RU2632721C1 - Die preventer - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention relates to equipment for sealing well head of oil and gas wells in their operation and repair for safety purposes, prevention and elimination of oil-gas-water manifestations, subsoil reserves and environmental protection. The preventer has a body with a vertical axial channel and side horizontal channels located symmetrically relative to it. The cavities of the horizontal channels have a rectangular shape in cross section. In horizontal channels, there are arranged die blocks, in each of which upper tube and bottom blind dies are arranged. The bodies of dies have a rectangular shape in cross section. The body of the lower blind dies are the bodies of the die blocks. Bodies of upper tube dies are located in rectangular recesses of bodies of lower dies. The dies are provided with elastic seals located in shaped slots made in bodies of dies. Hand-operated die control drives include drive rods of upper and lower dies. The longitudinal axes of the drive rods of dies are spaced relative to each other in vertical diametric plane and interact with two threaded holes of cover connected to the body.

EFFECT: expansion of operational capabilities, increase of reliability and safety, reduction of labour input in operation and maintenance.

10 dwg

Description

The invention relates to equipment for sealing the mouth of oil and gas wells during their operation and repair in order to ensure safety, prevention and elimination of oil and gas manifestations, protection of the subsoil and the environment.

Known die-type preventer PPM-156x21 with a manual drive design of JSC "Sibneftegazmash Plant" (Abubakirov V.F. and other Drilling, blow-out and wellhead equipment: Reference, manual .: In 2 t. T. 1. - M .: LLC IRC Gazprom, 2007. - p. 488, Fig. 8.15.), Containing:

- a housing with a vertical passage hole and a horizontal cavity,

- dies placed in the bodies of the dies installed with the possibility of movement in the horizontal cavity of the housing,

- mechanisms for moving die bodies.

The well-known preventer is single in design and its disadvantages include additional labor costs during operation, due either to the need to replace deaf dies with pipe dies when using blowout preventer equipment (PO) in the circuits that allow the use of a single preventer, or to the need to install another preventer on its upper flange when installed in software circuits that allow the use of only a dual preventer. At the same time, in addition to increased labor costs during installation and maintenance of two preventers, the layout of wellhead blowout equipment will have significant high-altitude characteristics, which entails an increase in labor costs when installing a drilling rig.

The combination of these circumstances increases the complexity in the operation of the known preventer.

The well-known "Preventor" (Patent No. 2237795, ЕВВ 33/06, publ. 10.10.2004.), Containing:

- a housing with a vertical axial channel and symmetrical lateral horizontal channels relative to it with a circular cross-section, the longitudinal axis of the horizontal channels being perpendicular to the axis of the vertical channel,

- installed in horizontal channels with the possibility of longitudinal movement of the cylinder blocks of cylindrical shape, in each of which there is an upper tube die with a radial recess under the sealed pipe and a lower blind die, equipped with elastic seals that interact with each other side and horizontal surfaces, and the die blocks are installed in horizontal channels with gaps,

- and manual dice control drives, including drive rods of the upper and lower dies, having threaded connections for interaction with a nut connected to the housing,

- moreover, the die blocks are connected to the horizontal channels of the housing by a keyed connection made, for example, in the form of a key fixedly installed along the generatrix in the lower part of the horizontal channel, and interacting with a keyway made along the generatrix in the lower part of the die block.

The disadvantages of the known preventer include increased labor costs during maintenance and operation, due to the shape of the horizontal channels, the cross section of which is made round, and the cylindrical shape of the die blocks. Therefore, to prevent rotation of the blocks from the drive rods during the rotation of the helms during their movement in horizontal channels, it is necessary to fix the blocks from turning in the form of a key connection made, for example, in the form of a key fixedly installed along the generatrix in the lower part of the horizontal channel, and interacting with the key a groove made along the generatrix in the lower part of the die block, as a result of which during the circulation of the drilling fluid the cavity of the guide grooves can be filled with a solid phase ohm precipitate from the drilling fluid which, because of frictional resistance to movement will create a spot of blocks and increase the force moving the spot blocks. This fact will also make it difficult to disassemble the known preventer, carried out to change the size of the seal or maintenance.

