Reservoir Management of the Dulang Oil Field, Offshore Peninsular Malaysia: The Heuristic Approach

Abstract

ABSTRACT This paper describes reservoir management practices for the early development stages of the Dulang oil field, a multiple reservoir field offshore Peninsular Malaysia. The Dulang field is located approximately 130 kilometres offshore Kuala Terengganu in a water depth of about 76 metres in the South China Sea. The reservoir sands are of late Miocene Age and exhibit a complex stratigraphic layering within an elongated anticline divided by numerous faults. Two platforms are onstream at an average rate of 45,000 barrels of oil per day. The third and fourth platforms are scheduled to go onstream by late 1993, and late 1994 concurrent with planned pressure maintenance operations in late 1994. The understanding of the reservoir performance gained from all stages of the field development will be used to define the ultimate reservoir management strategies. Pressure maintenance operations were deliberately deferred in view of anticipated geological complexity. The geological complexity, multiple completion, reservoir variation and varying depletion mechanism necessitate prudent reservoir management practices in the Dulang field. The overall reservoir management strategy developed for the Dulang oil field may entail up to fifty separate depletion plans for identified reservoir units. Individual wells and reservoir units have been ranked according to quality and productive potential. Quantitative guidelines for reservoir quality, utilising site specific factors, have been developed and applied on an ongoing basis. This paper also presents the scope of the reservoir description and surveillance guidelines, performance monitoring procedures, data acquisition and analysis, which collectively serve as the basis for formulating optimum reservoir management strategies in this field. Logistical considerations with respect to operational simplicity and flexibility were also incorporated into the field development and reservoir management plans.