The Middle Miocene Ngrayong sand member of Tawun Formation in Well-X, Kawengan oil field, can be divided into 7 (seven) parasequence sets based on EMI log interpretation and the outcrop studies.
The interesting fact is that the highstand system tract (bioclastic obbitoidal grainstone facies) has good porosity and permeability and acts as the reservoir rocks for hydrocarbon. Sandy facies of transgresive system tract (sand bar) appears as the main reservoir rock and shale facies of lowstand system tract acts as seal (cap rock) of every producing layers.
The result of detail analyses of EMI log is recommended to support the geoproduction job in Kawengan oil field.
Author : M. Johannes PK