CN210798907U

CN210798907U - Simple casing head capable of being installed and sealed quickly

Info

Publication number: CN210798907U
Application number: CN201921537264.5U
Authority: CN
Inventors: 储明来; 窦正道; 叶红; 苏德胜
Original assignee: China Petroleum and Chemical Corp; Sinopec Jiangsu Oilfield Co
Current assignee: China Petroleum and Chemical Corp; Sinopec Jiangsu Oilfield Co
Priority date: 2019-09-12
Filing date: 2019-09-12
Publication date: 2020-06-19
Anticipated expiration: 2029-09-12

Abstract

The utility model relates to a simple and easy casing head of quick installation and sealed, including center tube, locating part, gland, annular steel sheet, top casing coupling, top casing, production casing coupling, production sleeve pipe, ring channel and second pore. The utility model provides a simple and easy casing head of quick installation and sealed, simple structure installs convenient to use.

Description

Simple casing head capable of being installed and sealed quickly

Technical Field

The utility model relates to a casing head correlation equipment technical field, concretely relates to is a simple and easy casing head of quick installation and sealed.

Background

The casing head is one of necessary well heads in drilling engineering, and is an important connecting piece between a surface casing and a large four-way joint of a well head, a blowout preventer and the like. The main function is to suspend the casing and seal the annular space. The casing head should have the following functions:

1. sufficient load bearing capacity. Having axial forces to support the weight of the upper blowout preventer and wellhead and to suspend layers of casing other than the surface casing and possibly increase downhole operations.

2. And pressure sealing is formed between the inner and outer casing strings. The pressure release device can adapt to complex conditions in the well, release pressure which is possibly accumulated between two layers of casing strings, and avoid oil, gas and water leakage at the well mouth.

3. With controllable side holes. The method is used for providing a liquid inlet and outlet channel between two layers of casing strings, and can be used for repairing cement from a side hole when the quality problems of insufficient return height of well cementation cement (even incapability of sealing a target layer) and the like are caused by reasons such as underground leakage and the like; when in acidizing and fracturing, pressure balancing liquid can be injected from the side hole to protect the inner casing.

4. Has a stop function. I.e. to prevent movement of components inside the casing head.

5. Simple structure, convenient installation and use and low price.

At present, the casing head used for deep wells, high-pressure oil and gas wells and offshore drilling has to use the standard casing head with complex and huge structure, large installation difficulty and high price due to the pressure bearing capacity and the sealing requirement. However, for shallow wells and low-pressure wells, the use of the above products is obviously very wasteful, firstly, the installation cost is greatly increased, the standard casing head is installed before the blowout preventer is installed, the installation difficulty is increased, and the cost of the subsequent drilling process is increased; secondly, the standard casing head is expensive. Therefore, in order to reduce the cost and the installation difficulty, two-petal seat hanging type casing heads are always used in part of oil fields. The two-valve seat hanging type casing head has the advantages of enough bearing capacity, simple structure and low cost. However, pressure sealing cannot be formed between the inner casing string and the outer casing string, namely pressure bearing is not realized, oil, water and gas are easy to generate at a well mouth, and potential safety hazards and environmental pollution exist; the controllable side holes are not provided, a measure channel is not provided between the inner casing string and the outer casing string, so that cement can not be injected for compensation when the well cementation quality is poor, pressure balancing liquid can not be injected during acidizing and fracturing, and the pressure between the inner casing string and the outer casing string can not be displayed; there is no stop function, i.e. it is not possible to prevent the components inside the casing head from moving up and down.

As shallow wells, medium-deep wells and low-pressure wells in China account for the majority, a simple casing head which meets five functions of the casing head and has a two-petal seat hanging type casing head installation method and a construction sequence is urgently needed on site.

Disclosure of Invention

An object of the utility model is to provide a simple and easy casing head of quick installation and sealed to solve foretell technical problem.

