| 摘要 |
<p>A heave compensation and tensioning apparatus (10) for use on a floating vessel. Said apparatus includes a frame (12) having an upper section (20) adapted for attachment to an top drive system (120, fig 1) and a lower section (22) adapted to interface with a flowhead assembly (130, fig 1), and a pair of hydraulic cylinders (14) that are fixed to the lower section of the frame. Respective free ends of the piston rods of the hydraulic cylinders are operatively associated with the upper section of the frame. The apparatus is also provided with a pair of accumulators which are in communication with pressure vessels and the cylinders by means of a pneumatic fluid line and a primary hydraulic fluid line, respectively. A control valve assembly (65, fig 2a) is arranged to control fluid flow through the primary hydraulic fluid line, allowing the piston rods to retract or extend in response to, and to compensate for, heave of the floating vessel. An isolation valve (74, fig 2a) is operatively disposed on the primary hydraulic fluid line to hydraulically lock the piston rods. The primary hydraulic is further provided with a bypass fluid flowpath comprising a first bypass line (76, fig 2a) and a second bypass line (78, fig 2a). Each piston rod may be hollow and in fluid communication with a respective blind side of each respective cylinder via an aperture in the piston head, defining a gas accumulator.</p> |
