Shale gas zone characterization in North Sumatera area using neural network multi attribute analysis

The energy needs is increasing over time. New energy sources are needed to overcome the energy shortage. One of the energies that can be produced from shale layer is gas called shale gas. Indonesia has a lot of source rock that can be used as a source for shale gas. One of the basins which is potential as shale gas reservoir is North Sumatera Basin. Petrophysical analysis and Seismic Data Processing have been done to map the shale gas layer in North Sumatera Basin Zone. The resulting value of petrophysical property in North Sumatera area is about 46% for clay volume, 53% for water saturation, 5% for porosity, and 0.02 milli Darcy (mD) for permeability. In addition, the total organic content (TOC) estimation is calculated using Carbolog Method to identify the maturity of source rock which depends on the resistivity and velocity value (Sun et al., 2013). The result of TOC estimation is above 1%. Brittleness index (BI) is calculated using the relation between Poisson's ratio and elastic modulus, result of BI estimation is about 0.45. The result of BI value indicates that the shale characteristic in the potential zone is brittle. The model of TOC and BI distribution in the potential zones can be traced horizontally using multiattribute neural network of two-dimensional (2D) Seismic Data. The high value of TOC and Brittleness Index indicates the shale gas layer in Belumai Formation. The shale gas layer thickness is 32 meters at 2496 to 2528 meters depth in Belumai Formation.