The University of Aberdeen
Room No. 131A, Department of Geology and Petroleum Geology, School of Geosciences, Meston Building, King’s College,University of Aberdeen, Aberdeen AB24 3UE, UK
BSc & MS in Geology, University of Dhaka, Bangladesh
PhD Student- April 2015 to present
Sedimentology and Petroleum Geology
Sedimentology and characterisation of marginal reservoir facies in fluvial and delta top depositional systems
Fluvio-deltaic sandstones are significant petroleum reservoirs around the world. Sandstones deposited in these settings are volumetrically important but very heterogeneous as petroleum reservoirs. Fluvial and delta top settings comprise channel deposits and overbank deposits which include levees, crevasse splays, splay complexes, and mires. The channel related sandstones are the major reservoir bodies and as such have received considerable attention in the literature. Marginal sandstone facies in the overbank settings—the crevasse splays have been largely ignored although these sandstones are the prominent features of many river and delta systems and considered to be economically important petroleum reservoir rock especially in “tight gas”―systems. Moreover, overbank fluvial processes have a great role to explain the channel migration, avulsion, fluvial sedimentations and palaeo-environmental conditions of deposition.
The research aims to improved understanding of overbank crevasse splay sandstones from a reservoir perspective providing their facies model, a new classification scheme, architectural data, controlling factors and role as a reservoir. To achieve the goal modern fluvio-deltaic setting in high-resolution Google Earth Pro imagery, and outcrop and subsurface data from the Middle Jurassic Ravenscar Group of Cleveland Basin, NE England are being studied.
Analysing the Google Earth Pro imagery of nine lower river valley and delta top settings this study identified the most important overbank features―the crevasse splays, measured their size, geometrical properties and determined the factors that control their evolution and extension. Outcrop data were collected by field observations, LiDAR scanning, and UAV (drone) photogrammetry from ten outcrops along a 40 km long, 30 to 130 m thick section between Kettleness and Yons Nab on the Yorkshire Coast. Sedimentary logs were collected from 40 accessible localities along the outcrop and 27 borehole cores behind the Long Nab outcrop. Well logs from a further 15 boreholes behind the Ravenscar outcrop were also incorporated. LiDAR and drone data were used to build scaled photorealistic virtual outcrops (VO) from which sandstone body geometry (e.g., width, thickness), stacking pattern, distribution and average lithofacies were studied.
Google Earth gives plan view data with high degree of coverage, and the outcrop and borehole data give the cross-section view of the deposits. Both the data sets are being used to build a series of high-resolution three-dimensional geocellular models to study the distribution and connectivity of sandstone bodies, and the role of crevasse splay deposits in fluvial-deltaic reservoirs.
Commonwealth Scholarship Commission