Predicting Distribution of Total Organic Carbon (TOC) and S2 with Δ Log Resistivity and Acoustic Impedance Inversion on Talang Akar Formation, Cipunegara Sub Basin, West Java

Abstract

The quality of source rock can be determined from the Total Organic Carbon (TOC), and S2 (amount of hydrocarbons produced from pyrolysis). At a certain level of maturity, organic matter will be transformed into hydrocarbons. This transformation is recorded by resistivity log and can be modeled using ΔlogR (resistivity) technique. The technique itself is based on the magnitude of separation of resistivity and sonic curve which indicates presence of mature source rock, calibrated to TOC and level of organic maturity (LOM). The value of S2 can also be calculated as TOC has a linear correlation with S2. These calculated TOC and S2 are plotted against the Acoustic Impedance (AI), also obtained from the well. Using nonlinear equation derived from the cross plots, the resulting values are distributed into the seismic data by applying the AI inversion technique.