the inner diameter size of the slip assembly is adjusted, and the inner cavity of the casing pipe of the casing pipe head body forms a step. Therefore, the diameter of the casing hanger can be adapted. The operation condition that the hanger step of the inner cavity of the casing head needs to be adjusted or retracted due to various reasons can be solved, the operation is simple and reliable, and the operation cost and time can be reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of oil and gas drilling equipment, and specifically relates to an inner cavity step variable casing head device. BACKGROUND

[0002] In oil and gas drilling operations, the casing head is an important component connecting the casing string and the wellhead device. The inner cavity size of the general casing head is fixed, and a step for bearing the casing hanger is needed, so the inner cavity size will be limited to some extent, which limits the fluid flow capacity and the adaptability of the casing during drilling to some extent.

[0003] With the continuous development of drilling technology, the drift diameter requirement of the casing head is continuously improved, and the connection requirement of different sizes of casings needs to be adapted. Therefore, the existing fixed inner cavity casing head often has the following problems when facing complex drilling conditions and casings of different specifications: first, the drift diameter is limited, which not only restricts the size of the drill bit, but also affects the flow efficiency of the drilling fluid and oil and gas; second, the inner cavity size cannot be flexibly adjusted, resulting in the need to replace different casing heads when connecting casings of different diameters, increasing the operation cost and time.

[0004] After searching, the Chinese utility model patent authorized publication No. CN209129572U discloses a variable-diameter casing head device, which comprises: a casing head body comprising a convex connecting body and a concave connecting body, the convex connecting body being arranged on the concave connecting body and being in communication with each other to form a containing space; and a variable-diameter component comprising a locking assembly and a telescopic step assembly, the locking assembly being embedded in a first mounting hole of the convex connecting body, and the telescopic step assembly being embedded in a second mounting hole of the concave connecting body; the utility model can temporarily increase the minimum vertical drift diameter size of the casing head device during drilling to adapt to the passage of the drill bit, and can provide a sufficient bearing step to suspend the hanger when the hanger is installed. The locking assembly structure of the patent is complex and has high cost. In addition, a special hanger is needed. UTILITY MODEL CONTENTS

[0005] The technical problem to be solved by the utility model is to provide a casing head device with an inner cavity step size that can be adjusted by using a slip with a sawtooth thread, which can also assist in bearing the hanger. Moreover, the form of the inner step of the casing head is not changed, so a special hanger is not needed, and the inner cavity step variable casing head device can meet the needs of the use scenario without changing the original hanger design.

[0006] The technical problem to be solved by the utility model can be solved by the following technical solutions:

[0007] A kind of inner cavity step variable casing head device, including casing head body, several sets of top thread components and slip assembly;The casing head body is provided with a for accommodating casing and drill bit pass through casing inner cavity and for installing several sets of top thread components and slip assembly installation hole;The installation hole is arranged along the axis of the casing inner cavity circumferentially spaced;Each top thread component is movably connected with corresponding installation hole, and the axis of each top thread component is perpendicular to the axis of casing inner cavity;The slip assembly includes several slips, each slip is installed on each top thread component, so that several slips form a circular ring, each slip is driven to move along the axis direction perpendicular to the casing inner cavity by each top thread component, to adjust the inner diameter size of slip assembly, so that the casing inner cavity of casing head body forms step, to adapt to the diameter of casing hanger.

[0008] In a preferred embodiment of the present application, each set of top thread component includes a top thread body and a top thread cap, the top thread cap is provided with a top thread cap inner thread and a top thread cap outer thread, the top thread cap outer thread is connected with the inner thread of the installation hole in the installation hole of the casing head body, the top thread body is provided with a top thread body outer thread, the top thread body outer thread is connected with the top thread cap inner thread, rotating the top thread cap can drive the top thread body to move along the axis perpendicular to the casing, and then drive each slip to move along the axis direction perpendicular to the casing, to adjust the inner diameter size of slip assembly, so that the casing inner cavity of casing head body forms step, to adapt to the diameter of casing hanger.

[0009] In a preferred embodiment of the present application, a circular ring-shaped installation groove is further provided in the casing head body, the installation groove is located between the casing inner cavity and the installation hole and communicates the casing inner cavity with the installation hole, and the slip assembly is slidably arranged in the installation groove;The installation groove can limit the radial movement of the slip assembly, form an annular step, and hold the casing hanger.