A disadvantage of the known device is also the low reliability of sealing the bottom blind dies of the vertical axial channel of the housing of the preventer without a flat drill pipe. This is due to the fact that the volume of the sealing material of the protruding elastic seals of the blank dies, ensuring tightness, will move due to fluidity under the influence of borehole pressure into the open radial recess for the pipe, since in this case the elastic seals are not covered by completely metal surfaces of the housing of the die block.

In addition, a disadvantage of the known preventer is its low operational safety, due to the need for sequentially closing first the upper and then lower dies, which increases the length of time for closing the preventer in the absence of a drill pipe or tubing. And since in the event of an emergency, the operator’s time for closing the preventer is counted by minutes and even seconds, the result of inoperability in this case may be an open gas and oil fountain, the elimination of which will require significant costs.

And finally, the well-known preventer has limited operational capabilities that do not allow it to be used in emergency operations at the well. This is due to the coaxial arrangement of the rods of the upper and lower dies, which eliminates the possibility of connecting to them simultaneously two extension cords with helms for remote control of the preventer by maintenance personnel located behind the protective screen at a certain distance from the mouth, as a result of which it becomes necessary to approach the service personnel directly to the preventer for it open-close, i.e. to the wellhead under pressure, which is unsafe.

The combination of the above disadvantages of the known preventer significantly reduces the reliability and safety of its use, increases the complexity of the operation, and also limits its operational capabilities.

The objective of the invention is to provide a technical solution to the preventer, devoid of the above disadvantages.

The technical result of solving this problem is to expand operational capabilities, increase reliability and safety, reduce the complexity of operation and maintenance.

To ensure this technical result in a known preventer containing

- a housing with a vertical axial channel and symmetrical lateral horizontal channels relative to it, the longitudinal axis of which is perpendicular to the axis of the vertical channel,

- installed in horizontal channels with the possibility of longitudinal movement of the die blocks, in each of which placed tube and blind dies, equipped with elastic seals,

- and manual dice control drives, including drive rods of the upper and lower dies, having threaded connections for interaction with the cover connected to the housing,

ACCORDING TO THE INVENTION

- the cavity of the lateral horizontal channels and the housing of the block blocks in cross section have a rectangular shape,

- lower blind dies directly overlap the vertical axial channel of the housing, and their housing is the housing of the die blocks,

- the case of the upper tube dies in cross section have a rectangular shape and are placed in rectangular recesses of the bodies of the lower dies with the possibility of movement,

- while elastic seals are placed in curly grooves made in the bodies of the dies,

- and the longitudinal axis of the drive rods of the dies are spaced relative to each other in a vertical diametrical plane and interact with two threaded holes of the cover.

The invention is illustrated by drawings, which depict:

in FIG. 1 - longitudinal section of the preventer, all dies are open;

in FIG. 2 is a view A from FIG. one;

in FIG. 3 - elastic seal 12;

in FIG. 4 - elastic seal 18;

in FIG. 5 is a longitudinal section of a preventer, pipe dies are closed on a deflated pipe;

in FIG. 6 is a section BB of FIG. 5;

in FIG. 7 - a longitudinal section of the preventer, blind dies are closed;

in FIG. 8 is a section BB of FIG. 7;

in FIG. 9 is a longitudinal section through a preventer, pipe dies are closed, blind dies are closed all the way into a deflated pipe.

in FIG. 10 is a section G-G of FIG. 9.

The preventer includes a housing 1 (Fig. 1) with a vertical axial channel 2 through which a pipe string 3 is lowered into the well and horizontal lateral channels 4 symmetrically located relative to the vertical channel 2, and their longitudinal axis is perpendicular to the axis of the latter. The cavity of each of the channels 4 has a rectangular cross-section and contains a horizontal working surface for sealing 5 and vertical boundary surfaces 6 and 7 (Fig. 2).

