RU2713032C1 - Ram-type blowout preventer for wells with two-row string pipe - Google Patents

Abstract

FIELD: oil and gas industry.

SUBSTANCE: invention relates to sealing equipment of wellheads of oil and gas wells during their operation and repair in order to ensure safety, prevention and elimination of oil, gas and water ingresses (OGWI), including at wells with inclined mouth of two-row pipe string, protection of entrails and environment. Ram-type blowout preventer for borehole with two-row string comprises upper and lower flanges rigidly connected to housing, housing is equipped with a vertical circular axial channel, relative to the axial channel there are symmetrically arranged side horizontal channels, longitudinal axis of the side horizontal channels are located perpendicular to the axis of the vertical channel, in the first horizontal channels made in the housing with the possibility of longitudinal movement, there are installed ram blocks, in which the pipe rams are installed, equipped with elastic seals, and manual control drives of rams, which include drive rods of rams, having threaded connections for interaction with covers screwed into housing, at that, the cavities of the housing of the ram blocks in the cross section have a rectangular shape, and the elastic seals are placed in slots made in the tube rams. Upper part of the axial channel of the housing is equipped with a conical mounting surface narrowing downwards for installation of a replaceable sealing bushing. In upper flange second horizontal channels are made and have round shape in cross section. Outside, side screw stops are screwed into the horizontal channels of the upper flange in a sealed design, side screw stops interact with draw-out cylindrical sliders arranged in the horizontal channel; at that, draw-out sliders are equipped with key and shaped slots. Upper flange is equipped with keys installed in key slots of draw-out sliders, having the possibility of radial movement within the limits of key slots and rigid fixation of replaceable sealing bushing in conical mounting surface of housing by shaped slots of sliders. In preventer ram blocks there are tube rams provided with elastic seals on the basis of maximum outer diameter of pipe string of double row string, and for sealing of pipe string with minimum outer diameter of two-row pipe string in its assembly at wellhead there installed is emergency branch pipe with maximum outer diameter of pipe string equal to maximum outer diameter of pipe string from two-row string of pipes. Emergency branch pipe is equipped at the top with a ball valve, and at the bottom – with a reducer equipped with a thread from below, corresponding to thread of a pipe string coupling with minimum outer diameter of a two-row pipe string. Elastic seals are made of heat-resistant rubber, operating in temperature range from minus 65 to plus 300 °C.

EFFECT: proposed ram-type blowout preventer for well with two-row string has simple design; compact and easy to use; versatility during operation with two-row pipe string; accelerated installation at the well head of inclined wells; high efficiency in operation; high safety of work at wellhead of inclined wells in case of OGWI occurrence; high-quality air-tightness in case of steam release at temperature up to plus 300 °C.

1 cl, 4 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 liquidation of oil and gas manifestations (NGVP), including wells with an inclined mouth of a double-row pipe string, protection of the subsoil and the environment.

Blow-out ram preventer (patent No. 2214499, IPC ЕВВ 33/06, publ. 10/20/2003 in bull. No. 29), including a housing with a vertical barrel channel and a ram channel with sealing elements, covers and actuators are provided on both sides of which the ram channel has a circular cross-section, the preventer further comprises a hollow interchangeable element in the form of an open cylindrical insert with through holes in the side cylindrical surface installed in the boring of the ram channel through holes through the holes aligned with the stem a vertical channel, while on the outer lateral cylindrical surface of the replaceable element along its guides on two sides of the vertical barrel channel nests are provided for sealing elements, and the inner surface of the cylindrical insert is in contact with the dies.

The disadvantages of this device are:

- firstly, the complexity of the design, due to the large number of nodes and parts (a hollow interchangeable element in the form of an open cylindrical insert with through holes);

- secondly, not the universality of the design of the device, i.e. it is impossible to work with a double-lift pipe string in the well during tripping without replacing the pipe dies and elastic gaskets with the required pipe size. For example, a two-row pipe string was lowered into the well (for example, a tubing string 89 mm and a tubing string 60 mm). First, pipe dies with elastic elements for 89 mm tubing are installed in the preventer, then after finishing work with a 89 mm tubing string, it is necessary to replace pipe dies and elastic elements for a 60 mm tubing string. According to the safety requirements for the work, the replacement of tube dies and elastic elements should be carried out on a test bench with subsequent hydraulic crimping. For this, the preventer must be removed from the deviated wellhead. Take to the production service base, where to replace the tube dies and elastic elements with the required size (for tubing 60 mm). Hydraulic crimping of the replaced tube dies and elastic elements on the test bench. After that, the preventer with replaced tube dies and elastic elements must be returned to the well and installed on an inclined mouth for further work with a 60 mm tubing string. Or at the wellhead it is necessary to have an oppressed second preventer for the required size (tubing 60 mm) in order to replace the preventers directly at the inclined wellhead;

