Drill string stabilizer

Claim 2

A stabilizer toot for use on a drill collar, which stabilizer is characterized in that: a cylindrical body is configured with a longitudinal bore, internally threaded end portions, and at least one tapered surface extending between each said end portion and a relatively thicker central portion; a hollow end cap at each end of said body is threaded externally to mate with the corresponding internally threaded portion of said body and has a circumferential groove in the internal surface thereof near the outboard end thereof within said body; a plurality of slip segments within each end of said body with at least one tapered surface is adapted to mate and wedge against the tapered inner surface(s) at said end of said body upon entry of one of said end caps into said end of said body; said slip segments being distributed around said body, each slip segment having a longitudinal slot and a circumferential recess in the exterior surface thereof near the outboard end of said slip segment facing said end cap, said circumferential recess defines a retaining lip on the external surface of said slip segment which fits within said circumferential- groove in said end cap; an expansible member is configured to engage the inner surfaces of said slip segments to urge the lips of said slip segments radially into said circumferential groove of said end cap; a compressible renitent member positioned within said slip segment is recessed between the threaded terminus of said end cap and said slip segment so as to be compressed upon entry of said end cap into said body; and a locking device interengages the said slip segment longitudinal slot in said body to resist rotational movement therebetween.

Claim 3

A stabilizer tool according to claim 1, wherein said cylindrical body is configured with a double-tapered inner surface extending between each said end portion and the relatively thicker central portion and wherein each said slip segment has a double tapered surface adapted to mate and wedge against the double-tapered inner surface at said end of said body.

Claim 4

A downhole tool for positioning on a drill collar, characterized in that: a body with a longitudinal bore is internally threaded at each end, said body has an internal double-tapered surface between each threaded end and a relatively thicker central section of said body; an end cap with exterior threads, and an interior circumferential groove is threaded into each end of said longitudinal bore; a plurality of slip segments each slip segment configured with: interior gripping teeth, a longitudinal slot, a circumferential retainer ring slot, double-tapered surface matching said interior doubled-tapered surface of said body, and a circumferential lip configured to fit said circumferential groove of said end caps; a retainer ring is inserted in said retainer ring slots exerting a radially outward force on said slip segments; a locking device is positioned at each end of the interior of said body to resist rotational movement of said slip segments relative to said body.

Claim 5

A downhole tool for positioning on a drill collar, characterized in that: a body with a longitudinal bore is internally threaded at each end, said body has an internal double-tapered surface between each threaded end and a relatively thicker central section of said body; an end cap with exterior threads, and an interior circumferential groove is threaded into each end of said longitudinal bore; a plurality of slip segments each slip segment configured with: interior gripping teeth, a longitudinal slot, a circumferential retainer ring slot, double-tapered surface matching said interior doubled-tapered surface of said body, and a circumferential lip configured to fit said circumferential groove of said end caps; a retainer ring is inserted in said retainer ring slots exerting a radially outward force on said slip segments; a locking device is positioned at each end of the interior of said body to resist rotational movement of said slip segments relative to said body.

Claim 6

A downhole tool capable of positioning on a drill collar, characterized in that: a tubular body is configured with interior threads and an interior double-tapered surface at each end of said body; separate end caps are configured with exterior threads and a circular receiving groove threaded into each end of said body; a plurality of slip segments fits in the receiving groove of said end cap each slip segment configured with: gripping teeth, a double-tapered surface on each segment matching the said interior double-tapered surface of said body, a longitudinal slot, a lip on each slip segment on the end opposite the gripping teeth and, a retainer ring slot in each slip segment; a retainer ring is placed in each set of said retainer slots exerting outward force on said slip segments; and a locking device is positioned at each end of the interior of said body preventing rotational movement of said slip segments.

Claim 7

A downhole tool capable of positioning on a drill collar, characterized in that: a tubular body is configured with interior threads and an interior double-tapered surface at each end of said body; separate end caps are configured with exterior threads and a circular receiving groove threaded into each end of said body; a plurality of slip segments fits in the receiving groove of said end cap each slip segment configured with: gripping teeth, a double-tapered surface on each segment matching the said interior double-tapered surface of said body, a longitudinal slot, a lip on each slip segment on the end opposite the gripping teeth and, a retainer ring slot in each slip segment; a retainer ring is placed in each set of said retainer slots exerting outward force on said slip segments; and a locking device is positioned at each end of the interior of said body preventing rotational movement of said slip segments.