The technical scheme of the application is as follows: a simple casing head capable of being quickly installed and sealed comprises a central pipe, a limiting piece, a gland, an annular steel plate, a surface casing coupling, a surface casing, a production casing coupling, a production casing, an annular groove and a second pore passage; the gland is sleeved on the upper part of the central pipe, the top end of the gland is fixed on the central pipe through a limiting piece, an O-shaped sealing ring is arranged between the gland and the central pipe, a controllable side hole is formed in the top of the gland, and a first pore channel communicated with the controllable side hole is arranged below the controllable side hole; the top end of the production casing coupling is in threaded connection with the bottom end of the central pipe, and the bottom end of the production casing is in threaded connection with the top end of the production casing; the top of the surface casing coupling is positioned on the outer side of the gland and is in threaded connection with the gland, the bottom of the surface casing coupling is positioned on the outer side of the surface casing and is in threaded connection with the surface casing, the surface casing is sleeved on the casing, and the bottom end of the surface casing coupling is sleeved at the top of the surface casing coupling; an inverted step is arranged below the O-shaped sealing ring of the central tube, an accommodating space for accommodating an annular steel plate is formed between the inverted step and the surface sleeve, and the annular steel plate is clamped in the accommodating space by the surface sleeve and the inverted step; annular grooves used for being communicated with the first pore channels are formed in the top ends of the annular steel plates and the bottom ends of the first pore channels, second pore channels communicated with the annular grooves are formed in the annular steel plates, communicating channels used for cement circulation are formed in the surface layer sleeve, and the second pore channels are communicated with the communicating channels; and a rubber sealing ring is arranged between the annular steel plate and the gland.

Preferably, the annular steel plate is a split annular steel plate.

Preferably, the limiting part is a limiting pin.

Preferably, the O-shaped sealing rings are multiple and are arranged at intervals in the longitudinal direction.

Preferably, the rubber sealing ring is an angular rubber sealing ring.

The application provides a simple and easy casing head of quick installation and sealed has following advantage:

2. And pressure sealing is formed between the inner and outer casing strings. The pressure that can adapt to the complicated condition in the pit, controllable side opening can release and probably gather between two-layer casing string, stops the well head and produces oil, gas, water phenomenon.

4. Has a stop function. The movement of parts in the casing head is prevented, and the function can be conveniently realized by arranging the limiting pin.

5. Simple structure, convenient installation and use and low price.

Drawings

FIG. 1 is a schematic cross-sectional view of a quick-install and sealed simple casing head of example 1;

in the figure: 1. a central tube; 2. a limit pin; 3. a gland; 4. an O-shaped sealing ring; 5. a rubber seal ring; 6. an annular steel plate; 7. a surface casing collar; 8. a surface casing; 9. producing a casing coupling; 10. producing a sleeve; 11. a controllable side hole; 12. a first duct; 13. an annular groove; 14. a second porthole, 15, a communication channel.

Detailed Description

The present invention will be further explained with reference to the drawings and examples.

The utility model provides a simple casing head which can be installed and sealed quickly, comprising a central tube 1, a limiting part, a gland 3, an annular steel plate 6, a surface casing coupling 7, a surface casing 8, a production casing coupling 9, a production casing 10, an annular groove 13 and a second pore channel 14; the gland is sleeved on the upper part of the central pipe, the top end of the gland is fixed on the central pipe through a limiting piece, an O-shaped sealing ring 4 is arranged between the gland and the central pipe, a controllable side hole 11 is arranged at the top of the gland, and a first pore passage 12 communicated with the controllable side hole is arranged below the controllable side hole; the top end of the production casing coupling is in threaded connection with the bottom end of the central pipe, and the bottom end of the production casing is in threaded connection with the top end of the production casing; the top of the surface casing coupling is positioned on the outer side of the gland and is in threaded connection with the gland, the bottom of the surface casing coupling is positioned on the outer side of the surface casing and is in threaded connection with the surface casing, the surface casing is sleeved on the casing, and the bottom end of the surface casing coupling is sleeved at the top of the surface casing coupling; an inverted step is arranged below the O-shaped sealing ring of the central tube, an accommodating space for accommodating an annular steel plate is formed between the inverted step and the surface sleeve, and the annular steel plate is clamped in the accommodating space by the surface sleeve and the inverted step; annular grooves 13 used for being communicated with the first pore channels are formed in the top ends of the annular steel plates and the bottom ends of the first pore channels, second pore channels 14 communicated with the annular grooves are formed in the annular steel plates, communicating channels 15 used for cement circulation are formed in the surface layer sleeve, and the second pore channels are communicated with the communicating channels; and a rubber sealing ring 5 is arranged between the annular steel plate and the gland. In this application, the annular steel sheet is preferably run from opposite directions annular steel sheet, and it is more convenient to run from opposite directions the steel sheet installation, spacing pin 2 can generally be selected to the locating part, O type sealing washer is a plurality of, and generally usable 3 sets up at interval on vertical, forms multiple sealed protection like this, and sealed effect is better, rubber seal ring is preferably the rubber seal ring of taking the angle. The threaded connection preferably adopts a conical threaded connection mode, so that the sealing effect is better.

