Longford Gas Plant Project – Gyro Survey

Client: Wood Group PSN

Services Provided: Gyro Survey

Completion Date: June 2013

Project Scope of Work: 

Sixteen DN160 conduits were installed by HDD for high voltage and earth cables under the Longford Gas Plant in Sale Victoria. This would be the first time HDD would be used to pass below live processing facilities in Australia.

The conduits were installed uncased, grouped in four bundles of four in a trefoil configuration at a drilled length of just over 1,000m.

The minimum spacing distance between the parallel bores for the high voltage cables was critical to maintain adequate cable ratings, as the current ratings are influenced by mutual heating from adjacent conduit groups. Stockton Drilling Servcies conducted gyro surveys of each installed bundle.

Results and Client Benefit:

The surveys provided independent third party verification and confirmation of the exact position of each conduit, and therefore separation distance.