It has been three years since a major accident took place at a mobile offshore drilling unit (MODU) – rig – in the Gulf of Mexico (GOM). As offshore exploration and development activities recaptures momentum, Operators and Drilling Contractors (DC) are compelled to incorporate lessons learned from the incident. At least one of the investigation reports questioned the rig's barriers for fire, explosion and emergency evacuation; the United States Coast Guard (USCG) marine casualty investigation of the event [1]. However, the main regulations for the design and construction of mobile offshore drilling units (MODU) are dictated by the International Maritime Organization (IMO) and marine Class requirements (e.g. American Bureau of Shipping [ABS] and Det Norske Veritas [DNV]), have not been updated to reflect the USCG proposed amendments.
This case study is presented from the perspective of a new development field Operator to approach assurance of adequate barriers in the design and construction of MODUs – ship shaped or drillships that will be leased in the near future for GOM development. The focus was to capitalize learning to improve MODU newbuild designs tackling the most effective controls in the risk hierarchy– Eliminate, Substitute, Isolate, and Engineer – (Refer to Figure 1); mechanisms related to process safety design. Personnel safety belongs to the Organizations, Procedures, and Personnel Protection Equipment risk controls, and is not within the scope of this case study.
