Bulletin of the Geological Society of Malaysia, Volume 42, Dec. 1998, pp. 39 – 45
Sarawak Shell Berhad, Locked Bag No.1, 98009 Miri, Sarawak
Abstract: The D35 oilfield was discovered in 1983 and over the next seven years, six appraisal wells were drilled to test the reservoir and hydrocarbon distribution. The productive reservoirs comprise exclusively of channel deposits of Early to Middle Miocene age, which exhibit highly variable lateral reservoir distribution. Development drilling in the field began in 1993 with fifteen wells drilled from two platforms.
Results from this initial development campaign indicated that a secondary objective, the Cycle III Channel Sand was absent over much of the field. This resulted in a downward revision in the inplace oil volumes for this reservoir unit and downgraded its prospectivity.
As part of efforts to enhance the structural and stratigraphic understanding of D35 prior to further development, a 3D survey was acquired in 1995 aimed at giving superior lateral and vertical resolution. The initial result of the interpretation appears promising. Seismic amplitude extractions at and near the Cycle III Channel Sand level have revealed features which are diagnostic of reservoir geometry and has helped explain much of the disappointing results from the first round development. More significantly the new 3D has highlighted additional scope for hydrocarbon recovery from this reservoir.