Abstract
Located offshore East Malaysia, S-C Field is considered a marginal oil field with first development in 2008. While it is a shallow marine with storm and wave influence setting, the reservoir sealing is provided by the unconformity and Major Fault in the west side and further split into three major sub-blocks namely North, Middle and South Block. Middle Block carries two third of total field production as it also carries 80% of total oil volume making it the biggest producing block in S-C field.
The field separation into sub-block came as a surprise during the development drilling which has totally impacted the production strategy and oil recovery as the field is initially expected to be a single buried hill with two separate major oil accumulations. Sand discontinuity and multi-stacked nature of the reservoir proved to be major challenges during development drilling and production phase. Despite the successful drilling and production from most of the development wells, excessive sand production lurks as major threat to oil production and well life. Careful implementation of drawdown limit and sand count monitoring was implemented, nonetheless the oil recovery remained low and the need for additional drainage points was assessed to unleash the full field potential.
This paper captured the case study on this marginal oil field redevelopment which has substantially revived its oil production and successfully overcame the production challenges despite the geological surprises, lesser in-place volume, unoptimised completion and forecasted lower recovery compared to initially prognosed. From the early identification of potential additional infill candidates, project acceleration and economic improvement, the post-production performance has indicated a huge transformation towards realising more oil incremental at reduced cost. Additionally, there were significant lessons learned on subsurface planning and project execution. These were then highlighted for way forwards plan for S-C field and S Cluster in general to further sustain production and extend the field life.