Browse by author
Lookup NU author(s): Dr Martin Jones, Professor Ian Head, Emeritus Professor Neil GrayORCiD, Dr Arlene Rowan, Dr Carolyn Aitken, Dr Barry Bennett, Haiping Huang, Dr Angela SherryORCiD, Bernard Bowler, Thomas Oldenburg, Professor Stephen Larter
Full text for this publication is not currently held within this repository. Alternative links are provided below where available.
Biodegradation of crude oil in subsurface petroleum reservoirs has adversely affected the majority of the world's oil, making recovery and refining of that oil more costly. The prevalent occurrence of biodegradation in shallow subsurface petroleum reservoirs has been attributed to aerobic bacterial hydrocarbon degradation stimulated by surface recharge of oxygen-bearing meteoric waters. This hypothesis is empirically supported by the likelihood of encountering biodegraded oils at higher levels of degradation in reservoirs near the surface. More recent findings, however, suggest that anaerobic degradation processes dominate subsurface sedimentary environments, despite slow reaction kinetics and uncertainty as to the actual degradation pathways occurring in oil reservoirs. Here we use laboratory experiments in microcosms monitoring the hydrocarbon composition of degraded oils and generated gases, together with the carbon isotopic compositions of gas and oil samples taken at wellheads and a Rayleigh isotope fractionation box model, to elucidate the probable mechanisms of hydrocarbon degradation in reservoirs. We find that crude-oil hydrocarbon degradation under methanogenic conditions in the laboratory mimics the characteristic sequential removal of compound classes seen in reservoir-degraded petroleum. The initial preferential removal of n-alkanes generates close to stoichiometric amounts of methane, principally by hydrogenotrophic methanogenesis. Our data imply a common methanogenic biodegradation mechanism in subsurface degraded oil reservoirs, resulting in consistent patterns of hydrocarbon alteration, and the common association of dry gas with severely degraded oils observed worldwide. Energy recovery from oilfields in the form of methane, based on accelerating natural methanogenic biodegradation, may offer a route to economic production of difficult-to-recover energy from oilfields. ©2007 Nature Publishing Group.
Author(s): Jones DM, Head IM, Gray ND, Adams JJ, Rowan AK, Aitken CM, Bennett B, Huang H, Brown A, Bowler BFJ, Oldenburg T, Erdmann M, Larter SR
Publication type: Article
Publication status: Published
Journal: Nature
Year: 2008
Volume: 451
Issue: 7175
Pages: 176-180
ISSN (print): 0028-0836
ISSN (electronic): 1476-4687
Publisher: Nature Publishing Group
URL: http://dx.doi.org/10.1038/nature06484
DOI: 10.1038/nature06484
PubMed id: 18075503
Altmetrics provided by Altmetric
