Champion East, Low Cost Redevelopment of Shallow, Stacked and Faulted Heavy Oil Reservoirs

Abstract

Abstract The Champion East area offshore Brunei Darussalam consists of around 50 stacked, intensely faulted heavy oil reservoirs, spanning a depth of 200–1200 m ss. These reservoirs have been under development since 1975 and have to date produced just 8% of the oil initially in place. Over the period 1998–2003 Brunei Shell Petroleum (BSP) is embarking on a major redevelopment, with the aim of converting a further 30 million m3 of oil-in-place volume into commercial reserves—requiring at least a 50% reduction in unit development cost against the background of the prevailing, economically tough business environment. An overview will be given of how new technology is adding value to the total redevelopment, supported by actual application results and learning points. At the same time, Shell’s process of converting notional ‘scope-for-recovery’ volumes into bottom-line reserves additions through forward planning of requirements for technology, studies, IT tools and data, will be highlighted. The primary development of Champion East is now nearing completion, with a 30-well infill drilling campaign almost finished. This campaign uses existing facilities and ultra-shallow long-reach horizontal wells—with innovative sand exclusion and downhole ‘intelligence’—and has achieved a 60% unit cost reduction over previous drilling campaigns in the area. The only way to unlock another 5–15% of the oil-in-place volume is to start secondary recovery through water injection, in combination with the use of Electric Submersible Pumps. Long term business value will be secured in two ways: (1) by implementing a limited pilot water injection scheme, using mostly existing wells and facilities, in 2001—again aiming for a 60% unit cost reduction over previously proposed schemes; (2) by data acquisition, studies and sponsoring of joint research programmes (in-house and 3rd party) covering 4-component OBC seismic, chemical and mechanical water shut-off techniques, geochemistry, special core analysis, development of slimhole high-GOR ESPs, produced water reinjection and geomechanics.