Shale gas refers to natural gas that is trapped within shale formation. The gas can be trapped in the shale that has the characteristics as source rock. Because of low permeability of shale, the hydrocarbon gas generated tend to be trapped inside the shale itself. In order to release and extract the gas inside, the shale need to have secondary fracture porosity, whether occurred by natural process or artificially made. Shale gas over recent years has become one alternative candidate fossil energy needs, which oil and gas reservoirs get decreasing production approached the limit of its economic rate, and until now it is undiscovered or has not begun exploitation yet for the new field.
In Indonesia, shale gas is one of the alternative fossil energy being developed besides Coal Bed Methane (CBM). Indonesian shale gas potency is predicted around 574 TSCF. It is bigger than CBM, which is about 453,3 TSCF and gas 334,5 TSCF. Based on identification result held by the government, there are seven basins in Indonesia containing shale gas. The most number basins are in Sumatera; there are three formations with carrier shale gas formation that is Baong Shale, Telisa Shale and Gumai Shale. While in Java Island and Kalimantan, shale gas each is in 2 basins. In Papua, there Salawati basin with Klasafet Formation as shale gas carrier formation. Salawati Basin began to develop as the result of transtensional pull-apart regime induced by movement of Sorong Fault during Miocene. Klasafet as the shale gas carrier estimated to be approximately 1900 m thick. The calcareous fine clastics of Klasafet Formation regarded as the best potential source rocks in Salawati Basin, but the Klasafet Shale also known as mature source rock.
The research purpose is to discuss and determine the presence of shale gas in Salawati Basin. As for the research methods used literature study concerning regional stratigraphy and geologic structure. The secondary data is the geophysical data that support in determining the focus area. Therefore, according to us this is very interesting to be studied and researched in order to get a concept and a better understanding in shale gas exploration.
Keywords: Shale gas, Salawati Basin, Klasafet Formation, Geophysics
Authors : Jonathan Kristian, Tadeo Ditia, Felix Sihombing