[0010] In a preferred embodiment of the present application, a T-shaped sliding groove is provided in each slip, and a head portion of the top thread body is provided with a T-shaped block, the T-shaped block is slidably embedded in the T-shaped sliding groove, so that each slip is arranged on the head portion of each top thread body.

[0011] In a preferred embodiment of the present application, each top thread component further includes a top thread sealing ring assembly, the top thread sealing ring assembly is sleeved on the top thread body and located between the top thread cap and the head portion of the top thread body, to seal the gap between the top thread body and the installation hole.

[0012] In a preferred embodiment of the present application, each top thread component further includes a top thread dustproof ring, the top thread dustproof ring is arranged between the top thread body and the top thread cap.

[0013] In one preferred embodiment of the present application, the upper and lower ends of the casing head body are respectively provided with interfaces connected with the wellhead device and the casing string.

[0014] Due to the above technical scheme, the present application can make the casing inner cavity of the casing head body have a larger drift diameter, increase the available size of the drill bit, significantly improve the flow efficiency of the drilling fluid and oil and gas, and reduce the flow resistance. The variable casing inner cavity size can adapt to the connection of casings with different diameters, improve the versatility and flexibility of the casing head, and meet the use requirements. The good sealing performance can effectively prevent fluid leakage and ensure the working stability.

[0015] The casing head body of the present application is made of high-strength alloy steel, which has sufficient strength and rigidity to withstand various loads during drilling. An initial large drift diameter inner cavity is formed inside the casing head body for accommodating the casing and drill bit.

[0016] The top screw assembly of the present application is connected with the slip, and when it is necessary to connect casings with different diameters, the operator can adjust the top screw assembly to move the slip to the appropriate position, thereby changing the inner cavity size of the casing head, which can adapt to the requirements of large-diameter drill bits and different-diameter casing hanger bearing steps. The adjustment mechanism can also be dynamically adjusted according to the actual requirements during drilling to ensure the best drilling effect.

[0017] The top screw assembly of the present application also has a sealing function, which can protect the inner cavity sealing surface of the casing head and ensure that fluid leakage can be effectively prevented under different inner cavity sizes and pressures. The sealing system also has an automatic compensation function, and when the inner cavity size changes, the sealing assembly can automatically adjust the sealing pressure to maintain good sealing performance. BRIEF DESCRIPTION OF DRAWINGS

[0018] The structure and working principle of the present application will be described below with reference to the accompanying drawings

[0019] Figure 1 It is a general connection diagram of the casing head device of the present application.

[0020] Figure 2 It is an enlarged variable inner cavity step structure diagram of area A of the casing head device of the present application.

[0021] Figure 3 It is a structure diagram of the top screw assembly of the present application.

[0022] Figure 4 It is a structure diagram of the slip assembly of the present application. DETAILED DESCRIPTION

[0023] To make the purpose, technical scheme and advantages of the present application more clear, specific embodiments will be further described in detail below with reference to the drawings. However, it should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the scope of the present application. In addition, in the following structure, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concept of the present application.

[0024] In the description of the present application, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom end" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description. It is not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application. In addition, "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0025] As shown in Figure 1 The casing head body 400 is provided with a casing inner cavity 410 for accommodating the casing and drill bit to pass through and a mounting hole 420 for mounting a plurality of top screw assemblies 200 and slip assemblies 300; the mounting holes 420 are arranged in a circumferential interval along an axis perpendicular to the casing inner cavity 410; in addition, a circular mounting groove 430 is arranged in the casing head body 400, and the mounting groove 430 is located between the casing inner cavity 410 and the mounting hole 420 and communicates the casing inner cavity 410 and the mounting hole 420. The casing head body 400 is provided with interfaces at the upper and lower ends thereof for connecting with the wellhead device and the casing string.

[0026] As shown in Figure 2 The top screw assembly 200 comprises a top screw body 201, a top screw dustproof ring 202, a top screw pressing cap 203 and a top screw sealing ring assembly 204. The top screw pressing cap 203 is provided with a top screw pressing cap inner thread and a top screw pressing cap outer thread, and the top screw body 201 is provided with a top screw body outer thread.

[0027] As shown in Figure 3 The slip assembly 300 is composed of a plurality of slips 301, each of which is slidingly installed in the mounting groove 430 of the casing head body 100 to form a circular ring, and the mounting groove 430 can limit the radial movement of the slip assembly 300 to form an annular step to hold the casing hanger.