- thirdly, low efficiency due to limited functionality, since the design of the device does not allow to block the bore of the vertical trunk channel of the body during gas-water supply, as well as a number of technological operations: washing the face, cleaning the outer surface of the pipes, sealing the geophysical cable and etc .;

- fourthly, the low safety of work at the mouth of deviated wells of extra-viscous oil during routine and overhaul during oil and gas production in wells with a double-row pipe string, since when replacing a preventer, the wellhead remains open, and there is no way to quickly seal the mouth of deviated wells with extra-viscous oil (block the passage section of the barrel vertical channel of the body).

The closest in technical essence and the achieved result is a ram preventer (patent No. 2632721, IPC ЕВВ 33/06, published on 09/10/2017 in bull. No. 28), containing the upper and lower flanges rigidly connected to the housing, the housing is equipped with a vertical round axial the channel, relative to the axial channel, the lateral horizontal channels are symmetrically located, the longitudinal axis of the lateral horizontal channels are perpendicular to the axis of the vertical channel, in the first horizontal channels made in the housing with the possibility of longitudinal They were equipped with die blocks, in which tube dies equipped with elastic gaskets are placed, and manual dies control drives, including dies driving rods, having threaded connections for interacting with covers screwed into the housing, while the cavity of the housing of the die blocks in rectangular cross section shape, and elastic seals are placed in grooves made in pipe dies. The lower blind dies placed in the die block directly overlap the vertical axial channel of the housing, their bodies being the bodies of the die blocks, the upper tube dies in the cross section in a rectangular shape and placed in rectangular recesses of the lower die bodies with the possibility of movement, with elastic seals placed in shaped 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 STI and interact with the two screw holes on the cover.

The disadvantages of this device are:

- firstly, the complexity of the design, due to the large number of nodes and parts (blind dies, covers, etc.);

- secondly, the large dimensions and weight of the structure, due to the presence of two die blocks;

- thirdly, not the universality of the design of the device, i.e. it is not possible to work with a double-row pipe string in the well during the hoisting operations without replacing the pipe dies and elastic gaskets with the required size. For example, a two-row pipe string was lowered into the well (for example, a tubing string 89 mm and a tubing string 60 mm). First, pipe dies with elastic elements for 89 mm tubing are installed in the preventer, then after finishing work with a 89 mm tubing string, it is necessary to replace pipe dies and elastic elements for a 60 mm tubing string. According to the safety requirements for the work, the replacement of tube dies and elastic elements should be carried out on a test bench with subsequent hydraulic crimping. For this, the preventer must be removed from the deviated wellhead. Take to the production service base, where to replace the tube dies and elastic elements with the required size (for tubing 60 mm). Hydraulic crimping of the replaced tube dies and elastic elements on the test bench. After that, the preventer with replaced tube dies and elastic elements must be returned to the well and installed on an inclined mouth for further work with a 60 mm tubing string. Or at the wellhead it is necessary to have an oppressed second preventer for the required size (tubing 60 mm) in order to replace the preventers directly at the inclined wellhead;

- fourthly, the lengthy installation process of the preventer, due to the need to mount the wellhead reinforcement on the support flange in the inclined position of the ram preventer having large dimensions of more than 600 mm and a weight of more than 500 kg, while only mounting the preventer on the support flange of the wellhead reinforcement without sealing the mouth takes 10 15 minutes;

fifthly, low operational efficiency due to limited functional capabilities that do not allow technological operations (flushing of the face, cleaning of the outer surface of the pipes, sealing of the geophysical cable, etc.) in the well after the pipe string is lowered into the well;

- sixth, the low safety of work at the mouth of deviated wells of extra-viscous oil during routine and major repairs during the liquidation of oil and gas production due to the inability to quickly install a preventer on the support flange and seal the mouth of deviated wells with extra-viscous oil;

seventh, the elastic elements of the preventer do not ensure the tightness of the device in the event of the release of steam injected into the steam injection well at a temperature of 200-250 ° C.

