Rolling cutter drill bit.

摘要

Rolling cutter bit has a hollow bit body and cutters rotatably mounted on downwardly extending legs. A jet device is in fluid communication with the hollow portion of the bit body and directs a fluid spray across the cutting elements protruding from the cutters. The rotational axes of the cutters are offset from the rotational axis of the bit by about 1/16th inch or more per inch of bit dia. Used for drilling boreholes through underground formation for oil and gas. The penetration rate and drilling efficiency is increased when drilling in soft to medium-soft formations. The fluid spray cleans the cutting elements without impinging the cutter cone surfaces and causing wear. The spray is also directed against the formation to flush and clean the cuttings as they are produced.