RU2726656C1 - Shutoff hydraulic-controlled device for sealing of flow well mouth - Google Patents

Abstract

FIELD: oil and gas industry.SUBSTANCE: invention relates to oil-producing and geological-prospecting industries and is intended for sealing of flow well at elimination of open gas and oil fountains with high flow rates and abnormally high pressures of well medium. Disclosed is a hydraulic shutoff device for sealing the flow well mouth, comprising a unit consisting of a cross piece, an adapter, a housing, a cover and provided with upper and lower vertical feed flanges, a vertical through passage, with two lateral taps, equipped with remote controlled hydraulically driven single-block valves with two shut-off elements in each, two, with through axial working channels, ball gates arranged in the lower and upper bores of the housing pressed to the seats by spring-loaded supports and equipped with two rotary, remotely controlled hydro-drive units arranged on the housing. At that, in cross piece passage channel is made stepped – increased diameter in its lower part and reduced in upper part. Side branches are arranged in increased cross piece lower part at angle to vertical axis. Besides, seats of ball gates arranged in annular grooves of inner collar of housing and lower end of cover, include external and internal metal bushes, which are supported by upper ends on sealing elastically deformable inserts, which annular ledges are arranged between metal bushes and contact with ball gates, and lower ends of sleeves are made with spherical surfaces, which correspond to outer diameters of ball gates, wherein on spherical surfaces of external metal inserts there are radial and annular channels.EFFECT: proposed device allows reliable sealing of wellhead with flow column with diameter of more than 273 mm at high production rate and abnormally high pressure of well medium more than 35 MPa.1 cl, 4 dwg

Description

The invention relates to the oil and gas production and exploration industries and is intended to seal the wellhead with a gushing string with a diameter of more than 273 mm at high flow rates and abnormally high pressure of the wellbore environment of more than 35 MPa.

To seal the wellhead of an open-flowing well and then stop the outflow of the wellbore environment by shutting it off in order to perform further emergency work to kill the well, a dual ram preventer is most often used as a shutoff element as a shutoff element as part of a guided shut-off-wellhead assembly (ZUS).

Known "Preventer hydraulic double ram with a technological cone" (1) designed to seal the wellhead with a lowered string of pipes with pipe dies and to seal the well without a lowered string of pipes with blind dies.

The known preventer has the following disadvantages:

- there is no additional safety barrier, since the closure of the channel to stop the outflow of the wellbore fluid is carried out with only one set of rams, thereby reducing the reliability of the preventer;

- dies and sealing elements with a large flow rate of the gushing jet and an abnormally high wellhead pressure of more than 35 MPa can be damaged and pulled out of the seats, which will lead to the failure of the preventer.

Known "Double-ball wellhead valve" (2) is designed to close the channel in order to stop the flow of the working medium from the well.

The well-known two-ball wellhead valve has the following disadvantages:

- the design of the crane is excessively complex and laborious to manufacture and assemble;

- is not equipped with controls for the possibility of remote closing of ball valves, which reduces the level of safety for the operational staff.

There is also known a pipe head (3), which can be used as part of the ZUS when sealing the mouth of a gushing well.

The known pipe head has the following disadvantages:

- not equipped with controls for the possibility of remote closing of the ball valve, which reduces the level of safety for the operational staff;

- the design of the pipe head is excessively complex and laborious to manufacture and assemble;

- there is no additional safety barrier, since the closure of the channel to stop the outflow of the wellbore fluid is carried out with only one ball valve, thereby reducing the reliability of sealing the wellhead.

The purpose of the invention is to perform reliable sealing of the wellhead, with a gushing string with a diameter of more than 273 mm at a high flow rate and an abnormally high pressure of the wellbore medium of more than 35 MPa, by means of a remote, to ensure the safety of operating personnel, guidance at the wellhead of a hydraulic shut-off device with minimum weight and size characteristics, and having the ability to remotely terminate the outflow of the borehole medium by closing it with the shut-off devices of the device in order to perform further emergency work to kill the well.

