APPARATUS AND PROCESS FOR DRILLING A BOREHOLE IN A SUBTERRANEAN FORMATION

摘要

An apparatus and process is disclosed for drilling a borehole into a subterranean formation with reverse circulation of drilling fluid. A tubular drill pipe extends into a subterranean formation. A bottom hole assembly connected to the drill pipe includes a drill bit for excavating the subterranean formation. A downhole motor is adapted for receiving electrical power from a cable extending into the subterranean formation. A downhole pump is powered by the motor and is configured for reverse circulating drilling fluid from the annular space surrounding the drill pipe to the interior space of the drill pipe. The drilling fluid is pumped upwards in the drill pipe by the downhole pump to carry excavated cuttings upwards through the interior space of the drill pipe.