The technical objectives of the invention are to simplify the design of the preventer, reduce the dimensions and weight, universalize the design of the preventer, as well as reduce the time required to install the preventer, expand the functionality of the preventer and increase the safety of work during water and oil manifestations at the mouth of an inclined well with extra-viscous oil with a double-row pipe string, and ensuring the tightness of the device in case of steam release.

The stated technical problems are solved by a ram preventer for a well with a double-row pipe string containing upper and lower flanges rigidly connected to the body, the body is equipped with a vertical round axial channel, lateral horizontal channels are symmetrically located relative to the axial channel, the longitudinal axes of the lateral horizontal channels are perpendicular to the axis of the vertical channel , in the first horizontal channels made in the housing with the possibility of longitudinal movement installed block blocks in the cat Tube dies are provided with elastic gaskets and manual dies control drives, including dies driving rods having threaded connections for interacting with covers screwed into the housing, while the cavity of the housing of the die blocks in cross section are rectangular in shape and the elastic gaskets are placed in grooves made in pipe dies.

New is the fact that the upper part of the axial channel of the housing is equipped with a conical seating surface, tapering from top to bottom for installing a replaceable sealing sleeve, while the second horizontal channels are made in the upper flange and have a circular cross-sectional shape, from the outside into the horizontal channels of the upper flange in lateral screw stops interacting with sealed execution, interacting with extendable sliders of cylindrical shape placed in a horizontal channel, while the extendable sliders are equipped with veneers and the grooves, and the upper flange is equipped with dowels installed in the keyways of the sliding sliders, which can radially move within the keyways and rigidly fix the removable sealing sleeve in the conical seating surface of the housing with the figured grooves of the sliders, while the tube blocks in the preventer blocks equipped with elastic seals based on the maximum outer diameter of the pipe string of the double-row pipe, and for sealing the pipe string with a minimum of external an emergency pipe with a maximum outer diameter of the pipe string equal to the maximum outer diameter of the pipe string from the double-row pipe string is installed from the diameter of the double-row pipe string into its layout at the wellhead; the emergency pipe is equipped with a ball valve on top and a sub equipped with a corresponding thread on the bottom pipe string couplings with a minimum outer diameter of a double-row pipe string, and the elastic seals are made of heat-resistant rubber operating in the temperature range from minus 65 to plus 300 ° C.

In FIG. 1-4 in longitudinal section schematically in the process shows the proposed preventer die for a well with a double-row pipe string.

A block preventer for a well with a double-row pipe string contains an upper 1 (Fig. 1) and lower 2 flanges rigidly connected to the casing 3. The casing 3 is equipped with a vertical circular axial channel 4. Two lateral horizontal channels 5 'and 5ʺ are symmetrically located relative to the axial channel 4 and 6 'and 6ʺ. The longitudinal axis of the lateral horizontal channels 5 'and 5ʺ and 6' and 6ʺ are perpendicular to the axis of the vertical channel 4.

In the first horizontal channels 5 'and 5ʺ, made in the housing 3 with the possibility of longitudinal movement, die blocks 7' and 7ʺ are installed, in which tube dies 8 'and 8ʺ are placed, equipped with elastic seals 9' and 9ʺ, respectively. Also, in the lateral horizontal channels 5 'and 5ʺ, manual actuators 10' and 10 '' for controlling tube dies 8 'and 8ʺ are installed, including drive rods 11' and 11ʺ of the corresponding tube dies 8 'and 8ʺ, respectively, having threaded connections 12' and 12ʺ for interactions with caps 13 'and 13ʺ.

