WDS Limited is one of Specialty Rental’s largest customers in Queensland. They were awarded the contract to design, build and commission a major pipeline running from the new QGC facility adjacent to the Condamine Power Station, some 8 km east of Miles, to the Gas Hub at Wallumbilla for AGL. The gas was supplied from QGC’s new CSG fields at Berwyndale and Kenya in Queensland.
 
The pipeline is 112 kilometres long and constructed from 400mm diameter API X70 trilaminate coated steel pipe. During construction installed sections of the line were progressively pre-cleaned to remove all contaminants from the line and then tie in for hydrostatic testing.
 
There were four test sections required. The locations of these were dictated by water source and construction progress. WDS ability to meet the tight schedule required that the testing and subsequent drying processes were not left to the last.
 
The four test sections were approximately 5kms, 42kms, 40kms and 24kms long working from east to west. On successful completion of each section water was pumped from the section into the subsequent section via a break tank at which time chemical dosing was undertaken. Bi directional pigs were then driven through the section to remove residual water and the foam pigs were introduced to be propelled through the section using dehydrated air to further clean and dry the section. Once the required dewpoint had been achieved the section was sealed to await the process to be completed at the adjacent section, whereupon the final tie-ins were completed.