Provenance of Ben Nevis Formation Reservoir Sandstones, White Rose Field, Grand Banks, Newfoundland
Angela F. Dearin1 and Rudi Meyer2
1 Memorial University of Newfoundland, St John's, NF
2 University of Calgary, Calgary, AB
The White Rose oil field is located in the Jeanne d'Arc Basin approximately 350 km east of St John's, Newfoundland, Canada. The field contains both oil and gas, and the reservoir rock is in the Aptian-age Ben Nevis Formation, a very fine- to fine-grained, generally well-sorted sandstone with variable thicknesses of up to 300m. Based on subcrop patterns, the older (Tithonian-Berriasian) and coarser-grained Hibernia Formation sandstones are thought to be one of the possible sediment sources.
The objectives of this study are the changes of provenance with time, within- and adjacent-to selected reservoir intervals of the Ben Nevis Formation. Relevant questions are whether the sands were 1st-cycle deposits, or if they resulted from the erosion of previously deposited sediment (2nd-cycle), whether the sediments have been derived from more than one source area, and how source(s) and dispersal paths may have evolved through time.
A data set of 128 point counts and 300 geochemical analyses were completed on both core and cuttings of the Ben Nevis, Avalon and Hibernia Formations. Initial point count data define the Ben Nevis sandstones as sublitharenites and further point count data aims to compare them to Hibernia Formation sandstones to test possible provenance relationships.. Preliminary major and trace element data are interpreted to establish lateral trends across the Ben Nevis Formation reservoir within the White Rose Field. Scattergrams of various elements are used to determine element mobility and compare the Ben Nevis Formation to the Hibernia Formation as a possible sediment source. Qz-Pl-Ks and A-CN-K ternary diagrams are applied together with the chemical index of alteration (CIA) to test petrogenetic links among sampled formations (following Nesbitt et al., 1997).