HYDRAULIC CUSHION

摘要

Drilling mud is lifted subsea to a drilling vessel with a mud pump having an internal bladder. Applying pressurized water to one side of the bladder urges it against a quantity of the mud to impart a lifting force onto the mud. Mud flow to and from the pump is controlled by valves driven by actuators. The actuators include a piston in a cylinder, a stem that connects the piston to a valve member, and ports for supplying fluid to opposing ends of the piston for selectively reciprocating the piston. Cavities are strategically location in the cylinder for absorbing vibrational forces generated when the piston reaches an end of its stroke.

主权项

1. A system for lifting drilling mud from a subsea wellbore comprising:
mud pumps selectively disposed subsea; a valve in a flow line that contains drilling mud from the wellbore; and an actuator coupled with the valve comprising,
an actuator body,a cylinder in the body,a piston in the cylinder, anda cavity in the body in unrestricted communication with the cylinder.