Models for Estimating Total Organic Carbon from Well Logs

Abstract

These days unconventional reservoir is more intense to discuss because of its potentially prospective to be produced due to the depletion of conventional hydrocarbon reserves. To find out the potential of hydrocarbons in source rocks it is necessary to analyze the content of total organic carbon (TOC) as one of its parameters. The method used to estimate the value of TOC is using well log data, the most famous and widely used is Passey's TOC model. The use of well log data is more preferred than other methods such as coring and cutting done in the laboratory as it only exists at certain points, requires a long time, and needs expensive cost. The TOC model that is obtained may not be suitable to use in all conditions of formation, therefore a summary of the TOC models are made from the results of direct tests in the fields to make it easier or as a reference for development wells. There are 25 models to predict TOC using well log data from 14 shale formation around the world, those are: Antrim Shale, Bakken Shale, Baong Shale, Brown Shale, Devonian Shales, Duvernay Shale, Goldwyer Shale, Green River Shale, Jiaoshiba Shale, Kimmeridge Formation, Longmaxi Shale, Monterey Formation, Talang Akar Formation, and Woodford Shale. These TOC models are different based on its condition. So, the TOC equation chose must be considered to the characteristics of formation.