Microseismic Monitoring and Geomechanical Modelling of CO2 - bris

1
4
8
4
CHAPTER 3.
INVERTING SHEAR-WAVE SPLITTING MEASUREMENTS FOR FRACTURE PROPERTIES
Frac strike
180
160
140
120
100
80
60
40
20
4
4
2
2
2
4
8
16
0
0 0.05 0.1 0.15 0.2
Frac density
16
32
32
Gamma
0.15
0.1
0.05
(a)
0.2
0.2
4
2
4
8
4
1
2
8
4
0
0 0.05 0.1 0.15 0.2
Frac density
16
8
16
32
32
Gamma
0.15
0.1
0.05
2
4
2
4
2
2
0
0 50 100 150
Frac strike
(b) (c) (d)
8
4
1
8
4
2
0.2
0.2
8
16
4
0.15
4
4
0.15
Delta
0.1
0.05
4
2
1
1
2
2
4
8
8
16
32
0
0 0.05 0.1 0.15 0.2
Frac density
Delta
0.1
0.05
2
1
2
4
0
0 0.05 0.1 0.15 0.2
Gamma
4
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Figure 3.10: Synthetic inversion results for Phase IB. The initial model is constructed using two
fracture sets, with the NE-SW set having a higher density. However, the inversion result images
the fracture set that strikes to the NW-SE. In (b)-(f) I show the normalised misfit contours as a
function of ξ, α, γ and δ. The inversion finds the fractures striking to the NW.
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