Abstract: A reamer includes a housing, a first reamer block, and a second reamer block. The first reamer block includes a leading wall. A second reamer block includes a trailing wall, the trailing wall including a recess. The leading wall is inserted into or nested in the recess to increase the coverage-to-exposure ratio.

Abstract: A downhole tool assembly coupled to a drill string includes a drill string motor that rotates the drill string, the downhole tool assembly including a tool body defining a perimeter, one or more cutting elements positioned on the perimeter of the tool body, where the one or more cutting elements are positionable between an extended position, in which the one or more cutting elements extend outwardly from the perimeter of the tool body, and a retracted position, where the one or more cutting elements are positioned further outward from the perimeter of the tool body in the extended position than the retracted position, and a tool motor coupled to the tool body, where the tool motor is structurally configured to rotate the tool body as fluid passes through the tool motor.

Abstract: A lubricating nutating single cone drill bit 10 is disclosed. Bit 10 includes a bit shank 12 with an axially skewed bore 18 rotatably retaining a cutter body 22. A plurality of cutter elements (46, 48) are affixed to the cutter body 22. Bearings (26, 28, 30, 32) enable rotation of the cutter body 22 and lubricant is dispensed to the bearings from a lubricant chamber (76, 76?) by a plunger 80 driven by drilling fluid. A method to drill includes attaching the bit 10 to a drill string, engaging the bit 10 into a formation (WB), pumping a drilling fluid into a plunger 80 in the lubricant chamber 76 to dispense lubricant to the bearings (26, 28, 30, 32). The method can include pumping the drilling fluid through a fluid passage 90 in the bit 10 and out of a low pressure orifice 94 on the cutter body 22.

Abstract: A well tool for use in a down-hole drilling assembly wherein the drill bit is rotated without drill pipe rotation comprising a generally tubular body and a plurality of roller assemblies secured to the body, the roller assemblies including rollers which rotate around axes generally transverse to an axis passing lengthwise through the body of the well tool.

Abstract: In boring apparatus of the type having cutters mounted for rotation about respective cutter axes in a frame which is in turn rotatable about a frame axis, each cutter having a body carrying teeth which in operation sweep a surface which is oblique to the axis of advance of the apparatus, that improvement wherein each cutter has selected tooth regions, preferably of alternating high and low tooth densities, spaced along the respective cutter axis, the tooth regions of the cutters are arranged in an ordered cycle progressing along the frame axis, and regions adjacent each other in the cycle are on different cutters and overlap each other along the frame axis.