Vale Nickel Mine – New Caladonia South Pacific Island

Hagstrom Drilling Case Study
Vale Nickel Mine – The Goro Nickel Project
New Caledonia, South Pacific island

Laterite Ore Bod on Remote Islands Receives Support from Hagstrom Drilling Foundation Assessment

What was the challenge?

The key mission was to assess the foundation along a new proposed conveyor alignment. This required specific equipment, including the sonic drill rig. Communication and the project’s actual location made for some of the biggest challenges. A project as large and remote as this comes with multiple challenges. First was the language barrier, as most of the mining employees speak French. The team used translation software to overcome this challenge and keep the project on task with accurate communication. Next, was the remote location. However, we have completed many similar projects so we had the experience to lean on. Our familiarity with dealing with international logistics and stringent quarantine requirements was helpful. Per these requirements, we made sure all equipment was fumigated, washed down, and routinely inspected.

How did we deal with it?

The Goro Nickel project is the largest mining project on the New Caledonia island with 55Mt of mineral reserves. Vale New Caledonia (VNC) sought a drilling partner to investigate the foundation. The investigation was focused on major span support foundations for truckload out facility including wet weather stockpile conveyor terminal site. There was also a proposed truckload facility to include a wet weather stockpile conveyor. There were two scopes of work.

The investigation included:

DWPT2

  •  20 boreholes to depths varying from 10.0m to 30.0m Below Ground Level (BGL)
  • 6 Seismic Cone Penetration tests through softer underlying strata to a maximum of 30.0m BGL or refusal on pre-drilled and cased boreholes
  • Dilatometer and Seismic Dilatometer tests through softer underlying strata to a maximum of 30.0m BGL or refusal
    KO2 Berm
  • 24 boreholes ranging in depth between 3.0m – 89.0m BGL
  • Vibrating Wire Piezometer Installations (VWP) to 40.0m BGL
  • Shelby tube samples
  • Downhole shear van test
  • Seismic Cone Penetration test
  • Piezocone (CPTu) test within 6 boreholes with dissipation testing
  • Dilatometer and Seismic Dilatometer tests conducted through softer underlying strata

What was the solution?

We used a sonic drill rig which is new and relatively unknown in the area. With this type of machinery, continuous core drilling is possible. The scope also included a track-mounted CPT rig with the capability of conducting various types of testing methods.

How did we implement the solutions?

We had a great team: supervisor, driller, two driller assistants, and a CPT operator. What made the difference for the client when we were installing the solution was that we didn’t cause any disruption to their normal operations, which could have cost them.
When we used the sonic rig, we were able to get 100mm samples consisting of fill and natural geology. Because we used this method, 100 per cent core recovery was possible. Previously, they had been unable to penetrate this far.

What was the result?

The inclinometer instrumentation was installed successfully. It was placed in the rock fill through the 6″ diameter sonic casing.
Throughout the project, we were there to ensure the client was taken care of as well as always working by our motto: Quality Service Safely. The project actually came in under budget with additional work performed outside the expected scope.