The Use of Multiple Geophysical Techniques to Detect Structural - - PowerPoint PPT Presentation

BBUGS & BOHOGS 2015 Supplier and Consultant Day

The Use of Multiple Geophysical Techniques to Detect Structural Features

Author: Wes Nichols Co-Author: Warwick Smyth

Mine-Scale Case Study – Fault

• TSIM

– Shallow layer VLF-EM technique (down to 50m) – Uses VLF transmissions (e.g. 19.8kHz @ NW Cape) – Resistivity contrast

• Borehole Acoustic Scanner

– Measures acoustic impedance of borehole wall – Defect/bedding/structure identification

• RIM

– In-seam borehole-borehole radio imaging – Used for confirmation only

Fault Detection

• Near-surface

expression

TSIM Grid (100m x 150m – 10m)

Holes targeted to TSIM Results

Downhole Acoustic Scanner

Example: Chip hole R1833

Level of fault

Direction of highwall advance

RIM: In-seam EM

(Borehole-Borehole)

Geotechnical Implication

Wedge failure risk

Interpretation

• f Structural

Regime

3D Schematic Interpration

Top of Coal Surface Showing Interpreted Faults

Mine-Scale Case Study - LOX

• TSIM

– Shallow layer VLF-EM technique (down to 50m) – Uses VLF transmissions (e.g. 19.8kHz @ NW Cape) – Resistivity contrast

• Confirmed by drilling

LOX

Definition

Mine-Scale Case Study – Alluvium/Surface Channel Deposits

• TSIM

– Shallow layer VLF-EM technique (down to 50m) – Uses VLF transmissions (e.g. 19.8kHz @ NW Cape) – Resistivity contrast

• Confirmed by drilling

Alluvial Thickness Mapping

TSIM – Structural Targets

• Near surface expression of geological

structures of Geotechnical Importance

• Target types outlined in this presentation

– Faults (TSIM + Scanner + RIM) – LOX/subcrop (TSIM) – Alluvium (TSIM)

TSIM VLF-EM

• Provider to industry
• $100,000+ in R&D

expenditure

• Development of new

TranSIM instrument in progress

• Handleability and

ease of operation

• Cost advantage
• Saving in Drilling

Costs

Scanner Interpretation Services

• Defect mapping
• Stress regimes
• Full interpretive

report

Questions?