RU2191884C2 - Device for wellhead sealing - Google Patents

Abstract

FIELD: equipment applicable in well remedial works on oil and gas wells for wellhead sealing in emergency situations o n well or in prolonged shutdown of wells. SUBSTANCE: device has body with axial channel and conical seat made in axial channel. Installed into conical seat may be sealing conical insert with ball valve and lifting branch pipe for suspension of well equipment. Installed below conical seat are movable rams with sealing members and drive for sealing of lifting branch pipes. Movable gate plate with drive for shutoff of hole between sealing members during removal from body of sealing conical insert is located in guide recesses of one of rams. The other ram has stop for locking of gate plate in closed position. Vertical dimension of device does not require lifting and reequipment of working platform that is required in case of use of ram-type blowout preventers. EFFECT: higher operating reliability without application of high-size ram-type blowout preventers. 2 cl, 8 dwg

Description

 The invention relates to equipment used in the underground repair of oil and gas wells, and is used to seal the mouth in the event of an emergency at the well, as well as during a long break in work.

 A device for sealing the wellhead, comprising a housing with a tapered seat, a sealing insert made in the form of a tapered sleeve with a sealing element on the tapered surface, a lifting pipe with a locking element [1].

 A disadvantage of the known device is the inability to seal the mouth when icing the landing cone or getting on its surface foreign objects that prevent the conical sleeve from landing in the reciprocal landing seat. To ensure a guarantee of sealing of the mouth, the known device must be installed on a ram preventer having a significant vertical dimension (from 500 mm and above), requiring re-equipment and lifting of the working platform.

 It is also known a device for sealing a wellhead, comprising a body with a conical hole, a sealing insert made in the form of a conical sleeve with a sealing element on the conical surface, a lifting pipe with a shut-off element, adopted as a prototype [2].

 A disadvantage of the known device is the impossibility of sealing the mouth when icing the landing cone or getting on its surface foreign objects that impede the landing of the conical sleeve in the reciprocal landing seat. To ensure a guarantee of sealing of the mouth, the known device must be installed on a ram preventer having a significant vertical dimension (from 500 mm and above), requiring re-equipment and lifting of the working platform.

 The technical problem solved by the invention is to increase the reliability of sealing the wellhead without installing the inventive device on a ram preventer.

 The problem is solved in that the device for sealing the wellhead, comprising a housing with an axial channel and a conical seat saddle made in the axial channel, and a sealing cone insert with a spherical shutter and a lifting nozzle for suspending the downhole equipment installed in the conical seat, is provided with the following tapering seat saddle with movable dies with sealing elements and a drive for sealing the lifting nozzle and a movable slide plate with a drive for overlap of openings between the sealing elements when removed from the body of the sealing cone-shaped insert, wherein the sliding plate is positioned in the guide grooves of one of the dice and the other die provided with an abutment for fixing the slide plate in position "Closed".

The invention is illustrated by drawings, which depict:
In FIG. 1 is a General view of the device in section along a vertical plane with the removed sealing conical insert.

 In FIG. 2 - sealing conical insert with a partial vertical section.

 In FIG. 3 - a die with a sealing element.

 In FIG. 4 is a view of the die in the direction of arrow E and the slide plate.

 In FIG. 5 is a view of the device at the time of installation of the sealing cone insert in the seat seat, while the mechanisms for driving the dies and the drive of the slide gate are not shown.

 In FIG. 6 is a view of the device at the moment of operation of the movable dies and sealing by the sealing elements of the lifting pipe, the drive mechanism is also not shown.

 In FIG. 7 - a fragment of the device at the moment of operation of the movable dies with the removed lifting pipe.

 In FIG. 8 is a fragment of the device at the moment the slide plate is actuated and the wellhead is sealed with the lifting pipe removed.

 The device comprises a housing 1 with an axial channel 2, a tapered landing seat 3, dies 4 and 5 with a drive 6, a slide plate 7 with a drive 8, an abutment 9 for fixing the slide plate 7 (Fig. 1). The drive 6 of the dies 4 and 5 is carried out by a removable steering wheel (not shown), the connection point of which is closed by a cap 10. The drive 8 of the slide plate 7 is made by a removable steering wheel (not shown), the connection point of which is closed by a cap 11. The housing 1 is equipped with a sealing ring 12 (Fig. 1), a sealing conical insert 13 with a ball valve 14 and a lifting pipe 15 for connecting to a string of tubing through a sub 16 (Fig.2). The die 4 is equipped with a stop 9 and a sealing element 17 (figure 1). The die 5 is equipped with a sealing element 17 and guide grooves 18 for movably accommodating the slide plate 7 (Figs. 3, 4).

 The device operates as follows. If it is necessary to seal the wellhead, the sealing conical insert 13 is connected by means of a sub 16 to the tubing string and it is installed in the conical landing seat 3 with fixation from axial displacement (Fig. 5). In the event of complications when installing the sealing cone insert 13 in the seat saddle 3 (due to icing, the presence of foreign objects, etc.) using the drive 6, the dies 4 and 5 are set in motion towards each other until their sealing is tight and tight elements 17 around the lifting pipe 15 (Fig.6). In the event of similar complications, but in the absence of a tubing string in the well, the wellhead is sealed in two stages: first, the dies 4 and 5 are set in motion until their sealing elements 17 are tightly and tightly sealed into a ring (Fig. 7), then using a drive 8 drive the slide plate 7 until it contacts the stop 9 (Fig. 8). The slide plate 7 hermetically closes the annular space formed by closed sealing elements, providing a sealing of the wellhead in the absence of a tubing string in the well.

 The use of the claimed device in the practice of underground well repair will provide a higher level of reliability of operation without resorting to the use of high-sized ram preventers. The vertical dimension of the claimed device 365 mm does not require lifting and re-equipment of the working platform, as required by ram preventers.

Sources of information
1. SU 1838541 A3 (Kurtov V.D.), Е 21 В 33/03, 08/23/93.

 2. RU 21603S5 C1 (Abramov A.F.), Е 21 В 33/03, 05/13/99,

Claims (2)

 1. A device for sealing the wellhead, comprising a housing with an axial channel and a conical seat saddle made in the axial channel, and a sealing cone insert with a ball valve and a lifting nozzle for suspending the downhole equipment installed in the conical seat, characterized in that it is equipped with installed below the conical seat, movable dies with sealing elements and a drive for sealing the lifting nozzle and a movable slide plate with a drive for overlapping holes between the sealing elements when removing the sealing cone insert from the housing.  2. The device for sealing the wellhead according to claim 1, characterized in that the slide plate is located in the guide grooves of one of the dies, while the other die is equipped with a stop for fixing the slide plate in the "Closed" position.

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