WO2016101681A1

WO2016101681A1 - Well head structure

Info

Publication number: WO2016101681A1
Application number: PCT/CN2015/091876
Authority: WO
Inventors: 刘刚; 杨彬; 刘清宇
Original assignee: 新奥气化采煤有限公司
Priority date: 2014-12-25
Filing date: 2015-10-13
Publication date: 2016-06-30
Also published as: CN204457562U

Abstract

Disclosed is a well head structure of an underground gasification furnace. The well head comprises a blowout preventing box (1), a sealing device, a middle-high pressure gas injection device (3) and a well pipe (4). The middle-high pressure gas injection device (3) comprises a first communication pipe (7) and a first gas injection pipe (8), and the first communication pipe (7) is in communication with the first gas injection pipe (8). The blowout preventing box (1), the sealing device, the first communication device (7) and the well pipe (4) are sequentially arranged and communicate with one another. A continuous oil pipe enters from the blowout preventing box (1) into the well pipe (4) sequentially through the sealing device and the first communication pipe (7). The first gas injection pipe (8) is in communication with an outer gasifying agent source via a middle-high pressure gasifying agent pipeline, and a middle-high pressure gasifying agent enters the first communication pipe (7) through the first gas injection pipe (8) and then enters the well pipe (4). The well head structure is reasonable in design and simple in structure, the descending operation of the continuous oil pipe can be achieved, and it is guaranteed that the whole operation process is simple, convenient and safe.

Description

Wellhead structure

The present application claims priority to Chinese Patent Application No. 20142084571, filed on Dec. 25, 2014, the entire disclosure of which is hereby incorporated by reference.

Technical field

The present application relates to the technical field of oil and gas exploitation, and in particular to a wellhead structure.

Background technique

Underground gasifiers usually consist of process wells such as gas injection wells and gas outlets. The gas injection well is to inject and quantify the gasification agent into the underground coal gasification layer, usually to reduce the cost, improve the safety and control level. The same gas injection well is often injected with multiple gasification mediums or multiple measurement and control equipment. The gasification agent includes, for example, air, CO2, oxygen, water, etc., and the measurement control equipment includes a coiled tubing, a gas injection nozzle, a thermocouple, and the like.

Existing conventional gas injection wells have relatively simple well structure due to the non-moving downhole gas injection equipment and measuring tools, and the gasification agent directly sends the gasification agent to the bottom of the well through the gas injection pipeline or the gas injection well.

Summary of the invention

The purpose of the application is to provide a wellhead structure which is reasonable in design, simple in structure, can complete the operation of the coiled tubing, and ensures that the whole operation process is simple, convenient and safe.

To achieve the above objectives, the technical solution adopted in the present application is:

Providing a wellhead structure for an underground gasifier comprising:

Blowout prevention box, sealing device, medium and high pressure gas injection device and well pipe;

The medium and high pressure gas injection device includes a first communication pipe and a first gas injection pipe;

The first gas injection pipe and the first communication pipe are penetrated;

The blowout prevention box, the sealing device, the first communication pipe and the well pipe are arranged and connected in sequence;

a coiled tubing enters from the blowout preventer box and sequentially enters the well tubular tube through the sealing device and the first communication tube;

The first gas injection pipe is connected to the external gasification agent source through the medium and high pressure gasification agent pipeline, and the medium and high pressure gasification agent enters the first communication pipe through the first gas injection pipe, and then enters the well pipe.

As an improvement of the above technical solution, wherein

The wellhead structure further includes a low pressure gas injection device;

The low pressure gas injection device includes a second communication pipe and a second gas injection pipe;

The second gas injection pipe and the second communication pipe are penetrated;

And the second communication tube is respectively in communication with the sealing device and the first communication tube;

The second gas injection pipe communicates with the external gasifying agent source through the low pressure gasifying agent line, and the low pressure gasifying agent enters the second communication pipe through the second gas injection pipe, and enters through the first communication pipe Said in the well pipe.

As an improvement of the above technical solution, wherein

A first valve is disposed between the first communication tube and the second communication tube for controlling circulation of a gasifying agent between the first communication tube and the second communication tube.

As an improvement of the above technical solution, wherein

A first control valve is disposed on the second gas injection pipe for controlling a low pressure gasifying agent sent from the external gasifying agent source to the second gas injection pipe.

As an improvement of the above technical solution, wherein

The number of the second gas injection pipes is one or more.

As an improvement of the above technical solution, wherein

The low pressure gas injection device and the medium and high pressure gas injection device are provided with monitoring accessories.

