Abstract

A deterministic approach for constructing a large multi-layered model is being applied to the Attaka field, offshore East Kalimantan. The field consists of numerous stacked reservoirs in a complex fluvial/deltaic environment. Developing a full field model is not practical while use of individual reservoir models is limited by extensive commingling of completions.

A parallel approach is used to construct single reservoir models. The reservoirs are ranked by the degree of commingled production and an adaptive history matching technique is used. The history match is performed within the uncertainty range of allocated oil, gas and water production, and is guided by wells with the least degree of commingling. The individual models are stacked together to form multi-reservoir, sequence and multi-sequence models. At each stage the degree of commingled production with reservoirs outside of the model is reduced and the history match is improved.