Managed pressure drilling (MPD) has been used for more than a decade onshore to drill an increasing number of challenging wells. However, the offshore drilling industry has only recently begun to adopt this innovative drilling technique. This paper will address some of the reasons delaying the application of this proven drilling method to drill offshore. It will describe offshore implementation and risk factors to consider for MPD.
MPD methods deliver advantages in drilling operations and risk reduction compared to conventional drilling methods. Benefits such as drilling previously unreachable targets, better kick control, smaller kick size and increased safety have led offshore operators to deploy MPD for offshore wells. For this reason, MPD technology is moving offshore from land-based application, where operational practices and environmental conditions are different. Applying MPD offshore requires consideration of additional design, operational, maintenance and safety issues. This paper will discuss some of these high-level issues and mitigations based on ABS experience gained working on various MPD projects for high-specification offshore floating rigs. Issues are identified based on offshore drilling practices, rig configuration, integration, offshore environments, limited space, training and regulatory requirements.
Based on various project experiences, ABS determined that additional improvements are needed to most effectively operate MPD systems offshore. This paper summarizes major concerns to be addressed and provides necessary mitigation measures. Heightened awareness of drilling conditions during MPD will often eliminate unscheduled events, or lessen their duration, and help minimize drilling risk. The result is reduced time on location, a safer drilling operation and lower total well costs.