Smith International, Inc.

Reed Rock Bit Company

Reed Tool Company

Kenneth W Jones

George Fyfe

Ronald B Crockett

Richard H Dixon

Percy W Schumacher

Paul E Pastusek

Henry W Murdoch

Christopher A Reed

Michael C Lockwood

A unitized polycrystalline composite diamond stud type drag bit cutter having no high temperature braze of a PDC wafer to a carbide stud is disclosed. The diamond cutting surface may be planar, convex, curved or a truncated cone. The unitized construction of the cutter eliminates the problems associated with the high temperature brazing of a PDC wafer to a carbide stud.

Diamond drag bit cutting elements

A diamond drag type drill bit for drilling in an earthen formation consists of a body forming a first cutting end formed from a matrix material and a second open threaded pin end. The first cutting end consists of a multiplicity of substantially radially disposed ridges and flow channels formed by the matrix material. The flow channels intersect a fluid discharge port and radially extend outwardly toward a peripheral edge formed by the cutter end. The ridges contain, along their apical, radially extended edges, a multiplicity of essentially equidistantly spaced diamond cutters having each of their cutting edges formed therein aligned substantially along the apical edge. The space between each diamond cutter contains a metallic filler material aligned along the apical edge that is less hard than either the diamond or the supporting matrix material forming the first cutting end of the drag bit. The filler material wears away rapidly during operation of the bit in the earthen formation allowing the diamond cutters to protrude an extent necessary to obtain optimum formation cutting rates.

Thermally stable polycrystalline diamond drill bit

A fishtail type drag bit is disclosed consisting of multiple blades, each blade forming radially disposed grooves. Each groove contains equidistantly spaced diamond cutters along its length. The cutters are additionally oriented at a negative rake angle with respect to a borehole bottom. The vertical alignment of the diamond cutters paralleling an axis of the bit are staggered to destroy kerfs which remain in the formation from preceding eroded rows of diamond cutters as the bit works in the borehole.

Fishtail expendable diamond drag bit

A diamond insert for a rotary drag bit consists of an insert stud body that forms a first base end and a second cutter end. The cutter end of the insert is formed in a convex or spherical shape of polycrystalline diamond material. The convex layer of diamond is oriented relative to an axis of the stud body with a negative rake angle from 0.degree. to about 45.degree. inclusive.

Convex shaped diamond cutting elements

A sub-surface borehole underreamer is disclosed having freely rotatable precessing diamond cutters attached to extendable arms connected to the body of the underreamer. The diamond cutting face is skewed to a degree that tangential contact of the peripheral edge of the diamond cutter causes the rotating cutter to precess as the underreamer body is rotated by a drill string.

Underreamer with revolving diamond cutter elements

A fishtail type drag bit having abradable cutter blades attached to a body of the bit is disclosed. A multiplicity of axially aligned tubes are welded together to form a blade each blade being sustantially parallel with an axis of the bit body. Each tube of the blade contains an annulus of a diamond cutter material matrix. The center of the annulus forms a fluid conduit that communicates with a fluid plenum chamber formed by the body of the bit. The cutting edge of the diamond matrix therefore, is always immediately adjacent the fluid nozzle regardless of the degree of blade erosion during operation of the bit in a subterranean formation.

Expendable diamond drag bit

A drag type drilling bit having a plurality of radially disposed raised lands on the bit face is disclosed. A multiplicity of polycrystalline diamond compacts are strategically disposed on the raised lands. At least a pair of lands are joined at the outside periphery of the bit thereby closing the valley formed between the lands, thus forming a plenum for drilling fluid that exits the bit interior through ports or nozzles communicating therewith. Highly turbulent fluid confined in the plenum continually scrubs and scavenges the hole bottom while simultaneously and uniformly cooling and cleaning the PDC cutters during operation of the bit in a borehole.

Fluid flow control for drag bits

A bearing for a rotary cone for a rock bit is disclosed. The bearing consists of a multiplicity of small synthetic diamond particles nested within a matrix base, each with an exposed flattened surface to form the bearing. The diamond particles are strategically positioned on a bearing surface and secured within the matrix base. A substantially identical synthetic diamond bearing is concentrically positioned adjacent to the first bearing to form the bearing package.

