The world’s first project to turn coal seam gas into liquefied natural gas
Upon completion in 2014, Queensland Curtis LNG Plant (QCLNG) will convert coal seam gas into liquefied natural gas (LNG), providing cleaner hydrocarbon energy for export markets, along with creating thousands of jobs and boosting the local economy. The project is being developed by QGC Pty Ltd, a division of the BG Group, a leading player in the global energy market with operations in more than 25 countries across five continents. Equipment from Putzmeister has been working to place concrete at the site since last fall. The future LNG production plant QCLNG, located on Curtis Island in Gladstone Harbour, Australia, consists of the construction of a world-class LNG plant. Upon completion, the plant will comprise two LNG production units, known as trains, each able to produce more than 4 million tons of LNG per year; two storage tanks each able to hold nearly 140,000m³ of LNG; a marine facility for passenger and equipment transportation between the mainland and Curtis Island; and marine loading facilities for LNG cargoes. Most of the 120,000m³ of concrete needed for the plant and accompanying structures for the project is being placed by Putzmeister equipment, including two 47 Meter and two 36 Meter truck-mounted concrete boom pumps along with six MX 43 Meter placing booms.
Occupying less than two percent of the island, the plant facility is surrounded by an environmental protection zone. The site can accommodate an expansion to more than 12 million tonnes per year of LNG, a colourless, odourless, non-toxic and non-corrosive liquid. For the project, Bechtel Australia Pty Ltd. was chosen as the general contractor and purchased the Putzmeister placing systems. Meales Concrete Pumping fromBisbane is supplying the Putzmeister truck-mounted concrete pumps and high pressure trailer pumps.
One of the more challenging aspects of the QCLNG project is that it is located on an island, which means all equipment, supplies and workers need to be transported across the harbour from Gladstone, Queensland. As a result of the approximately 3,000 workers needed for the job, a temporary construction camp, which houses up to 1,700 workers, has been established on the island. This has helped to reduce road traffic and relieves pressure on the Gladstone housing market. Additional local workers ferry across from the mainland to the island each day. All aggregate materials for the site’s concrete are shipped across to the island on bulker barges, then transferred into six-wheel dump trucks and transported to the two 120m³/hr batch plants set up by the project’s concrete supplier, Boral Concrete. All other construction materials and equipment, including the Putzmeister boom pumps and placing booms, also arrived via water transport.
Creating Marine Access
Being based on an island, adequate marine facilities are an essential part of the QCLNG project. Thus, the first phase of the construction process involved building a material offloading facility that ships can pull up against during construction to unload their cargo. The construction team has been using a 36 Meter concrete pump to place the 8,000 -10,000m³ of concrete required for all marine facilities. Because of a congested work site and since most of these areas are not accessible by land, building the marine facilities has been a challenge. As a result, much of the work has been performed from barges located in the water.
Additional marine facilities consist of ferry terminals for passenger ferries, along with docks and ramps for the barges that transport all the construction vehicles. Eventually, a “jetty” will be built, which will be where ships will pull into to get loaded with LNG once the plant is completed.
Placing the “Trains”
The two LNG production units, or “trains,” are where the coal seam gas travels through the various processing stations to eventually be converted to LNG. To build the massive trains, two Putzmeister 47 Meter truck-mounted concrete boom pumps are working to place the majority of the 90,000m³ of concrete for the footings, mat pours, pedestals and columns.
On occasion, to supplement the M 47Z’s, a M 36 Meter assists in the placement of concrete. The M 36 is used in addition to the M 47’s on mat pours greater than 1,200m³, and for smaller miscellaneous pours, such as many of the pedestals that will support the plant upon completion.
Circling the Tanks
After the gas is liquefied in the processing plant, it will be transferred to one of two massive storage tanks before exportation. To build the 90m by 40m high tanks, both placing booms and truck-mounted boom pumps are being used. Approximately 19,600m³ of concrete will be placed for each tank. Six MX 43 Meter placing booms, three surrounding each tank, are mounted on 40m high freestanding lattice tower sections. Each lattice tower has two ties back to the tank to help support the free stand height. The systems utilize three BSA 2109 HD stationary concrete pumps.
Since the MX 43-5 is the industry’s largest placing boom that does not require a counterweight, it has helped to significantly reduce congestion on the work site. The crew also is using the M 47’s to support the placing boom systems on larger tank wall pours.
Each tank will require 10 wall pours at about 4m high, each of which are poured in a complete ring. The base of each tank will be poured in four sections that include two outer ring pours and two inner floor pours with each pour consisting of about 1,000m³ of concrete.
»The tanks are about 90m in diameter, which gives you a circumference of more than 280m,« explained Lethbridge. »The placing booms were chosen because they gave the crew complete coverage of the walls, and offer enough reach to access the top of the tanks to pour the roof.« The placing booms are primarily responsible for placing concrete for the walls, and roof of the tank structures. On the lower sections of the tank walls, which are thicker than the top portions, and therefore require more concrete placement, the M 47’s are being used to help supplement the pours. »The truck-mounted pumps allow the pours to be finished in a shorter period of time than if just the three placing booms were being used,« explained Lethbridge. »This helps the crew to better meet its deadlines, which is vital to any construction project.«