MINERAL EXPLORATION
The Delamerian NDI campaign has confirmed that the 500-million-year-old basement rocks buried beneath sedimentary sequences of the Murray Basin were formed in a geological setting conducive to the formation of base and precious metal mineral deposits . MinEx CRC CEO Andrew Bailey said geologists have long speculated that eastern South Australia contains basement rocks equivalent to the mineral-rich Mount Read belt of western Tasmania .
“ Although relatively shallow , the cover sediments of the Murray Basin are difficult to drill and have proven to be a significant deterrent to exploration ,” he said . “ The Delamerian NDI campaign was designed to overcome the technical challenge of drilling beneath the Murray Basin cover and characterising the basement rocks beneath .”
The drilling campaign included both conventional drilling and innovative coiled tubing ( CT ) drilling techniques developed by MinEx CRC . Coiled tubing ( CT ) drilling systems offer a range of efficiencies in comparison to the state-of-theart technology used in mineral exploration , including faster penetration , reduced operational hazards for drill crew , lower fuel use , and reduced environmental footprint .
The Delamerian NDI campaign was the first production-scale field trial of the MinEx CRC CT drilling platform , with over 5,000 m drilled in 18 holes . This concerted effort has allowed researchers and drill crews to improve the CT drilling infrastructure and workflows and to benchmark performance against conventional
MinEx CRC coiled tubing drill
drilling techniques .
The CT drill holes were drilled significantly faster , with less water , lower fuel consumption and subsequent carbon emissions than the conventional drill holes , delivering significant cost savings and environmental advantages .
Drill cuttings delivered by the MinEx CRC CT platform were logged and assayed by portable XRF in field providing near real-time geological feedback during the drilling campaign . Comparison between geochemistry and gamma logs indicates that the CT cuttings can be confidently attributed to a depth interval , with good sample integrity .
The Delamerian NDI campaign also saw the first deployment of MinEx CRC ’ s CT selective diamond coring capability , which was used to collect bottom-of-hole drill core in 16 of the 18
CT holes . “ We think the newly developed coring capability is a game-changer for the MinEx CRC CT platform ,” MinEx CRC ’ s Chief Scientific Officer Professor David Giles said . “ Now geologists have the option to collect high-quality core samples , containing valuable textural and structural information , from any depth of their choosing ”.
Before drilling , the GSSA conducted an extensive review and synthesis of prior work , collecting new geophysical data and applying cutting-edge machine learning techniques to target and prioritise drill holes . A vital component of the GSSA contribution was landholder consultation , environmental evaluations , and cultural surveys to ensure stakeholder engagement , minimise impact and manage land access at industry-leading standards .
Geological and geophysical logs and in-field geochemistry collected during the drilling campaign are now available via the South Australian Drilling Atlas . This Atlas was the first time the GSSA had released as near real-time data as possible during the drilling campaign . This allowed the GSSA , as well as companies and researchers to gain early access and visualise raw data .
Drill core and cuttings samples from the NDI drill holes will be the subject of in-depth analysis over the coming year , designed to add detail to the emerging geological model and provide guidance on the exploration techniques most likely to lead to the discovery of new
deposits .
IM
Devico continues to steer directional drilling
Devico is the inventor and leading worldwide provider of directional core drilling ( DCD ), with its DeviDrill steerable wireline core barrel . In addition to directional drilling technology it also produces state-of-the-art borehole surveying products for downhole navigation , core orientation , drill rig alignment and QA / QC data management .
After extensive development and a thorough trial period Devico has just announced the release of its latest innovation , the DeviDrill RSS ( Rotary Steerable System ). Building on the advanced directional drilling technology it is known for , this new one-of-a-kind directional drilling tool it says “ sets a new standard for reliability and productivity .”
DeviDrill RSS boasts the same proven capabilities of the DeviDrill , but with a further range of innovative and patented solutions , in a shorter more compact solution that has up to five times the penetration rate . It helps ease operation and secure stable and high production in both hard and compact to fractured rock formations .
Integrated in the DeviDrill RSS is the DeviGyro , controlling the orientation , inclination , and direction as the DeviDrill RSS steers the hole towards the target . When drilling to deep exploration targets or requiring high accuracy this combination ensures that the targets are hit precisely
in a time and cost-efficient manner .
In front of the DeviDrill RSS sits a full-face drill bit specially designed
for long life continuous operation , making it especially suitable for achieving directional targets , particularly in broken ground , but also in most other applications . “ Going on 35 years with over 500,000 Directional
Devico ' s latest innovation is the DeviDrill RSS ( Rotary Steerable System )
Core Drilling metres worldwide , the feedback from our clients is clear , they value our proven ability to steer their drill holes on target time and time again and most are less concerned about the core sample during steering .”
Key features include no locking pin , efficiency in all rock formations which is up to five times faster than directional core drilling . It has a continuous orientation capability with no muleshoe required with an integrated DeviGyro survey system . It offers long life & minimal maintenance requirements plus the directional drilling length is limited only by rig & rod string capacity .
Smooth curvature maximises dogleg capacity and it operates with a standard diamond drill rig , pump & N-size rod string . There are no reaming requirements plus low water consumption . Applications include mineral exploration , underground and surface diamond drilling , branch hole drilling programs ( delineation , definition , resource drilling ), deviation control , geotechnical investigation and pilot holes .
FEBRUARY 2023 | International Mining 75