Reservoir potential of sands formed in glaciomarine environments: An analog study based on Cenozoic examples from McMurdo Sound, Antarctica

Authors

Christopher R. Fielding, University of Nebraska-LincolnFollow
Brian A. Blackstone, University of Nebraska-Lincoln
Tracy D. Frank, University of Nebraska-LincolnFollow
Zi Gui, University of Nebraska-Lincoln

Date of this Version

4-2012

Comments

Published in M. Huuse, J. Redfern, D. P. Le Heron, R. J. Dixon, A. Moscariello, & J. Craig, eds., Glaciogenic Reservoirs and Hydrocarbon Systems; Geological Society, London, Special Publications, 368 (2012); doi:10.1144/SP368.10 Online at http://dx.doi.org/10.1144/SP368.10 Copyright © 2012 The Geological Society of London. Used by permission.

Abstract

This paper provides documentation of unexpectedly high-reservoir-quality glaciomarine sands found in the Cenozoic succession beneath McMurdo Sound, Antarctica, as an analogue study for evaluations of hydrocarbon prospectivity in basins elsewhere. The Oligocene to Lower Miocene succession of the Victoria Land Basin, an extant portion of the West Antarctic Rift System, comprises diamictites, mudrocks, and sandstones with minor conglomerates. These lithologies are arranged in repetitive stacking patterns (cycles), interpreted to record repeated advance and retreat of glaciers into and out of the basin, with attendant eustatic and isostatic effects. Phases of ice retreat within the cycles comprise an array of mudrocks, sandy mudrocks, and sandstones, deposited mainly during relative sea-level highstands. Clean, wellsorted, unconsolidated, and porous sands <25 m thick from such intervals, which are interpreted to be mainly deltaic in origin, were encountered. Some of these sands, which have visible porosity as high as 41%, flowed into the well bore together with significant volumes of cold formation water. Diagenetic modification of sands in these intervals is minimal, which can be attributed to the low-temperature nature of the subsurface environment. Accordingly, glaciomarine sands in near-field glaciogenic successions should be considered as potential reservoir facies in prospectivity assessments.