Camco International (uk) Limited

Other

Camco Drilling Group Limited of Hycalog

Stephen Martin Evans

David Truax

Terry R Matthias

Douglas Bruce Caraway

Andrew D Murdock

Tom Scott Roberts

Andrew Bell

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

A wear resistant drill bit of the matrix bodied type has a bit body comprising a tungsten carbide material bound with a binder material, wherein the tungsten carbide material includes at least some tungsten carbide particles of generally spherical shape. The tungsten carbide material includes particles having a relatively hard central core and a softer skin. The skin includes a large proportion of a high temperature phase of tungsten carbide.

Wear resistant drill bit

A rotary drill bit is manufactured by a method including the step of forming at least a portion of the bit body from a precipitation hardening alloy, and brazing cutters to the bit body by a heating and cooling cycle during which the bit body is first heated to a temperature sufficient to melt the brazing material and is then cooled to room temperature, the heating and cooling brazing cycle being controlled in a manner so as also to effect precipitation hardening of the alloy from which the bit body is formed. In the case where the bit body is formed from solid infiltrated matrix material around a solid preformed mandrel, the heating and cooling cycle of the matrix forming process may also be controlled in a manner to effect precipitation hardening of the alloy from which the mandrel is formed.

Methods of manufacturing rotary drill bits

A rotary drill bit is manufactured by a powder metallurgy process by placing a metal mandrel in a mold, packing the mold with particulate matrix-forming material, infiltrating the material with a molten binding alloy, and cooling the assembly to form a solid infiltrated matrix bonded to the mandrel. The mandrel comprises an outer part surrounded by the matrix-forming material and an inner part, secured to the outer part but out of contact with the matrix-forming material. The outer part of the mandrel is formed from a material having thermal characteristics close to those of the matrix, so as to reduce the tendency for the matrix to crack under thermal stress, while the inner part of the mandrel is formed from a precipitation-hardening material, the strength and hardness of which increases in the infiltration process and the subsequent heating/cooling cycle for brazing the cutters on to the drill bit. The threaded shank of the drill bit is formed directly on the inner part since it will have sufficient strength and hardness for this purpose.

A drill bit comprises a main body part having a shank for connection to a drill string, an end face, an internal passage for supplying drilling fluid to the end face, a number of blades extending from the end face outwardly and longitudinally of the central axis of rotation of the bit, and a number of cutters mounted on each said blade. Each blade comprises a central metal core at least partly surrounded by solid infiltrated matrix material. A method of manufacturing such a drill bit includes the steps of forming a main body part from metal, applying to the outer surface of the main body part a coating layer of wax which liquefies at elevated temperature, applying to the coated body part mold-forming material to provide a self-supporting mold surrounding the coated body part, and raising the temperature of the body and surrounding mold sufficiently to liquefy the coating material. The liquefied coating is then drained from the mold, and the cavities left by the coating material are packed with powdered matrix material, which is then infiltrated with a binder alloy at elevated temperature to form a solid infiltrated matrix layer, on the bit body part, corresponding to the layer of wax previously applied.

Matrix hard facing by lost wax process

A drill bit comprises a main body part having a shank for connection to a drill string, an end face, an internal passage for supplying drilling fluid to the end face, a number of blades extending from the end face outwardly and longitudinally of the central axis of rotation of the bit, and a number of cutters mounted on each said blade. Each blade comprises a central metal core at least partly surrounded by solid infiltrated matrix material. A method of manufacturing such a drill bit includes the steps of providing a metal mandrel having said shank and internal passage, and providing on the mandrel, so as to be supported by it, a number of blade cores each having a portion extending outwardly and longitudinally of the central axis of the mandrel, casting infiltrated matrix material around at least a part of each core and around at least a part of the mandrel to form the blades, and then removing portions of the cores so as to detach each core from support by the mandrel to leave within each blade a core which is substantially wholly supported by the surrounding matrix material.

Growing community of inventors

Standish, United Kingdom

Stephen Martin Evans