CN111456688B

CN111456688B - Multi-anchor-pipe self-adaptive wellhead supporting platform suitable for marine hydrate exploitation

Info

Publication number: CN111456688B
Application number: CN202010272150.3A
Authority: CN
Inventors: 刘康; 陈国明; 秦源康
Original assignee: China University of Petroleum East China
Current assignee: China University of Petroleum East China
Priority date: 2020-04-08
Filing date: 2020-04-08
Publication date: 2021-11-09
Anticipated expiration: 2040-04-08
Also published as: CN111456688A

Abstract

The invention discloses a multi-anchor-pipe self-adaptive wellhead supporting platform suitable for marine hydrate exploitation, and relates to the technical field of wellhead supporting and connecting devices for underwater exploitation. The device comprises a bracket main body, a sensing leveling module arranged on the bracket main body, lifting lugs arranged on the periphery of the bracket main body, a pipeline unit arranged on the bracket main body and at least 3 identical suction anchor pipes; the outer wall of the suction anchor pipe is provided with a chute A in the vertical direction; the suction anchor pipe is connected with the hoop bracket on the bracket main body in a sliding way through the chute A; the hoop bracket is provided with an electromagnetic lock tongue A; the outer wall of the suction anchor pipe is provided with an A tooth socket which is matched with the A electromagnetic lock tongue in a buckling mode in the vertical direction. The suction anchor pipe is more stable in the process of penetrating, more beneficial to leveling, more stable in support after being placed in place and capable of coping with shallow soil environment with complex geological parameter characteristics.

Description

Multi-anchor-pipe self-adaptive wellhead supporting platform suitable for marine hydrate exploitation

Technical Field

The invention relates to the technical field of wellhead support connecting devices for underwater exploitation.

Background

At present, for deepwater drilling engineering, the technology of jetting and running in a surface layer guide pipe is commonly adopted in China to maintain the stability of a wellhead, the guide pipe is installed by a jetting method, a guide pipe column which is connected according to the designed length is sent to the mud surface of the sea bottom by a sending drill column, the installation operation of the guide pipe is completed when the drill column is sent to the mud surface of the sea bottom along with the jetting drilling of the sending drill column and the designed mud running depth of the guide pipe, then the drill column is sent to be separated from the guide pipe, the surface layer drilling is continued, and after the surface layer drilling is completed, a surface layer sleeve pipe is drilled and run in, and the sleeve pipe well cementation operation is implemented. This technique needs to play the drilling many times, and the operation ageing is low, and economic cost is high, and the well head bearing capacity mainly relies on the top layer pipe to provide, and the pipe installation income mud is too shallow, and is not enough to the well head holding power, and the well head accident of sinking easily appears. Aiming at the instability of the jet method drilling in shallow resource development.

The suction foundation is considered to be one of the most potential foundation forms for application in deep water engineering, and is increasingly applied to ocean engineering in recent years. The suction foundation is generally a cylindrical structure with a closed upper end and an open lower end, and during the sinking process, the suction foundation firstly sinks into the seabed by a certain depth by using self weight to form a closed environment in the cylinder, and then seawater in the cylinder is pumped out by using a pumping device and continues to sink under the action of the pressure difference between the inside and the outside of the cylinder until the seawater penetrates into the set depth. In recent years, under the condition that the application of a single-cylinder suction anchor is increased, a multi-cylinder suction anchor structure also appears in the field of vision of people by virtue of the characteristic that the multi-cylinder suction anchor structure is stronger in stability than the single-cylinder suction anchor structure, but a fixed multi-cylinder suction anchor structure has higher geological requirements during installation, geological exploration is required to be carried out to judge whether the installation requirements are met, if the seabed flatness is poor, the installation gradient is overlarge, the installation is required to be reinstalled, and a large amount of economic loss is caused.

