SU1730427A1 - Multi-purpose preventer - Google Patents

Abstract

The invention relates to equipment for sealing a wellhead during repair work. The purpose of the invention is to increase the efficiency of the preformer when sealing the wellhead, both with and without drill pipes. The preventer consists of a housing 1 in which an annular sealing element (CI) 2 is installed, containing the top 3, center 4 and bottom 5 sections (C), forming the internal cavity (P) 6. The top C 3 has a shoulder 7, the bottom C 5 and C 3 are reinforced with segments 8. In case 1, the UE 2 is sealed with a cover 9 with an annular groove 10. Moreover, P 6 is connected to the well through channel 15 and valve 16, and to external source of pressure through channel 17 and valve 18. Through channel 17 from The external pressure source in F6 is supplied with compressed gas. In doing so, C 3 is pressed up, and C 4 is compressed by the drill pipe. The valve 18 is closed, and the valve 16 is opened, connecting the valve with a space. When this occurs, annular space self-consolidation occurs due to well pressure. With increasing pressure in the well, the upper ends of the segments 8 are pressed against the cover 9. The burst 7 engages the groove 10, preventing the C 3 from detaching from the sleeve 14. When the last drill pipe leaves the UE 2, the well pressure C 4 is pressed upwards and the segments 8 abut into cover 9 and rotated, preventing extrusion of UE 2. 3 sludge. cl

Description

The invention relates to equipment for sealing a wellhead during repair work.

The aim of the invention is to increase the efficiency of the preventer during the sealing of the wellhead, both with and without drill pipes.

FIG. 1 shows a preventer with a column pipe in it; in fig. 2 - pipe sealing preventer; in fig. 3 - closed preventer.

The preventer consists of a housing 1 in which an annular sealing element 2 is installed, comprising an upper 3, a central 4 and a lower 5 section, forming an internal cavity 6. The upper section of the sealing element has a shoulder 7 located on its outer surface. The lower and upper sections of the sealing element are reinforced with 8-gauge segments. The sealing element is fixed in the housing by a cover 9, on which

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an annular groove 10 is made under the collar 7. The tightness of the cavity 6 is provided with rings 11 and 12 installed in the grooves of the sleeves 13 and 14 gummed in the rubber of the sealing element. The annular cavity of the sealing element is connected to the well through the channel 15 and the valve 16, and through the channel 17 and the valve 18 to an external pressure source. A spacer ring 19 is inserted from the outside into the annular sealing element, consisting of individual segments, between which slots 20 are formed.

The preventer works as follows.

When performing hoisting operations without pressure at the wellhead, the sealing element freely passes the string of pipes, without being subjected to wear, since the diameter of the bore hole in the seal is larger than the diameter of the coupling connections of the string.

When pre-sealing the annulus through an open valve 18 through the channel 17 from the external source of pressure in the cavity 6 serves compressed gas (valve 16 is closed).

Under the pressure of the gas, the sealing element increases in volume, its lower section 5 rests on the housing 1, and the upper 3 is pressed upwards, the central section 4 compresses the rough. When the pressure in the cavity 6 is close to the pressure in the well, the valve 18 is closed, disconnecting the external pressure source, and the valve 1G is opened connecting the cavity 6 with the well space through the slots 20 of the spacer ring 19 and channel 15 (Fig. 2). The annular space self-consolidation occurs due to the pressure in the well. Since the pressure in the annular cavity 6 is equal to the pressure at the wellhead, the lower section 5 of the sealing element 2 is unloaded and acts as a separator between the cavity of the seal and the well space. The pipes are lowered or raised under pressure. With increasing pressure in the well, the upper ends of the segments 8 of the seal section 3 are pressed against the cover 9. The collar 7 of the upper section 3 engages with the groove 10 of the cover 9, preventing the seal section 3 from tearing from the sleeve 14. As the last pipe leaves the seal ( pipe lift) downhole pressure of the central section 4 of the seal is pressed up, and

as the upper ends of the segments 8 abut against the cover 9, and the vertical ends move upwards, the segments 8 rotate until the seal bore closes (Fig. 3). As the pressure increases in the well, the force increases, locking the sealing element up to the stop of the segments 8 into each other. Thus, thanks to the L-shaped form, the segments 8 in the closed

The preventer rests against the top end of the cover 9, and the vertical ends of each other and securely lock the preventer in the absence of pipes in it, preventing extrusion of elastic material by well pressure through the hole in the cover 9.

The proposed preventer design allows to increase the service life of the sealing element approximately 10 times,

provide automatic self-consolidation and well shut-off when the last pipe is extracted by using well pressure.

The effectiveness of the preventer consists of reducing the time for installation and dismantling, increase of the overhaul life, reduce the cost of construction and will be about 3 thousand rubles. in one well-operation.

Invention Formula

A universal preventer comprising a housing with a lid, a valve and an annular chamber made in the housing, and an annular sealing element placed in the annular chamber and containing the upper, central and lower sections forming the inner cavity, which increasing the effectiveness of the preventer during sealing the wellhead with or without drill pipes, the annular sealing element is made with segments and installed in the housing with the possibility of axial displacement of its central section ns, while its upper section has a shoulder disposed on its outer surface, and the body is made

with a channel for communicating the inside of the annular sealing element with a borehole and an additional valve for closing this channel, and the housing cover is made with a bore for accommodating a collar in it, with the upper and lower sections of the annular sealing element being tapered.

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FIG. 2

FIG. 3

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Claims (1)

Claim A universal preventer, including a housing with a cover, a valve and an annular chamber made in the housing, and an annular sealing element located in the annular chamber and containing the upper, central and lower sections forming an internal cavity, characterized in that, in order to increase the efficiency of the preventer when sealing the wellhead with or without drill pipes, the annular sealing element is made with segments and installed in the housing with the possibility of axial movement of its central section, etc. and this its upper section has a collar located on its outer surface, and the housing is made with a channel for communicating the internal space of the annular sealing element with the well and an additional valve for blocking this channel, and the housing cover is made with a groove for accommodating the collar, the upper and the lower section of the annular sealing element is made conical. Fi 2.1 FIG. 2 FIG. 3 Compiled by S. Dolgov Editor Z. Khudakova Tehred M. Morgenthal Corrector S. Lyzhova Order 1503 Circulation Subscription VNIIIPI of the State Committee for Inventions and Discoveries at the State Committee for Science and Technology 113035, Moscow, Zh-35, Raushskaya nab., 4/5 Production and Publishing Combine Patent, Uzhgorod, 101 Gagarin St.