Directional Drilling in Australia
Directional drilling has come of age in that it is being specified for river crossings new pipeline projects in Australia. The need for the specialist HDD contractors to argue the benefits of directional drilling is fast diminishing. The environmental benefits and simplicity of HDD are now recognised widely.
Natural Gas Pipelines:
Deregulation and privatisation of the natural gas pipeline industry in Australia have sparked new pipeline projects such as Australian Gas Light's 254 km Dubbo pipeline and the 140 km "Logical Link" from Wodonga to Wagga Wagga, PG&E's 180 km Gladstone to Bundaberg pipeline, and Coastal's western Victorian pipeline. HDD is specified for the river crossings on all of these projects.
A.J.Lucas Contractors Pty. Ltd., the contractor building the 254 km long 8 inch diameter Dubbo pipeline has gone one step further using mini HD rigs for all the road and rail crossings on this pipeline. In the past, these would have been auger bored with concrete casing pipe required by the authorities. HDD saves the trouble of using the casing pipe as the gas pipeline is buried deeper for not only the road / rail itself, but also under the adjacent table drains.
Optical Fibre Cable Rollout:
The Optical Fibre cable roll out in Australia has finished its first phase with the next phase about to start. It would not have been possible without HDD and the many guided boring rigs which have appeared like mushrooms after heavy rain in spring. Prices dropped from an initial $50 per metre down as low as $19 per metre such was the sudden supply of rigs. This revolutionised the cable roll out with cable being placed in locations at first not thought to be economically feasible.
Other HDD news in Australia:
A 250 tonne HDD rig is being used by A.J.Lucas for the landfall of two international optical fibre cables from Indonesia at Floreat Beach, Perth, Western Australia. The conduits for the cables are drilled some 1000 metres out to sea under sensitive coastal sand dunes and the pristine surf zone. The same 250 tonne rig will then drill a new natural gas pipeline 520 metres long and a bundle of cable ducts under Middle Harbour at the Spit, one of the most picturesque locations in the beautiful city of Sydney. Without HDD, the crossing would never have gone ahead.
This project follows on from the HDD of 750 metres of 350 mm diameter natural gas pipeline drilled under the George's River at Taren Point, another picturesque location in Sydney. Here, an old gas main failed and there has been room on the adjacent bridge only for a temporary gas main. Environmental consideration made dredging an impossibility. A.J.Lucas' HDD rigs came to the rescue.
Sewer pumping stations are being replaced by A.J.Lucas HDD rigs drilling into the Blue Mountains sewer tunnel west of Sydney. The boreholes pass under houses and ridges eliminating pumping systems with gravity mains. The longest borehole to date is 650 metres with the target only 2 metres x 2 metres - a good feat considering that the tunnel is too deep for Tru-Tracker to be used.
BP Australia for years dreamt of running a aviation fuel pipeline from its Brisbane refinery to the adjacent international airport but because of the nearby swamps and planning difficulties, was locked into sharing pipelines with its competitors. Then it realised that A.J.Lucas has large directional drilling rigs in Australia and its pipeline became a reality. A 200 mm diameter aviation fuel pipeline has been drilled under environmentally sensitive swaps and the airport main runway and taxiway using HDD. The longest crossing was 950 metres long.
HDD continues to grow in Australia now the method of "first choice" by clients. All that hard work by the HDD and Trenchless Technology evangelists is starting to look worthwhile.
By Andy Lukas