RU2221146C1 - Device sealing well-head - Google Patents

Abstract

FIELD: mining industry, sealing of well-head when coal formation is outgassed. SUBSTANCE: device has directing pipe, sealing member, pipe-lines with branch pipes and connection cocks. Sealing member is put on directing pipe with formation of circular space between external surface of directing pipe and internal surface of sealing member. Sealing member comes in the form of multilayer sealing enclosure wound as coil from hydraulic insulation tape, for instance, high-pressure polyethylene, with sealing banding around butts. Circular space is connected through pressure regulator, cock and branch pipe to water main line under pressure and directing pipe is connected through three-way cock to vacuum main line and water main line under pressure. Device is fitted with additional directing pipes and sealing members manufactured similar to first directing pipe and sealing member to seal coal mass at greater depth. In this case circular spaces formed by directing pipes and sealing members are joined in sequence with the aid of branch pipes connected tightly. EFFECT: simplified design of device, reduced cost of its manufacture and maintenance, possibility of multiple usage of device thanks to secured reliable sealing by supply of water. 2 cl, 5 dwg

Description

The technical solution relates to mining and can be used to seal the wellhead during degassing of coal seams.

A device is known for sealing degassing wells (see RF patent No. 20044827, class E 21 F 7/00, published in BI No. 45-46, 1993), including a guide pipe and an elastic sleeve placed on the pipe, as well as located between the guide tube and the first elastic sleeve, the second elastic sleeve, one end of which is mounted on the guide pipe, the other end is muffled, while the first elastic sleeve is mounted on the guide pipe with the possibility of dismantling, and its working surface is made of adhesive coating.

A disadvantage of the known device is the limited length of the sealing section of the well, the inability to reuse due to the fact that the elastic sleeve is glued to the wall of the well.

Also known is a device for sealing a wellhead (see ed. St. USSR No. 1348538, class E 21 F 7/00, publ. In BI No. 40, 1987), including a casing pipe consisting of links connected by couplings, a flange located at the end of the pipe from the side of the wellhead, and an injection pipe for supplying the fastener, as well as glasses, to the outer annular surface of which elastic seals are attached, having spacer elements in the form of springs, while the glasses are installed and fixed on the casing by the inner surfaces of each other to a friend, and pump The milk tube is rigidly connected to the hole made in the glass.

A disadvantage of the known device is a very complex design and the inability to reuse due to the fixing of the elements of the device to the walls of the wells by means of a fixture.

The closest in technical essence and the achieved result is a well sealant (see ed. St. USSR No. 1484977, class E 21 F 7/00, published in BI No. 21, 1982), including a support rod connected to the support a hollow rod having a seal placed on it between the thrust washer and the clamping nut, and the sealant is provided with an additional support rod buried on the slot with a thrust washer, a sealant and the clamping nut connected by means of a coupling to the main support rod, while supporting the rods are made with multidirectional threads and are equipped with spools mounted on a common rod in the cavities of the support rods having longitudinal holes and ring grooves, and the thrust washers of each support rod are equipped with spring-loaded stoppers fixed in the annular grooves made in the thrust washers and in the radial holes made in the supporting rods, the spools being installed with the possibility of interaction with their annular grooves with spring-loaded stoppers, and the surface of the supporting rods between the seals firs perforated, wherein the supporting rod is provided with a well bottom support plate with the pusher and the clamping plate connected by a flexible connection with the thrust spool.

A disadvantage of the known device is the complexity of the design, the complexity of manufacturing a large number of interconnected parts, which requires increased maintenance costs, and the inability to reuse.

The objective of the technical solution is to simplify the design, reduce the complexity of manufacturing and maintenance and the possibility of reuse by providing reliable sealing with water supply.

The problem is solved as follows.

In the device for sealing the wellhead, including a guide pipe, a sealing element, pipelines with nozzles and connection taps, to solve the problem, the sealing element is placed on the guide pipe with the formation of an annular cavity between the outer surface of the guide pipe and the inner surface of the sealing element, the latter being made in the form of a multilayer sealing casing wound with a roll of waterproofing film, for example high-pressure polyethylene, sealing the ends of shrouds, the annular cavity through the pressure regulator valve and a branch pipe connected to the pipeline pressurized water, and the guide pipe via a three way valve - to a vacuum manifold and the manifold water pressure.

