Dubai Khazzan Pioneer of Large Undersea Storage Systems

Abstract

Ali Baba in his wildest dream could not have imagined storing oil in the likes of the bottle that lies in 150 feet of water in the Arabian Gulf off Dubai. Introduction In June, 1966, oil in commercial quantities was found offshore the Shiekdom of Dubai. The firms involved in this enterprise were, besides Dubai Petroleum Co. (a wholly owned subsidiary of Continental Oil Co. and operator for the group), Dubai Marine Area Ltd. (Compagnie Francaise des Petroles and British Petroleum), Deutche Erdol-Aktiengesellschaft and Dubai Petroleum), Deutche Erdol-Aktiengesellschaft and Dubai Sun Oil Co. Hispanoil has now replaced British Petroleum as a partner of the DUMA group. Petroleum as a partner of the DUMA group. The Shiekdom of Dubai is one of seven Trucial States on the southern end of the Arabian Gulf (Fig. 1). It is an established center of commerce for coastal shipping out of a shallow-water port. However, its shoreline has no natural deep-water area near shore, which is essential for crude oil export in deep-draft tankers. The discovery well, Fateh A-1, flowed 30 degrees API crude from the Lower Cretaceous Ilam and Thamama at 7,500 to 8,500 ft. Two confirmation wells were drilled 2 miles to the southwest and 2 miles to the northeast on each side of the original well and along the major axis of the structure. These first three wells confirmed the presence of the Fateh field some 60 miles offshore in water depths ranging from 110 to 180 ft (Fig. 2) and triggered a number of feasibility studies to determine the optimum development method. Concept After the field discovery and confirmation drilling, a carefully designed plan for its economical development was formulated, with the objective of placing the field on production as soon as possible and in a manner that would allow expansion should initial reserve estimates prove conservative. The concept ultimately developed prove conservative. The concept ultimately developed was to build a completely selfcontained offshore producing, storage and loading system at the field site. producing, storage and loading system at the field site. This system was implemented because it was appreciably cheaper than the more conventional approach of piping the oil to a shore terminal. A feasibility study that was completed in Aug., 1967, for the design and operation of the field indicated that the location of the storage and offloading facilities was a key variable and included three possible alternatives:offshore (floating tanker possible alternatives: (1) offshore (floating tanker forebodies in the field area);onshore mainland Dubai; andonshore the island of Sirri, claimed by Iran, which is about 23 miles northeast of the field. The last alternative was dismissed for political reasons, leaving the choice of selecting a field site terminal or bringing the oil to Dubai and offloading near shore. The first step in comparing the economics of these methods was to group all of the flow process and equipment down stream of the well flow lines and to determine investment and operating costs over a 10-year period. The initial investigation was concerned with the floating units for onsite storage vs the conventional pipeline-to-shore installation; but another onsite pipeline-to-shore installation; but another onsite storage alternative was soon developed. This concept, which was ultimately included in the over-all analysis, was submerged storage. JPT P. 1065