Print this pageLower Westphalian C Fluvial Sandbodies In Eastern England and the Southern North Sea, UK
AITKEN, JOHN F., PAUL D. GUION, and DAVID G. QUIRK
The Glass Houghton, Mexborough and Ackworth Rocks (Westphalian C, Bolsovian, Upper Pennsylvanian) in eastern England are major, multistorey sandbodies formed in a delta/alluvial plain environment with minimal marine influence. The Mexborough Rock is an oil reservoir in the region and equivalent sandstones form important reservoir targets in the Southern North Sea.
The Glass Houghton Rock is the least well developed of the studied sand bodies and comprises several discrete channel sandstones which are locally amalgamated to form a stacked sandbody up to 30 m in thickness. The Mexborough Rock overlies a significant unconformity, readily identifiable on seismic sections, and consists of at least three major channel systems which are amalgamated to form a sheet-like sandbody in excess of 65 m thick and 60 km in width at its maximum development. Similarly, the Ackworth Rock comprises a number of separate channel systems which combine to form a large sandbody up to 50 m in thickness and several 10s of kilometres m width.
Seismic, well log and core data from onshore coal and hydrocarbon exploration, where wells are closely spaced, is supplemented with data from the Southern North Sea, where wells are widely spaced. This has enabled the detailed subsurface mapping of these sandbodies leading to the development of a sequence stratigraphic-tectonic model for lower Westphalian C fluvial sandstones which has important implications for the exploration and production of these and analogous reservoirs.