Power slips
AssigneeTesco Corporation
InventorMilan Cerovsek
Life of this patent
Estimating the term…
Abstract
A slip assembly for gripping pipe during well drilling operations has a housing with a hole for receiving a section of pipe. Pockets in the housing are spaced circumferentially around the hole. Each of the pockets has side walls that face toward each other and are connected to each other by a back wall that has at least one ramp surface. A slip segment is located in each pocket, each slip segment having side edges that engage the side walls of one of the pockets. Each slip segment has a back side with a ramp surface that engages the ramp surface on the back wall of the pocket. Each of the slip segments is movable within its pocket from an upper outward position to a lower inward position in gripping engagement with the pipe.
Claims20
A slips assembly for gripping pipe, comprising:
- first and second housing segments that arc secured to each other by a hinge, defining a housing having a hole therethrough for receiving a section of pipe;
- a plurality of pockets in the housing and spaced circumferentially around the hole, the pockets and the housing being movable in unison with each other, each of the pockets having two circumferentially spaced apart side walls that face toward each other, me side walls being connected to each other by a circumferentially extending back wall that has at least one ramp surface;
- a slip segment located in each pocket, each slip segment having side edges on opposite circumferential sides of the slip segment, at least one of the side edges contacting one of the side walls of one of the pockets in operation to transfer torque between the slip segments and the housing, and each of the slip segments having a circumferentially extending back side with at least one ramp surface that engages the ramp surface on the back wall of the pocket;
- and
- each of the slip segments being slidable on the ramp surfaces within its pocket from an upper outward position to a lower inward position in gripping engagement with the pipe.
A slips assembly for gripping pipe, comprising:
- first and second housing segments that are secured to each other by a hinge, defining a housing having a hole therethrough for receiving a section of pipe;
- a plurality of pockets in the housing and spaced circumferentially around the hole, each of the pockets being movable in unison with the housing, each of the pockets having an upper end, a lower end, and side walls that are flat, parallel to each other and connected to each other by a back wall that extends circumferentially between the side walls, the side walls extending from the lower end to the upper end of the pocket;
- at least one upper ramp surface on the back wall of each of the pockets, the upper ramp surface sloping inward and downward toward an axis of the hole;
- at least one lower ramp surface on the back wall of each of the pockets below the upper ramp surface, the lower ramp surface sloping inward and downward toward the axis, the lower ramp surface having an upper end that is closer to the axis than an upper end of the upper ramp surface and farther from the axis than a lower end of the upper ramp surface, the lower ramp surface having a lower end that is closer to the axis than the lower end of the upper ramp surface;
- a slip segment located in each pocket, each slip segment having side edges, at least one of the side edges of each of the slip segments contacting one of the side walls of the pocket during operation to transfer torque between the slip segments and the housing;
- upper and lower ramp surfaces on a back side of each of the slip segments that engage the upper and lower ramp surfaces on the back wall of the pocket;
- and
- the ramp surfaces of each of the slip segments being slidable along the upper and lower ramp surfaces of the back wall within its pocket from an upper outward position to a lower inward position in gripping engagement with the pipe.
A method of gripping a first pipe and subsequently a second pipe of a different diameter than the first pipe, comprising:
- (a) providing a slips housing and mounting a plurality of slip segments therein, each slip segment having a slip body and a first adapter plate mounted thereon, and mounting a top plate on the slips housing over at least a portion of each first adapter plate;
- (b) extending the first pipe through the top plate and slips housing, then moving the slip segments downward and inward relative to the housing into gripping engagement with the first pipe;
- then, to grip the second pipe after removal of the first pipe from the housing,
- (c) removing the top plate to provide access to the first adapter plates, then removing the first adapter plates from the slip bodies and securing second adapter plates to the slip bodies while the slip bodies remain mounted in the housing, then re-attaching the top plate to the housing over at least a portion of the second adapter plates;
- then
- (d) extending the second pipe through the top plate and slips housing, then moving the slip segments downward and inward into gripping engagement with the second pipe.
Dependencies are inferred from the claim text.