The covers 13 'and 13ʺ are screwed into the housing 3. The cavities of the housing 3 of the die blocks 7' and 7ʺ in a cross section are rectangular in shape, and the elastic seals 9 'and 9ʺ are placed in grooves (not shown in FIGS. 1-4) made in pipe dies 8 'and 8ʺ. The upper part of the axial channel 4 of the housing 3 is equipped with a conical seating surface 14, tapering from top to bottom to install a replaceable sealing sleeve 15. For example, the angle of inclination of the conical surface α = 8 °, which allows you to place a replaceable sealing sleeve 15 in the upper part of the axial channel 4 of the housing 3. The second horizontal channels 6 'and 6ʺ are made in the upper flange 1 and have a circular shape in cross section. Outside, lateral screw stops 16 'and 16ʺ are screwed into the horizontal channels 6' and 6ʺ of the upper flange 1 in a sealed design. The screw stops 16 'and 16ʺ (shown in Figs. 1-4 conditionally) interact with the corresponding sliding sliders 17' and 17ʺ of a cylindrical shape placed in the horizontal channels 6 'and 6ʺ. The sliding sliders 17 'and 17ʺ are equipped with keyways 18' and 18ʺ and curly grooves 19 'and 19ʺ, respectively. The upper flange 1 is equipped with dowels 20 'and 20ʺ installed in the corresponding keyways 18' and 18ʺ of the sliding sliders 17 'and 17ʺ, with the possibility of radial movement within the keyway 18' and 18ʺ and rigid fixation of the replaceable sealing sleeve 15 in the conical seating surface 14 cases 3 shaped grooves 19 'and 19ʺ of the respective sliders 17' and 17ʺ. When carrying out tripping operations in a well with a double-row pipe string 21 and 22, in the block blocks 7 'and 7ʺ (Fig. 1) of the preventer, tube dies 8' and 8ʺ are equipped with elastic seals 9 'and 9ʺ based on the maximum outer diameter D used pipe string 21.

If it is necessary to seal the pipe string 22 with a minimum outer diameter d, an emergency pipe 23 (Fig. 2) with a maximum outer diameter D _a equal to the maximum outer diameter D, is installed in its layout at the wellhead. (D _a = D) pipe string 21.

The emergency pipe 23 is equipped with a ball valve 24 on top and a sub 25 on the bottom, connected from below to a pipe string 22 having a minimum outer diameter from a double-row pipe string.

The first horizontal lateral channels 5 'and 5ʺ made in the housing 3, and the second horizontal channels 6' and 6ʺ made in the upper flange 1, can be made parallel to each other (as shown in Fig. 1, 3, 4), and rotated 90 ° relative to each other (in Fig. 1-4 is not shown).

When using the device in steam injection wells, where the temperature of the injected steam is 200-250 ° C, in order to exclude the release of injected steam from the well, elastic seals 9 'and 9ʺ are made of heat-resistant rubber. As heat-resistant rubber, for example, silicone heat-resistant rubber or heat-resistant sponge VRP-1, manufactured according to TU 38.105.673-74 for sealing various types of detachable joints operating in the temperature range from minus 65 to plus 300 ° C, is used.

Tightness in the lateral horizontal channels 5 'and 5ʺ and 6' and 6ʺ in the process of operation of the device provide sealing rings (in Fig. 1-4 are shown conditionally).

The proposed preventer die for a well with a double-row pipe string works as follows.

A super-viscous oil deposit is developed by horizontal injection wells with an inclined wellhead, and a double-row pipe string is used. Steam is pumped through one pipe string 21, for example a tubing string with a diameter of 89 mm, and heated oil is drawn through another pipe string 22, such as a tubing string with a diameter of 60 mm, the pumping and sampling zones being separated by a packer. To implement the above technology in the process of operating and repairing wells, it is necessary to sequentially carry out the round-trip operations of pipe columns, for example tubing strings of two sizes 89 and 60 mm, for this, the proposed preventer is used for the ram.

On the basis of the service, where there is a test bench (not shown in FIGS. 1-4) for hydraulic crimping of the preventer in the first lateral horizontal channels 5 'and 5ʺ (as shown in FIG. 1), die blocks 7' and 7ʺ are mounted, corresponding to the maximum size tubing run into a well with a diameter of 89 mm. For this, a pipe, for example, 5 m long, equipped with a bottom packer (of any known design), is lowered into a test well (not shown in Fig. 1-4), a packer is planted, and then the pipe is passed through a vertical round axial channel 4 of the housing 3, and it is fixed a preventer on the support pipe of a test well. On the test bench, the upper end of the nozzle is tied to a pump (of any known design).

