Baker Hughes Corporation

James A Norris

Christopher C Beuershausen

Mark William Dykstra

Roland Illerhaus

Michael P Ohanian

Rudolf C O Pessier

John R Spaar

Rudolf Carl Pessier

Roger W Fincher

Steve R Matson

Danny Eugene Scott

Gordon A Tibbitts

Jeffrey B Lund

Michael L Doster

Robert James Costo, Jr

A PDC-equipped rotary drag bit especially suitable for directional drilling. Cutter chamfer size and backrake angle, as well as cutter backrake, may be varied along the bit profile between the center of the bit and the gage to provide a less aggressive center and more aggressive outer region on the bit face, to enhance stability while maintaining side cutting capability, as well as providing a high rate of penetration under relatively high weight on bit.

Rotary drill bits for directional drilling exhibiting variable weight-on-bit dependent cutting characteristics

A rotary drag bit suitable for directional drilling. The bit includes a bit body from which extend radially-oriented blades carrying PDC cutters. The blades extend to primary gage pads, above which secondary gage pads are either longitudinally spaced or rotationally spaced, or both, defining a gap or discontinuity between the primary and secondary gage pads through which drilling fluid from adjacent junk slots may communicate laterally or circumferentially. Longitudinally leading edges of the secondary gage pads carry cutters for smoothing the sidewall of the borehole. The cutters are preferably configured and oriented so as to provide a relatively aggressive cutting edge to the formation in both longitudinal and rotational directions of bit movement, the cutting edges lying adjacent cutting surfaces preferably disposed at negative rake angles to the formation material of the borehole wall for enhanced durability. Cutters may likewise be disposed on the trailing ends of the secondary gage pads to provide an up-drill capability to facilitate removal of the bit from the borehole. The tandem primary and secondary gage pads provide enhanced bit stability and reduced side cutting tendencies. The discontinuities between the primary and secondary gage pads enhance fluid flow from the bit face to the borehole annulus above the bit, promoting formation cuttings removal. The tandem gage arrangement also has utility in conventional bits not designed specifically for directional drilling.

Rotary drill bits for directional drilling employing tandem gage pad arrangement with cutting elements and up-drill capability

A PDC-equipped rotary drag bit especially suitable for directional drilling. Cutter chamfer size and backrake angle, as well as cutter backrake, may be varied along the bit profile between the center of the bit and the gage to provide a less aggressive center and more aggressive outer region on the bit face to enhance stability while maintaining side cutting capability, as well as providing a high rate of penetration under relatively high weight on bit.

Rotary drilling bits for directional drilling exhibiting variable weight-on-bit dependent cutting characteristics

A drill bit and method of drilling a subterranean formation are disclosed in which the drill bit is configured with a non-axial gage portion of a bit body. The non-axial gage portion of the bit body presents a peripheral profile which is not parallel to the centerline of the bit body to provide a contact area for engagement of the sidewall of the borehole by at least one cutting element carried by the non-axial gage portion to enlarge the borehole from a first diameter cut by cutting elements on the bit face. The configuration of the drill bit lessens loading on the cutting elements of the drill bit, facilitates maneuverability of the drill bit downhole and enhances steerability of the drill bit.

Drilling structure with non-axial gage

A rotary drill bit suitable for directional drilling. The bit includes a bit body from which extend legs carrying rotatable cutters. The body carries primary gage pads, above which secondary gage pads may be either longitudinally spaced or rotationally spaced, or both. Longitudinally leading edges of the gage pads may carry cutting structure for smoothing the sidewall of the borehole. Cutting structure may likewise be disposed on the trailing ends of the gage pads to provide an up-drill capability to facilitate removal of the bit from the borehole. The gage pads provide enhanced bit stability and reduced side cutting tendencies, as well as reducing lateral loading on the rotatable cutters and associated bearing structure and seals. The invention also has utility in bits not specifically designed for directional drilling.

Rotary drill bits for directional drilling employing movable cutters and tandem gage pad arrangement with active cutting elements and having up-drill capability

A rotary drag bit being suitable for directional drilling. The bit includes a bit body from which extend radially-oriented blades carrying PDC cutters. The blades extend to primary gage pads, above which secondary gage pads are either longitudinally spaced or rotationally spaced, or both, defining a gap or discontinuity between the primary and secondary gage pads through which drilling fluid from adjacent junk slots may communicate laterally or circumferentially. Longitudinally leading edges of the secondary gage pads may carry cutters for smoothing the sidewall of the borehole. The tandem primary and secondary gage pads provide enhanced bit stability and reduced side cutting tendencies. The discontinuities between the primary and secondary gage pads enhance fluid flow from the bit face to the borehole annulus above the bit, promoting formation cuttings removal. The tandem gage arrangement also has utility in conventional bits not designed specifically for directional drilling.

Rotary drill bits employing tandem gage pad arrangement

A rotary drag bit being suitable for directional drilling. The bit includes a bit body from which extend radially-oriented blades carrying PDC cutters. The blades extend to primary gage pads, above which secondary gage pads are either longitudinally spaced or rotationally spaced, or both, defining a gap or discontinuity between the primary and secondary gage pads through which drilling fluid from adjacent junk slots may communicate laterally or circumferentially. Longitudinally leading edges of the secondary gage pads carry cutters for smoothing the sidewall of the borehole. The tandem primary and secondary gage pads provide enhanced bit stability and reduced side cutting tendencies. The discontinuities between the primary and secondary gage pads enhance fluid flow from the bit face to the borehole annulus above the bit, promoting formation cuttings removal. The tandem gage arrangement also has utility in conventional bits not designed specifically for directional drilling.

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Sandy, UT, United States of America

James A Norris