Challenging Project Completed in Alaska’s Cook Inlet

UTEC Survey, USA, has completed a major harsh-environment project in Alaska. The company was asked to provide a positioning solution for the installation of a monopod liquid natural gas platform and a 30-kilometre-long, 10-inch LNG pipeline for a major operation located in Alaska’s Cook Inlet. A total of 24 field employees were mobilised and engaged with CodaOctopus for use of the Echoscope technology to provide positioning and survey services for five vessels. 

The project was the first monopod installation in the Cook Inlet for 25 years and also the first time that four Echoscope systems operated simultaneously. The intended use of the Echoscope sonar was a final verification of the deployment position, but due to poor visibility caused by tidal changes, 6-7 knot currents and heavy silt, UTEC chose to use multiple Echoscopes in combination with measurements for completion of the installation.

Three Echoscopes 

The Echoscope provides a real-time 3D detailed, georeferenced image of moving and static subsea hardware and features – even in low to zero visibility conditions. Three Echoscopes were installed on the pipelay barge (one on the bow, one on the aft and one on the end of the stinger). This combination allowed monitoring of touchdown and pipe position in the stinger as well as identification of potential hazards on the route.

Utilising four Echoscopes simultaneously allowed the monopod to be seen as it was lowered to accurately position it onto a kingpile. By taking an innovative, solutions driven approach, UTEC and their client were able to see operations in real-time; rotate the viewing perspective and make measurements. Combining the measurements and on-screen images resulted in increased efficiency and accurate positioning of pipelines, mattresses and the monopod.

Image: Dataset showing the pipe being laid down.