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. Eight 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, Kawengan, and Lidah cycles. Tuban is commonly believed as a regional seal for Kujung I play. Careful construction of stratigraphic 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. Tuban formation is consisted by mostly shale. But it doesn’t mean that we only have thick shale interval during Tuban deposition in fact there is sandstone deposition encountered in several well in particularly Pangkah Area. Tuban cycle in Pangkah PSC consisted by predominantly shale intercalated with limestone and sandstone. Detail observation within the Tuban has been done to several exploration and also development well showing sandstone interval with significant gas show recorded on the gas log. Well correlation from the northern part to the southern part of Pangkah Block is showing that this sandstone interval within Tuban cycle thicken to the north as shown on Ronggolawe-1 well. This phenomenon has opened our eyes to the fact that Tuban Cycle has an overlooked reservoir potential that is underexplored.