AIG-ADIA Drilling for Geology seminar
1/8/2014
DRILLING HOLES
DRILLING INDUSTRY SECTORS
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Geotechnical
Mineral exploration/investigation
Oil and gas
Environmental
Water bores
Foundation/Construction
Blast hole/seismic
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AIG-ADIA Drilling for Geology seminar
1/8/2014
DRILLING IS ESSENTIAL
Resources Industries
• mineral rich
• gas rich
Construction Industry
• build infrastructure
Rural Industries/Communities
• water supplies
Monitoring
• water resources
• environmental
COMMON TO ALL TYPES OF DRILLING
• A hole has to be drilled
• Most rocks we drill into contain
groundwater
• May penetrate more than one geological
formation
• May penetrate more than one aquifer
• Drilling introduces foreign material into
the hole
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AIG-ADIA Drilling for Geology seminar
1/8/2014
GROUNDWATER
• 22% of Australia’s annual water consumption
• Main source of drinking water for many cities
and towns
• Only reliable water supply for much of
Australia’s inland areas
• 33% of Queensland's stock/domestic use
• Two thirds of Western Australia’s entire water
requirements
• Bottled from natural springs, used to make soft
drinks and beer
RISKS TO GROUNDWATER
Holes left open:
• provide a conduit for surface water runoff
• provide a vertical connection between
aquifers
• create pathways for gas
And may result in:
• contamination/pollution
• loss of pressure
• water supply problems
• safety issues
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AIG-ADIA Drilling for Geology seminar
1/8/2014
SURFACE WATER RUNOFF
INTERMIXING
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AIG-ADIA Drilling for Geology seminar
1/8/2014
Gas
WHAT COULD WE DO
Drive away and hope no one notices, or
Design drilling program to prevent:
• entry of surface water runoff
• intermixing of fluids and pressures
between aquifers
• fugitive gas emissions
• injury and harm to people and animals
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AIG-ADIA Drilling for Geology seminar
1/8/2014
WE DO
NOTICE
• On major road
• More than
100 metres
deep
• Hutton
Sandstone
STANDARDS/CODES IN QLD
 Code of environmental compliance,
exploration and mineral development projects.
 Code of Practice for constructing and
abandoning coal seam gas wells and
associated bores in Queensland. (COP)
 Minimum Construction Requirements For
Water Bores in Australia. (MCR)
 Minimum standards for the construction and
reconditioning of water bores that intersect the
sediments of artesian basins in Queensland.
All are legislative requirements in QLD
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AIG-ADIA Drilling for Geology seminar
1/8/2014
MCR
Minimum Construction Requirements For
Water Bores in Australia.
• nationally endorsed standard for water
bore construction
• first published in 1997
• edition 3 current version
• legislation in QLD
The MCR has principles that could be
applied across any drilling sector.
SEALING HOLES
Holes must be sealed to:
• protect groundwater from
contamination
• maintain aquifer pressure & quality
• not allow fugitive gas emissions
We can do this by either:
• casing and sealing the annular zone
• sealing the drilled hole
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AIG-ADIA Drilling for Geology seminar
1/8/2014
CASING AND SEALING ANNULAR ZONE
The casing and seal must be installed so
that:
• there is no vertical connection of aquifers
• it does not allow ingress of surface water
• the casing is capped at the surface
If the result is a water bore it must be
constructed by:
• licensed driller
• petroleum company under the COP
CASED & SEALED HOLE
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AIG-ADIA Drilling for Geology seminar
1/8/2014
DECOMMISSIONING THE HOLE
Various methods:
• Depends on type:
• single aquifer non flowing
• multiple aquifer non flowing
• flowing
Combination clean fill and sealing
materials
MATERIALS
Clean uncontaminated fill
• sand
• coarse gravel
• clay
• drill cuttings
Sealing materials
• grout
• bentonite grout
• bentonite pellets/chips
• concrete
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AIG-ADIA Drilling for Geology seminar
1/8/2014
PREFERRED METHOD
• Fully grouted from the top to
the bottom of the hole.
GROUTED FROM TOP TO BOTTOM
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AIG-ADIA Drilling for Geology seminar
1/8/2014
LINKS to STANDARDS/CODES
• http://www.ehp.qld.gov.au/licencespermits/compliance-codes/pdf/code-explorationmineral-development-em586.pdf
• http://www.dnrm.qld.gov.au/__data/assets/pdf_file/001
1/119666/code-of-practice-csg-wells-and-bores.pdf
• http://www.dnrm.qld.gov.au/__data/assets/pdf_file/000
9/99765/minimum-construction-req-au.pdf
• http://www.dnrm.qld.gov.au/__data/assets/pdf_file/000
7/99763/minimum-standards-bores.pdf
QUESTIONS
?
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