Selection and Operation of Production Facilities for Handling High Pourpoint Crude Oils

Abstract

ABSTRACT The increasing capital and operating cost of production facilities, together with the decrease in the value of the produced barrel have given impetus to achieving acceptable product unit cost whilst providing operable and maintainable plant. The review of operations philosophy, field development plan and mode of operation is a way to achieve this goal. Contractual and environmental obligations of oil companies have resulted in a change in practice of controlling the production of individual fields towards an overall approach of operating integrated systems, thus ensuring system flexibility in a buyers market situation. The paper discusses the effect of the Operations Philosophy on design and selection of surface and subsurface facilities in fields producing a high pourpoint crude oil. A general discussion is followed by a more specific look at a recent project and development in Gabon (West Africa). The field described (Rabi) was discovered by Shell Gabon in 1985 some 130 km north from their existing fields and export terminal. Crude oil will be degassed in four gathering stations, each 40,000 b/d capacity, and dehydrated and metered in a central plant, capacity 140,000 b/d, prior to pumping to two export terminals operated by Elf and Shell respectively. Specific attention is paid to preventing and combatting wax deposition in surface and subsurface facilities and the influence on pumpability and restartability of crude in the minimum pourpoint condition and application of wax interaction modifiers. The paper highlights the importance of operations input during initial field development and its effect on facilities selection, mode of operation and operating cost.