1. Geophysical exploration in and around CTD

2. Applied Method GPR Electrical Resistivity Tomography (2D, 3D)
Elastic Velocity (3D)

3. ERT Image (2D) Survey Area CTD Plug Survey Date Line1 Line2
Water conducting fracture
End of CTD
Plug
13MI40,41
Borehole
(pressure monitoring)
A~D Borehole for 3D tomography (Resistivity, Elastic wave)
Conducted only on the same side as line1
Survey Date
Before closure test
July, 2014
After closure test (1st )
October, 2017
After closure test (2st )
February, 2018

4. Time lapse Resistivity Image(Line1)
Before closure test (July, 2014)
Pressure monitoring (13MI41) B E A
A, B, E Borehole for tomography
Fracture
Water Conducting Fracture
After closure test (1st, October, 2017)
Pressure monitoring (13MI41) B E A
After closure test (2nd, February, 2018)
Pressure monitoring (13MI41) B E A
End of CTD
Plug

5. Time lapse Resistivity Image(Line2)
Before closure test (July, 2014)
Pressure monitoring (13MI40)
A, B, E Borehole for tomography
Fracture
Water Conducting Fracture
After closure test (1st, October, 2017)
Pressure monitoring (13MI40)
After closure test (2nd, February, 2018)
Pressure monitoring (13MI40)
End of CTD
水圧観測孔
Plug

6. Tomography Image (Resistivity, Elastic wave)
Survey Area
CTD
Plug
Line1
Line2
Target area
Water conducting fracture
End of CTD
Plug
13MI40,41
Borehole
(pressure monitoring)
Wall on only 1 side (13MI40 side)
5 Boreholes
Length of each borehole: 2m
Survey Date
Before closure test
July, 2014

7. Tomographic Image (Resistivity)
Scanned Volume: 1.75[m]*1.75[m]* 2.0[m] D C C
End of CTD D
Plug
End of CTD
Plug B A B
Depth
Wall
Depth A
Wall

8. Tomographic Image (P wave velocity)
Scanned Volume: 1.75[m]*1.75[m]* 2.0[m]
Plug
End of CTD
Wall
Wall
Depth
Plug
End of CTD
Depth

9. Tomographic Image (Elastic wave attenuation)
Scanned Volume: 1.75[m]*1.75[m]* 2.0[m]
Plug
End of CTD
Wall
Wall
Plug
End of CTD
Depth
Depth

10. GPR Image (GPR Reflection)
Survey Area
Both in inclined drift and CTD.
Total length of measurement line: 505m (Not all profiles are shown in this slide)
Survey Date
Before closure test
Several times before March, 2014

11. CTD (Wall) Configuration CMP Frequency 5～500MHz Wall (Left side)
Wall (End of CTD)
Plug
End of CTD

12. CTD (floor) Configuration 0 offset Frequency 800MHz End of CTD

13. CTD (Both floor and Wall)
Configuration
0 offset
Frequency
800MHz
Left wall
Left wall
Floor
End of CTD
Plug
Floor
Wall of End of CTD
Floor
Floor
Right wall
Right wall
Right wall

14. Inclined (3D like profile)
Floor (Inclined)
5Parallel survey lines
Shaft
Configuration
0 offset
Frequency
800MHz
Plug

15. Inclined (Right wall) Configuration 0 offset Frequency 800MHz Shaft
Plug