Abstract: A cutter for a well construction tool has a cutting structure affixed to a substrate, which defines a monotonically decreasing diameter with respect to an axial distance from an interface between the cutting structure and the substrate. A shear surface formed in the cutting structure intersects a surface of the cutting structure between the interface and an apex of the cutting structure, and defines a smaller angle with respect to a reference than the cutting structure proximate the interface and a larger angle with respect to the reference than the cutting structure proximate the apex. The apex is rotationally symmetric about a centerline of the cutting structure in all rotational directions, and a radius of curvature of the apex is at most 75 percent of a diameter of the substrate. A well construction tool includes a tool body with at least one such cutter attached to the tool body.

Abstract: A reaming tool includes a reaming tool body configured to be coupled within a drill string or a string of drilling tools. A plurality of reaming blocks is attached to the reaming tool body at circumferentially spaced apart locations. At least one reaming block comprises at least a first row of gouging cutters and a second row of gouging cutters. The gouging cutters in the first row define a first profile. The gouging cutters in the second row define a second profile. The first row is rotationally ahead of the second row. The first profile at any longitudinal position along the at least one reaming block defines a larger reaming diameter than the second profile.

Abstract: A drill bit includes a bit body; a plurality of gouging cutters rotatably mounted to the bit body so as to define a first profile; and a plurality of gouging cutters non-rotatably mounted to the bit body so as to define a second profile. The first profile is longitudinally ahead of the second profile in a direction of drilling of the drill bit by a selected distance.