Publications

Careful construction of stratigraphic-structural frameworks, using a sedimentary cycle model approach, has led to a more complete understanding of various play types and their fairways in East Java Basin. The Tertiary sediments in East Java Basin can be divided into a number of sedimentary cycles, each, if complete, would ideally consists of a Regressive System Tract followed by Transgressive System Tract bounded by maximum flooding and/or unconformity surfaces. Each cycle is characterized by renewed clastic sedimentation capped by carbonate. The cycle boundaries are often characterized by discordances on seismic horizons including onlap, downlap and truncation. Seven sedimentary cycles have been identified within the Tertiary sediment, including the Ngimbang (Eo-Oligocene), Kujung III (Oligocene), Kujung II/I (Oligo-Miocene), Tuban (Lower Miocene), Ngrayong , Wonocolo, and Kawengan. But only six can be identified over the study area except Wonocolo. The Ngimbang, Kujung III and Kujung I/II Cycles represent an overall transgressive mega-sequence with major unconformity at the base and major maximum flooding surface at the top. This megasequence are associated with rifting episode in the Paleogene. This is followed by an overall regressive mega sequence during the rest of the Tertiary. More than 2 BboeOil and gas have been discovered and some of which have been produced from several plays throughout the stratigraphic levels, including: Ngimbang sand, Ngimbang carbonate, Kujung III carbonate, Kujung I/II carbonate, Tuban clastic, Tuban carbonate, Ngrayong shallow marine sand, Ngrayong turbidite, Kawengan sand, Kawengan carbonate, Kawengan Volcani-clastics. The fairways of these plays have been mapped which reveal that the East Java Basin remains under-explored. Many plays exist in East Java Basin and most of them have been proven productive. The sedimentary cycle approach has identified under-explored play.