In the cavities of the channels 4, there are installed die blocks 8 (Fig. 1), the cases of which are rectangular in cross section and are at the same time the cases 9 of the lower blind dies 10, in which figured grooves 11 are made with elastic seals 12 placed in them with working surfaces 13 and 14 (in FIG. 3). Moreover, in the working position, the surfaces 13 of the seals 12 interact with the surfaces 5 of the cavities of the horizontal channels 4, and the surfaces 14 interact with each other when the ram blocks 8 come closer to completely overlap the axial channel 2 in the absence of a pipe 3 in it.

The upper tube dies 15 contain bodies 16 having a rectangular cross-section and movably placed in rectangular recesses 17 made in the bodies 9 of the lower blind dies 10, and elastic seals 18 with working surfaces 19, 20 and 21 (in Fig. 4), placed in curly grooves 22 made in the housings 16. In this case, in the working position, the surfaces 19 of the seals 18 interact with the surfaces 5 of the cavities of the channels 4, the surfaces 20 interact with each other when the dies 15 approach each other to overlap the axial channel 2 if there is no m of pipe 3, and the surface 21 interact with the pipe 3.

Manual drives contain rigidly connected to the housing 1 of the cover 23, forming in the vertical diametrical plane threaded connections 24 and 25 with the drive rods 26 and 27, which curly ends 28, made, for example, in the form of a hexagon, interact with the helms 29 provided with extensions 30 s mating holes made therein, interacting with the curly ends 28 of the rods 26 and 27. To ensure the necessary sealing between the parts, the preventer is equipped with sealing elements 31 (Fig. 1).

The inventive preventer works as follows.

The preventer is installed at the wellhead (the landing flange of the downstream equipment is not shown).

When conducting tripping operations, the equipment on the pipe string 3 is moved through the vertical axial channel 2 of the housing 1 (Fig. 1).

To seal the wellhead with a deflated pipe string 3, the handwheels 29 with extension cords 30 and drive rods 26 are rotated in a clockwise direction (Fig. 5). In this case, the drive rods 26, interacting with the threaded connections 24 of the covers 23, move the pipe dies 15 with elastic seals 18 along the lateral limiting surfaces 6 and 7 (in Fig. 2), and horizontal working surfaces 5 towards the deflated pipe string 3. When moving tube dies 15 working surfaces 19 of the elastic seals 18 are located under the working surfaces to seal 5 cavities of the horizontal channels 4 of the housing 1, the working surfaces 20 (Fig. 6) are pressed against the working surfaces 20 of the elastic seals her 18 opposite pipe dies 15, and the working surface 21 to the deflated pipe string 3, tightly cover her, thereby sealing the wellhead. The working surfaces 19 of the elastic seals 18 form a closed loop. The pressure of the borehole medium arising under the tube dies 15 (Fig. 5) presses this circuit against the working surfaces 5 of the cavities of the horizontal channels 4 of the housing 1. The sealing material of the elastic seals 18, completely covered by the metal surfaces of the grooves 22 of the dies 15, does not move under the influence of fluidity and reliably seals the contact points of the pipe dies 15 with the column of deflated pipes 3. The position of the pipe dies 15 is controlled by the position of the helms 29.

To open the preventer after depressurizing, it is necessary to retract the tube dies 15 by rotating the handwheel 29 counterclockwise to its original position until the vertical axial channel 2 of the preventer housing 1 is fully open (Fig. 1).