The above greatly simplifies the design of the sealing element at the wellhead. A multilayer sealing casing wound with a roll of waterproofing film having high strength (tensile strength of a high-pressure polyethylene film 1 mm thick - 14.7-26.7 MPa) and relatively large elongation at break (up to 45%) provides sealing and reliability of work. The manufacture of a multilayer sealing casing by coil winding on a guide tube simplifies the manufacturing technology of the device.

At the same time, sealing is carried out with water under pressure located in the annular cavity, which simplifies the installation technology of the device in the well, and also allows dismantling with minimal labor costs, that is, reduces the complexity of maintenance.

The connection of the guide pipe through a three-way valve with a vacuum line and a pressure water line provides the possibility of using the well to degass the array and saturate the coal with water under pressure with minimal labor costs by switching the three-way valve.

It is advisable to provide a device for sealing the wellhead with an additional guide pipe and an additional sealing element, the latter being placed on the additional guide pipe with the formation of an additional annular cavity between the outer surface of the additional guide pipe and the inner surface of the additional sealing element, made in the form of a multilayer sealing casing wound with a roll of said waterproofing film, wherein said col evye cavity interconnect sealingly connected in series by pipes.

This technical solution allows you to expand the scope of use of the device for coal arrays of large fractures, when it is necessary to seal the wellhead to a greater depth, and the dimensions of the excavation do not allow using the device with a long rigid guide tube.

It is advisable that the guide pipe and the additional guide pipe be made of a flexible polymer pressure-suction hose reinforced with an elastic spiral, for example, steel with a coating that removes static electricity.

The implementation of the guide pipe and the additional guide pipe flexible allows the installation of a sealing device in long curved wells. At present, a wide variety of flexible hoses, including polymer pressure-suction hoses, have been created and manufactured by the industry. The same hose can be used to transfer fluid under pressure and exhaust gases. Moreover, flexible hoses are made with a diameter of 25 to 300 mm, a length of 5 to 50 m in a bay with a working pressure of up to 25 atm.

Reinforcing the specified hose with an elastic spiral, for example, steel wire, ensures the operability of the pressure-suction flexible hose when methane is sucked and retains its original cross section. When water is injected, an elastic spiral increases the strength of the hose. Reinforcement with steel wire provides greater performance of a flexible pressure-suction hose. In order to prevent the accumulation of static electricity and sparking, it is necessary to electrically isolate the turns of steel wire from the environment with a coating that removes static electricity.

The essence of the technical solution is illustrated by an example of a device for sealing a wellhead, a description of its operation and the drawings of figures 1-5, which show:

in Fig 1 is a schematic diagram of a device for sealing a wellhead a longitudinal section;

figure 2 is the same, section I-I in figure 1;

figure 3 is a schematic diagram of a device for sealing a wellhead with an additional guide tube - a longitudinal section;

figure 4 - node a in figure 3 - connection of the guide pipe and the additional guide pipe;

figure 5 - node In figure 3 - placement on the guide tube of the sealing casing of a flexible polymer pressure-suction hose reinforced with an elastic spiral, for example, steel wire with a coating that removes static electricity.

A device for sealing the wellhead consists of a guide pipe 1 (Fig. 1), through a three-way valve 2 connected to a vacuum line 3 and a water line 4 under pressure.

On the guide pipe 1 on the outside there is a sealing element in the form of a multilayer sealing casing 5 (figure 2), wound with a roll of waterproofing film, such as high-pressure polyethylene. There is an annular cavity 6 between the outer surface of the guide tube 1 and the inner surface of the sealing element in the form of the specified casing 5 and sealing bandages 7 and 8 at the ends (Fig. 1). The annular cavity 6 through the element 9 of the water inlet, the pressure regulator 10, the valve 11 and the pipe 12 is connected to the line 4 of water under pressure.

