A novel synthesis of 1,2-disubstituted 1,2-dihydroquinazoline 3-oxides 8 and the first ever examples of 1,3-dipolar trapping of these nitrones to homonuclear dipolarophiles is described. The new dipoles 8 reacted with N-methyl maleimide, generating diastereomeric adducts 14-16. In the reaction between 8 and dimethyl acetylenedicarboxylate, primary cycloadducts 17 and/or stable rearrangement products, azomethine ylides 18, are formed depending on the substitution pattern of the dipole. The structure of 18c is unambiguously assigned by X-ray crystallographic analysis. An X-ray crystal structure determination is also presented for the cyclopropylisoxazoloquinazoline 22 formed by a [3 + 2] addition of 8a to 21, the dimethyl acetylenedicarboxylate tetramer.
Summary This paper presents an overview of the Zaafarana Oilfield Development and a more detailed account of the conversion of its Floating Production, Storage and Offloading Facility (FPSO), concentrating on the contractual and cost elements of that work. The development presented a series of unique challenges and set a number of firsts. These included the re-deployment of an internal turret mooring system, use of a turret based electrical cable jumper system and the permanent use of cable-deployed electric submersible pumps in the gravel pack well completions. The Zaafarana FPSO was delivered with change order work amounting to less than 3% of the contracted price and within 10 days of schedule (adjusted for permitted delays). Award of Contract to first oil was one year. This was achieved through the adoption of a low-cost approach, concentrating on obtaining only essentials, with a minimum of preferential engineering. Flexibility of approach to problem solving and maintenance of a non-confrontational attitude between contracting parties proved essential. Introduction The Zaafarana Oilfield, offshore Egypt, is the first international oilfield development undertaken by British Gas E&P as Operator, from the acquisition of the exploration acreage through to field start-up. The development presented a series of unique challenges and set a number of firsts, both for the company and for the oil industry in general, including the redeployment of an internal turret mooring system, use of a turret based electrical cable jumper system and the permanent use of cable-deployed electric submersible pumps in the gravel pack well completions. During the exploration phase, BG Egypt was the Operator of the North Zaafarana Concession which contains the Zaafarana Field. The concession was acquired in June 1989 with Union Pacific Suez Limited and Yukong Limited as the other partners, each with a 25% working interest. Following a detailed 3D seismic program the field was discovered by the first well in December 1990. Four subsequent appraisal wells were drilled, and the discovery well and two of the appraisal wells tested oil at rates ranging from 2,000 to 10,100 BPD. The final well was suspended, without testing, as a future producer. Initial development plans called for the use of two conventional platforms with a pipeline to a shore-based treatment and storage terminal. Subsequently, data acquired from latter wells of the 1991 drilling program was incorporated into the mapping and reserve estimates and estimated recoverable reserves were downgraded sharply. This, along with a revised pricing scenario, resulted in the need for an amended development plan with significantly lower costs. This plan, based on the use of a Floating Production, Storage and Offloading Facility (FPSO) and a single drilling/wellhead platform, connected by a pipeline and electrical and control umbilicals, was approved in October 1992. Agreement on the Development Plan was reached with partners and the Egyptian General Petroleum Corporation (EGPC) in January 1993. The joint operating company, Zaafarana Oil Company (ZAFCO), was established in February 1993 to develop and operate the field. First oil was achieved on 16 November 1994. The field is producing approximately 18,000 barrels of oil per day and cumulative production reached six million barrels of oil in the first year of operation.
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