A Dedicated Production Support Vessel For Offshore Operations

Abstract

Abstract A dedicated support vessel for production providing facilities for stimulation, nitrogen service, endless coiled tubing and production testing, was used successfully by Brunei Shell to service offshore wells. Four years of experience showed the tremendous flexibility and versatility of the vessel in an area where wells and fields are scattered. The vessel has shown to be a profitable resource for repairing problem wells to restore production. Indirectly, much rig time has been saved as a result. Introduction Brunei Shell has six oil/gas producing fields offshore. Offshore production started in the mid sixties and has been the main activity of production started in the mid sixties and has been the main activity of Brunei Shell's production. The development of offshore fields is very active and has grown into a complex network of structures and pipelines linking the wells to the oil terminal and the Brunei Liquified Natural Gas plant. The Headquarters of Brunei Shell are located in Seria, which is plant. The Headquarters of Brunei Shell are located in Seria, which is also the location of the onshore oil field (Figure 1). The reservoirs development are all sandstone layers in complexly faulted anticlines. Offshore production at the end of 1982 was about 144,000 b/d of oil and 900 MMscf of gas. At present, there are 5 tenders, 1 jack-up and 1 semi-sub operating offshore Brunei waters. On average, about 40 new wells per year were completed offshore for the past 3 years and about 15 wells were worked over per year. A production support vessel complements the offshore drilling per year. A production support vessel complements the offshore drilling resources. TECHNICAL ENVIRONMENT Brunei Shell has about 500 connected wells offshore scattered in six fields at present. The majority of the wells are drilled from 12-slot platforms. There are a number of satellite wells which are supported by small jackets. The wells are usually multi-zone completions with dual production tubing (Figure 2). All the oil bearing reservoirs are sandstone formation ranging in depth from 1000 feet to 12000 feet. Gravelpacks are extensively used for sand exclusion. Active wells have specific offtake requirements. In many a case, problems develop (impairment, sand, mechanical etc.) and in order to meet drainage objective, problem wells will have to be serviced. p. 8–110 p. 8–110