Publications

Arc-related volcanism has been active in Java since the Eocene, producing primary volcanic rocks and thick volcaniclastic sequences that serve as reservoir for at least one commercial gas accumulation. Porosity prediction in volcaniclastic reservoirs remains problematic. However, volcaniclastic deposition can also promote hydrocarbon maturation in marine settings. In restricted marine environments, volcaniclastics act as a fertilizer to stimulate organic growth, causing algal blooms and elevating the total organic carbon (TOC) of marine sediment (e.g., the Eagle Ford shale, Texas, USA). Furthermore, zeolites are common decay products in volcaniclastics that can act as catalysts to accelerate the maturation of source matter. The result is a self-sourced petroleum system that could exist in large, and as yet under-explored, areas in Java and elsewhere on Sundaland. In this paper presents data from several tested or producing gas wells that support the concept of volcanic-enhanced petroleum systems. Despite indisputable problems with respect to the predictability of reservoir quality, the proximity to a growing energy market and available infrastructure makes Indonesian volcaniclastic gas plays worth further pursuit. Keywords: Volcaniclastic, Andesite, Zeolite, Secondary Porosity, Maturation