Shear seal blowout preventer
AssigneeNational Oilwell Varco, L.P.
InventorDenzal Wayne Van Winkle
Life of this patent
Estimating the term…
Abstract
A shear/seal ram provides a knife edge at the shearing edge and the knife edge is inclined to minimize the cutting force required and to leave a clean cut edge. The knife edge is presented in an opening of the ram, thus the opening is positioned at the axis of the BOP, and consequently the coiled tubing, before the coiled tubing is run through the BOP. A biasing means, such as for example a Bellville spring, forces a sealing sleeve against the underside of the ram to prevent leakage of pressure from below the BOP. Similarly, a plurality of biasing means, referred to herein as “skates”, forces the ram down against the sealing sleeve to seal pressure from above the BOP.
Claims20
A blowout preventer for severing a tubular, the tubular positionable in a wellbore penetrating a subterranean formation, comprising:
- a body having an axial bore and a radial bore therethrough, the tubular positionable through the axial bore, the body having a tube receiving cavity extending radially about a portion of the axial bore and defining a pocket between the axial bore and the radial bore to receive a portion of the tubular upon severing, the pocket extending about a portion of a horizontal circumference of the axial bore;
- and
- a ram having a ram bore therethrough, the ram slidably positionable in the radial bore between a refracted position and an extended position, the tubular positionable through the ram bore and the axial bore when the ram bore is in the retracted position;
- and
- a knife positionable about the ram bore to sever the tubular as the ram moves from the retracted to the extended position, a severed end of the tubular receivable in the tube receiving cavity as the tubular is severed.
A system for severing a tubular, the tubular positionable in a wellbore penetrating a subterranean formation, comprising:
- a blowout preventer, comprising:
- a body having an axial bore and a radial bore therethrough, the tubular positionable through the axial bore, the body having a tube receiving cavity extending radially about a portion of the axial bore and defining a pocket between the axial bore and the radial bore to receive a portion of the tubular upon severing, the pocket extending about a portion of a horizontal circumference of the axial bore;
- and
- a ram having a ram bore therethrough, the ram slidably positionable in the radial bore between a retracted position and an extended position, the tubular positionable through the ram bore and the axial bore when the ram bore is in the retracted position;
- and
- a knife positionable about the ram bore to sever the tubular as the ram moves from the retracted to the extended position, a severed end of the tubular receivable in the tube receiving cavity as the tubular is severed;
- a seal positionable in the body adjacent the ram by a spring;
- and
- a depressor to compress the at least one seal into the body.
A method for severing a tubular, the tubular positionable in a wellbore penetrating a subterranean formation, comprising:
- positioning a blowout preventer about the tubular, the blowout preventer comprising:
- a body having an axial bore and a radial bore therethrough, a ram having a ram bore therethrough, and a knife positionable about the ram bore, the body having a tube receiving cavity extending radially about a portion of the axial bore and defining a pocket between the axial bore and the radial bore, the pocket extending about a portion of a horizontal circumference of the axial bore;
- severing the tubular by engaging the tubular with the knife while slidably moving the ram in the radial bore from a retracted position with the tubular positioned through the radial bore and the axial bore and an extended position a distance therefrom;
- and
- receiving a severed end of the tubular in the tube receiving cavity.
Dependencies are inferred from the claim text.