Post on 01-Oct-2020
James Whitford
BHUC November 2019
Borehole Inspection: Methods, When and Why?
Scratching the surface
Looking Deeper…
Why Inspect?Physical Condition
Casings
Physical Condition
2013 2014 2016
Screens
Why Inspect?
Why Inspect?
Physical Condition
Borehole stability
Why Inspect?
Physical Condition
Pump location and position
Why Inspect?
Hydrogeology
• Water movement – in/out flows
• Velocities and volumes
• Changes in water quality/chemistry
Why Inspect?
Formation Evaluation
• Identification lithology
• Porosity and porewater chemistry
• Fractures
Why Inspect?
New Boreholes
Techniques
CCTV
Techniques
Cement Bond Logging (CBL)
Techniques
Depth (m)
10
20
30
Density increases
Channelling of cement grout behind steel casingDensity Gamma Log
Density
Techniques
Acoustic Imager
Techniques
Fluid Logs• Temperature and Conductivity• Impellor Flowmeter• Heat Pulse Flowmeter• Nitrate
TechniquesFluid Logs
Techniques
Formation Logs• Natural Gamma• Resistivity and Induction• Caliper• Gamma Density• Neutron Porosity• Optical and Acoustic Imagers
TechniquesFormation Logs
When to inspect
• During the drilling programme• New boreholes• Regular inspection programme• When pumps are removed• Increases in turbidity• Variations in water quality• Contamination
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