Publications

The Kutei Basin has produced approximately eight Billion Barrel Oil Equivalent from middle to late Miocene deltaic clastic reservoirs in several gas and oil fields which have been discovered since 1900 (IHS, 2015). However, the early Miocene deltaic to shelfal-clastic play has only been partly explored, and tested, with lack of economic success so far. This paper considers the main factors controlling reservoir quality in the early Miocene and how they may be used to predict reservoir quality away from well control. Well data are derived from three major onshore fields and four other exploration wells were used to create a relational database to evaluate the controls on reservoir quality. Subsequently, basin modeling result is used to analyze the impact of thermal maturity (chemical compaction) and overburden stress (mechanical compaction) to the prediction of reservoir deliverability. Macroscopic factors consist of mechanical compaction (depth), facies, and litho-types. Microscopic factors include authigenic cementation. The BP proprietary Reservoir Quality Predictor tool was used to predict porosity and analyse the controls on reservoir quality. A well penetration suggests the Early Miocene deltaic sandstone has good reservoir quality based on logs and core samples. This is one of the indications of its potential in the onshore Kutei Basin. Based on the relational database cross-plots, analysis, and analogues, it is summarized that the reservoir quality in the Early Miocene is influenced by macroscopic and microscopic factors, Quartz Ductile Rigid (QRD) grains. The 1-D modelling shows that Early Miocene Deltaic in Kutei Basin is predicted to have 1-16 % porosity and 7.6 mD – 1D permeability, depending on facies, depth, and litho-type.