The OPTI-EX Floating Production System (FPS) was commissioned on speculation. Its foreseen areas of deployment were the Gulf of Mexico, Brazil or WestAfrica. Before the project was sanctioned, a marketing study was undertaken onpotential prospects to support the formulation of a basis of design (Phase I). The marketing study summarized all known marginal fields and early-developmentfields for which an FPS could be suitable. The study helped to confirmviability of a speculative FPS and helped the design team to focus on the rightsize of production facility.
A production system (Phase II) was designed that was highly modular, whichallowed for a maximum of flexibility in production. The capacity of thetopsides comprised 40 Mbop/d plus 50 MMscf/d. For equipment that was toofield-specific, only space, payload and utilities were provided. The FPS wasbuilt and subsequently laid-up, awaiting a deployment contract.
When the current owner procured the FPS, they completed the facility by addingthe field-specific equipment and modules to it (Phase III). Also, the capacitywas increased to 60 Mbop/d plus 150 MMscf/d. The paper describes how theseupgrades were achieved, where the original design philosophy worked well, andwhere it was deficient.
The paper addresses the possibilities and limitations of generic productionfacilities design, using the " Who Dat" deployment of the OPTI-EX FPS as a casestudy.
Most of the modifications of the facilities in effect, comprised the additionof the field-specific equipment and modules originally anticipated. Only alimited number of existing systems were converted. By adopting a modular designwith sufficient flexibility and capacity, a wide range of field conditions canbe accommodated.
There is an industry tendency to " prototype" a standard facility time and timeagain. In a field development, significant schedule and cost gains can be madeby using an existing FPS, provided its facilities have sufficient capacity /flexibility and the FPS has adequate spare payload, space and utilities.
The Exmar OPTI-EX™/ LLOG Who Dat project was unique from start to finish. Theunique deep-draft semisubmersible OPTI-EX floating production system (FPS), conceived by Exmar Offshore Company (EOC), was designed and constructed to bere-deployable for use in early production and marginal field developmentopportunities, for medium to large reservoirs, and in waters ranging up to10,000 feet. It was the first independently-owned facility with this capabilityand the first speculative FPS constructed in the industry. One of the mostunique features of the structure was its generic single-level topsides, whichmade it capable of being modularized for customization to be used multipletimes in global fields. Fully outfitted, the OPTI-EX is capable of producing60,000 barrels of oil per day (bop/d) plus 150 million standard cubic feet ofgas per day (MMscf/d).
