Active-heave compensation benefits North Sea operations
Active-heave-compensation (AHC) systems have become prominent in semisubmersible drilling-rig (SDR) operations. The increasing number of retrofit AHC systems being introduced to the semisubmersible fleet has permitted actual comparisons and field evaluation of semisubmersibles having AHC systems with similar semisubmersibles having passive compensation only. The passive drillstring compensator (PDC) was designed to allow floating drilling rigs to maintain a near-constant load while in operation. The PDC can be described as damping or a low-rate spring device used to reduce disturbance or load variation caused by wave motion. The term active refers to the ability to react to movement, in real time, and maintain a high degree of hook-load stability. AHC, therefore, means the ability to keep the load (drillstring) in a stable position in reference to the seabed or well bottom throughout all the floating drilling rig`s heave motion. The AHC system comprises an actuating accumulator cylinder, heave sensors, a control unit (computer), an operator panel, and a hydraulic-power unit.
- OSTI ID:
- 465176
- Journal Information:
- JPT, Journal of Petroleum Technology, Vol. 49, Issue 4; Other Information: PBD: Apr 1997
- Country of Publication:
- United States
- Language:
- English
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