Steerable drilling system

摘要

A steerable drilling system including a bias unit and a separator. The separator is arranged to remove particulate matter from the supply of pressurized drilling mud to the actuator of the bias unit. The separator includes a hydrocyclone located upstream of the actuators. The hydrocyclone includes a housing defining a substantially conical recess having a large diameter end and a small diameter end. An inlet is in fluid communication with the large diameter end for providing the drilling mud thereto. A first outlet is in fluid communication with the small diameter end for outlet of relatively dirty mud. A second outlet is in fluid communication with the large diameter end for outlet of a supply of relatively clean mud for the plurality of actuators.