If there is a need to seal the wellhead without running down equipment, the helms 29 with extension cords 30 are moved to the drive rods 27 (Fig. 7) of the bodies 9 of the lower blind dies 10, then the preventer is closed by turning clockwise the helms 29 with extensions 30 and drive rods 27. When this drive rods 27, interacting with threaded connections 25 of the covers 23, move the die blocks 8, including blind dies 10 with elastic seals 12, along the lateral boundary surfaces 6 and 7 and horizontal x working surfaces 5 of the cavities of the horizontal channels 4 (in Fig. 2) towards the vertical axial channel 2 of the housing 1 (Fig. 7). When moving the die blocks 8, including blank dies 10, the working surfaces 13 of the elastic seals 12 are located under the working surfaces to seal 5 cavities of the horizontal channels 4 of the housing 1, and the working surfaces 14 (Fig. 8) are pressed against the working surfaces 14 of the elastic seals 12 of the opposite deaf dies 10, thereby sealing the wellhead. The working surfaces 13 of the elastic seals 12 form a closed loop. The borehole pressure arising under the die blocks 8 with blank dies 10 (Fig. 7) presses this circuit against the horizontal working surfaces 5 of the cavities of the channels 4 of the housing 1. The sealing material of the elastic seals 12, completely covered by the metal surfaces of the grooves 11 of the dies 10, does not “flow” and reliably seals the joints of the die blocks 8, including deaf dies 10. The position of the die blocks 8 with deaf dies 10 is controlled by the position of the helms 29.

The rectangular shape in the cross section of the lateral horizontal channels 4 and the bodies of the die blocks 8 with the surfaces 6 and 7 securing it against rotation ensures the necessary conditions for the movement of the die blocks 8, and the absence of a keyway that can be filled with the solid phase of the drilling fluid and sludge will not create conditions for resistance to movement of the die blocks 8 and an increase in the force of their movement, thereby reducing labor costs during operation of the inventive preventer.

To open the preventer, after depressurizing, it is necessary to divert the housing of the die blocks 8 with the blind dies 10 by turning the steering wheels 29 counterclockwise to the initial position until the vertical axial channel 2 of the preventer case 1 is fully open (Fig. 1).

The operations required to close the inventive preventer without running out of equipment require significantly less time compared with the prototype, since reliable sealing of the wellhead in this situation ensures the closure of only the lower dies, i.e. blind dies 10, there is no need to close the tube dies 15. This ensures increased safety during the operation of the inventive preventer.

If it is necessary to suspend the pipe string 3 on the closed pipe dies 15 to increase the supporting surface under them, the housing of the die blocks 8 is moved by turning the handwheels 29 (Fig. 9) until the deaf dies 10 stop in the deflated pipe 3 (Fig. 10).

To replace the pipe dies 15 (Fig. 1) and the elastic seal 18 when changing to another pipe size or their wear, the die blocks 8 are easily removed from the horizontal cavities of the channels 4 of the housing 1, which significantly reduces the complexity of operation and maintenance.

To ensure safe remote control of the preventer dice 15 and 10, the helms 29 and extension cords 30 are removed. Cardan shafts with extension tubes (not shown) are connected to the drive rods 26 and 27. Helms 29 are installed at the ends of the extension pipes in a safe area. Due to this, there is the possibility of using the inventive preventer during emergency operations at the well, which ensures the expansion of the operational capabilities of the inventive device.

This technical solution of the preventer provides reliable sealing of the wellhead, increasing safety, reducing labor costs during operation and maintenance, and expanding operational capabilities.

Claims (10)

Spot preventer containing - a housing with a vertical axial channel and symmetrical lateral horizontal channels relative to it, the longitudinal axis of which is perpendicular to the axis of the vertical channel, - installed in horizontal channels with the possibility of longitudinal movement of the die blocks, in each of which placed tube and blind dies, equipped with elastic seals, - and manual dice control drives, including drive rods of the upper and lower dies, having threaded connections for interaction with the cover connected to the housing, characterized in that - the cavity of the lateral horizontal channels and the housing of the block blocks in cross section have a rectangular shape, - lower blind dies directly overlap the vertical axial channel of the housing, and their housing is the housing of the die blocks, - the case of the upper tube dies in cross section have a rectangular shape and are placed in rectangular recesses of the bodies of the lower dies with the possibility of movement, - while elastic seals are placed in curly grooves made in the bodies of the dies, - and the longitudinal axis of the drive rods of the dies are spaced relative to each other in a vertical diametrical plane and interact with two threaded holes of the cover.

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