The new gWatch technology from ETV’s portfolio company Gravitude was successfully deployed for gravimetry surveys on the Aasta Hansteen and Ormen Lange fields in 2018.
License partner companies on the Aasta Hansteen field are Equinor (operator), Wintershall, OMV and ConocoPhillips. License partner companies at the Ormen Lange field are Norske Shell (operator), Petoro, Equinor, INEOS E&P Norge and ExxonMobil.
Gravitude’s technology allows measuring tiny changes in the gravitational field and deformations of the seabed in time lapses of years. Such measurements can be interpreted in terms of fluid flow and deformation in the reservoirs and allow oil companies to exploit their hydrocarbon reserves more efficiently.
There are typically three reservoir parameters that relate, directly or indirectly, to the observations: Aquifer strength from gravity measurements, pressure depletion and pore compressibility from subsidence. The aquifer strength is important for understanding material balance and the energy drivers in your reservoir. This has an impact on estimates of in-place volumes, remaining reserves, production profiles and the value of IOR/IGR measures. Subsidence, which is related to pressure depletion, can indicate sealing faults. For some depletion-drive fields, pore compressibility can be an important uncertainty parameter, and there is no other way of constraining this than measuring seafloor subsidence.