Abstract

The distribution and geochemical significance of dibenzofurans, phenyldibenzofurans and benzo[b]napthofurans in source rocks from Niger Delta basin, Nigeria, were investigated by Rock–Eval pyrolysis and gas chromatography-mass spectrometry (GC–MS). The data obtained from the source rocks evaluation showed that the rock samples contained type II/III kerogen capable of generating oil and gas and were within immature to early mature stage. The relative abundance of the C0-, C1- and C2-dibenzofurans range from 1.75% to 29.82%, 27.60% to 40.52% and 29.66% to 68.89%, respectively. The dibenzofurans were dominated by C2-dibenzofurans. Among the C1-dibenzofurans, 2-+3-methyldibenzofuran was the most abundant in the rock samples while 1-methyldibenzofuran appeared to be the least. The relative abundance of benzo[b]naphtho[1,2-d]furan ([1,2]BNF), benzo[b]naphtha[2,1-d]furan ([2,1]BNF) and benzo[b]naphtha[2,3-d]furan ([2,3]BNF) in the rock extracts range from 12.01% to 52.58%, 32.61% to 75.21% and 10.27% to 52.43%. The wide range of values recorded for the three isomers of benzo[b]napthofurans in the samples suggest source rocks formed from mixed organic matter. Among the phenyldibenzofuran isomers, 4-phenyldibenzofuran was the most abundant while 1-phenyldibenzofuran was the least. Phenyldibenzofuran ratio-1 (PhFR-1) and phenyldibenzofuran ratio-2 (PhFR-2) values range from 0.13 to 1.20 and 0.11 to 2.11, respectively. The results showed that the relative abundance of PhFR-1 and PhFR-2 increase gradually with increasing burial depth and maturity (VR0 ≤ 0.77%, MPI-1 ≤ 0.62, Tmax ≤ 443 °C), and have a good correlations with calculated vitrinite reflectance, MPI-1 and maximum Temperature (Tmax). This range of values suggested immature to early mature source rocks. The source rocks were found to have shale and coal lithologies and deposited in a lacustrine/fluvial/deltaic settings within immature to early mature stages based on the distribution of dibenzofurans, phenyldibenzofurans and benzo[b]naphthofurans in the source rocks. This study showed that dibenzofurans, phenyldibenzofurans and benzo[b]naphthofurans were effective in determining the origin, depositional environment and thermal maturity of source rocks in Niger Delta basin, Nigeria.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.