Mark Reilly

PhD student - Geo

Biography

Mark Reilly received his BAppSc (Geology) from Queensland University of Technology (QUT) in July 1999 and completed BSc Honours (Petroleum Geology) at the National Centre for Petroleum Geology and Geophysics (NCPGG) in 2001, studying outcrops of Early Cambrian deepwater deposits in the Flinders Ranges. In 2002 he started a PhD with the NCPGG studying facies distribution within modern ephemeral delta/splay complexes at Lake Eyre, Central Australia. Member: PESA, AAPG, SPE.

PhD Research Project

Facies distribution within a dryland river channel belt and terminal splay complex, Umbum Creek, Lake Eyre, Central Australia

Supervisors: Associate Prof Simon Lang and Dr Steven Hill

Project support: Lake Eyre Basin Consortia & CRCLEME

Scholarship support: CRCLEME & Lake Eyre Basin Consortia

Project Description

Exploration for oil and gas within existing and frontier basins is a high risk venture, especially in ephemeral lake delta depositional environments that have complex amalgamation of splays, channels, distributaries and mouth bars. Of particular interest is the potential lateral connectivity of the resultant amalgamated sand sheets, both stratigraphically and laterally to older and younger systems as well as up dip to their associated fluvial systems. Analogue studies of ancient and modern depositional environments provide data of physical attributes, such as aspect ratios of bedforms and channels, to fractal relationships of distributary channel bifurcation, lengths, breadths and depths. Theses attributes all contribute to a better understanding of the internal architecture of these complexes, especially the heterogeneity and connectivity of individual flow units within reservoirs that will provide physical data for modelling of such reservoirs.

Benson et al (1997), Hicks (1998) and Lang et al (2000) presented results of the first detailed phase of documentation of Quaternary Sediments and depositional plan-form geometries of the Neales River delta, West Lake Eyre. A key recommendation of those studies was to further investigate stratigraphic connectivity between channels and mouth bars of the present day system with the underlying fluvial sand sheets. The underlying sheet sands are known from numerous drill holes to be five to ten metres below the present surface. Furthermore, it was recommended that geomorphic and stratigraphic studies be extended further south of the Neales River delta to encompass the entire alluvial fan on the western side of Lake Eyre.

This PhD project proposes to investigate the modern playa lake alluvial fan lacustrine delta system of Umbum Creek, where it enters the western side of the Lake Eyre basin, at the southern end of the Neales Fan. The purpose of this study will be to develop an analogue model for reservoir facies distribution and interconnectivity within the delta/splay complex and immediate fluvial component. The analogue will be useful to improve our understanding of ancient reservoirs in comparable settings.

The study will be based on detailed sub-surface data gained from auger drilling (hand and mechanical), coring (bonne-esperance percussion corer), and ground penetrating radar (GPR) 3D surveys. Extensive grid surface sediment sampling, aerial photo and satellite image interpretation, and time-series geomorphic comparisons are also an important part of the study and will be the data base for facies semi-variograms, which will be used for reservoir modelling. Age dating of sub-surface sediments using carbon fourteen thermo-luminescence (TL) and optically stimulated luminescence (OSL) techniques is essential to unravel the stratigraphic relationships and the relative timing between adjacent systems.

The significance of reservoirs deposited in ephemeral lacustrine environments is substantial: huge production is current from petroleum fields in Algeria, North Sea and Caspian Sea, and improvements in our understanding of these reservoirs will assist exploration and reservoir development. Ideas developed from this project will have broader applications to lacustrine related reservoirs, e.g. Cooper and Eromanga basins.

Percussion Drilling, Umbum Creek Channel Belt, Western Lake Eyre, Central Australia

Umbum Creek Channel Belt, Western Lake Eyre, Central Australia

Umbum Creek Delta, Western Lake Eyre, Central Australia

Publications

• N. Ceglar, M.R.W. Reilly , T.H.D. Payenberg and S.C.lang, 2004, Deepwater outcrop analogue study - Basal Bunkers Sandstone, Donkey Bore Syncline, Northern Flinders Ranges, Australia, EABS Journal 2004.
• S.C. Lang, T.H.D. Payenberg, M.R.W. Reilly , J. Kassan, T. Hicks, J. Benson, 2004, Reservoir geometry in sand-dominated fluvial-deltaic and terminal-splay facies - lessons from recent flooding in Central Australia, APPEA Journal 2004.
• M.R.W. Reilly , S.C. Lang, T.H.D. Payenberg and J. Kassan, 2004, Sedimentary processes and facies geometry of a sandy ephemeral terminal splay complex, Umbum Creek, Lake Eyre, Central Australia, AAPG Hedburg Conference, Baku, Azerbaijan, 2004. (Abstract)
• M.R.W. Reilly , S.C. Lang and S. Hill, 2003, Landforms and sediments of Umbum Creek and adjacent plains, Lake Eyre Basin, South Australia, CRCLEME Symposium, Adelaide, 2003. (Extended Abstract)
• M.R.W. Reilly , S.C. Lang, 2003, A ponded basin floor fan outcrop analogue: Bunkers Sandstone, Northern Flinders Ranges, Australia, APPEA Journal 2003
• M.R.W. Reilly , S.C. Lang, J. Kassan, 2003, Modern Analogue of an Ephemeral Fluvial-Lacustrine Inland Delta - Umbum Creek, Lake Eyre, Central Australia, AAPG Conference, Salt Lake City, 2003 (abstract)
• M.R.W. Reilly , S.C. Lang, J. Kassan, 2002, Sedimentation in an ephemeral fluvial-lacustrine inland delta - Umbum Creek, Lake Eyre, Central Australia, Dryland Rivers: Process and Product, University of Aberdeen, 8-9 August, 2002. (Abstract)
• M.R.W. Reilly , S.C. Lang, and N.M. Lemon, 2002, A basin Floor Fan Outcrop Analogue: Reservoir Heterogeneity and Sequence Stratigraphy, 16th Australian Geological Convention, Adelaide, July 2002. (Abstract)