Patent ID: 8678109

Claim:
A system for coring an underground formation surrounding a borehole, comprising: a tool body that can be positioned in the borehole near the formation to be cored, the tool body including a motor; a rotary drive head connected to the motor, wherein the rotary drive head has a female connector to which the coring tool connects, and a hollow shaft extending away from the rotary drive head into the tool body, and wherein the motor connects to the outer surface of the hollow shaft to drive the rotary drive head; a rotary tool connected to the rotary drive head and one end and carrying a drill bit at the other end, wherein the rotary tool is a tubular coring tool conveying an annular drill bit; a drive mechanism including an operable anchor for anchoring in the borehole and an axial drive for advancing tool body and the rotary tool; and a guide for urging the rotary tool laterally from the borehole into the surrounding formation.