Integrated whole-rock trace element geochemistry and heavy mineral chemistry studies: aids to the correlation of continental red-bed reservoirs in the Beryl Field, UK North Sea
J. Preston, A. Hartley, M. Hole, S. Buck, J. Bond, M. Mange and J. Still
Journal name: Petroleum Geoscience
Issue: Vol 4, No 1, February 1998 pp. 7 - 16
Organisations: Geological Society of London
Info: Article, PDF ( 1.02Mb )
Price: € 30
Correlating continental red-bed successions in the sub-surface is a common problem for the hydrocarbon industry. These successions are typically barren of fauna and often monotonous, leading to non-diagnostic wire-line log signatures. A high-resolution, high precision study of detrital garnet chemistry within Triassic reservoir sandstones from the Beryl Field of the North Sea failed to subdivide the sequence satisfactorily. However, the whole-rock concentrations of immobile trace elements such as Zr, Nb and Cr can be shown to be controlled primarily by the abundances of the heavy minerals zircon, rutile and chrome-spinel, respectively. The chemistry of detrital rutile and chrome spinel varies widely within any one sample, implying that the whole-rock concentrations of Nb and Cr are also a function of the chemistry of these heavy minerals. Having calibrated a type well with a detailed mineralogical and geochemical study, it was possible to correlate between wells using whole-rock geochemical cross-plots.