Nearly every reservoir-level process generates and propagates outward a pattern of strain that can be detected using sensitive deformation-monitoring technologies. Microdeformation monitoring seeks to precisely detect and characterize strain patterns caused by fluid production and injection, thermal process such as steam flooding, cyclic steam stimulation (CSS), and steam-assisted gravity drainage (SAGD), as well as CO2 Sequestration (CCS). By solving a geophysical inverse problem, well-characterized strain measurements can be used to identify and illustrate reservoir-level changes on a wide variety of spatial and temporal scales. Bringing surface deformation measurements down to the reservoir level to obtain the fluid migration pathways, volumetric strain, pressure fronts, or thermal fronts allows operators and asset managers to improve their understanding of how different storage and recovery methods work in different types of reservoirs at significant cost savings compared to traditional monitoring technologies.
A variety of independent yet complimentary technologies currently exist that allow a complete and accurate characterization of ground deformation patterns required to geomechanically invert for reservoir-level processes. Examples of recent work from California's thermal enhanced oil recovery (EOR) environments using tiltmeters, GPS, and interferometric synthetic aperture radar (InSAR) are highlighted and discussed, showing how the microdeformation process has been employed to improve production surveillance and project operations.