Case study

Horizontal Extraction Well

In 2014 Dunstans Construction Group designed, constructed and installed a 180mm vented HDPE horizontal extraction well in Melbourne.

Our 45-tonne Horizontal Directional Drill (HDD) Spread was mobilised to complete the 385m crossing, bored diagonally under a Melbourne factory to remove a hydrocarbon plume from a leaking storage tank.

  • Instead of the conventional method of installing vertical wells to extract the plume, HDD technology was used for the first time in Australia.
  • The perforated pipe was installed underneath a working factory with limited access to the floor for steering purposes. Vigilant monitoring of drill fluid pressures ensured that in the event of fluid loss to the surface, impact to the factory’s workflow would be minimised.
  • Vital services including telecommunications, sewer, high-pressure gas and water mains also had to be negotiated at entry and exit.
  • Due to the slotting in the product pipe, installation was carefully monitored to detect any possible stretch, allowing for a 30% decrease in integrity.
  • To prevent environmental impact, both cuttings and drill fluid
    were tested before disposal.

The innovative well installation was completed successfully with no impact to the plant or surrounding work areas. Hydrocarbon extraction can be applied to other potential sites requiring similar rehabilitation, as urban centres spread and industrial areas are re-purposed.

Project quick facts




Horizontal Dewatering Well Installation

Project date

June – July 2014

Project location

Melbourne, Victoria

Hole length


Project cost