Two PhD studentships Chlorite consortium-funded research opportunity
University of Liverpool
Clay minerals in modern, sand-rich estuarine sediments: analogue for sandstones in the subsurface: 2 PhD studentships offered
The PhD projects on offer
Two PhD students are sought for fully-funded positions, on the distribution of clay minerals in modern estuarine sand-rich sediments. This work will be mainly undertaken on 20 geotechnical sediment cores drilled in the modern Ravenglass estuary in NW England. It is likely that the work will involve new field work including drilling several new 1-m cores and drone imagery of the surface sediments in the estuary to develop a digital elevation model.
PhD student-1 will work on detailing the clay mineralogy in the cores, primarily using X-ray diffraction but also using light optics and electron microscopy. This part of the work will quantify the absolute and relative amounts of different clay minerals as a function of interpreted sedimentary facies, and position in the estuary and produce new ways of predicting the occurrence and distribution of clay minerals in marginal marine environments.
PhD student-2 will quantify clay coat coverage on sand grains in the same cores using light and electron optical techniques and the semi-automated software, Petrog. This work will produce a detailed 3D understanding of clay coat formation, and evolution during shallow burial, in modern estuarine sands. The two PhD students will work closely together. Both projects may be taken to the point of modelling the movement of sediment and clay coated grains over the 10,000 years of sediment accumulation in the Ravenglass estuary using Delf3D.
The two PhD projects will produce data that are applicable to furthering the understanding of the distribution of minerals within deeply buried sandstone reservoirs for oil and gas exploitation and carbon capture and storage in the subsurface.
You will present your findings to the Chlorite Consortium company sponsors during regular update meetings, at Liverpool, online and possibly in company offices. It is expected that you will attend and present at international conferences.
You will work with Professor Worden as the primary supervisor and other sedimentology academic staff at the University of Liverpool, Dr Iris Verhagen and Dr Rob Duller, as secondary supervisors.
The Ravenglass estuary in NW England has been used for several years by Liverpool staff and students involved in the Chlorite Consortium, as a test bed for developing understanding of the distribution of clay minerals in sandstones via a modern analogue (Daneshvar and Worden, 2018; Griffiths et al., 2018; Griffiths et al., 2019a; Griffiths et al., 2019b; Wooldridge et al., 2017a; Wooldridge et al., 2017b; Wooldridge et al., 2018, 2019a; Wooldridge et al., 2019b).
The research at the University of Liverpool has led to numerous high-profile discoveries about clay minerals in sands and sandstones. It is expected that the new PhD studentships will continue with this highly productive research area. The work undertaken thus far (see below) has been on surface sediments and on 1-m cores. High quality geotechnical cores have now been collected by a drilling contractor. These cores have been described in terms of sedimentary facies and have undergone detailed grain size analysis and bulk geochemical analysis with an XRF device. The cores now need to undergo further detailed assessment of clay minerals, using XRD and SEM, and clay grain coats , using light optics and SEM, matching the work on the surface sediments and 1-m cores. These geotechnical cores will therefore enable the conversion of a 2-D data set into a 3-D dataset across an area of several square kilometres.
The data that you produce will enable the population of 3-D computer-based simulations with the sediment architecture, sediment mineralogy (especially clay minerals) and coats on sand grains, using industry standard software such as Petrel, at a scale relevant to oil and gas exploitation and subsurface carbon capture and storage sites.
You will have a good geoscience first degree with a minimum of a 2:1 classification in your BSc. You will be keen to work on modern sediment analogues of ancient and deeply buried sand-rich sediment. While an MSc is not essential, a postgraduate course relevant to sediments, sedimentary rocks, process sedimentology, or sediment geochemistry, would be an advantage. It would be helpful if you have a working knowledge of sedimentary mineralogy, although this can be picked up during training with the supervisors. It is not essential that you have prior experience of XRD or SEM techniques, but you should be able and willing to undertake laboratory work involving either XRD or SEM analyses. A working knowledge of GIS techniques and statistical analysis of geological data would be helpful.
How to apply
Please send an application before the 23rd of July, by email to firstname.lastname@example.org. Please include in your application:
Please contact: Professor Richard Worden: email@example.com for further details.
Background reading to research on the Ravenglass modern sedimentary analogue
Daneshvar, E., and Worden, R. H., 2018, Feldspar alteration and Fe minerals: origin, distribution and implications for sandstone reservoir quality in estuarine sediments, in Armitage, P. J., Butcher, A. R., Churchill, J. M., Csoma, A. E., Hollis, C., Lander, R. H., Omma, J. E., and Worden, R. H., eds., Reservoir Quality of Clastic and Carbonate Rocks: Analysis, Modelling and Prediction, Volume 435, p. 123-139.
Griffiths, J., Worden, R. H., Wooldridge, L. J., Utley, J. E. P., and Duller, R. A., 2018, Detrital clay coats, clay minerals, and pyrite: a modern shallow-core analogue for ancient and deeply buried estuarine sandstones: Journal of Sedimentary Research, v. 88, no. 10, p. 1205-1237.
Griffiths, J., Worden, R. H., Wooldridge, L. J., Utley, J. E. P., and Duller, R. A., 2019a, Compositional variation in modern estuarine sands: Predicting major controls on sandstone reservoir quality: American Association of Petroleum Geologists Bulletin, v. 103, no. 4, p. 797-833.
Griffiths, J., Worden, R. H., Wooldridge, L. J., Utley, J. E. P., Duller, R. A., and Edge, R. L., 2019b, Estuarine clay mineral distribution: Modern analogue for ancient sandstone reservoir quality prediction: Sedimentology, v. 66, no. 6, p. 2011-2047.
Wooldridge, L. J., Worden, R. H., Griffiths, J., Thompson, A., and Chung, P., 2017a, Biofilm origin of clay-coated sand grains: Geology, v. 45, no. 10, p. 875-878.