Liquefied Natural Gas (LGN) Shore Trunkline Microtunnel
Location: Onslow, Western Australia
Market sector: Energy, liquefied natural gas
- MasterFlow 871
- MasterFlow 700
How do you seal an underwater natural gas trunk line near a whale shark breeding ground?
This was the challenge faced by BASF technical services team working at the Chevron’s Wheatstone Liquified Natural Gas (LNG) processing plant, off Western Australia’s Pilbara Coast.
At Wheatstone, LNG and domestic gases are transported from subsea wells through a trunk line, several kilometers off shore, to their processing plant. The last kilometer of this trunk line runs from ocean to shore through a protective micro tunnel.
BASF technical services team’s task was to anchor the trunk line within the micro tunnel, with a precision grout plug for the last 70 meters to shore, as the area is a whale shark breeding ground with zero tolerance for environmental impact. The placement of the grout must be done underwater with low visibility, requiring new design concepts for placement and mixing.
To solve this challenge, MasterFlow 871, a brand new high strength non-shrink deep pour precision grout, was developed as well as a new grout delivery system designed to carry the delivery line and inflatable grout bags down the 70 meter microtunnel underwater.
The successful micro tunnel plug installation – the first of its kind worldwide – significantly reduces future corrosion costs, extends the trunk line’s durability, allows early demobilization for lower onsite costs and allows the plant to run business as usual – for man and shark alike.
The Wheatstone Project is located in close proximity to an important whale shark breeding ground, meaning various environmental factors needed to be considered when developing BASF’s grout devlivery system.