Novel rotary drill bits and drilling process
AssigneeConstruction de Materiels de Mines S.A.
InventorGeorges Cagnioncle
Life of this patent
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Abstract
A rotary drilling bit is provided which includes means for providing a protective stream of a high pressure fluid for its cutting edges fed parallel to the drilling axis directed perpendicular to the cutting edges. The drilling bit also includes means for providing a stream of low pressure fluid for flushing away pulverized rock cut by the drilling bit. The drilling bit is mounted on the end of boring tubing made up of a pair of coaxially positioned tubings, the innermost one supplies the high pressure fluid and the outermost one supplies the low pressure fluid. A drilling process which employs the drilling bit and boring tubing efficiently drills through both soft and non-abrasive rock and hard or abrasive rock.
Claims9
A rotary drill bit comprising a body having at least one cutting plate with a cutting edge and a cutting face thereon, and means for passing a protective stream of high pressure fluid outwardly from the drill bit in a direction perpendicular to said one cutting edge and parallel to the axis of drilling, said means for passing a protective stream of high pressure fluid comprising at least one small fluid exit porthole located in said one cutting face for passing the stream of high pressure fluid therethrough in a manner such as to provide a film for protecting said cutting edge.
A rotary drill bit comprising a body having at least one cutting plate with a cutting edge and a cutting face thereon, and means for passing protective stream of high pressure fluid outwardly from the drill bit in a direction perpendicular to said at cutting edge and substantially parallel to the axis of drilling along the greater portion thereof, said one cutting edge having a leading edge in the direction of rotation of the drill bit, and said means for passing a protective stream comprising at least one small fluid exit porthole located in said cutting face and slightly forward in the direction of rotation of the leading edge of said at least one cutting edge for passing the protective stream of high pressure fluid therefrom in a manner such as to provide a film for protecting said at least one cutting edge.
A rotary drill bit comprising a body having at least one cutting plate with a cutting edge and a cutting face thereon, and fluid means for passing a protective stream of high pressure fluid from the drill bit in a direction parallel to the axis of drilling, said fluid means comprising at least one first smaller fluid exit porthole located in said cutting face at a position relative to said cutting edge for allowing high pressure fluid to be exhausted from the interior of the drill bit in a manner such as to form a protective film over said cutting edge, and a second larger fluid exit porthole relative to said first smaller fluid exit porthole, positioned forward with respect to the direction of rotation of the drill bit from said first smaller fluid exit porthole for passing lower pressure fluid from the interior of the drill bit for carrying off through the borehole, when drilling operations are being conducted therein, rock particles produced by boring resulting from the combined action of the cutting edge and the high pressure fluid.
Dependencies are inferred from the claim text.