Mineral Exploration Drilling
BG Drilling runs a modern, well maintained fleet of drill rigs for mineral exploration programs across NSW and the east coast of Australia, backed by skilled, experienced and qualified crews, field supervision, maintenance support and regional bases. We have been drilling exploration holes since 2012.
Exploration drilling is how a deposit goes from a theory to a resource. It recovers samples from depth so geologists can establish what minerals are present, at what grade, and how the rock units relate to each other from the surface down. Which method suits depends on the stage of the program, the ground and how precise the sample has to be, and we carry the equipment for reverse circulation, diamond coring and the supporting work in between.
Our Mineral Drilling Services Include:
Down Hole Hammer (90 to 400 mm)
Mud Rotary (75 to 500 mm)
Wire Line Diamond Coring (NQ, HQ, PQ)
Conventional Coring (NMLC, HMLC, PMLC, 4c, 6c, 8c)
Packer Testing
Reverse Circulation Drilling
Reverse circulation, or RC, drilling collects rock chip samples quickly and at a lower cost per metre than coring, which makes it the workhorse of early stage exploration and of grade control once a deposit is being mined. A large rotary rig and a high volume air compressor drive a down hole hammer on dual wall rods. Air travels down the outer tube and the cuttings return up the inner tube to a cyclone at the surface, where they are split into sample bags by depth interval. Because the sample never touches the hole wall on the way up, it is clean and its depth is known.
Our down hole hammer capability runs from 90 to 400 mm, and we carry a range of hammer sizes plus cyclones with the rigs. Where the ground is soft or the hole makes water, a tricone bit can take over from the hammer. Our tracked and truck mounted rigs cover sites from open ground to restricted access.
Diamond Core Drilling
Diamond coring produces a solid, intact cylinder of rock that is brought to the surface for logging, structural measurement and assay. It is slower and costs more per metre than RC or air core, but it gives the most accurate picture of a deposit, which is why it follows RC once targets have been defined and wherever the resource estimate has to stand up to scrutiny.
We drill wireline diamond core in NQ, HQ and PQ, and conventional core in NMLC, HMLC and PMLC as well as 4C, 6C and 8C sizes. Depth capabilities:
- NQ to 2,000 m
- HQ to 1,500 m
- PQ to 1,000 m
- 4C, 6C and 8C conventional coring
Mud Rotary and Packer Testing
Mud rotary drilling from 75 to 500 mm supports the hole with drilling fluid where the formation will not stand open, and is used for pre-collars, larger diameter holes and ground that air drilling cannot hold. Packer testing measures the permeability of a section of the hole in place, which matters for the hydrogeology around a deposit and for dewatering design.
Choosing Between RC and Diamond
In practice most programs use both. RC covers a large area quickly at the reconnaissance stage and defines where the mineralisation is. Diamond core then goes into the defined targets to confirm grade, geometry and rock quality. Where the two are run in sequence, the RC hole is often used as a pre-collar and the diamond tail is drilled through it, which saves metres. We will tell you which combination suits the stage you are at and the ground you are drilling.
Rigs, Crews and Support
BG Drilling operates a fleet of 20 drill rigs, with tracked and truck mounted units suited to exploration work, and 9 tight access rigs for sites a full size machine cannot reach. Every program is supported by field supervision, maintenance support and regional bases, so a rig is not stood down waiting on parts or a decision. Our crews are experienced and qualified, and work to our safety and environmental systems on every site.
Exploration programs often sit alongside other drilling scopes. Our geotechnical drilling crews cover site investigation for mine infrastructure, and our environmental drilling crews handle monitoring well installation and sampling. We also offer drill rig and plant hire.
Talk to BG Drilling about your exploration program. Tell us the location, target depths, hole sizes and whether you need RC, diamond core or both, and we will put together the rigs and crews to suit. Get in touch.