Time-lapse crosswell seismic and VSP monitoring of injected CO2 in a brine aquifer

摘要: Seismic surveys successfully imaged a small scale CO2 injection (1,600 ton) conducted in brine aquifer of the Frio Formation near Houston, Texas. These time-lapse borehole seismic surveys, crosswell and vertical profile (VSP), were acquired to monitor distribution using two boreholes (the new well pre-existing used for monitoring) which are 30 m apart at depth 1,500 m. The survey provided high-resolution image between wells via tomographic imaging P-wave velocity decrease (up 500 m/s). simultaneously S-wave tomography showed little change velocity, as expected fluid substitution. A rock physics model was estimate saturations 10–20% from change. VSP resolved large (∼70%) reflection amplitude horizon. This induced allowed estimation extent beyond on three azimuths. result is compared with numerical modeling seismically modeled estimated survey.