Shale Hydrocarbon Potential 1n Brown Shale 0f Pematang Formation Based 0n Total Organic Carbon Content and Geomechanic Approach

The shale hydrocarbon potential can be defined by analyzing the geochemical and geomechanical characteristics. This research discusses how to examine the shale hydrocarbon potential in Brown Shale of Pematang Formation, Central Sumatra basin, Bengkalis trough. The analysis is done by considering the total organic carbon content and geomechanical approach based on the brittleness index and fracability index. TOC is predicted using Passey (2010) method, brittleness index is predicted using Grieser and Bray (2007) method, and fracability index is predicted using Jin et al. (2014) method. Analysis results show that the Brown Shale exists at 7867–8851 ft (interval of 984 ft) and it contains average TOC of 2.17 wt% (0.71–8.02 wt%), indicated as a very good category. From the geomechanics approach, average BI of 0.68 (0.42–0.88) indicated as brittle rocks and average FI of 0.76 (0.57–0.86) indicated as frackable zone. Those parameters were selected using modified cut-off from McKeon’s (2013) and Bai (2016), it means the shale hydrocarbon of Brown Shale is prospect to be developed.

Keywords: shale hydrocarbon; brown shale; total organic carbon; geomechanic; brittleness index; fracability index