Well logs response characteristics and quantitative prediction model of organic carbon content of hydrocarbon source rocks in coal-bearing strata measures

Coal-bearing strata are rich in organic rocks,which can result in complex logging response. Based on the de- termined TOC data,the logging response characteristics of organic carbon content in coal,carbonaceous mudstone and mudstone were analyzed. It was found that the organic carbon content and parameters of the electrical resistivity log,a- coustic log,natural gamma log,density log and neutron porosity log were well correlated. According to previous analysis, multiple regression and Δlog R models for calculating the organic carbon content of source rocks with different lithologies in coal measures were obtained. Combined with the study formation,single factor model,binary regression model,five variables regression model and the overlapping model were respectively established. Moreover,the models mentioned a- bove were used for calculating the TOC content and the error analysis were conducted. Results show that the calculation error of five variables regression model is the smallest,but is larger at the intervals where there are no measured TOC da- ta;the calculation error of overlapping method is the largest,while the predicted TOC content value is more consistent with the lithological characteristics over the whole interval. The study of organic carbon content prediction in coal meas- ures aims to provide a reference for the comprehensive evaluation of the geochemical parameter in coal-bearing source rock,which also has some referential value for related application research in the future.