摘要 |
A drilling system, including: a drill bit; and a thruster to apply a force to the drill bit. The thruster may include: an inner tubular member disposed within and configured to axially move within an outer tubular member; a thrust piston to transmit a hydraulic force to the inner tubular member, the thrust piston separating an upstream fluid chamber and a downstream fluid chamber between the inner and outer tubular members; at least one pressure switch fluidly connected to the downstream fluid chamber to control flow of a fluid to and from the downstream fluid chamber via at least one fluid inlet and at least one fluid outlet. |