Combination of Computed Tomography and Petrography in Reservoir Characterization

1
Fracture around the connecting and PRACLAY
gallery observations and comparison
Exhange meeting30 September 2008, Mol
2

• Excavation induced fractures
• Fracture pattern?
• Fracture extent?

3

• Connecting gallery
• diameter 4.8 m
• length 80 m
• progress 3 m/d

Connecting gallery
Praclay gallery
Conclusions
4
Excavation technique Tunnelling machine
Connecting gallery
Praclay gallery
Conclusions
5
Excavation technique
Connecting gallery
Praclay gallery
Conclusions
6
Excavation technique
Connecting gallery
Praclay gallery
Conclusions
7
Excavation technique
Connecting gallery
Praclay gallery
Conclusions
8
Excavation technique
Connecting gallery
Praclay gallery
Conclusions
9
Fracture pattern
Connecting gallery
Praclay gallery
Conclusions
10
Fracture characterisation programme Observations
on sidewalls
Connecting gallery
Praclay gallery
Conclusions
11
Fracture characterisation programme Observations
on sidewalls
Connecting gallery
Praclay gallery
Conclusions
12
Fracture characterisation programme Observations
on sidewalls
Connecting gallery
Praclay gallery
Conclusions
13
Fracture characterisation programme Observations
on sidewalls
Connecting gallery
Praclay gallery
Conclusions
14
Fracture characterisation programme Observations
on excavation front
Connecting gallery
Praclay gallery
Conclusions
15
Fracture characterisation programme Observations
on excavation front
Connecting gallery
Praclay gallery
Conclusions
16
Fracture characterisation programme Observations
on excavation front
Connecting gallery
Praclay gallery
Conclusions
17

• Extent fractured zone
• Radial extent 1 m
• ? borehole
• Axial extent 6 m
• ? modelling
• ? observation near Test Drift

Connecting gallery
Praclay gallery
Conclusions
18

• Extent fractured zone
• Radial extent 1 m
• ? borehole
• Axial extent 6 m
• ? modelling
• ? observation near Test Drift

Connecting gallery
Praclay gallery
Conclusions
19
Extent hydraulic disturbance Pore water pressures
vs gallery distance
Connecting gallery
Praclay gallery
Conclusions
20
Praclay gallery
Connecting gallery
Praclay gallery
Conclusions
21

• Praclay gallery
• same excavation technique
• diameter 2.5 m (connecting gallery 4.8 m)
• length 45 m
• progress 2 m/d (connecting gallery 3 m/d)

Connecting gallery
Praclay gallery
Conclusions
22

• Fracture characterisation programme
• observed fracture pattern

Connecting gallery
Praclay gallery
Conclusions
23

• Fracture characterisation programme
• observations sidewalls same pattern observed

Connecting gallery
Praclay gallery
Conclusions
24

• Fracture characterisation programme
• observations sidewalls
• observations excavation front
• ? measurements
• ? stereographic pictures

Connecting gallery
Praclay gallery
Conclusions
25

• Fracture characterisation programme
• observations excavation front

Connecting gallery
Praclay gallery
Conclusions
26

• Fracture characterisation programme
• observations excavation front

Connecting gallery
Praclay gallery
Conclusions
Dip pole 1 44 Dip pole 2 46
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• Extent fractured zone
• boreholes for instrumentation
• pore pressures near Praclay gallery
• ? P30 1.75 m south of gallery
• ? P35 0.75 m north of gallery

Connecting gallery
Praclay gallery
Conclusions
28

• Fracture characterisation programme
• fractures observed from connecting gallery?

Connecting gallery
Praclay gallery
Conclusions
29

• Fracture characterisation programme
• front next to connecting gallery

Connecting gallery
Praclay gallery
Conclusions
30

• Praclay gallery
• excavation front 4.5 m

Connecting gallery
Praclay gallery
Conclusions
31

• Praclay gallery
• excavation front 6.0 m

Connecting gallery
Praclay gallery
Conclusions
32
Praclay gallery Pore water pressures vs gallery
distance
Connecting gallery
Praclay gallery
Conclusions
33

• Conclusions
• Fracture pattern
• Research on fracture extent is ongoing
• Hydraulic disturbance reaches further than
  fracture zone

Connecting gallery
Praclay gallery
Conclusions