For carbon capture and storage projects such as the Northern Light, the pipelines will often need to be installed across the Norwegian continental slope. This may require a substantial amount of pre-lay rock berms for support. The conventional geotechnical design involves manually checking of the slope stability in a series of 2D cross sections and then add counter fills when needed. This is a time-consuming iterative process for determining the optimal counter fill design and a high number of engineering hours is required.
A digital solution where the counter fill design is automated is developed in an app called Au2Rox. The input is the seabed topography, soil strength and location of rock berms. The software typically completes the design automatically in less than 1 min per berm. Another benefit of the automated design is the possibility to optimize the counter fill. On a case study, one berm volume was reduced from 2000m3 to 1170m3 which is equal to 11 tons CO2 saved for one berm.
The automated design of the counter fills enables several routing options to be checked for rock tonnages for selection of the route with lowest rock tonnages. Further, the instant digital design, enables rock installation sooner in the project; hence, allowing for pipeline installation months earlier than for a conventional project.