| 摘要 |
Method of stabilising a riser 106 comprises applying an oscillating force to the riser 106, using one or more subsurface thrust units 108, 120, 122, possibly in pairs, which are mounted on the riser 106, possibly in a frame, so as to provide thrust to counteract the oscillating movement of the riser 106 detected by a sensor, which is connected to the thrust unit by a controller. The thrust units 110a, 112a, 114a or 120, 122, 208 may be positioned at antinodes of the oscillating movement, arranged in pairs and preferably each comprise three pairs of thrusters 110, 112, 114 respectively configured to provide thrust in three evenly spaced directions. Provision of computer programme product to perform a method comprising receipt of movement indications from at least one sensor, which causes a thrust unit to apply a oscillating force to the riser to counteract the movement detected by the sensor. |
