WELL-LOG BASED TOC ESTIMATION USING LINEAR APPROXIMATION METHODS

Abstract

Diverse measured physical parameters using open-hole wireline logging methods used for indicating source rock intervals and estimating total organic carbon (TOC) content are compared. Different methods (i.e., Passey, Schmoker, Uranium and Clay Indicator) for estimating TOC content in a data set of five wells from the Northern Sea (Norway) were tested, making it possible to delimit the organic-rich source rock intervals in the wells and estimate the TOC content for each well; results were compared with laboratory TOC data. It was shown that Passey’s method is a robust tool to evaluate TOC content that is unlike other methods, since it considers more physical parameters for the petrophysical evaluation (e.g., resistivity, level of maturity, porosity), making it the most accurate method to evaluate TOC content. However, the other methods show good agreement with the measured TOC content.