A long-term seafloor deformation monitoring campaign at Ormen Lange gas field

Seafloor deformation monitoring is a new technology concept for offshore reservoir monitoring. Complementary to other areal monitoring techniques, it has the potential to cheaply and continuously monitor production induced changes in the reservoir and overburden. At Ormen Lange, Norway´s second largest gas field, a small trial network was deployed on the seafloor in 2007, followed by a full-field network in 2010. The network was operational for 5½ years before being retrieved in 2016. This article describes the technology, planning and execution of the survey at Ormen Lange, and findings from the data.