Banyumas Sub-basin is a hydrocarbon bearing area as indicated by numerous oil and gas seepages found in the surfaces. Several wells have been drilled in this area but unfortunately failed to discover hydrocarbon. Structural patterns developed in this sub-basin are characterised by commonly NW-SE and NE-SW lineaments. Two major paleogene strike-slip faults are recognised as synthetic fault called (1) the Muria- Kebumen, and (2) the Pamanukan-Cilacap Faults. The two faults are affected by oceanic plate movement to the north (Indian oceanic plate). Stratigraphy of the basin recorded from seismic comprises Gabon Formation of Oligo-Miocene age and conformable overlain by Upper Tertiary succession as Penanjung, Kalipucang, Halang, Kumbang, Bantardewa, Talanggundang Formations, and the uppermost Quaternary Volcanic. Source rock identified includes Paleogene of Nanggulan and Late Miocene of Halang Formations. Based on GCMS analysis of oil available seepages reflect fluviodeltaic kerogen origin. Reservoirs identified include Gabon, Kalipucang and Halang Formations. Several leads were found in this area. Hydrocarbon migrated through faults and trapped structurally and stratigraphically.
Keywords : hydrocarbon, structure, stratigraphy, source rock, reservoir rock, migration
Author : A. Guntur, Sriwijaya, A. Ruswandi, Y. Setyoko