Disclosure of Invention

Aiming at the technical defects, the invention provides a multi-anchor-pipe self-adaptive wellhead supporting platform suitable for marine hydrate exploitation, which has stronger terrain adaptability and can reduce the early exploration workload; and it is more stable when placed in place.

The technical scheme adopted by the invention is as follows: a multi-anchor pipe self-adaptive wellhead supporting platform suitable for marine hydrate exploitation comprises a support unit and a suction anchor pipe unit; the bracket unit comprises a bracket main body, a sensing leveling module arranged on the bracket main body, lifting lugs arranged on the periphery of the bracket main body and a pipeline unit arranged on the bracket main body; each lifting lug is connected with an external power device through a sling; the control end of the external power device and the sensing leveling module form feedback; the suction anchor pipe unit comprises at least 3 identical suction anchor pipes; the suction anchor pipes are uniformly distributed and installed on the periphery of the bracket main body; the outer wall of the suction anchor pipe is provided with a chute A in the vertical direction; the suction anchor pipe is connected with the hoop bracket on the bracket main body in a sliding way through the chute A; the hoop bracket is provided with an electromagnetic lock tongue A; the outer wall of the suction anchor pipe is provided with an A tooth socket which is in snap fit with the A electromagnetic lock tongue in the vertical direction; the suction anchor pipe is of an inverted bucket-shaped structure; the pipeline unit comprises trunk pipes and branch pipes for communicating each suction anchor pipe with the corresponding trunk pipe; the trunk pipe is communicated with an external hydraulic pump.

Further, the multi-anchor pipe self-adaptive wellhead supporting platform is suitable for marine hydrate exploitation, and an annular isolation cavity is concentrically arranged on the inner side of the pipe wall of the lower end part of the suction anchor pipe; and a mud-water separation window is arranged at the upper part of the inner wall of the annular isolation cavity.

Further, the multi-anchor pipe self-adaptive wellhead supporting platform is suitable for marine hydrate exploitation, and a follow-up supporting plate is connected to the inner side of the pipe wall of the upper end part of the suction anchor pipe in a sliding mode; the middle part of the follow-up supporting plate is provided with an electromagnetic switch valve A; the servo supporting plate is in sliding connection with a tooth groove B on the wall of the suction anchor pipe through a sliding block B; and a B electromagnetic lock tongue matched with the B tooth socket in a buckling manner is arranged on the B sliding block.

Furthermore, the multi-anchor-pipe self-adaptive wellhead supporting platform is suitable for marine hydrate exploitation, the upper part of the annular isolation cavity is provided with a B electromagnetic switch valve, and the pipe wall of the suction anchor pipe is provided with a B electromagnetic switch valve.

Furthermore, the multi-anchor-pipe self-adaptive wellhead supporting platform suitable for marine hydrate exploitation is characterized in that a guide pipe sleeve is mounted on a support main body, and an upper port of a guide pipe is provided with a flaring conical surface.

Compared with an underwater wellhead supporting device, the multi-anchor-pipe self-adaptive wellhead supporting platform suitable for marine hydrate exploitation has the technical effects that:

1. the self weight of each suction anchor pipe is the same as the downward pressure under the same negative pressure difference, and the bearing capacity of the seabed soil at the corresponding position of each suction anchor pipe is different, so that the penetration depth of each suction anchor pipe is different. In the traditional way, all be through carrying out the roughness to seabed soil in advance and survey, hardness detection etc to it is less to ensure that the soil difference that every suction anchor pipe corresponds, prevents that suction anchor pipe from transferring the in-process because the depth of penetration is different, causes the whole slope of supporting platform. In order to maintain the angle of the support platform as a whole, the pressure difference of each suction anchor pipe is regulated to prevent inclination. However, this causes a phenomenon: in the case of a flat support platform, the support force provided by each suction anchor tube is different. When the supporting platform works and carries a load, one or more suction anchor pipes can be caused to settle, and the inclination can occur.

