PAPER TITLE :ESTIMATION OF SOURCE ROCK ORGANIC RICHNESS FROM WIRELINE LOGS OVER “CHARIS” FIELD, ONSHORE NIGER DELTA, NIGERIA

JOURNAL Of SUSTAINABLE TECHNOLOGY | VOLUME 10 NUMBER 1 2019

Paper Details

  • Author(s) : Abiola, O.*; Abe, S.J. and Balogun, O.
  • Abstract:

This study evaluated and assessed the organic richness of five shale sections in the
Agbada Formation (Shale A, Shale B, Shale C, Shale D and Shale E), which cut across six wells in the
“Charis” field Niger Delta. The organic richness was estimated by quantifying the Total Organic
Carbon (TOC) present using the density log and a combination technique of the resistivity and
porosity logs (Δ log R Technique). In organic-lean rocks, the porosity and resistivity logs were
overlaying each other, whereas in organic-rich rocks, the two logs were separate. Shale C and Shale
D were diagnostic of much organic matter and were also located in the vicinity of a hydrocarbon
bearing reservoir. It was observed that the interval Shale C had the highest TOC wt. % values ranging
from 1.70 to 6.20 wt. %. These results show that TOC of the Shale C interval exceed the threshold of
0.5 wt. % set to generate crude oil, indicating that they have above minimum potential 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. Due to its relative enrichment in the TOC% content,
the Shale C interval is considered a possible source of the hydrocarbon in the overlying reservoir. The
lateral distribution maps also showed that most of the TOC% enrichments are concentrated at
central south-eastern part of the study area. Therefore, the shale in the lower Agbada Formation may
have contributed in generating hydrocarbon within the study area.
Keywords: Organic richness, total organic carbon, organic matter, hydrocarbon reservoir, paralic sediments