For many offshore developments, there is a drive to minimize the required manning and enabling remote operations to reduce personnel exposure and to reduce the overall cost (lighter topsides, simpler hull, less maintenance). This paper considers semisubmersible production facilities and investigates the opportunities and challenges of an unmanned hull from an overall field development perspective.
The unmanned hull poses challenges related to typical practice for the frequency of inspections inside the hull and the closed compartments within the hull. In order to achieve a fully unmanned hull, inspections should be minimized, and ideally completely avoided during the intended service life, if possible. The paper highlights key design features required to achieve a hull design with minimal inspections.
Opportunities that will be discussed include, minimizing the hull equipment and system requirements (e.g. ballasting operations), implementing sealed compartments, and enhancing the fatigue life of the hull structure to avoid inspection requirements during the lifetime of the unit.
The paper discusses several design challenges associated with an unmanned hull. These include addressing Class and Flag requirements, (i.e. Class and shelf state regulations that may be a barrier for unmanned operations), risk of entering the unmanned hull, damage tolerance, and damage response capability.