Mobilizing subsea foundations

Mobile foundation technology could offer an economic solution to some stranded offshore hydrocarbon reserves. One of the challenges the industry faces is unlocking the huge hydrocarbon reserves offshore Australia, and elsewhere, that are currently unreachable. Australian research and development into mobile foundation technology is one piece of the jigsaw. Subsea developments involve a number of wells across a field connected by a network of pipelines, so-called infield flowlines. A variety of pipeline infrastructure supports the flowlines, such as pipeline end terminations (PLET), pipeline end manifolds (PLEM) and in-line tee structures (ILT). This seabed infrastructure is typically supported on shallow mat-type foundations, so-called mudmats, that are ideally small enough to be installed by the same vessel that lays the subsea pipelines, which transport oil or gas from wells to processing facilities. Offshore pipelines undergo cycles of thermal expansion and contraction over the lifetime of a field through cycles of start-up and shutdown.