A new study in Communications Engineering shows that helically bonded fiber sensors can measure poroelastic strain in rock cores during CO2 injection, and that this strain signal appears ahead of the CO2 plume front. The strain follows pressure disturbances propagating through the brine phase, not the CO2 saturation itself. This means distributed strain sensing could act as an early warning for pressure changes in geologic carbon storage sites, before CO2 reaches a given location. The experiment used laboratory core flooding with supercritical CO2, combining time-lapse X-ray CT imaging with fiber-based circumferential strain measurements. The strain data, when paired with saturation imaging and sparse pressure gauges, gives a more complete picture of the subsurface response. This matters for operational monitoring of CCS projects, especially in tectonically active regions where pressure and deformation need to be tracked carefully.