[0028] As shown in Figure 1As shown, the top pin pressure cap 203 is screwed into the internal thread of the installation hole 420, the top pin body 201 is screwed into the internal thread of the top pin pressure cap 203, so that the top pin body 201 is installed in the top pin pressure cap 203, the top pin dustproof ring 202 is arranged between the top pin body 201 and the top pin pressure cap 203, the top pin dustproof ring 202 plays a role of protecting the top pin body 201, and a set of top pin assembly 200 is formed, in addition, the top pin sealing ring assembly 204 is sleeved on the top pin body 201 and located between the top pin pressure cap 203 and the head 201a of the top pin body 201, so as to seal the gap between the top pin body 201 and the installation hole 420 and play a role of preventing fluid leakage.

[0029] The top pin assembly 200 is connected with the T-shaped groove 301a on each slip 301 through the T-shaped block of the head of the top pin body 201, after installation, the top pin body 201 can drive the slip 301 to move radially by adjusting the top pin pressure cap 203, so that the inner cavity 410 of the casing head forms a step, so as to adapt to the diameter of the casing hanger.

[0030] Because of the above structure, the working principle of the utility model is as follows Figure 4

[0031] In actual drilling operation, after the operation of the large-size drill bit is completed, the operator adjusts the top pin assembly 200 shown in the figure, so that the slip assembly 300 can move radially in the inner cavity of the casing head main body structure 100 and be adjusted to a suitable position, so as to adapt to the diameter of the casing hanger. Figure 2

[0032] The inner cavity step variable casing head device of the utility model can be customized according to different drilling requirements to meet the requirements of various complex drilling conditions, and can be used in high-temperature, low-temperature, high-pressure and high-hydrogen sulfide environments for a long time, and will not cause metal sealing failure due to chemical reaction in acid, sulfur and oil and gas medium for a long time.​​

Claims

1. A cannula head device with variable inner cavity step, characterized in that: It includes a casing head body, several sleeve top screw assemblies and a slip assembly; the casing head body is provided with a casing inner cavity for accommodating the casing and the drill bit to pass through, and mounting holes for installing several sleeve top screw assemblies; the mounting holes are arranged circumferentially at intervals along an axis perpendicular to the casing inner cavity; each top screw assembly is movably connected to the corresponding mounting hole, and the axis of each top screw assembly is perpendicular to the axis of the casing inner cavity; the slip assembly includes several slips, each slip is installed on each top screw assembly, so that the several slips form a ring.

2. The cannula head device with variable inner cavity step according to claim 1, characterized in that: Each set of top screw components includes a top screw body and a top screw pressure cap, wherein the top screw pressure cap is provided with an internal top screw pressure cap thread and an external top screw pressure cap thread, wherein the external top screw pressure cap thread is connected to the internal thread of the mounting hole in the mounting hole of the casing head body, and the top screw body is provided with an external top screw body thread, wherein the external top screw body thread is connected to the internal top screw pressure cap thread.

3. The cannula head device with variable inner cavity step according to claim 2, characterized in that: A circular mounting groove is also provided in the casing head body. The mounting groove is located between the casing inner cavity and the mounting hole and connects the casing inner cavity with the mounting hole. The slip assembly is slidably arranged in the mounting groove. The mounting groove can limit the radial movement of the slip assembly to form an annular step to hold the casing hanger.

4. The cannula head device with variable inner cavity step according to claim 3, characterized in that: A T-shaped slot is provided in each slip, and a T-shaped block is provided at the head of the top screw body. The T-shaped block is slidably embedded in the T-shaped slot, so that each slip is installed on the head of each top screw body.

5. The cannula head device with variable inner cavity step according to claim 4, characterized in that: Each jack screw assembly further comprises a jack screw sealing ring assembly which is sleeved on the jack screw body and located between the jack screw pressing cap and the head of the jack screw body to seal the gap between the jack screw body and the mounting hole.

6. The cannula head device with variable inner cavity step according to claim 5, characterized in that: Each jack screw assembly further comprises a jack screw dust ring, which is arranged between the jack screw body and the jack screw pressing cap.

7. The cannula head device with variable inner cavity step according to claim 6, characterized in that: Interfaces for connecting with the wellhead device and the casing string are respectively provided at the upper and lower ends of the casing head body.

Images