When filling the annular cavity 6 with water under pressure, the sealing casing 5 made of the specified film elastically deforms and is pressed against the wall of the well 13. To ensure sealing of the wellhead 13 to a greater depth (more than 3 m), it is advisable to use an additional guide pipe 14 (Fig. 3 ) and an additional sealing element in the form of a sealing casing 15 (figure 4), placed with the formation of the annular cavity 16 between the outer surface of the additional guide pipe 14 and the inner surface to olnitelnogo sealing element. The annular cavity 6 and 16 are interconnected in series by means of hermetically connected nozzles 17 (figure 4). The sealing casing 15 is made of the same material as the sealing casing 5. It is advisable to guide the pipe 1 and the additional guide pipe 14 from a flexible polymer pressure-suction hose 18 (figure 5), reinforced with an elastic spiral 19, for example, coated steel wire, allowing to remove static electricity.

The connection of the guide pipe 1 (Fig. 3) to the evacuation line 3 can be made through the valve 20, and to the pressure water line 4 through the valve 21, when there is a big difference in the diameters of these lines.

The device operates as follows.

The guide pipe 1 with the sealing casing 5 connected by means of the bandages 7 and 8 is inserted into the wellhead 13. The end part of the guide pipe 1 is connected via a three-way valve 2 to the vacuum pipe 3 and the pressure water pipe 4. The annular cavity 6 through the element 9 of the water inlet, the pressure regulator 10, the valve 11 and the pipe 12 is connected to the line 4 of water under pressure.

Turn on the tap 11, and pressurized water flows from the line 4 into the annular cavity 6 and presses the sealing casing 5 from the waterproofing film to the wall of the well 13. The elasticity of the waterproofing film allows you to tightly seal the wellhead. By means of the pressure regulator 10, the necessary pressure is set for reliable sealing.

By means of a three-way valve 2, the evacuation process is controlled by connecting the guide pipe 1 to the evacuation line 3, or to inject water into the coal seam from the line 4.

When using a device with an additional guide pipe 14 (Fig. 3), the process of sealing the wellhead 13 is similar, it differs only in that through the nozzles 17, water under pressure enters the annular cavity 16 of the additional guide pipe 14, which ensures sealing of the wellhead 13 for a length additional guide pipe 14.

When used as a guide pipe 1 and an additional guide pipe 14, a polymer pressure-suction hose 18, reinforced with an elastic, for example, steel spiral 19, allows you to seal curved wells and remove static electricity.

This ensures the operability of the device by maintaining the cross section of the curved guide tubes both during evacuation and when pumping water.

The proposed design of the device for sealing the wellhead makes it easy to dismantle and reuse. To do this, turn off the water supply through the tap 11 and discharge it from the annular cavity 6, and when using an additional guide pipe 14 and from the annular cavity 16. After that, the device is removed from the well 13 by known methods.

Claims (3)

1. A device for sealing a wellhead, including a guide pipe, a sealing element, pipelines with nozzles and connection taps, characterized in that the sealing element is placed on the guide pipe with the formation of an annular cavity between the outer surface of the guide pipe and the inner surface of the sealing element, the latter made in the form of a multilayer sealing casing wound with a roll of waterproofing film, for example, high-pressure polyethylene, with sealing ruyuschimi bandages at the ends, wherein the annular cavity through the pressure regulator valve and a branch pipe connected to the pipeline pressurized water, and the guide pipe via a three way valve - to a vacuum manifold and the manifold water pressure. 2. The device according to claim 1, characterized in that it is provided with an additional guide pipe and an additional sealing element, the latter being placed on the additional guide pipe with the formation of an additional annular cavity between the outer surface of the additional guide pipe and the inner surface of the additional sealing element and is made in the form a multilayer sealing casing wound with a roll of the specified waterproofing film, while these annular cavity soy ineny interconnected in series by pipes connected hermetically. 3. The device according to claim 1 or 2, characterized in that the guide pipe and the additional guide pipe are made of a flexible polymer pressure-suction hose reinforced with an elastic spiral, for example, steel, with a coating that removes static electricity.

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