As an improvement of the above technical solution, wherein

A second control valve is disposed on the first gas injection pipe for controlling the medium and high pressure gasification agent sent from the external gasification agent source to the first gas injection pipe.

As an improvement of the above technical solution, wherein

The number of the first gas injection pipes is one or more.

As an improvement of the above technical solution, wherein

The sealing device is disposed between the blowout prevention box and the second connecting tube At the office.

As an improvement of the above technical solution, wherein

The sealing device is a blowout preventer disposed between the blowout prevention box and the second communication tube.

The beneficial effects of the application are: reasonable design, simple structure, can complete the operation of the coiled tubing, and ensure that the whole operation process is simple, convenient and safe.

DRAWINGS

1 is a schematic structural view of an embodiment of a wellhead structure of the present application;

2 is a schematic structural view of another embodiment of a wellhead structure of the present application;

Among them: 1 blowout prevention box; 2 low pressure gas injection device; 3 medium high pressure gas injection device; 4 well pipe; 5 second communication pipe; 6 second gas injection pipe; 7 first communication pipe; 8 first gas injection pipe; a valve; 10 first control valve; 11 second control valve; 12 second valve; 13 blowout preventer.

detailed description

In order to make the objects, technical solutions and advantages of the present application more clear, the wellhead structure of the present application will be further described in detail below with reference to the accompanying drawings and embodiments. It is understood that the specific embodiments described herein are merely illustrative of the application and are not intended to be limiting.

As shown in FIG. 1 and 2, a wellhead structure of an underground gasification furnace includes: a blowout prevention box 1, a sealing device (not shown), a medium and high pressure gas injection device 3, and a well pipe 4;

The medium-high pressure gas injection device 4 includes a first communication pipe 7 and a first gas injection pipe 8, and the first gas injection pipe 7 and the first communication pipe 8 are penetrated;

The blowout prevention box 1, the sealing device, and the first communication pipe 7 and the well pipe 4 are sequentially arranged and connected;

The coiled tubing enters from the blowout prevention box 1 and passes through the sealing device, the first communication pipe 7 and then into the well pipe 4;

The first gas injection pipe 8 communicates with the external gasification agent source through the medium and high pressure gasification agent pipeline, and the medium and high pressure gasification agent enters the first communication pipe 7 through the first gas injection pipe 8, and then enters the well pipe 4.

The wellhead structure of the underground gasification furnace of the present application has reasonable design and simple structure, and can be completed. It is operated as a coiled tubing and ensures that the entire operation process is simple, convenient and safe.

The wellhead structure of the underground gasification furnace is further provided with a low pressure gas injection device 2, the low pressure gas injection device 2 includes a second communication pipe 5 and a second gas injection pipe 6, a first control valve 10;

The second gas injection pipe 6 and the second communication 5 pipe wall penetrate;

The medium and high pressure gas injection device 3 further includes a second control valve 11;

The blowout prevention box 1, the sealing device, the second communication pipe 5, the first communication pipe 7, and the well pipe 4 are sequentially arranged and connected;

The coiled tubing enters from the blowout prevention box 1 and sequentially enters the well tubular tube 4 through the sealing device, the second communication tube 5 and the first communication tube 7;

The second gas injection pipe 6 communicates with the external gasification agent source through the low pressure gasification agent pipeline, the low pressure gasification agent enters the second communication pipe 5 through the second gas injection pipe 6, and enters the well pipe 4 through the first communication pipe 7;

The first gas injection pipe 8 communicates with the external gasification agent source through the medium and high pressure gasification agent pipeline, and the medium and high pressure gasification agent enters the first communication pipe 7 through the first gas injection pipe 8, and then enters the well pipe 4. Preferably, as an implementable embodiment of the present application, a first valve 9 may be disposed between the blowout prevention box 1 and the first communication tube 7 for controlling the circulation of the gasifying agent therebetween, and also Their joints act as a seal. Simply connecting the pipeline directly can also solve the problem of the present application and complete the coiled tubing decentralization operation.

Of course, in the above application, the first control valve 10 and the second control valve 11 may not be provided, and the first gas injection pipe 8 is directly connected to the external gasification agent source through the medium and high pressure gasification agent pipeline, and the second gas injection pipe 6 is connected. The medium transfer between the low-pressure gasifying agent pipeline and the external gasifying agent source is realized, and the first control valve 10 and the second control valve 11 are provided for the external gasifying agent source to the first The low-pressure gasification agent delivered by the two gas injection pipes is controlled, and the high-pressure gasification agent sent from the external gasification agent source to the first gas injection pipe is controlled to increase the controllability of the gas injection process.

