An exhumed fill and spill hydrocarbon fairway in the Entrada Sandstone of the Moab Anticline, Utah



I. R. Garden1, S. C. Guscott2, K. A. Foxford3, S. D. Burley2,4, J. J. Walsh3 & J. Watterson3.
1 - Reservoir Description Research Group, Department of Petroleum Engineering, Heriot-Watt University, Edinburgh, U.K.
2 - Diagenesis Research Group, Department of Earth Sciences, University of Manchester, Manchester, U.K.
3 - Fault Analysis Group, Department of Earth Sciences, University of Liverpool, Liverpool, U.K.
4 - British Gas Research, Ashby Road, Loughborough, Leicestershire, U.K.

Abstract - The Moab Anticline, south-east Utah is an exhumed hydrocarbon palaeo-reservoir which was supplied by hydrocarbon stringers that migrated up dip towards the structural crest of the anticline. Iron oxide reduction in porous, high permeability aeolian sandstones provides a record of the hydrocarbon migration pathways through the Middle Jurassic Entrada Sandstone of the anticline. The distribution of the reduction patterns across the flanks and the crest of the anticline permits examination of the impact of structural and sedimentological heterogeneity on hydrocarbon migration. Field observations indicate that reduction fronts were not affected either by individual slip bands in damage zones around faults, or by faults with sand:sand juxtapositions, but were influenced by sand/mudstone juxtapositions and fault zones containing shale-smears.


Geofluids II - Contributions to the Second International Conference on fluid evolution, migration, and interaction in sedimentary basins and orogenic belts. (Eds. Hendry, J.P., Carey, P.F., Parnell, J., Ruffell, A.H. & Worden, R.H.), 287-290, 1997.