Skip to Main Content
Book Chapter

Vanadium isotope composition of crude oil: effects of source, maturation and biodegradation

By
Yongjun Gao
Yongjun Gao
1
Department of Earth and Atmospheric Sciences, University of Houston, Houston, TX 77584, USA
Search for other works by this author on:
John F. Casey
John F. Casey
1
Department of Earth and Atmospheric Sciences, University of Houston, Houston, TX 77584, USA
Search for other works by this author on:
Luis M. Bernardo
Luis M. Bernardo
2
Repsol, USA, 2455 Technology Forest Blvd., The Woodlands, TX 77381, USA
Search for other works by this author on:
Weihang Yang
Weihang Yang
1
Department of Earth and Atmospheric Sciences, University of Houston, Houston, TX 77584, USA
Search for other works by this author on:
K. K. (Adry) Bissada
K. K. (Adry) Bissada
1
Department of Earth and Atmospheric Sciences, University of Houston, Houston, TX 77584, USA
Search for other works by this author on:
Published:
January 01, 2018

Abstract:

We present a study of vanadium (V) isotope compositions for 17 crude oils spanning a wide range of concentrations and formation ages. Bulk organic geochemical and biomarker compositions are investigated for 11 co-genetic crude oils from the Barbados oil field. About 2‰ V isotope fractionation was observed and they are primarily correlated with V/Ni ratios and most likely reflect the depositional environment of the petroleum source rocks. Factors such as the lithology of the source rocks, Eh and pH of the depositional environment, and possibly the V isotope composition of seawater could all play a role in the V isotope composition. The Eh and pH conditions determine the speciation and coordination of V ions in fluids, whereas the lithology of the source rock defines the competing phases for available V ions in solution. The V isotopes are significantly modified by maturation and biodegradation. The V isotope fractionation during biodegradation has most probably resulted from the microbial activity-induced changes in the species and coordination geometries of V ions in fluids. The progressive decrease of δ51V with the increase of maturation might suggest a preferential loss of 51V during de-metalation and/or a preferential incorporation of 50V in the newly formed V-organometallic compounds.

You do not currently have access to this article.

Figures & Tables

Contents

Geological Society, London, Special Publications

From Source to Seep: Geochemical Applications in Hydrocarbon Systems

M. Lawson
M. Lawson
ExxonMobil Upstream Research Company, USA
Search for other works by this author on:
M.J. Formolo
M.J. Formolo
ExxonMobil Upstream Research Company, USA
Search for other works by this author on:
J.M. Eiler
J.M. Eiler
California Institute of Technology, USA
Search for other works by this author on:
Geological Society of London
Volume
468
ISBN electronic:
9781786203687
Publication date:
January 01, 2018

GeoRef

References

Related

Citing Books via

Close Modal
This Feature Is Available To Subscribers Only

Sign In or Create an Account

Close Modal
Close Modal