The invention has the difference that the supporting platform is controlled to be in a horizontal state by using an external rope; then, at the same pressure differential, each suction anchor tube reaches a certain depth. Although the penetration depth of each suction anchor tube is different, the final bearing capacity is the same. After each suction anchor pipe is placed in place, the suction anchor pipes and the support main body are locked through the A electromagnetic lock tongues, the power of the rope is withdrawn, and the supporting platform keeps a horizontal posture. When the work is in load bearing, because the supporting force obtained by each suction anchor pipe is the same, the inclination is not easy to occur. Therefore, the dependence of the whole supporting platform on the terrain can be reduced, and the stress can be more stable and uniform when the supporting platform bears the load.

2. At the in-process of suction anchor pipe penetration earth, the annular isolation chamber that partial earth can constantly impress, earth gets into behind the annular isolation chamber, and moisture is extruded from the mud-water separation window, and inside earth reduces the water content of earth along with the increase of the degree of depth of penetration, and the compactness improves. Finally, the lower end part of the annular isolation cavity forms an annular blocking area with high compactness, and the blocking area can prevent the conduction of the internal environment and the external environment of the suction anchor pipe. The annular isolation cavity can prevent excessive soil from entering the suction anchor pipe from the outer side when the suction anchor pipe is penetrated by negative pressure, so that soil is blocked.

3. The suction anchor pipe penetrates into a preset depth, after the suction anchor pipe enters a working state, the bearing capacity of the suction anchor pipe is larger and larger along with the increase of pipelines entering a wellhead, the support performance of the suction anchor pipe is the friction force between the side wall and seabed soil, and the internal water pressure (negative pressure penetration is adopted when the suction anchor pipe penetrates into the suction anchor pipe, after the suction anchor pipe reaches the preset depth, the negative pressure is stopped, and the internal and external pressure difference is kept the same) in a sealing state is supported. When the bearing weight of the suction anchor pipe is increased, the internal water pressure of the suction anchor pipe can be increased, and if the internal pressure is leaked due to the conduction of the inside and the outside of the suction anchor pipe, the suction anchor pipe can be settled. In the technical scheme, in the process that the follow-up support plate is placed down from the suction anchor pipe, the electromagnetic lock tongue B keeps a recovery state, and the electromagnetic switch valve A keeps an opening state; under the push of soil, the follow-up support plate moves upwards, and the muddy water mixture with poor support property flows away from the electromagnetic switch valve. When the suction anchor pipe is put in place, the electromagnetic switch valve A and the electromagnetic lock tongue B are closed, at the moment, the follow-up supporting plate is equivalent to the inner bottom surface of the suction anchor pipe, and the follow-up supporting plate directly presses on soil, so that stronger supporting force can be provided. When the suction anchor pipe is recovered, the electromagnetic switch valve A is opened, and pressure and leakage can be realized.

4. The B electromagnetic switch valve on the suction anchor pipe can improve the working efficiency when the integral supporting platform is placed and lifted. When the supporting platform is lifted, air can be pressed into the suction anchor pipe, water is discharged from the B electromagnetic switch valve, and the lifting force is reduced by utilizing the gas-liquid buoyancy difference. When the suction anchor pipe penetrates to a preset depth, the electromagnetic switch valve B is switched on to quickly eliminate the internal and external pressure difference.

5. The guide pipe sleeve can provide certain support and guide for later-stage guide pipe placement, and is favorable for reducing the shaft aligning difficulty of the guide pipe.

