Emerging Geophysical Tools for Reservoir Monitoring

Geophysical monitoring tools are based on measurements of physical properties and their contrasts over the producing life of a reservoir. Each tool responds to contrasts in a physical property like electrical resistivity, magnetic susceptibility, density and elastic modulii. For reservoir monitoring a variety of seismic and non-seismic instruments are permanently installed along with other instruments in the total infrastructure. These measurements will image reservoir fluid distribution during the life of a field. Some tools are proven while many others are emerging. Electromagnetic or EM methods, on the other hand, rely on changes in electrical properties due to reservoir saturation changes as hydrocarbons are produced and water injected. Surface deformation caused due to pore pressure changes in reservoirs with production and injection activities can be continuously monitored using satellite radar interferometry (InSAR), ground-based GPS, and surface tilt meters.