Removal, movement and substitution of fluids with different densities affect the mass distribution within the subsurface. That explains why measuring changes in gravity provides a picture of the dynamical behavior of the subsurface.
OCTIO Environmental provides a unique surveying technology that gives 4D gravity measurements at the seafloor with an accuracy orders of magnitude better than what can be obtained by ship or airborne gravity measurements.
Applications of 4D gravity are e.g. within enhanced geothermal systems or groundwater reservoir management and provide data for:
- Mapping fluid movements and eventual compartmentalization
- Quantifying mass changes in the subsurface
- Mapping reservoir properties far away from wells (e.g. permeability)
Gravity monitoring yields a very specific set of data: gravity changes at selected positions on the seafloor. Forward-modelling changes in gravity is an unambiguous and straight-forward procedure, which involves summing Newton’s law on the volume elements in the reservoir model. In other words: gravity is easy to introduce in any model updating workflow.