Drawings

FIG. 1 is a schematic illustration of the present invention prior to settling;

FIG. 2 is a schematic view of the present invention from another perspective prior to sinking;

FIG. 3 is a schematic illustration of the present invention after it has been submerged;

FIG. 4 is a partial schematic view of the annular isolation chamber and follower support plate;

in the figure, 1, a stent main body; 2. a sensing leveling module; 3. lifting lugs; 4. a suction anchor tube; 5. a, a chute; 6. a, an electromagnetic lock tongue; 7. a, tooth space; 8. a trunk pipe; 9. a branch pipe; 10. an annular isolation chamber; 11. a mud-water separation window; 12. a follow-up support plate; 13. a, an electromagnetic switch valve; 14. b, sliding blocks; 15. b, tooth grooves; 16. b, an electromagnetic lock tongue; 17. b, an electromagnetic switch valve; 18. a guide pipe sleeve; 19. and (4) flaring conical surfaces.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

As shown in fig. 1 and 3, the multi-anchor pipe self-adaptive wellhead supporting platform suitable for marine hydrate production comprises a bracket unit, a suction anchor pipe unit; the support unit comprises a support main body 1, a sensing leveling module 2 arranged on the support main body 1, lifting lugs 3 arranged on the periphery of the support main body and a pipeline unit arranged on the support main body 1; each lifting lug 3 is connected with an external power device through a sling; the control end of the external power device and the sensing leveling module 2 form feedback;

the suction anchor pipe unit comprises at least 3 identical suction anchor pipes 4; the suction anchor pipes 4 are uniformly distributed and arranged around the bracket main body 1; the outer wall of the suction anchor pipe 4 is provided with an A sliding chute 5 in the vertical direction; the suction anchor pipe is connected with the hoop bracket on the bracket main body in a sliding way through the chute A; the hoop bracket is provided with an electromagnetic bolt A6; the outer wall of the suction anchor pipe 4 is provided with an A tooth groove 7 which is in snap fit with the A electromagnetic lock tongue 6 in the vertical direction; the suction anchor pipe 4 is of an inverted bucket structure; the pipeline unit comprises a trunk pipe 8 and branch pipes 9 which are used for communicating each suction anchor pipe 4 with the corresponding trunk pipe 8; the main pipeline 8 is communicated with an external hydraulic pump; an annular isolation cavity 10 is concentrically arranged on the inner side of the pipe wall of the lower end part of the suction anchor pipe 4; a mud-water separation window 11 is arranged at the upper part of the inner wall of the annular isolation cavity 10; a multi-anchor pipe self-adaptive wellhead supporting platform suitable for marine hydrate exploitation is characterized in that the inner side of the pipe wall of the upper end part of a suction anchor pipe 4 is connected with a follow-up supporting plate 12 in a sliding manner; the middle part of the follow-up support plate 12 is provided with an A electromagnetic switch valve 13; the follow-up support plate 12 is in sliding connection with a B tooth groove 15 on the wall of the suction anchor pipe 4 through a B sliding block 14; the B sliding block 14 is provided with a B electromagnetic bolt 16 which is in snap fit with the B tooth groove 15; the upper part of the annular isolation cavity 10 and the pipe wall of the suction anchor pipe 4 are provided with a B electromagnetic switch valve 17; the bracket main body 1 is provided with a guide pipe sleeve 18, and the upper end opening of the guide pipe sleeve 18 is provided with a flaring conical surface 19.

As shown in fig. 3, the supporting platform is controlled to be in a horizontal state by using an external rope; then, at the same pressure difference, each suction anchor tube 4 reaches a certain depth each. Although the penetration depth of each suction anchor tube 4 is different, the resulting bearing capacity is the same. After each suction anchor pipe 4 is placed in place, the suction anchor pipes 4 and the support main body 1 are locked through the A electromagnetic lock tongues 6, the power of the rope is withdrawn, and the supporting platform keeps a horizontal posture. When the work is bearing, because the supporting force obtained by each suction anchor pipe 4 is the same, the inclination is not easy to occur.

According to the technical scheme, due to the adaptability to the submarine topography, the support main body 1 is selected to be connected with the suction anchor pipe 4 in a sliding mode, the support main body 1 is hung and positioned firstly, and the stable horizontal posture is kept. Therefore, a carrying device of a supporting platform (a multi-anchor pipe self-adaptive wellhead supporting platform suitable for marine hydrate mining, which is referred to as a supporting platform for short) is required to have a stable hoisting machine (adopting a boom for hoisting), and in order to provide leveling attitude feedback for the hoisting machine, a leveling sensing module 2 is installed on the bracket main body 1 in the embodiment and is used for providing real-time attitude feedback for the hoisting machine.