The set goal is achieved by a hydraulically controlled shut-off device for sealing the wellhead of a gushing well, including a block consisting of a cross, an adapter, a body and a cover, equipped with upper and lower connecting flanges and a vertical passageway, with two side branches equipped with remotely controlled hydraulic monoblock valves with two shut-off bodies each, with two ball valves placed inside the body, with through axial working channels, pressed against the seats by spring-loaded supports and equipped with two rotary, remotely controlled hydraulic units located on the body, which has a passage channel in the cross, for use in wells with large flow rate and abnormally high pressures of the wellbore medium, made stepwise, and side branches are located in its enlarged part at an angle to the vertical axis and provide a part of the wellbore fluid from the crosspiece through open monoblock sliders allowing, thereby, to significantly reduce the pressure of the wellbore fluid on the ball valves when they are closed, and the seats located in the body and the cover include metal and elastic-deformable sealing inserts, the annular protrusions of which are located between the metal bushings and contact the ball valves , and the lower ends of the bushings are made with spherical surfaces corresponding to the outer diameters of the ball valves, moreover, radial and annular channels are made on the spherical surfaces of the outer metal inserts, which ensure the penetration of the borehole medium into the outer metal insert, thereby reducing the area of effect of abnormally high pressure on the ball valves with a corresponding decrease in the specific pressure at the sealing points, while maintaining the necessary contact area for uniform distribution of the forces transmitted by the ball valves to the seats when the passage channel is closed.

In FIG. 1 shows the assembled device; in fig. 2 - the same, view along the section A-A of FIG. 1; in fig. 3 - the same, top view B of Fig. 1; in fig. 4 is a view of the seals of the ball valves along the callout B of FIG. 2.

The device (Fig. 1) includes a block 1 consisting of a cross 1.1, an adapter 1.2, a body 1.3 and a cover 1.4. The passage channel in the crosspiece is made stepped - with an increased diameter in the lower part and a reduced diameter in the upper part. The lateral branches of the crosspiece 1.1 are made in its passage channel of increased diameter, are located at an angle to the vertical axis and provide a part of the borehole medium from the enlarged passageway of the crosspiece, and its channel of reduced diameter reduces the buoyancy force of the borehole medium acting on the ball valves. At the same time, the reduced diameter in the crosspiece passage channel provides reduced weight and size characteristics of the device by reducing the diameter of the ball valves and, accordingly, the outer diameter of the body. The connecting flanges of the side outlets are equipped, through the elbows 2, with hydraulically controlled monoblock valves 3 with two shut-off bodies on each. On the outer side surface of the body 1.3, along the vertical axis, there are two rotary hydraulic drive units 4 diametrically located, consisting of brackets 4.1, hydraulic cylinders 4.2 and adjustment mechanisms 4.3. Hydraulic cylinders 4.2 provide rotation of the ball valves 9 (Fig. 2) at an angle of 90 °, using levers 6 (Fig. 1) connected to the hydraulic cylinder rods 4.2 by pins 5 and spindles 7 located in the radial channels of the body and articulated rectangular protrusions with reciprocal rectangular samples of ball valves. On the levers 6, the risks "O" and "Z" are made, indicating the "open" and "closed" positions of the ball valves when they are combined with the risks applied to the body. The coaxiality of the passage channels of the ball valves with the bore of the body is ensured by adjusting the strokes of the hydraulic cylinders with mechanisms 4.3 equipped with forks with threaded rods located in the lugs of the brackets 4.1 and adjusting nuts resting on the lugs of the brackets. Piston and rod cavities of hydraulic cylinders 4.2 and monoblock valves 3 are equipped with quick couplings for connecting hydraulic control lines to them. In the lower and upper bores of the housing are placed, pressed against the seats 10 by the supports 11, by means of springs 13 placed in the cage 12, two ball valves 9 (Fig. 2), with through axial channels, ensuring the overlap of the passage channel in order to stop the outflow of the gushing medium ... Saddles 10 (Fig. 2), for sealing the ball valves 9, consist of external 10.1 and internal 10.2 metal bushings (Fig. 5), supported by their upper ends on elastic deformable sealing inserts 10.3, the annular protrusions of which are located between the metal bushings and contact the ball gates, and the lower ends of the bushings are made with spherical surfaces corresponding to the outer diameters of the ball valves. At the same time, radial and annular channels are made on the spherical surfaces of the outer metal inserts, which ensure the penetration of the borehole medium into the contact zones of the external metal inserts and ball valves, bounded by the annular channels, thereby reducing the area of effect of abnormally high pressure on the ball valves with a corresponding decrease in the specific pressure at the sealing points, while maintaining the necessary contact area for uniform distribution of the forces transmitted by the ball valves to the seats when the bore is closed.

