This document summarizes Auke Barnhoorn's research on quantifying fracture patterns in shales. His main research question is how the rock fabric affects fracture initiation and propagation. He studies the Posidonia shale in the Netherlands through experimental fracturing and 3D rock characterization. His goal is to predict fracturing behavior in Dutch shale plays and potentially optimize fracture patterns.

1. Shale gas research in the Netherlands:
Role of Fracture Network Complexity
Auke Barnhoorn
Department of Geoscience and Engineering
Faculty of Civil Engineering and Geosciences
Delft University of Technology
Challenge the future
1

2. Shalegas: a ‘hot topic’
Challenge the future
2

3. Posidonia shale in the Netherlands
Posidonia shale
Toarcian age
~ 180 Ma
Challenge the future
Wong, 2007
3

4. Shalegas in the Netherlands:
how much & where: very little known
Challenge the future
4

5. Shaliegas in the Netherlands:
how much & where: very little known
• Rough estimates: 200 – 500 bcm gas.
• Uncertain how much we can produce
out of the shales
• Very little Posidonia core materiaal
available: 2-3 old wells
• More research in shale gas potential
vital
• Exploration wells will give some
necessary info on the potential
Challenge the future
5

6. My main research question
What is the effect of the rock fabric on
fracture initiation and propagation?
Challenge the future
6

7. Lithology determines fracture
pattern
Example from Kings Canyon,
Australia
Challenge the future
7

8. Lithology determines fracture
pattern
finely layered
silt-sandstone
massive sandstone
Challenge the future
8

9. Lithology determines fracture
pattern
finely layered
massive sandstone
silt-sandstone
Challenge the future
9

10. Lithology determines fracture
pattern
finely layered
massive sandstone
spacing ~ 150 m
silt-sandstone
Challenge the future
10

11. Lithology determines fracture
pattern
finely layered
massive sandstone
spacing ~ 150 m
silt-sandstone
Challenge the
spacing ~ 10 future
m
11

12. also on a small scale: variations in fracture patterns present
12
Challenge the future

13. Colin Sayers, Geophysical Prospecting , 2013
Shales
• Highly anisotropic
• Often strong compositional layering
Geomechanical parameters from
acoustic measurement of shales
x3
0
O
x2
Challenge the future
13
x1

14. Main research question
Can we quantify the fracture pattern in shales?
- including the role of fabric anisotropy
- predict fracturing behaviour for Dutch shale plays
Later: Can we also optimize the fracture pattern?
Challenge the future
Jurassic limestone and shales (UK)
14
Fracture network map

15. Whitby, UK
Challenge the future
15

16. Cleveland Basin Stratigraphy
Predom.
mudstone
Predom. Mudst.,
Limest.
Predom. Ironst.,
Limest.
Cox et al., 1999
Predom. Sandst.,
siltstone
Challenge the future
Hobbs et al., 2012
16

17. Posidonia shale Whitby (UK)
May 2013 Fieldtrip: UU, TNO & TUD
Auke Barnhoorn, 2013
Challenge the future
17

18. Posidonia shale Whitby (UK)
Challenge the future
18
Auke Barnhoorn,

19. Posidonia shale Whitby (UK)
Auke Barnhoorn, 2013
Auke Barnhoorn, 2013
Challenge the future
19

20. Posidonia shale Whitby (UK)
Image of Dr. M. Houben (UU)
Challenge the future
20

21. Main research question
Can we quantify the fracture pattern in
shales?
including the role of fabric anisotropy
My research:
Experimental Fracturing and 3D rock
characterization
Challenge the future
21

22. Experimental Fracturing @ TU Delft
microstructure
s history
k history
statistics
• Conventional deformation device
• Controlled deformation conditions (stress, strain
rate, elevated temperatures, confining pressure
and fluid pressures)
• Measurement of volume changes of sample and
fluid (permeability, porosity)
e history
De Paola et al., 2009
22
Challenge the future

23. Fracture network growth - stress driven fracturing
1.
2.
3.
1. random fracture generation throughout sample
2. continuing fracture generation, fracture growth & linkup of
individual fractures
3. complete linkup of fractures & formation of shear fracture
Challenge the future 23
Barnhoorn et al., 2010 Geology 38, 779-782

24. Difference in fracture network growth
dry
random fracture generation
high Pf
high fluid pressure gradient
fracture growth at high Pf side
Challenge the future
24
Barnhoorn et al., 2010 Geology 38, 779-782

25. Difference in fracture network growth statistics
Challenge the future
25
Barnhoorn et al., 2010 Geology 38, 779-782

26. Difference in fracture network growth statistics
30º
conjugate fracture sets prominent in stress-driven fracturing
Challenge the future
26

27. Universities NL
Shale Gas research
Giovanni Bertotti (TUD)
David Smeulders (TUE)
Martyn Drury (UU)
Jan-Diederik van Wees (UU)
Auke Barnhoorn (TUD)
Collaboration
From basin scale to pore scale
Stress Modelling
Experiments
Rock Characterization
Fracture modelling
Fractures in unconventional rock types
Prediction of fracture
patterns in shales at a
multitude of scales
Topsector Energie
Challenge the future
27

28. From basin scale to pore scale
Shale characterization (UU)
Tectonic modelling (UU)
N
Fractured reservoir modelling (TUD)
Rock Physics & Frac. Experiments (TUD)
photo: N. Hardebol,
study: L. Laerhoven (MSc) (TNO)
Challenge the future
28
Fracture propagation modelling (TUE)

29. Other research at TU Delft
• Faculty of Civil Engineering and Geosciences
Dr. Rick Donselaar en Dr. Gert-Jan Weltje (Dept. G&E)
Sweet-spot determination for unconventional
gas opportunities in NL
Which sedimentological characteristics point to
best places for shale gas production?
Topsector Energie
Challenge the future
29

30. Thank you!
Johannes Vermeer
Gezicht op Delft (1660-1661)
Contact:
Email: auke.barnhoorn@tudelft.nl
Challenge the future 30
Internet: www.citg.tudelft.nl/abarnhoorn