Cavity 10 is kept apart to the annular, along with the sinking of suction anchor pipe 4, inside muddy water constantly separates at mud-water separation window 11 under pressure, and the earth water content in the annular isolation chamber 10 descends gradually, and hardness promotes, and mobility reduces, and it finally can extend whole annular isolation chamber and the annular isolation chamber below earth, finally forms the closely knit basis that prevents the muddy water flow together in the inboard of suction anchor pipe 4, the outside and the certain degree of depth in below like this. When the suction anchor pipe 4 is lowered and the suction anchor pipe 4 works and carries a load, the suction anchor pipe 4 is prevented from flowing inside and outside and is conducted to the utmost extent. In the lowering process, the soil plug is aggravated by the internal and external flow; the working load can cause the internal pressure to leak and the support platform to sink or incline; the annular foundation that prevents muddy water flowing who constructs among this technical scheme can prevent or alleviate above-mentioned two kinds of circumstances.

Claims

1. a multi-anchor pipe self-adaptive wellhead support platform suitable for marine hydrate exploitation, is characterized in that: comprise support unit, suction anchor pipe unit;

The bracket unit includes a bracket body (1), a sensing leveling module (2) installed on the bracket body (1), lifting ears (3) installed around the bracket body, and mounted on the bracket body (1) Each lifting lug (3) is connected to an external power device through a sling; the control end of the external power device and the sensing leveling module (2) constitute feedback;

The suction anchor pipe unit includes at least three identical suction anchor pipes (4); the suction anchor pipes (4) are evenly distributed and installed around the bracket main body (1); the suction anchor pipes (4) The outer wall is provided with an A chute (5) in the vertical direction; the suction anchor pipe is slidably connected with the hoop bracket on the main body of the bracket through the A chute; an A electromagnetic lock tongue (6) is installed on the hoop bracket ); the outer wall of the suction anchor pipe (4) is vertically provided with an A tooth slot (7) that is snap-fitted with the A electromagnetic lock tongue (6); the suction anchor pipe (4) is inverted barrel structure;

The pipeline unit includes a trunk pipe (8), a branch pipe (9) connecting each suction anchor pipe (4) with the corresponding trunk pipe (8); the trunk pipe (8) It communicates with the external hydraulic pump.

2. A multi-anchor pipe self-adaptive wellhead support platform suitable for marine hydrate exploitation according to claim 1, characterized in that the inner side of the pipe wall of the lower end of the suction anchor pipe (4) is concentrically provided with an annular isolation A cavity (10); a mud-water separation window (11) is arranged on the upper part of the inner wall of the annular isolation cavity (10).

3. A multi-anchor pipe adaptive wellhead support platform suitable for marine hydrate exploitation according to claim 2, characterized in that the suction anchor pipe (4) is slidably connected to the inner side of the pipe wall at the upper end with a follow-up A support plate (12); an A solenoid switch valve (13) is installed in the middle of the follow-up support plate (12); the follow-up support plate (12) passes through the B slider (14) and the suction anchor pipe (4) pipe The B tooth slot (15) of the wall is slidably connected; the B slider (14) is provided with a B electromagnetic lock tongue (16) snap-fitted with the B tooth slot (15).

4. A multi-anchor pipe adaptive wellhead support platform suitable for marine hydrate exploitation according to claim 3, characterized in that: the upper part of the annular isolation cavity (10), the suction anchor pipe (4) A B electromagnetic switch valve (17) is installed on the pipe wall.

5. A multi-anchor pipe adaptive wellhead support platform suitable for marine hydrate exploitation according to claim 4, characterized in that: a guide casing (18) is installed on the support main body (1), and the said The upper port of the guide sleeve (18) has a flared conical surface (19).