The lower part of the cross is represented by a connecting flange for attaching to it when sealing the wellhead of a gushing well, represented by a wellhead flange, a transition coil with a lower flange corresponding to the wellhead, or when sealing the wellhead of a gushing well, represented by a column head, a head in various versions, for example, a one-piece column flange type FKN or ZGT (4, p. 171 ... 174), self-sealing wedge column head (5). The upper parts of the cover and monoblock valves are also represented by connecting flanges for attaching branch pipes to them.

If it is necessary to open the ball valves under the pressure of the borehole environment, there are fittings 8 in the body equipped with quick couplings for connecting hydraulic lines and supplying working fluid to the over-ball cavities of the valves to create back pressure in them.

Working with the device when sealing the wellhead of a gushing well is performed in the following order.

The device is built into the ZUS, which either with the help of a remote-controlled hydraulic-driven coordinate-type guidance device mounted at the wellhead, or with the help of a self-propelled remote-controlled robotic complex, remotely at a safe distance from the control panel is directed to the mouth of a gushing well, represented either by a wellhead flange. equipment, or column head. Guidance is carried out with open ball valves and monoblock valves installed on the side branches of the cross. With open monoblock valves, part of the well fluid flow is directed to the side branches of the cross, thereby reducing the flow of well fluid passing through the ball valves.

After fixing the ZUS at the wellhead, high-pressure pressure hoses from the hydraulic station located outside the hazardous zone are connected to the hydraulic operating elements of the device. By supplying the working fluid to the rod cavity of the hydraulic cylinder of the turning unit of the lower ball valve, it is turned, closing the passage channel.

Under the action of the borehole pressure, the ball valve is pressed against the seat, while the metal inserts are pressed into the elastically deformable non-metallic insert, forcing it with an annular protrusion located between the metal inserts to tightly cover the ball valve and reliably seal the bore of the body. After that, the upper ball valve and monoblock side branch valves are closed in turn, reliably sealing the wellhead.

If it is necessary to open the ball valves under the pressure of the wellbore medium, through the fittings 8 (Fig. 1) equipped with quick-release couplings, the working fluid is supplied to the overball cavities of the valves to create a back pressure in them equal to the wellbore pressure.

The device can be used for sealing a flowing well with an underwater wellhead.

Sources of information

1. Patent for invention No. 167756. "Double ram hydraulic ram blower with technological cone" dated 03.03.2016

2. Patent for invention No. 2204073. "Two-ball wellhead crane" dated 19.02.2001

3. Patent for invention No. 2182218. "Pipe head" dated 07.06.2001

4. Equipment and tools for the prevention and elimination of fountains. Directory. Moscow, "Nedra", 1966.

5. Patent for invention №2138614. "Self-sealing wedge column head" dated 09/27/1999

Claims (1)

Hydraulically controlled shut-off device for sealing the mouth of a gushing well, including a block consisting of a cross, an adapter, a body, a cover and equipped with connecting flanges with an upper and lower, vertical passageway, with two side outlets, equipped with remotely controlled hydraulic monoblock valves with two shut-off elements through squares in each, two, with through axial working channels, ball valves located in the lower and upper bores of the body, pressed against the seats by spring-loaded supports and equipped with two rotary, remotely controlled hydraulic units located on the body, characterized in that there is a passage channel in the crosspiece, in order to reduce the weight and size characteristics and the buoyancy force of the borehole medium acting on the ball valves, it is made stepwise - with an increased diameter in its lower part and reduced in the upper part, and the side branches are located in its increased lower part at an angle to the vertical axis, in addition, the seats of the ball valves, located in the annular bores of the inner shoulder of the body and the lower end of the cover, include external and internal metal bushings supported by the upper ends on elastic-deformable sealing inserts, the annular protrusions of which are located between the metal bushings and contact the ball gates, and the lower ends of the bushings are made with spherical surfaces corresponding to the outer diameters of the ball valves, and radial and annular channels are made on the spherical surfaces of the outer metal inserts.

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