Total organic carbon content determined from well logs using ΔLogR and Neuro Fuzzy techniques

Total organic carbon (TOC) content present in potential source rocks significantly affects the response of several types of well logs. Wireline logs can be used to identify source rocks and serve as an indicator for the source rock potential. Because the source rock intervals generally show a lower density, higher sonic transit time, higher porosity and higher resistivity than other sedimentary layers, these phenomena can be used to identify source rocks on wireline logs. This paper attempts to establish a quantity correlation between standard well logs (sonic, density, neutron and resistivity) and total organic carbon by means of two techniques, namely, using ΔLogR and then using Neuro Fuzzy. Two pilot wells “A” and “B”, through Pabdeh and Gurpi formations in the Dezful Embayment, were selected for this study.