Next, the helms of the manual drives 10 'and 10ʺ are rotated clockwise 5-6 turns through the drive rods 11' and 11ʺ, which act in the axial direction on the corresponding tube dies 8 'and 8ʺ with elastic seals 9' and 9ʺ. As a result, pipe dies 8 'and 8ʺ with elastic gaskets 9' and 9ʺ radially move inward, and elastic gaskets 9 'and 9ʺ of a pipe with a diameter of 89 mm around the entire perimeter of its circumference. Then, using the pump, hydraulic pressure is created in the space between the tubing pipe 89 mm and the preventer, which occurs under the tube dies 8 'and 8ʺ (Fig. 4), while the created hydraulic pressure presses the elastic seals 9' and 9ʺ of the tube dies 8 'and 8ʺ to the outer surface of the pipe with a diameter of 89 mm, i.e. seal the space between the nozzle with a diameter of 89 mm and the preventer. For example, they test for two times the expected value of the steam injection pressure, equal to 20 MPa, with holding for 30 minutes, while the pressure drop and flow through the elastic seals 9 'and 9ʺ of the pipe dies 8' and 8ʺ are not allowed. After hydraulic pressure testing of the preventer by circular rotation of the handwheels of the manual drives 10 'and 10ʺ counterclockwise by 5-6 revolutions, tube dies 8' and 8ʺ with elastic seals 9 'and 9ʺ are returned, as shown in FIG. 1.

A preventer that successfully passes a leak test on a service base is sent to the well.

The preventer bottom flange 2 through the adapter (in Fig. 1-4 is not shown) is mounted on the supporting flange of the inclined wellhead.

Next, the descent of the pipe string 21 (tubing with a diameter of 89 mm) through the proposed transformer (Fig. 1). During the descent, the pipe string 21 is moved through the vertical axial channel 4 of the casing 3 (Fig. 1) until the bottom of the deviated well is reached (not shown in Fig. 1-4). Next, flush the well under pressure, for example up to 5.0 MPa. To do this, at the wellhead, in the conical landing surface 14 (Fig. 3) of the upper part of the axial channel 4 of the housing 3, a replaceable sealing sleeve 15 with a sealing collar (Fig. 2) is installed with a hole size corresponding to the diameter of the pipe string being sealed 21 (tubing with a diameter of 89 mm )

Then synchronously rotate the screw stops 16 'and 16ʺ clockwise for 5-6 turns clockwise, which interact with the corresponding sliding sliders 17' and 17ʺ of a cylindrical shape placed in the lateral horizontal channels 6 'and 6ʺ. Due to the rotation of the screw stops 16 'and 16ʺ, the sliders 17' and 17ʺ radially move in the lateral horizontal channels 6 'and 6ʺ into the housing 3 within the keyways 18' and 18ʺ, and the corresponding keys 20 'and 20ʺ do not allow the sliders 17' and 17ʺ radially rotate. As a result, the curly grooves 19 'and 19ʺ of the respective sliders 17' and 17ʺ, which do not have the possibility of circular rotation, rigidly fix the replaceable sealing sleeve 15 in the conical seating surface 14 of the housing 3. The replaceable sealing sleeve 15 hermetically covers the pipe string 21 along its outer diameter and is ready to work. Tie the upper end of the pipe string 21 with the pump unit and flush the bottom of the well along the string of pipes 21 under a pressure of up to 5 MPa in the amount indicated in the work plan with its simultaneous advancement along the sealing collar of the replaceable sealing sleeve 15. At the end of the flushing of the bottom of the well, synchronously 5 6 revolutions counterclockwise rotate the screw stops 16 'and 16ʺ, slide the sliders 17' and 17ʺ into the lateral horizontal channels 6 'and 6ʺ into the housing 3 until they interact with the ends of the screw stops 16' and 16ʺ (Fig. 1) and from attract a replaceable sealing sleeve 15 with a sealing sleeve from the upper part of the axial channel 4 of the housing 3.

If it is necessary to flush the well through the pipe string 22, use a replaceable sealing sleeve 15 with a sealing collar (Fig. 3) with a hole size corresponding to the diameter of the pipe string being sealed 21 (tubing with a diameter of 89 mm) and work on fixing the replaceable sealing sleeve 15 and flushing the well is repeated.

In the process of sequential tripping with pipe strings 21 and 22, NGVP can occur; for this, it is necessary to seal the space between the preventer and the pipe string 21 or 22 with elastic seals 9 'and 9ʺ of pipe dies 8' and 8ʺ, and also take the necessary technological measures to elimination of emission phenomena, i.e. block the interior of the pipe string 21 or 22.

