Unmanned / Minimally Manned Floating Deepwater Installations: Design and Safety Considerations

Abstract

The latest focus on floating offshore developments is to minimize or remove the human presence onboard by utilizing remote operations. This may reduce personnel exposure and potentially overall costs by using new technologies. Existing codes or regulations are not tailored to address unmanned (UM) or minimally manned (MM) floating installations. Such floating facilities are remotely operated from a nearby facility or a control center located onshore. Offshore facilities remotely operated require real time monitoring, control automation, and maintenance procedures incorporating remote diagnostics and simulations, with minimal human intervention. This concept brings into focus the design of the remote-control center, the communication infrastructure, smart functionalities, digital twins and simulation technologies. In order to achieve the objectives of an UM or MM facility, hull and machinery inspections onboard the facility are expected to be minimized, and design features adopted for remote inspection using new technologies. Enhancing the fatigue life of the hull structure and reliability of critical machinery are fundamental to this concept. This paper proposes guidance to develop and manage an UM or MM facility through lifecycle activities of design, construction, integration, testing, operation, monitoring, inspection and maintenance in comparison with conventional facilities. The adopted approach identifies risk related to the concept and proposes measures to help develop appropriate design and safety requirements under a lifecycle perspective. The existing codes, standards and class society rules contain applicable requirements for floating facilities related to design, operations and maintenance. The study is based on the review of existing rules and regulations including associated gap analysis. The study concludes that existing structural rules may be applied as a base requirement to address structural integrity, inspection and maintenance risk. From machinery perspective, new technologies will need to be implemented to address monitoring, control, inspection and maintenance issues. The paradigm shift will be in designing the facility to move from a traditional maintenance plan to a Condition-Based Maintenance (CBM) requiring human intervention on a minimal need-basis. This paper also addresses the design and safety considerations based on risks, new technology qualification (TQ) and human factors for continued operations, since the limited or temporary crew will be required to perform multidisciplinary activities, and habitability design should assist and augment onboard crew ability.