“…Its location is in the Southern part of the hydrocarbon prolific East Java inverted back-arc Basin which was formed during the Oligocene-Early Miocene (Sribudiyani et al, 2003), on the Eastern tip of the Kendeng Zone (De Genevraye and Samuel,1972). The Geology of the area is characterized by the rapid deposition of thick organic rich sediment as part of the Brantas delta, influenced by the extensional tectonic regime (Willumsen andSchiller, 1994, Schiller et al, 1994). Due to the rapid deposition, shales in the area are undercompacted and overpressured (Mazzini et al, 2007).…”