APA Group has contracted Diona to construct the Caltex Lateral Project, a 6 km extension to the Roma to Brisbane Pipeline (RBP) from the SEA Block Valve in Murrarie to the Caltex Oil Refinery in the Brisbane suburb of Lytton. The project is being constructed along one of Brisbane’s busiest roads, with heavy vehicles travelling to and from the port of Brisbane 24 hours a day. As such, six horizontal directional drills totalling 2.7 km are required along the pipeline route, including a crossing of one of the tributaries of the Brisbane River called the Aquarium Passage.
Caltex needs more natural gas
The 200 mm diameter, X52 class 600 high pressure Caltex Lateral is required to increase the current supply of natural gas to the Caltex Oil Refinery.
In order to supply natural gas to Caltex at the required rate, the 6 km lateral will operate at a maximum pressure of 4,200 kPa, which is the current maximum RBP pressure downstream of Mount Gravatt. The project involves the construction of a new gate station on the RBP at Muarrie, and a new metering station at the Caltex end of the pipeline.
Construction work on the lateral commenced on 31 March 2010. At the time of writing, construction was still underway, with completion scheduled for mid-August 2010.
Lytton Road and the route to the port of Brisbane is under continual urban development. APA General Manager Projects Rob McMaster said that this meant Queensland’s transport authority, the Department of Main Roads, required very precise technical specifications such as depth of the pipe and alignment.
“The pipeline needed to meet strict design criteria due to its urban location, which were achieved with support from pipe supplier Orrcon,” said Mr McMaster.
Protection from potential impact and the strength of the pipe were critical. At short notice Orrcon was able to change the specification of the DN 200 pipe while in production to meet an urgent request to test from X42 up to X52 for tensile strength. This allowed APA to meet the strict design criteria and the latest AS2885 standards without additional slabbing or other forms of pipeline protection.
In addition, undertaking construction works in densely populated metropolitan areas gives rise to a number of stakeholder issues which do not arise in remote areas.
“As part of the project approval, APA is required to maintain 24-hour-a-day access to each business along Lytton Road while the pipeline is being installed along the road reserve,” said Mr McMaster.
“A consistent focus on communication with local businesses meant that we passed 1,038 businesses and only lost one non-essential service, which was rectified within hours of the service being lost. The communication plan started three months before the construction, and each day we communicated with residential and commercial owners affected by the pipeline installation.”
Given the substantial restrictions on approvals from the Department of Main Road, it was necessary to horizontal directional drill in a number of areas along the route, with the pipe reaching depths of 8 m and the drill achieving a maximum length of 618 m for one drill. Furthermore, given the alignment of the pipeline along the boundary of the port of Brisbane, the pipeline installation was carried out in a tidal area, adding further complexity to the project.
Ensuring safety for all
Approximately 15 APA employees and up to 85 contracted personnel are involved in the project. Mr McMaster said that safety requirements on the project are very specific, taking into consideration the workers on the pipeline and the general public.
Traffic management techniques such as heavy traffic management, speed control, shiftwork, road closures and a police presence are being used to mitigate the risk. Other safety elements include trench management, and environmental control processes to make sure that the surrounding delicate marine environment is not impacted. The water crossings required along the pipeline route created challenges, having very specific environmental and approval processes that needed to be completed before work commenced.
Additionally, construction work along a section of the pipeline route had to be completed at night so as not to disturb a colony of nocturnal flying foxes located in mangroves along the pipeline route.
Delivering gas safely
Mr McMaster said that APA’s goal is to deliver natural gas to customers reliably and safely. The company has the knowledge, skills and experience to handle the challenges faced in this project – for APIA this is “˜business as usual’ .
“From APA’s experience, we know that these difficult and challenging projects can only be achieved with a good team and a commitment to work together to get the job done, and that is what we had for this project,” said Mr McMaster.