Diamond bearing for high-speed drag bits

A mechanism is disclosed for rock bits whereby cutting elements, rotatably mounted to fixtures with journals, are constantly forced to rotate or precess by the interaction of the earth formation and the cutter. The cutters are fixed in skewed or offset positions on a cutting face of a rotary drill bit head. These cutting elements act as drag or shear cutters when they are operated in an earth formation.

Revolving cutters for rock bits

Drag-type drilling bits are disclosed which have at least one blade and a plurality of fluid flow channels incorporated in the blade for conducting drilling fluid or drilling mud from the hollow interior of the bit to discharge or ejection ports located in the front cutting edge of the blade. Rods of diamonds or of like 'hard' cutter insert materials are incorporated in the blade in such a configuration that as the blade wears away or erodes and small pieces of diamonds are lost during drilling, more diamonds are exposed to the formation for drilling. During erosion or wear of the blades, the fluid discharge ports continue to operate to eject drilling fluid adjacent to substantially each diamond rod, whereby the flushing away of cuttings and cooling of the diamonds is greatly improved. In some embodiments of the invention rods of alternating hard and soft materials are also disposed substantially parallel with the diamond or like 'hard' cutter insert rods. When the soft material of the rods is exposed for drilling the formation, kerfs are formed which are thereafter 'chipped away' by the subsequently exposed hard material of the rods.

A rotary drill bit comprising a bit body having a plurality of drag cutting elements mounted on the bottom thereof. Each cutting element has a portion projecting down below the bit body and forward generally in the direction of rotation of the bit. This portion presents a leading face and a trailing face which converge at an acute angle to form a cutting edge. Each element is positioned on the bit body such that its leading and trailing faces present a positive rake angle and back clearance, respectively, to the surface of the well bore formation for improved cutting action. The bit body has an exit port at the bottom thereof for flow of drilling fluid under pressure, and sets of first and second generally parallel ridges defining watercourses extending from the exit port to the periphery of the bit. The cutting elements are mounted on the second or trailing ridge, and extend toward but stop short of the first or leading ridge. The leading face and cutting edge of each element thus extend into the watercourse and are cooled and cleaned by the drilling fluid. In addition the leading ridge extends down to a level below the bottom of the trailing ridge but above the cutting edges for limiting the depth of penetration of the cutting element.

Rotary drill bit having drag cutting elements

A rotary drill bit comprising a bit body having at least one depending leg at its lower end and at least one roller cutter rotatably mounted on the leg. The roller cutter comprises a frustoconical roller cutter body and a plurality of cutting elements projecting from the cutter body to tips adapted to bear on the bottom of the well bore, with the tips defining, upon rotation of the bit, a first cutting surface of the bit extending over substantially the entire area of the bottom of the well bore. At least one drag cutter extends down from the bit body and comprises a support and a plurality of drag cutting elements on the support, each having a lower cutting edge. The cutting edges of these elements are so arranged relative to the tips of the hard metal cutting elements as to define, upon rotation of the bit, a second cutting surface of generally the same configuration as the first but spaced above it, whereby upon drilling a relatively brittle formation only the hard metal cutting elements bear on the formation for cutting the formation by fracturing it thereby protecting the drag cutting elements, and upon drilling a relatively plastically deformable material which the hard metal cutting elements penetrate to a relatively deep depth without causing substantial fracturing of the formation, the drag cutting elements also engage the formation for improved drill bit cutting action and increased rates of drilling penetration.

Combination drag and roller cutter drill bit

An oil well drilling bit is disclosed of the type utilizing hard metal inserts in the rolling cutters wherein each row of inserts on each cutter is located thereon in a sinusoidal or varying pattern rather than the strictly circumferential pattern of the prior art.

Oil well drilling bit

Methods and apparatus are disclosed for the rapid and efficient drilling of oil well and other types of bore holes through tough abrasive underground formations, which methods and apparatus utilize high drag intermittent contact and cooling techniques to provide good rates of penetration with low wear and heat deterioration on the drilling tools.

Intermittent high-drag oil well drilling methods and apparatus

Drilling bits are disclosed which are particularly efficient drilling devices when used in soft plastic underground formations which normally are difficult or impossible to drill with conventional drilling bits. The bits of this invention are characterized by having relief openings formed in the individual cutting elements to provide extrusion of the soft formation face into removable chips.

Growing community of inventors

Kingwood, TX, United States of America

Kenneth W Jones