Publications

Recently there has been growing interest in gas exploration. Much of this focus has been directed toward thermogenic gas derived from cracking kerogen andlor previously generated liquid hydrocarbons. Such gases form late in a basin's history at elevated temperatures. A significant proportion of the global gas reserve-base is, however, not thermogenic but of bacterial origin. Biogenic gases form early in a basin's history at low temperatures. Because of their different origins, different exploration strategies are required for the two types of gas. The focus of this study is to examine those factors which ultimately result in the accumulation of commercial quantities of biogenic gas, to review the characteristics of several major biogenic gas accumulations, and to briefly comment on the potential economic significance of biogenic gas in Indonesia.Much of our current understanding of the formation of biogenic gas accumulations has been derived from the study of known occurrences. In order to gain insight into the constraints on formation of commercial biogenic gas deposits in the Po Valley (Italy), Cook Inlet (Alaska), Powder River basin (Wyoming) and West Siberian basin (Russia) are examined. Information from this review and an examination of biological and physical processes can then be used to establish the characteristics of gas source rocks, the influence of sedimentation rate, the role of thermal history, and the importance of relative timing.Currently available data suggests that significant potential for biogenic gas exists within the Indonesian archipelago.