The principle of the utility model is as follows: after well cementation, the upper part of a surface casing coupling 7 is detached from a short joint, a blowout preventer is lifted up, a split annular steel plate 6 is loaded, a production casing 10 pipe string is slowly lowered, a step at the lower part of a central pipe is seated on the split annular steel plate 6, after stable seating, a joint top is detached, the upper part of the surface casing is removed from the short joint and the blowout preventer, a rubber sealing ring 5 with an angle is sleeved outside the central pipe 1 and pressed downwards to the split annular steel plate, an O-shaped sealing ring 4 is sleeved on the central pipe, a pressing cover is sleeved on the central pipe and screwed with the surface casing coupling, a limiting pin 2 is screwed up, and all installation is completed.

The pore channel 2 is positioned in the split annular steel plate 6 and penetrates through the annular steel plate, the upper part of the pore channel 2 is a threaded hole, a bolt can be conveniently screwed in, the split annular steel plate 6 can be lifted, and the pore channel 2 is provided with a plurality of holes. The controllable side holes 11 are connected with the pore canal 1, and a plurality of controllable side holes are arranged, and the lower part of the pore canal 1 is provided with a circle of annular grooves 13 so as to facilitate the communication between the pore canal 2 and the pore canal 1. The controllable side hole 11 can be connected with a pipeline or a pressure gauge is installed. The limiting pins are provided with a plurality of limiting pins for limiting the central tube to move up and down. The inner hole of the gland 3 of the simple casing head is sealed to realize double sealing, wherein the angular sealing ring is used for realizing angular sealing, and the O-shaped sealing ring is used for realizing sealing with the gland. The outer ring of the gland 3 is sealed with the surface casing coupling 7 by the casing buckle.

The above description is only for the preferred embodiment of the present invention and is not intended to limit the present invention, and the words first, second, etc. are used only for the distinction of names and not for the limitation of technical terms, and it is obvious to those skilled in the art that the present invention can be variously modified and changed. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A simple casing head capable of being quickly installed and sealed comprises a central pipe (1), a limiting piece, a gland (3), an annular steel plate (6), a surface casing coupling (7), a surface casing (8), a production casing coupling (9), a production casing (10), an annular groove (13) and a second pore passage (14);

the gland is sleeved on the upper part of the central pipe, the top end of the gland is fixed on the central pipe through a limiting piece, an O-shaped sealing ring (4) is arranged between the gland and the central pipe, a controllable side hole (11) is formed in the top of the gland, and a first pore channel (12) communicated with the controllable side hole is arranged below the controllable side hole;

the top end of the production casing coupling is in threaded connection with the bottom end of the central pipe, and the bottom end of the production casing is in threaded connection with the top end of the production casing;

the top of the surface casing coupling is positioned on the outer side of the gland and is in threaded connection with the gland, the bottom of the surface casing coupling is positioned on the outer side of the surface casing and is in threaded connection with the surface casing, the surface casing is sleeved on the casing, and the bottom end of the surface casing coupling is sleeved at the top of the surface casing coupling;

an inverted step is arranged below the O-shaped sealing ring of the central tube, an accommodating space for accommodating an annular steel plate is formed between the inverted step and the surface sleeve, and the annular steel plate is clamped in the accommodating space by the surface sleeve and the inverted step;

annular grooves (13) communicated with the first pore channels are formed in the top ends of the annular steel plates and the bottom ends of the first pore channels, second pore channels (14) communicated with the annular grooves are formed in the annular steel plates, communicating channels (15) for cement circulation are formed in the surface layer sleeve, and the second pore channels are communicated with the communicating channels;

and a rubber sealing ring (5) is arranged between the annular steel plate and the gland.

2. A quick install and seal simple casing head according to claim 1 wherein the annular steel plate is a split annular steel plate.

3. The quick-install and sealed simple casing head according to claim 1, characterized in that the stop is a stop pin (2).

4. The quick install and seal simple casing head of claim 1, wherein said O-ring seals are plural and spaced longitudinally.

5. The quick install and seal simple casing head of claim 1, wherein the rubber seal ring is an angled rubber seal ring.