Sedimentology research steers high-value decisions in the hydrocarbon industry

Summary of the Impact

University of Leeds Research has been used by its specialist Turbidites Research Group (TRG) to underpin consultancy work for oil companies that has, in turn, steered them to make high-value decisions. Examples include an oil well placement, the development of an oil field, and a decision to only partially develop another. The TRG has been funded by 14 oil companies since 1992, and its annual income has risen from £125k/yr prior to 2008 to £380k/yr during the REF period. It is estimated that the cumulative value of oil company decisions based on TRG research exceeds several hundred million dollars. Following the impact, Leeds have replicated the TRG business model to form new specialist industrial research groups that have each generated further impact.

Underpinning Research

The aim of the TRG, led by Bill McCaffrey, is to study deep marine clastic sedimentary systems, which involves research into flow dynamics and deposits of turbidity currents and related flow types via outcrop studies, flume experiments, seismic studies and theoretical approaches. Gas and oil can be found in such marine sedimentary systems, and improved understanding of the processes involved in deposition leads to a better capacity to characterise and predict the properties of gas and oil reservoirs, which is of critical economic benefit to the oil industry.

The presence of channels in sedimentary systems has an important bearing on the architecture of the system and on reservoir characteristics. To obtain insights into the formation of these submarine channels and to be able to predict the patterns of sediment deposition within and around them, McCaffrey led field research into sedimentary rock channel formations in the French Alps as an analogous system [1, 2]. The research has resulted in improved understanding of processes such as channel incision, infill dynamics and other characteristics that can be applied to deep marine environments, and led British Gas (BG) to part-fund the work of Rufus Brunt (PhD student, University of Leeds 2000–2003).

In 2003, McCaffrey and collaborators from University College Dublin were the first to recognise a previously unknown type of deposit, the hybrid event bed phenomenon [3]. This type of sediment deposition gives rise to a range of sandstone architectures, which in turn affect the potential oil- or gas-bearing properties of the rock. This model of hybrid sediment flow was subsequently integrated with other models and refined by McCaffrey and co-workers in 2009 [4] to create a generic model of hybrid sediment gravity flow deposits that can be used to predict sediment architectures – and hence reservoir characteristics – in a wide range of settings.

In 2008, the TRG developed new models to account for patterns of deposition in sedimentary systems, providing key insights into the observed sandstone architectures and their spatial distribution [5]. In this work, co-authored by McCaffrey with collaborators from University College Dublin and industry, sedimentological analysis of Britannia core showed that spatial variability in the depositing particulate gravity currents produced corresponding spatial variability in the deposited reservoir sandstones in a way that was predictable and which could be exploited.

Between 2006 and 2009, new research led by McCaffrey has led to the finding that large scale slope failure could leave behind a newly defined “evacuated” bathymetric morphotype [6]. This bathymetry can be shown to control the location and orientation of the elongated sandstones comprising the middle part of the Britannia reservoir. The study also introduced the concept of the scale of observation required to substantiate sediment architecture models reliably.

Key Researcher

Bill McCaffrey, Research Fellow, Senior Research Fellow, and Principal Research Fellow (1993- 2007) and Professor of Clastic Sedimentology (2008-present) in the School of Earth and Environment, University of Leeds; NERC Knowledge Exchange Fellow (2011-present).

References to the Research

1. McCaffrey, W.D., Gupta, S. and Brunt, R. (2002). Repeated cycles of submarine channel incision, infill and transition to sheet sandstone development in the Alpine Foreland Basin, SE France, Sedimentology, 49, 623-635 DOI 10.1046/j.1365-3091.2002.00477.x
2. Brunt, R.L. and McCaffrey, W.D. (2007). Heterogeneity of fill within an incised channel: the Oligocene Grès du Champsaur, SE France, Marine and Petroleum Geology, 24, 529–539. DOI 10.1016/j.marpetgeo.2007.02.002
3. Haughton, P.D.W., Barker, S. and McCaffrey, W.D. (2003). ‘Linked’ debrites in sand-rich turbidite systems – origin and significance. Sedimentology, 50, 459-482. DOI 10.1046/j.1365- 3091.2003.00560.x
4. Haughton, P.D.W., Davies, C., McCaffrey, W.D. and Barker, S.D. (2009). Hybrid sediment gravity flow deposits – Classification, origin and significance. Marine and Petroleum Geology, 26, 1900-1918. DOI 10.1016/j.marpetgeo.2009.02.012
5. Barker, S.P., Haughton, P.D.W., McCaffrey, W.D., Archer, S.G. and Hakes, B. (2008). Development of rheological heterogeneity in clay-rich high-density turbidity currents: Aptian Britannia Sandstone Member, U.K. Continental Shelf, Journal of Sedimentary Research, 78, 45-68. DOI 10.2110/jsr.2008.014.
6. Eggenhuisen, J.T., McCaffrey, W.D. Haughton, P.D.W., Butler, R.W.H., Moore, I., Jarvie, A. and Hakes, W.G. (2010). Reconstructing large-scale remobilisation of deep-water deposits and its impact on sand-body architecture from cored wells: The Lower Cretaceous Britannia Sandstone Formation, UK North Sea, Marine and Petroleum Geology, 27, 1595-1615. DOI 10.1016/j.marpetgeo.2010.04.005.