MSc Presentation of my Independent Research Project.

1. Alexander Thomas Hughes-Wharton

2.  Produce several 1-D burial models across the
extent of the Cheshire Basin.
Model a series of alternate scenarios for the
burial history of the Northern Cheshire Basin.
Develop the models utilising Novva software.

3.  Sedimentary fill is
of Permian-
Jurassic age
 Vast erosion
leads to removal
of younger
sediments
 Thicknesses are
variable within
the basin
Source
Units
Blacon East – Input Stratigraphy

5. Mikkelsen and Floodpage 1997

6. Modified from Plant et al. 1999

7. IGas 2014

8.  Basin models
generated using
Novva software
 Data used in the
modelling process
was taken from
publicly available
sources
 Kerogen kinetics
information was
available for all
source units

10. Mikkelsen and
Floodpage 1997

11. Reduced Original Increased
Variscan Inversion 150m 300m 600m
Cimmerian Inversion 125m 250m 500m
Tertiary Inversion 400m 800m 1600m
 Cimmerian Inversion
controls final
maturity
 Re-generation is
unlikely in the
Tertiary
 Difference of 15% in
the transformation
ratios of the
Bowland-Hodder
Shales
Increased
Reduced

12. Adsorption increases with:
 Increasing pressure due to:
-burial
-generation pressure
-ice shield development
 Decreasing temperature due to:
-uplift / erosion
-decreasing heat flow or thermal
gradient
-glaciations
 Increasing TOC due to:
-higher original organic matter
content
Adsoprtion Potential
vs Temperature & Pressure
80
70
60
50
40
30
20
10
0
Declining Temperature
0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 11000 12000 13000 14000
Pore Pressure (PSI)
Adsorption potential (scf/ton)
0 (ºC)
20 (ºC)
40 (ºC)
60 (ºC)
80 (ºC)
100 (ºC)
120 (ºC)
140 (ºC)
160 (ºC)
180 (ºC)
200 (ºC)
220 (ºC)
240 (ºC)
260 (ºC)
280 (ºC)
300 (ºC)
Adsorption Potential
vs TOC & Pressure
180
160
140
120
100
80
60
40
20
0
2.5 (%)
2.0 (%)
1.5 (%)
1.0 (%)
0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000 11000 12000 13000 14000
Presssure (PSI)
Adsorption Potentail (scf/ton)
0.5 (%)
3.0 (%)
3.5 (%)
4.0 (%)
4.5 (%)
5.0 (%)
Increasing TOC

13.  Maximum
generation in the
Cretaceous
 Partial desorption
possible during
the Tertiary
igneous event
 Overall there is
good evidence for
adsorption
through time

14.  More aesthetic
outputs
 More accurate heat-flow
reconstruction
 User-defined
kerogen input
 Accessibility
 Requires addition of
more features

15.  Most prominent area for exploration is on the
northern basin slope, at a depth of around:1500-
2000m.
 Peak maturity is achieved around 180Ma (Cimmerian
inversion).
 Understanding the maximum burial and amount of
erosion during this event is paramount to identifying
the most prospective areas for shale-gas exploration.
 Re-triggering of generation in the Tertiary was unlikely
with the Carboniferous source rocks partially matured.

16.  Future exploration work should be targeted on the
basin slope – at depths of around 1750m to top
Permo-Trias.
 A technical evaluation of the source units; to
determine the effectiveness of artificial fracturing.
-No public domain data
-Common analogues are not applicable (Waters et al.
2009).
 Novva software needs to continue being developed,
improving reliability and adding functionality.

17.  Supervisors – James Armstrong and Kevin Taylor
 Software – Sirius Exploration Geochemistry
 Kerogen Kinetics data – Petroleum Systems ltd.

18.  Andrews, I. J. 2013. The Carboniferous Bowland Shale gas study: geology and resource
estimation. British Geological Survey for Department of Energy and Climate Change,
London.
 Armstrong, J. P., Smith, J., D’Elia, V. A. A., & Trueblood, S.P. 1997. The occurrence and
correlation of oils and Namurian source rocks in the Liverpool Bay-North Wales area. In:
Meadows, N. S., Trueblood, S.P., Hardman, M. & Cowan, G. (eds.) Petroleum Geology of
the Irish Sea and Adjacent Areas. Geological Society, London, Special Publications, 124,
195-211.
 Igas Energy (Ltd.) 2012. Results Presentation & Shale Update. June 2012. Energy
Institute, London.
 Mikkelsen, P. W. & Floodpage, J. B. 1997. The hydrocarbon potential of the Cheshire
Basin. In: Meadows, N. S., Trueblood, S. P., Hardman, M. & Cowan, G. (eds.) Petroleum
Geology of the Irish Sea and Adjacent Areas. Geological Society, London, Special
Publications, 124, 161-183.
 Plant, J. A., Jones, D. G. & Haslam, H. W. (eds.) 1999. The Cheshire Basin: Basin
evolution, fluid movement and mineral resources in a Permo-Triassic rift setting. British
Geological Survey for Department of Energy and Climate Change, London.
 Waters, C. N., Waters, R. A., Barclay, W. J. & Davies, J. R. 2009. A lithostratigraphical
framework for the Carboniferous successions of southern Great Britain (Onshore).
British Geological Survey Report, Nottingham.

19. Thank you for
your attention
Questions?

21. Figure - Early Carboniferous basins and
platforms of northern England. (Modified from
Andrews 2013) *CLH = Central Lancashire High;
HH = Holme High

24. Input Reason
TOC Evaluate present and assess original organic
richness
Depths/thicknesses of stratigraphic units Assess present day overburden
Eroded thicknesses Restore previously removed overburden
Lithology Aid in assessment of thermal conductivity,
enabling estimation of heat-flow through
history
Vitrinite Reflectance Calibrate the models heat-flow history
Geothermal Gradient Calibrate the post-depositional thermal
regime
As well as the key data, additional information was also gathered in order to produce
more precise models:
 Present day surface temperature
 Palaeo-surface temperature
 Well location
 Well datum
 Downhole temperature
 Sea level fluctuations through time (Palaeoelevation/palaeobathymetry)
 Tectonic history
 Kerogen information

25. Event/Unit Start age (Ma) Reference
Glacial 1 Aitkenhead et al. 2002
Tertiary unconformity 54 Kirby et al. 2000
Mesozoic deposition 176 Kirby et al. 2000
Mercia Mudstone Group 235 Aitkenhead et al. 2002
Sherwood Sandstone Group 245 Aitkenhead et al. 2002
Manchester Marl 251 Aitkenhead et al. 2002
Collyhurst Sandstone 260 Pearson and Russell2000
Variscan unconformity 277 Kirby et al. 2000
Westphalian deposition 312.5 Aitkenhead et al. 2002
Upper Namurian Limestone 316 Aitkenhead et al. 2002
Holywell Shales (Upper and Lower) 320 Fraser and Gawthorpe 1990
Lower Namurian Limestone 324 Pearson and Russell 2000
Upper Bowland Shale 328 Fraser and Gawthorpe 1990
Upper Dinantian Limestone Group 330 Fraser and Gawthorpe 1990
Lower Bowland Shale 334 Fraser and Gawthorpe 1990
Lower Dinantian Limestone Group 335 Fraser and Gawthorpe 1990
Hodder Shale 339 Fraser and Gawthorpe 1990

27. Original Inverted Average
Cimmerian Inversion 250m 800m 525m
Tertiary Inversion 800m 250m 525m
Reduced Original Increased
Variscan Inversion 150m 300m 600m
Cimmerian Inversion 125m 250m 500m
Tertiary Inversion 400m 800m 1600m