Development of the Central Luconia gas fields, located offshore Sarawak, started in 1982. To data three gas fields have been developed, E11, F23 and the third and largest gas field, F6, which came on stream in January 1987. The daily production rate averages some 1000 MMscf/d. The gas is delivered via a single 36" trunkline from E11 to the Malaysian LNG liquefaction plant for the Manufacture of LNG at approximately 6 million tonnes per year for a period of 20 years. Gas is also distributed to the ASEAN Bintulu Fertilisation plant for the production of urea and ammonia, and to Sarawak Electricity Supply Corporation for power generation. This paper describes the 3D simulation study that has been carried out for the F6 field which forms the basis for the development planning of the field. The plan proposed a total of ten producer and one observation well to be drilled from the drilling platform F6DP-A located near the crestal part of the field. Despite the large reservoir areal extent of about 168 km2, it is expected that the field can be adequately drained from a single platform with ten producers. The main uncertainties which may affect the field performance are the transmissibility of a tight argillaceous layer which may separate the gas bearing part of the field into two zones and the possibility of water drive. The likely impact of these uncertainties on the development plan and gas recovery has been addressed in the simulation study. Taking the above uncertainties into consideration, recovery factors are estimated to be between 61% and 75%. The Central Luconia province is situated some 100 miles offshore Sarawak. Malaysia in 230 - 290 ft of water (Fig. 1). During the late 1960's, Sarawak Shell Berhad (SSB) carried out exploration drilling in Central Luconia. Numerous gas accumulations were found in carbonate buildups and the gas reserves were evaluated to be large enough for a viable LNG scheme. Proposals were presented to the Malaysian government in 1971, which eventually led to the formation of Malaysian LNG Sendirian Berhad (MLNG) in 1978. Petronas (the Malaysian national petroleum company) took up 60% equity in this venture, while Shell Gas B.V. and Mitsubishi Corporation of Japan took up 17.5% each, and the State of Sarawak 5%. Central Luconia gas is further distributed to the ASEAN Bintulu Fertiliser plant for the production of urea and ammonia, and to Sarawak Electricity Supply Corporation to generate power for local use. The results of seismic surveys taken during the mid - 1960's indicated the possibility of large carbonate structures in Central Luconia. Exploration drilling in 1968 confirmed the existence of these carbonate structures. The first significant gas accumulation was discovered by well F6.1X in 1969. Exploration drilling in 43 carbonate structures within the period 1968-1975 led to the discovery of 20 gas accumulations, of which 10 contained significant quantities of non-associated gas. Appraisal drilling in the five largest gas fields, E11, F23, F6, ES and F13, which are committed to the LNG project. was completed before end 1978 to better define geology, reserves, productivities and wellstream compositions. E11 was the first gas field to be developed, being closest to shore. By 1982, the installation of offshore platform and associated facilities, and the 78 miles long 36" trunkline to shore was completed. P. 849^

In March 1995, what is believed to be the worlds first offshore coiled tubing deployed electrical submersible pump (ESP) was successfully commissioned in well AA-03Sl on Shell U.K. Exploration and Production (Shell Expro) Auk platform in the United Kingdom's Central North Sea. The ESP provides a new and important method of artificial lift for the 21 year old Auk platform, which hitherto had relied upon downhole hydraulic jet pumps to lift approximately half of the platform's oil production. The coiled tubing deploymentproved the viability of performing future work over with or without the assistance or indeed the presence of a drilling package. The novel completion design successfully catered for the wide variety of customer requirements; Well Engineering for a rigless workover, Petroleum Engineering for reservoir access and Facilities Engineering for a specified flowline height The experience gained during this project will be a valuable input in determining the future artificial lift strategy for this platform and for other prospects in terms of performance, reliability and operating costs. Introduction The Auk Alpha platform was brought on stream in 1975, producing from 11 oil wells. The reservoir pressure is supported by a strong aquifer drive and the fields water cut has currently reached 70%, The GORs are low, at approximately 175 sef/bbl with a bubble point of 680 psi. The existing method of artificial lift is by wire line retrievable ?downhole hydraulic jet pump, However, due to the limited capacity of the permanent artificial lift (PAL) system, no more than three wells could be lifted simultaneously. It was against this background that the decision was taken to proceed with a trial ESP installation as a complementary method of artificial lift. After deciding to use an ESP pump on the Auk (the first within Shell Expro) the method of deployment had to be considered, conventional deployment versus cable or coiled tubing deployment The preliminary work showed that using either cable or coiled tubing as the means of deployment for the ESP could give rise to significant savings. Opex reduction of 20% on future workoversInstallation times reduced by 50%. Bedding reduction of circa 100 mandays per workover The use of cable or coiled tubing deployment was also an opportunity to utilize new technology whilst being aware of the risks involved capitalizing on the work already done with large bore coiled tubing by Shell Expro in the Southern North sea. An invitation to tender was prepared which invited companies to tender for the supply and installation of all components for the completion excluding the tubing hanger and wellhead. They were also required to supply a Project Engineer to work with the Shell Exploration project team to bring the proposal to fruition. After evaluation of tie submitted tenders a pump manufacturer was selected.