To seal the wellhead with a deflated pipe string 21, the handwheels of the manual drives 10 'and 10ʺ (Fig. 4) rotate clockwise 5-6 revolutions through the drive rods 11' and 11ʺ, which act in the axial direction on the corresponding tube dies 8 'and 8ʺ with elastic seals 9' and 9ʺ. As a result, tube dies 8 'and 8ʺ with elastic seals 9' and 9ʺ radially move inward, and elastic seals 9 'and 9ʺ cover the column 21 around its entire circumference. The pressure of the borehole medium arising under the pipe dies 8 'and 8 гермет pressurizes the elastic seals 9' and 9ʺ of the pipe dies 8 'and 8ʺ against the outer surface of the pipe string 21, i.e. seal the space between the preventer and the pipe string 21.

The position of the tube dies 8 'and 8ʺ is controlled by the screwed-in position of the handwheels of the manual drives 10' and 10ʺ.

To overlap the inner space of the pipe string 21 at the mouth of an inclined well, a ball valve 24 of any known design (for example, grade KSh 70 × 21) is screwed onto the upper end of the pipe string 21 and the ball valve is turned, for example, by an angle of 90 °, clockwise internal bore. As a result, the inner space of the pipe string 21 is sealed and NGVP is eliminated.

After the elimination of NVGP i.e. after pressure relief in the well, the preventer is opened (the space between the preventer and the pipe string 21 is depressurized) and the interior of the pipe string 21 is restored.

First, a preventer is opened. To do this, rotating the handwheels of the manual drives 10 'and 10ʺ counterclockwise for 5-6 revolutions take pipe dies 8' and 8ʺ until the vertical axial channel 4 of the preventer body 3 is fully open, i.e. the tube dies 8 'and 8ʺ with elastic seals 9' and 9ʺ are returned to the position shown in FIG. 1.

Then, by turning the handle of the ball valve counterclockwise at an angle of 90 °, open the ball valve and, making sure that there is no discharge of NGVP along the pipe string, unscrew the ball valve from the upper end of the pipe string 21 and restore the internal space of the pipe string 21.

Sealing the mouth of an inclined well with a deflated pipe string 22 (Fig. 2).

At the mouth of the deviated well, the emergency pipe 23 with a ball valve 24 is screwed through the sub 25 to the upper end of the pipe string 22 (with a minimum outer diameter of the tubing string 60 mm in diameter).

Next, the string of pipes 22 is lowered relative to the preventer so that the emergency pipe 23 with its outer diameter D _a equal to 89 mm is located opposite the pipe dies 8 'and 8ʺ with elastic seals 9' and 9ʺ (Fig. 4)

Next, the preventer is closed. To do this, rotate the handwheels of the manual drives 10 'and 10ʺ (Fig. 4) clockwise for 5-6 turns through the drive rods 11' and 11ʺ, which act in the axial direction on the corresponding tube dies 8 'and 8ʺ with elastic seals 9' and 9. As a result, tube dies 8 'and 8ʺ with elastic seals 9' and 9ʺ radially move inward, and elastic seals 9 'and 9ʺ cover the column 22 around the entire circumference. The pressure of the borehole medium arising under the pipe dies 8 'and 8ʺ pressurizes the elastic seals 9' and 9ʺ of the pipe dies 8 'and 8ʺ against the outer surface of the pipe string 22. Thus, the space between the preventer and the pipe string 22 is sealed. The position of the pipe dies 8' and 8ʺ control by the screwed-in position of the helms of the manual drives 10 'and 10ʺ.

To overlap the inner space of the pipe string 22 at the mouth of an inclined well to the upper end of the pipe string 22, turn the knob clockwise through an angle of 90 ° to close the ball valve 24. As a result, the inner space of the pipe string 21 is sealed and NGVP is eliminated.

After the liquidation of the water supply pipe, that is, after depressurization in the well, the preventer is opened (the space between the preventer and the pipe string 22 is depressurized) and the internal space of the pipe string 22 is restored. The preventer is opened. To do this, rotating the handwheels of the manual drives 10 'and 10ʺ counterclockwise for 5-6 revolutions take pipe dies 8' and 8ʺ until the vertical axial channel 4 of the preventer body 3 is fully open, i.e. the tube dies 8 'and 8ʺ with elastic seals 9' and 9ʺ are returned to the position shown in FIG. 1.

Then, by turning the handle of the ball valve 24 counterclockwise by an angle of 90 °, open the ball valve 24 and, making sure that there is no discharge of NGVP along the pipe string 22, lift the pipe string 22 and turn off the emergency pipe 23 with a ball valve 24 and an adapter 25 from the upper end of the pipe string 22 and restore the inner space of the pipe string 22.

