New Elements in Production Technology and Operations

ABSTRACT The title of this presentation embraces quite a wide scope, however, focus will be on Mobile Production Systems (MPSS) and in particular on Floating Production, Storage and Offloading Units (FPSOS), for which we are presently witnessing a remarkable boost in interest particularly in the North Sea area. Over the last 20 years, pioneered by the Argyll TW 58 in 1975, 11 mobile systems have been/ are active in the North Sea, i.e. a growth of one for each second year. In 1994 alone a number of eight mobile production systems were contracted of which seven were FPSOS, This boost is following nine years of successful operation of the Petrojarl I and is also clearly linked to the success of the Kerr-McGee?s Gryphon A project. The title of this presentation reflects new elements in this business; the upturn in interest for FPSOS introduces new ways of thinking and acting. In this paper, the new elements are divided into the general trends; new commercial elements and new technological elements. GENERAL TRENDS Over the last 20 years the industry has seen around 70 applications of MPSS in terms of monohulls, semisubmersibles or jack-up solutions. Out of these a number of 11 are related to the North Sea. Only 10% of the applications are dedicated New buildings. Monohull solutions, which are normally converted tankers, account for less than 40%. of the cases on a worldwide basis. This presentation will deal with the business of mobile production systems in general, but the discussions of "new elements" are mainly related to the trends in the North Sea, UK and Norwegian sectors. The Gryphon A project, see Figure 1, that saw first oil in October of 1993 seems to represent a break-through for the dedicated monohull field development. The positive experiences from 1.5 year of operation on Gryphon has certainly had a positive effect on the dedicated monohull newbuildings seen in 1994. The MPS applications in the North Sea up to 1994 are shown in Figure 2. There are seven semis of which six are conversions. Three ships, all dedicated newbuilds for production, The West Omikron is a converted jack-up for water injection in the Ekofisk field. The two main parameters when selecting the concept is the water depth and the presence or not of infrastructure, see Figure 3. The major difference between the semi andthe FPSO is the storage capability and thereby the FPSO?s merit as a stand-alone solution. The main difference between the floating semi or FPSO and the seabed based jack-up is the water depth. If pipeline offtake is available the semi or jack-up solutions are attractive, When storage is needed the FPSO is the superior solution. When designing a system for a number of future fields for which the input parameters are not known, the FPSO solution is the most versatile offering all functions from one vessel only, This is certainly influencing the trend towards monohull solutions when contract duration field lifetime is less than say 10 years.