A study of the organic richness and petrophysical Characteristics of selected shales from the analysis of wireline logs: a case of “neya” field, Niger Delta

Abstract

This study evaluated and assessed the organic richness and some petrophysical properties of selected shale intervals from six wells in the “Neya Field”, Niger Delta. This was done by quantifying their average total organic carbon (TOC), thickness, volume of shale (VShale) and effective porosity (PHIE) from wireline logs. Six to seven shale intervals were delineated and their properties calculated empirically using established relations. The petrophysical properties of the intervals indicate they have the characteristics typical of shaly to shale zones. The TOC of the shales varies from 7.56 to 12.44 wt% in the wells which exceeds the threshold of 0.5wt% for shale source rocks. These indicate that they have above minimum TOC to generate hydrocarbon and are in fair agreement with TOC values earlier reported in some parts of the paralic sediments of onshore and offshore Niger Delta. Additional results indicate that organic enrichment (TOC) does not have clear dependence on thickness, volume of shale or effective porosity of the shales in the study area.

 Keywords: Shale, Petrophysical, TOC, Niger Delta, Nigeria