Claim 8

A slip-on stabilizer tool for positioning on a drill collar, characterized by a cylindrical stabilizer body with a bore that is adapted to fit around the exterior of a drill collar and has: threads on the interior surface of each end portion of said body, at least one tapering surface on the interior of said body said tapering surface extending from the threaded end portion toward the center of the body, and tapering toward a relatively thicker center portion of the body; and end cap at each end of the stabilizer body that is adapted to fit over the exterior of a drill string and has: threads on the exterior surface of one end of said cap for threading into the corresponding said interior threads of said body, a circumferential groove is formed in the interior surface of each said end cap and is positioned opposite the threaded end of said end cap; a set of slips for each of said end caps, each set of slips has a plurality of slip segments, each of said slip segments has an outside diameter adapted to fit the inside diameter of said end cap, each slip segment has: a circumferential recess defining a lip on the outer surface at one end sized to fit within said circumferential groove of the corresponding end cap, an interior surface with teeth for gripping the exterior surface of a drill collar, an exterior surface with at feast one tapered surface adapted to fit within said adjacent tapered surface on the interior of said body, a renitent device receiving and retaining slot, a retaining lip section extending into and being received by said end cap circumferential groove to retain said slip segment in position relative to said body and said drill string, a circumferential retainer ring slot on the interior of said slip segment adjacent the end opposite said gripping teeth, and a longitudinal slot; a retainer ring for insertion in said retainer ring slot of each said slip segment in order to exert a radially outward force on said segments; a renitent means mounted in said renitent device slot retaining each of said slips relative to said cap and exerts an outward force against said end cap exterior threads; a locking pin positioned at each end of the interior of said body and perces said body to engage at least one slip segment longitudinal slot and resists rotational movement of said slip segments relative to said body.

Claim 9

A slip-on stabilizer tool for positioning on a drill collar, characterized by a cylindrical stabilizer body with a bore that is adapted to fit around the exterior of a drill collar and has: threads on the interior surface of each end portion of said body, at least one tapering surface on the interior of said body said tapering surface extending from the threaded end portion toward the center of the body, and tapering toward a relatively thicker center portion of the body; and end cap at each end of the stabilizer body that is adapted to fit over the exterior of a drill string and has: threads on the exterior surface of one end of said cap for threading into the corresponding said interior threads of said body, a circumferential groove is formed in the interior surface of each said end cap and is positioned opposite the threaded end of said end cap; a set of slips for each of said end caps, each set of slips has a plurality of slip segments, each of said slip segments has an outside diameter adapted to fit the inside diameter of said end cap, each slip segment has: a circumferential recess defining a lip on the outer surface at one end sized to fit within said circumferential groove of the corresponding end cap, an interior surface with teeth for gripping the exterior surface of a drill collar, an exterior surface with at feast one tapered surface adapted to fit within said adjacent tapered surface on the interior of said body, a renitent device receiving and retaining slot, a retaining lip section extending into and being received by said end cap circumferential groove to retain said slip segment in position relative to said body and said drill string, a circumferential retainer ring slot on the interior of said slip segment adjacent the end opposite said gripping teeth, and a longitudinal slot; a retainer ring for insertion in said retainer ring slot of each said slip segment in order to exert a radially outward force on said segments; a renitent means mounted in said renitent device slot retaining each of said slips relative to said cap and exerts an outward force against said end cap exterior threads; a locking pin positioned at each end of the interior of said body and perces said body to engage at least one slip segment longitudinal slot and resists rotational movement of said slip segments relative to said body.

Claim 10

A stabilizer tool according to claim 5, wherein a double tapering surface extends from each threaded end portion toward the center of the body each first tapering surface ending at a point where the second tapered surface commences, the second tapered surface commencing at the end of the first tapered surface, and being tapered towards the relatively thicker center portion of the body; and wherein an exterior doubled-tapered surface of each slip segment is adapted to fit within the adjacent double-tapered surfaces of the stabilizer body.

Claim 11

A stabilizer tool according to claim 5 or claim 6, wherein a slot on the exterior surface of each said cap is positioned at the end opposite from the threaded end which grips an end cap on an adjacent stabilizer body and tightens said end cap on the adjacent stabilizer body when turned in one direction but slips when turned in the opposite direction.

Claim 12

A stabilizer tool according to claim 5 or claim 6, wherein ratchet teeth are provided on the exterior surface of each said cap positioned at the end opposite from the threaded end, which teeth are adapted to grip ratchet teeth on an end cap on an adjacent stabilizer body and act to tighten said end cap on the adjacent stabilizer body when turned in one direction but slip when turned in the opposite direction.

Claim 13

A tool according to any one of claims I to 8, further characterized in that said locking device consists of a plurality of locking pins at each end of said body to engage the longitudinal slots on each of said slip segments.

Claim 14

A tool according to any one of claims I to 9, comprising three slip segments.

Claim 15

A tool according to any one of claims I to 10 further characterized in that said threads on the interior surface of each end of said body and said threads on the exterior surface of said end caps consist of locking threads.

Claim 16

A tool according to any one of claims I to 11, further characterized in that said retainer ring shall have a rectangular cross-sectional area.

Claim 17

A tool according to any one of claims I to 12, further characterized in that said renitent device is a flat wave spring.

Claim 18

A tool according to any one of claims I to 13, further characterized in that said locking pin consists of a plurality of locking pins at each end of said body.