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US 4,545,441 AGranted
Drill bits with polycrystalline diamond cutting elements mounted on serrated supports pressed in drill head
OwnerKirk E. Williamsoninventor
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OwnerKirk E. Williamsoninventor
Estimating the term…
Drill bit for drilling bore holes in earth formations, the bit's cutting face provided with cutter preforms composed of polycrystalline diamonds on a tungsten carbide substrate mounted in sets from the center of the bit's face to its periphery. The first set consists of one center cutter preform. Each succeeding set has at least two preforms, all of which in a set are disposed at an equal radius from the bit's axis of rotation and, insofar as practical, are displaced from adjacent preforms in the same set by equal arcs around the axis, the cutting path of a set overlapping with that of the next set, the distance along the path between preforms for each set being not greater than about five inches. The outermost preform set is disposed in or above the junk slots. Gage protectors are optionally placed on the drill bit's sides to hold it away from the casing, such gage protectors composed of aluminum which wears to the diameter of the drill bit during use or a resilient material which compresses to the overall diameter of the drill bit during drilling operations and prevents damage to or from the casing when the bit is lowered or withdrawn. The drill bit is conveniently manufactured in three parts, a pin shank, a body spacer and a cap, with the body spacer welded to both the cap and the pin shank, the latter being threadably received through the body spacer by the cap, thus placing the body spacer in a state of compression.
A drill bit for oil or gas wells which comprises a pin shank, a drill head threadably connected to said pin shank and a body spacer in compression which is affixed to said pin shank and said head, a cylindrical bit body having an end surface and a side surface, said side surface including a plurality of gage pads, each said gage pad affixed in part to said head and in part to said body spacer and fluid channels defined between said gage pads, a plurality of cutters mounted on said end surface, one said cutter disposed to rotate proximate the bit's axis of rotation, a first set of cutters disposed at a first equal radius from said axis and displaced through equal arcs around said axis, and further successive sets of cutters disposed further radii equal in each said set and being displaced from each other by equal arcs in each said set around said axis, said cutters tracing circular cutting paths around said axis which overlap and substantially cover the entire area of said end surface.
A drill bit for oil or gas wells which comprises a shaft, a cylindrical steel bit body affixed to said shaft, said bit body having an end surface and a side surface, said side surface including a plurality of vertically deposited raised portions spaced around its circumference and fluid channels defined between said raised portions, a plurality of cutters mounted on said end surface, one said cutter disposed to rotate proximate the bit's axis of rotation, a first set of cutters disposed at a first equal radius from said axis and displaced through equal arcs around said axis, and further successive sets of cutters disposed further radii equal in each said set and being displaced from each other by equal arcs in each said set around said axis, said cutters tracing circular cutting paths around said axis which overlap and substantially cover the entire area of said end surface, a set of cutters extending normally from said side surface for a distance greater than the distance of said raised portions above the remaining part of said side surface, gage protectors secured to said side surface in said channels, said gage protectors extending from said side surface normally a distance beyond the greatest outboard projections of said cutters of said set which extend normally from said side surface.
A drill bit for oil or gas wells which comprises a shaft, a cylindrical bit body affixed to said shaft, said bit body having an end surface and a side surface, said side surface including a plurality of raised portions comprising gage pads and fluid channels defined between said raised portions, a plurality of cutters mounted in openings provided on said end surface, each said cutter comprising a supporting pin, each said pin composed of a material substantially harder than the material of said end surface surrounding said openings and including sides which have vertical parallel serrations, said pins pressed in said openings to cut corresponding serrations in the sides of said openings of such a character to secure said pins rigidly in said openings substantially integral with said bit body, one said cutter disposed to rotate proximate the bit's axis of rotation, a first set of cutters disposed at a first equal radius from said axis and displaced through equal arcs around said axis, and further successive sets of cutters disposed further radii equal in each said set and being displaced from each other by equal arcs in each said set around said axis, said cutters tracing circular cutting paths around said axis which overlap and substantially cover the entire area of said end surface.
A drill bit for oil and gas wells which comprises a shaft, a generally cylindrical steel bit body affixed to said shaft, said bit body having an end cutting surface and a side surfaee, said end cutting surface being convex, a plurality of cutters mounted in openings in said end surface, each said cutter comprising a supporting pin composed of tungsten carbide and including sides which have parallel vertical projections, said pins pressed into said openings to cut grooves corresponding to said projections in the sides of said openings of such character to secure said pins rigidly in said openings substantially integral with said bit body, a first set of said cutters disposed in a first circular cutting path at a first equal radius from said axis which are displaced from each other around said axis by arcs of equal degrees, a further successive set of said cutters disposed in a second circular cutting path a further radius from the axis of rotation of the bit farther than said first radius and which are also displaced from each other by equal degrees of arc, there being a greater number of said cutters disposed along said second cutting path than said first cutting path, said cutters in said second cutting path being closer together as measured along said second cutting path than said cutters in said first cutting path as measured along said first cutting path.
A method of manufacturing a steel drill bit for oil and gas wells which comprises the steps of:
Dependencies are inferred from the claim text.