China Offshore Fugro Geosolutions (Shenzhen) Co. Ltd. (COFG) orders two Ranger 2 underwater tracking systems from Sonardyne Asia.
The contract, part of the pre-installation phase of the Liwan 3-1 gas field development, includes the supply of Sonardyne’s new pre-calibrated GyroUSBL transceiver, establishing COFG as the first company in the region to benefit from its operational cost-saving features.
Discovered in 2006, Liwan 3-1 is located in the South China Sea, 350 kilometres south-east of Hong Kong in an average water depth of 1,300 metres. COFG is a joint venture between Fugro China and China Oilfield Services Limited and on this project, the company will be using its Ranger GyroUSBL systems to conduct route surveys of the proposed gas pipeline using ROVs.
Ranger 2 calculates the position of a subsea target by measuring the range and bearing from a vessel-mounted Ultra-Short BaseLine (USBL) transceiver to an acoustic transponder on the target. To achieve optimum positioning performance, conventional USBL transceivers require careful installation and a lengthy calibration procedure to calculate sensor offsets. However, the GyroUSBL ordered by COFG has a built-in Lodestar attitude and heading reference sensor which only requires the vessel to perform a simple ‘spin-test’ before subsea operations can begin. In addition, GyroUSBL can be deployed over the side of a vessel making temporary installation on vessels-of-opportunity simple and cost-effective.
Commenting on the deal, Mr. Qu YanDa, the General Manager of COFG said, “The Liwan 3-1 gas project is a challenging project requiring 260 kilometres of pipeline to be laid. In order to conduct the most precise survey with high accuracy results, we knew we needed the best available technology. Ranger 2’s deep water track record is impressive and the time and cost-savings GyroUSBL will bring to the project are expected to be significant. We now have the flexibility to move our Sonardyne systems from vessel-to-vessel without the need to perform a re-calibration.”
