A. Akinlua *1, T. R. Ajayi2, D. M. Jarvie3 and B. B. Adeleke4
1 Dept of Chemistry, Obafemi Awolowo University, Ile-Ife, Nigeria.
2 Dept of Geology, Obafemi Awolowo University, Ile-Ife, Nigeria.
3 Humble Geochemical Services, Humble, Texas, USA.
4 Dept of Chemistry, University of Ibadan, Ibadan, Nigeria.
*Author for correspondence, email: firstname.lastname@example.org
We analysed 34 shale samples from the Tertiary Agbada Formation
for TOC and Rock-Eval pyrolysis parameters in order to evaluate the effect of
oil-based mud contamination on source-rock characterization. The samples were
obtained from five wells in the offshore Niger Delta over a depth range of 5,460ft
to 11,580ft. The results indicated that the raw (unextracted) samples were dominated
by Type III kerogen. However, after extraction, both Types II/III and III kerogen
were identified, consistent with previous studies. These results demonstrate
that it is essential that shale samples should be extracted prior to TOC and
Rock-Eval pyrolysis for accurate source-rock evaluation.
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