Connect the coiled tubing injection head to the top of the blowout preventer box 1 and commission the coiled tubing equipment to meet the lowering conditions. The anti-spray box 1 has a sealing rubber barrel whose inner diameter is matched with the outer diameter of the coiled tubing. When a certain pressure is applied to the anti-jetting box, the sealing rubber barrel holds the coiled tubing to seal. The coiled tubing passes through the sealing device and the second connecting pipe in sequence 5 and the first communication pipe 7 enters the well pipe 4, and the gasifying agent can be injected into the well through the coiled tubing. When the coiled tubing is raised, the coiled tubing is opened and the coiled tubing is lifted. When it is lifted up between the sealing device and the blowout prevention box 1, the sealing device is closed, and the pressure of the blowout prevention box 1 is slowly lowered to form a gap with the coiled tubing. The gap, through which the gas in the blowout prevention box 1 and the coiled tubing is released, and when the pressure is released, the coiled tubing can be raised to the wellhead.

During the movement of the coiled tubing, the external gasifying agent source injects a low-pressure gasifying agent (such as low-pressure air, a gasifying agent medium such as CO2) into the second communicating pipe 5 through the second gas injection pipe 6, and is injected through the first communicating pipe 7. In the well pipe 4, the external gasifying agent source injects a medium-high pressure gasifying agent (such as air, CO2, N2, steam or water gasifying agent medium) into the first communication pipe 7 through the first gas injection pipe 8, and then injects into the well pipe. 4 in.

This ensures that the wellhead remains sealed and does not leak when the coiled tubing moves; and when a plurality of gasifying agents are injected into the well, it is ensured that different kinds of pressure, flow, temperature and gasification agents are simultaneously or separately injected into the well pipe 4 Effective control.

Preferably, as an embodiment of the present application, a first valve 9 is disposed between the second communication tube 5 and the first communication tube 7 for controlling the air between the second communication tube 5 and the first communication tube 7. The circulation of chemicals.

Since the pressure of the medium-high pressure gasifying agent injected into the first communication pipe 7 by the first gas injection pipe 8 is relatively high, since the second communication pipe 5 and the second gas injection pipe 6 can withstand high pressure, when the first gas injection pipe is used 8 The medium-high pressure gasifying agent injected into the first communication pipe 7 can close the first control valve 10, so that the medium-high pressure gasifying agent does not enter the low-pressure system, thereby causing damage to the low-pressure system, thereby ensuring that the medium-high pressure gasifying agent is Direct injection into the well pipe 4 prevents the high-pressure gasifying agent from entering the second gas injection pipe 6 through the second communication pipe 5, thereby causing the pressure of the medium-high pressure gasifying agent to damage the low-pressure gas injection device 2.

Preferably, as an embodiment of the present application, the second injection pipe 6 is provided with a first control valve 10 for controlling the low-pressure gasification agent supplied from the external gasification agent source to the second gas injection pipe 6.

This allows for better control of the injection of the low pressure gasifying agent.

Preferably, as an implementable embodiment of the present application, the number of second gas injection pipes 6 For one or more.

Preferably, as an embodiment of the present application, the first gas injection pipe 8 is provided with a second control valve 11 for controlling the medium and high pressure gasification agent sent from the external gasification agent source to the first gas injection pipe 8. .

This can better control the injection of medium and high pressure gasifying agent.

Preferably, as an embodiment of the present application, the number of the first gas injection tubes 8 is one or more, and preferably two.

Preferably, as an embodiment of the present application, the sealing device is a second valve 12 disposed between the blowout prevention box 1 and the second communication tube 5.

When the coiled tubing is placed under pressure, the second valve 12 is initially closed. When the coiled tubing is lowered into the blowout prevention box 1 and held by it, the second valve 12 is opened, and the coiled tubing passes through the second valve 12 and the second. The communication pipe 5 and the first communication pipe 7 enter the well pipe 4. When the coiled tubing is raised, the oil pipe is lifted between the second valve 12 and the blowout prevention box 1, the second valve 12 is closed, and the pressure of the blowout prevention box 1 is slowly lowered to form a gap with the coiled tubing, through which the gap will be The gas between the second valve 12 and the blowout preventer 1 and in the coiled tubing is released, and the coiled tubing can be lifted when the pressure is released.

Preferably, as an embodiment of the present application, the sealing device is a blowout preventer 13 disposed between the blowout prevention box 1 and the second communication tube 5.

The blowout preventer 13 is not an invention of the present application, but a prior art, which will not be described in detail herein.

