Fixed cutter drill bits and cutter element arrangements for same

Abstract

A drill bit for drilling a borehole in an earthen formation has a central axis and a cutting direction of rotation. The bit includes a bit body configured to rotate about the axis in the cutting direction of rotation. The bit body includes a bit face. The bit also includes a blade extending radially along the bit face. In addition, the bit includes a first cutter element mounted to a cutter-supporting surface of the blade and a second cutter element mounted to the cutter-supporting surface of the blade. The first cutter element has a central axis and includes a first forward-facing cutting face including a first cutting tip distal the cutter supporting surface and a first planar surface extending radially from the first cutting tip toward the central axis of the first cutter element. The first planar surface is oriented at a first effective backrake angle measured between the cutter supporting surface and a surface vector of the first planar surface. The second cutter element has a central axis and comprises a second forward-facing cutting face including a second cutting tip distal the cutter supporting surface and a second planar surface extending radially from the second cutting tip toward the central axis of the second cutter element. The second planar surface is oriented at a second effective backrake angle measured between the cutter supporting surface and a surface vector of the second planar surface. The second effective backrake angle is greater than the first effective backrake angle.