Drilling systems and hybrid drill bits for drilling in a subterranean formation and methods relating thereto

A drill bit for drilling a borehole in a subterranean formation, the borehole having a gauge diameter, the drill bit comprising:

• a bit body having a bit axis, a first end configured to be coupled to a lower end of a drill string, and a second end configured to engage the subterranean formation, wherein the bit body includes a plurality of legs circumferentially disposed about the bit axis, wherein each leg has a lower section extending axially from the second end of the bit body, wherein the lower section of each leg is circumferentially-spaced apart from each circumferentially adjacent lower section, and wherein each lower section has a leading surface relative to a cutting direction of bit rotation about the bit axis, a trailing surface relative to the cutting direction, and a radially outer surface extending circumferentially from the leading surface to the trailing surface of the corresponding lower section;
• a plurality of rolling cone cutters, wherein one rolling cone cutter is rotatably coupled to the lower section of each leg and positioned along the leading surface of the corresponding leg, wherein each cone cutter has a cone axis of rotation that is radially spaced from the bit axis and is substantially perpendicular to a plane containing the bit axis, wherein each cone cutter includes a backface adjacent the leading surface of the corresponding leg, a nose opposite the backface, and a central passage extending axially therethrough from the backface to the nose, wherein each cone cutter is rotatably mounted to a journal extending from the leading surface of the lower section of the corresponding leg into the central passage of the corresponding cone cutter;
• a plurality of circumferentially-spaced fixed blades, wherein one fixed blade extends radially outward from the radially outer surface of the lower section of each leg, wherein each fixed blade has a radially outer formation-facing surface;
• wherein each cone cutter includes a first plurality of cutter elements arranged in a first circumferential row extending about the corresponding cone axis of rotation, wherein each of the first plurality of cutter elements includes a planar cutting face that is configured to engage and shear the subterranean formation when the bit body is rotated about the bit axis in the cutting direction;
• wherein the trailing surface of the lower section of each leg includes a clearance recess configured to accommodate the first plurality of cutter elements of the circumferentially adjacent rolling cone cutter that trails the leg relative to the cutting direction during rotation of the rolling cone cutter about the corresponding cone axis and removal of the rolling cone cutter from the corresponding leg;
• a second plurality of cutter elements mounted to the formation-facing surface of each fixed blade and configured to engage and shear the formation when the bit body is rotated about the bit axis in the cutting direction.