When there is pressure in the well, the full seal of the blowout preventer 13 is in a closed state, and the coiled tubing is lowered into the blowout preventer 1 and held by it. The shutter of the blowout preventer 13 is opened, and the coiled tubing is sequentially introduced into the well pipe 4 through the blowout preventer 13, the second communicating pipe 5 and the first communicating pipe 7, and when the position is lowered to the designated position, the half seal of the blowout preventer 13 is closed. And the suspension gate, the coiled tubing is fixed, and further sealed to prevent the gas in the well from leaking along the outer wall of the tubing. The above operation completes the action of the coiled tubing under pressure.

The operation of the coiled tubing with pressure is reversed from that of the lowering process. First, the half seal of the blowout preventer 13 and the suspension shutter are opened, and the coiled tubing is lifted up, when it is lifted up between the blowout preventer 13 and the blowout preventer 1. , closing the full seal of the blowout preventer 13 and slowly reducing the pressure of the blowout preventer 1 A gap is formed between the coiled tubing and the coiled tubing, and the gas in the blowout preventer 1 and the coiled tubing is released through the gap, and the coiled tubing can be lifted when the pressure is released.

Preferably, as an implementable embodiment of the present application, the low pressure gas injection device 2 and the medium and high pressure gas injection device 3 are provided with monitoring accessories (not shown).

The monitoring accessory may be a measuring device such as a pressure gauge, a thermometer, a flow meter, etc., so as to monitor the pressure, temperature and flow rate of the low-pressure gasifying agent and the medium-high pressure gasifying agent injected into the well pipe 4, so as to inject the gasifying agent. become better.

The above embodiment makes the application have the advantages of reasonable design and simple structure, can complete the operation of the coiled tubing, can also meet the injection of a plurality of gasifying agents, and ensure that the whole operation process is simple, convenient and safe.

The above-mentioned embodiments are merely illustrative of several embodiments of the present application, and the description thereof is more specific and detailed, but is not to be construed as limiting the scope of the claims. It should be noted that a number of variations and modifications may be made by those skilled in the art without departing from the spirit and scope of the present application. Therefore, the scope of the invention should be determined by the appended claims.

Claims

A wellhead structure of an underground gasification furnace, characterized in that:

Including: blowout prevention box, sealing device, medium and high pressure gas injection device and well pipe;

The medium and high pressure gas injection device includes a first communication pipe and a first gas injection pipe;

The first gas injection pipe and the first communication pipe are penetrated;

The blowout prevention box, the sealing device, the first communication pipe and the well pipe are arranged and connected in sequence;

a coiled tubing enters from the blowout preventer box and sequentially enters the well tubular tube through the sealing device and the first communication tube;

The first gas injection pipe is connected to the external gasification agent source through the medium and high pressure gasification agent pipeline, and the medium and high pressure gasification agent enters the first communication pipe through the first gas injection pipe, and then enters the well pipe.
The wellhead structure of claim 1 wherein:

The wellhead structure further includes a low pressure gas injection device;

The low pressure gas injection device includes a second communication pipe and a second gas injection pipe;

The second gas injection pipe and the second communication pipe are penetrated;

And the second communication tube is respectively in communication with the sealing device and the first communication tube;

The second gas injection pipe communicates with the external gasifying agent source through the low pressure gasifying agent line, and the low pressure gasifying agent enters the second communication pipe through the second gas injection pipe, and enters through the first communication pipe Said in the well pipe.
The wellhead structure of claim 2, wherein:

A first valve is disposed between the first communication tube and the second communication tube for controlling circulation of a gasifying agent between the first communication tube and the second communication tube.
The wellhead structure of claim 2, wherein:

A first control valve is disposed on the second gas injection pipe for controlling a low pressure gasifying agent sent from the external gasifying agent source to the second gas injection pipe.
The wellhead structure of claim 2, wherein:

The number of the second gas injection pipes is one or more.
The wellhead structure of claim 2, wherein:

The low pressure gas injection device and the medium and high pressure gas injection device are provided with monitoring accessories.
The wellhead structure of claim 1 wherein:

A second control valve is disposed on the first gas injection pipe for controlling the medium and high pressure gasification agent sent from the external gasification agent source to the first gas injection pipe.
The wellhead structure of claim 1 wherein:

The number of the first gas injection pipes is one or more.
A wellhead structure according to any one of claims 1 to 8, characterized in that:

The sealing device is disposed at a junction between the blowout prevention box and the second connecting tube.
A wellhead structure according to any one of claims 1 to 8, characterized in that:

The sealing device is a blowout preventer disposed between the blowout prevention box and the second communication tube.