Compositional variation in modern estuarine sands: Predicting major controls on sandstone reservoir quality

Joshua Griffiths, Richard H. Worden, Luke J. Wooldridge, James E.P. Utley, Robert A. Duller
2019 American Association of Petroleum Geologists Bulletin  
Primary depositional mineralogy has a major impact on sandstone reservoir quality. The spatial distribution of primary depositional mineralogy in sandstones is poorly understood, and consequently, empirical models typically fail to accurately predict reservoir quality. To address this challenge, we have determined the spatial distribution of detrital minerals (quartz, feldspar, carbonates, and clay minerals) in surface sediment throughout the Ravenglass Estuary, United Kingdom. We have
more » ... for the first time, high-resolution maps of detrital mineral quantities over an area that is similar to many oil and gas reservoirs. Spatial mineralogy patterns (based on x-ray diffraction data) and statistical analyses revealed that estuarine sediment composition is primarily controlled by provenance (i.e., the character of bedrock and sediment drift in the source area). The distributions of quartz, feldspar, carbonates, and clay minerals are controlled by a combination of the grain size of specific minerals (e.g., rigid vs. brittle grains) and estuarine hydrodynamics. The abundance of quartz, feldspar, carbonates, and clay minerals is predictable as a function of depositional environment and critical grain-size thresholds. This study may be used, by analogy, to better predict the spatial distribution of sandstone composition and thus reservoir quality in ancient and deeply buried estuarine sandstones. is a professor of petroleum geology and geochemistry and leads the M.Sc. in petroleum reservoir geoscience at the University of Liverpool, United Kingdom. He gained his B.Sc. degree and his Ph.D. from Manchester University in the 1980s. Following a postdoctoral position in Edinburgh, Scotland, he worked for BP at their Sunbury-on-Thames site. He then took a lectureship at Queens University in Belfast, followed by a move to the University of Liverpool in 2000. His research interests include sandstone, mudstone, and carbonate petrology; diagenesis; reservoir quality; petrophysics and geochemistry; water-rock interaction; petroleum-rock interaction; thermochemical sulfate reduction; and the geology of CO 2 subsurface disposal. is a researcher in diagenesis, petroleum geology, applied mineralogy, and soils and clay mineralogy. He gained his master's in earth science at the University of Liverpool in 2008, remaining as a research assistant working on petrology, x-ray diffraction, and QEMSCAN ® analysis. James currently works on research projects in reservoir quality assessment, CO 2 sequestration, and volcanology.
doi:10.1306/09181818025 fatcat:2xy55amwprbinch3wonioxav3y