Total organic carbon (TOC) content in shale layer is one of the important component in the shale gas evaluation. However, the analysis of TOC is usually conducted in the well location only at certain depths. Correlation analysis between TOC and other physical properties are therefore commonly performed such that relationship between them could be attained.
This study utilizes Passey method for modeling TOC based on relationship between resistivity and sonic logs (better known as ΔlogR) which is related to maturity levels of organic carbon (Level of Organic Maturity). Further analysis using elastic parameters Mu-per-Lambda also show some promising relationship. This finding, thus allows us to make zonation of shale layer based on the level of richness of organic carbon and the brittleness level. Another important point is the fact that Mu-per-Lambda is a rock physical parameter. It can then be related and extracted from seismic data. This will, therefore, enable us to better map and quantify the shale gas potential seismically.
Authors : Oki Rizaldi, Dardji Noeradi, Sonny Winardhi