The proposed preventer die for a well with a double-row pipe string has a simple design (excluded horizontal side channel made in the housing with blind dies).

The proposed preventer die for a well with a double-row pipe string has a height of 350 mm and a weight of up to 200 kg, which is achieved by eliminating the lateral horizontal channel made in the housing with blank dies, and therefore the height of the housing is shortened, which is half lower in comparison with the prototype and makes Its more compact and easy to operate.

The proposed preventer die for a well with a double-row pipe string has a universal design, i.e. during the operation and repair of wells, it is possible to carry out tripping operations with a two-row pipe string without replacing the pipe dies and elastic gaskets with the required standard size with the removal of a preventer for crimping on a special stand, while all work is performed with a preventer in which pipe dies with elastic elements for the maximum diameter of the pipe string 21 (as described above tubing string with a diameter of 89 mm) with preliminary hydraulic crimping on a special stand based on the production aintenance M.

The proposed preventer die for a well with a double-row pipe string due to its lightness and compactness allows reducing the installation time of the preventer on the support flange of the wellhead in an inclined position by 2–3 times.

The elastic seals 9 ', 9', 'are made of a heat-resistant sponge VRP-1, which ensures the tightness of the preventer when the steam is released in the temperature range from minus 65 to plus 300 ° C.

The proposed preventer is highly effective in operation in comparison with the prototype, as it has enhanced functionality due to the fact that the design of the preventer contains a replaceable sealing sleeve. This allows you to carry out technological operations (washing the face, cleaning the outer surface of the pipes, sealing the geophysical cable, etc.) in the well after the descent of the pipe string into the well.

The safety of operations at the mouth of deviated wells of super-viscous oil is improved during routine and major repairs during the liquidation of oil and gas products, since the proposed preventer can quickly install it on the support flange of the deviated well heads of super-viscous oil and seal the mouth of deviated wells with super-viscous oil.

The proposed preventer die for a well with a double-row pipe string has:

- simple design;

- compactness and ease of use;

- universality when working with a double-row pipe string;

- accelerated installation at the mouth of deviated wells;

- high efficiency in work;

- high safety of work at the mouth of deviated wells in the event of oil and gas production;

- high-quality tightness in case of steam emission at temperatures up to plus 300 ° С.

Claims (1)

A die preventer for a well with a double-row pipe string containing upper and lower flanges rigidly connected to the body, the body is equipped with a vertical circular axial channel, lateral horizontal channels are symmetrically located relative to the axial channel, the longitudinal axes of the lateral horizontal channels are perpendicular to the axis of the vertical channel, in the first horizontal channels made in the housing with the possibility of longitudinal movement, installed block blocks, which are placed tube dies, equipped with acoustic seals and manual dies control drives, including dies driving rods having threaded connections for interacting with covers screwed into the housing, while the cavity of the housing of the die blocks in the cross section are rectangular in shape, and the elastic seals are placed in the grooves made in the tube dies characterized in that the upper part of the axial channel of the housing is equipped with a conical seating surface, tapering from top to bottom for installation of a replaceable sealing sleeve, while in the upper The second horizontal channels are made in this flange and have a circular cross-sectional shape; outside the horizontal channels of the upper flange in a sealed design, lateral screw stops are screwed in, interacting with sliding cylindrical sliders placed in the horizontal channel, while the sliding sliders are equipped with key and figured grooves and the upper flange is equipped with dowels installed in the keyways of the sliding sliders, which have the ability to radially move within the keyways and rigid fi of a replaceable sealing sleeve in the conical seating surface of the body with figured grooves of the sliders, while in the die blocks of the preventer there are tube dies equipped with elastic seals based on the maximum outer diameter of the pipe string of the double-row pipe, and for sealing the pipe string with the minimum outer diameter of the double-pipe pipe string in its layout at the wellhead an emergency pipe is installed with a maximum outer diameter of the pipe string equal to the maximum outer diameter of the pipe pipes from a double-row pipe string, and the emergency pipe is equipped with a ball valve on top and a sub with a thread on the bottom, corresponding to the thread of the pipe string coupling with a minimum outer diameter of the double pipe string, and the elastic gaskets are made of heat-resistant rubber operating in the temperature range from minus 65 to plus 300 ° C.

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