Camco International (uk) Limited

Other

Camco Drilling Group Limited

Tom Scott Roberts

Malcolm Roy Taylor

Douglas Bruce Caraway

Steven Taylor

Graham R Watson

John Hayward

Terry R Matthias

Stephen Martin Evans

Nigel Dennis Griffin

Clive Jarvis

Steven Barton

A method is disclosed comprising the steps of locating, on a surface of a downhole component, a plurality of thermally stable polycrystalline diamond (TSP) bearing elements, and then applying to the surface a settable facing material which bonds to the surface between the bearing elements and embraces the elements to hold them in place. A method in which bearing elements each comprising a body of TSP at least partly surrounded by a layer of less hard material are secured to the surface by welding or brazing part of the surface of each bearing element which comprises said less hard material to said component is also described.

Method of applying a wear-resistant layer to a surface of a downhole component

The present invention is a drag-type drill bit for drilling a borehole in the earth. The bit is designed to rotate about a central axis of rotation and has a bit body having a leading face, an end face, a gauge region, and a shank for connection to a drill string, a plurality of nozzles in the bit body for delivering drilling fluid to the end face, a plurality of blades upstanding from the leading face of the bit body and extending outwardly away from the central axis of rotation of the bit. Each blade terminates in a gauge pad with a surface which faces a wall of the borehole. A first plurality of cutters are mounted on the blades at the end face of the bit body and a second plurality of cutters are mounted the gauge pads and arranged such that in operation, they cut the wall of the borehole. Each one of the second plurality of cutters has a backrake less than or equal to about 20 degrees. A plurality of non-cutting bearing element are mounted on the gauge pads in a trailing relationship relative to the rotation of the bit behind at least some of the second plurality of cutters. The surface of each gauge pad is relieved from the borehole by at least 3 mm.

Active gauge cutting structure for earth boring drill bits

A rotary drill bit comprises a bit body having a leading face and a gauge region, cutting elements mounted on the bit body, fluid channels extending outwardly across the leading face towards the gauge region, and nozzles for supplying fluid to the channels. At the outer end of each alternate channel, in the gauge region, is an outwardly facing junk slot which extends across only a part of the width of the channel, and a bearing surface which extends across the other part of the channel and bears against a wall of the borehole being drilled. In the channel, inwardly of the bearing surface, is an opening into an enclosed passage which passes internally through the bit body to an outlet. The bearing surfaces at the end of the channels increase the peripheral bearing surface area of the drill bit, thus improving stability, but fluid can still escape from all parts of each channel.

Rotary drill bits with extended bearing surfaces

A rotary drill bit for use in drilling holes in subsurface formations comprises a bit body having a leading face and a gauge region, a number of blades formed on the leading face of the bit and extending outwardly away from the axis of the bit so as to define between the blades a number of fluid channels leading towards the gauge region, a number of cutting elements mounted side-by-side along each blade, and a number of nozzles in the bit body for supplying drilling fluid to the fluid channels for cleaning and cooling the cutting elements. In each of the fluid channels, adjacent the gauge region, is an opening into an enclosed passage which passes internally through the bit body to an outlet which, in use, communicates with the annulus between the drill string and the wall of the borehole being drilled. The gauge region of the drill bit comprises a substantially continuous bearing surface which extends around the whole of the gauge region.

Rotary drill bits

A preform cutting element for a rotary drag-type drill bit comprises a front facing table of superhard material having a front surface, a peripheral surface, a rear surface bonded to a substrate of less hard material, and a cutting edge formed by at least part of the junction between the front surface and the peripheral surface. The front surface of the facing table is formed with a chip-breaking formation which is located adjacent the cutting edge and is shaped to deflect transversely of the front surface of the facing table cuttings which, in use, are removed by the cutting edge from the formation being drilled. The chip-breaking formation may comprise a peripheral groove or rebate, or an upstanding ridge or insert.

Growing community of inventors

Quedgeley, United Kingdom

Tom Scott Roberts