SEISMIC FRACTURE CHARACTERIZATION USING AN ELASTIC DOUBLE BEAM METHOD AND SHEAR WAVE SPLITTING FOR SITE SELECTION IN GEOLOGICAL CARBON STORAGE

Geological carbon storage (GCS) can play an important role in mitigating global climate change. Detecting the presence of fractures in and around the storage reservoir is crucial in selecting GCS sites and assessing potential supercritical CO2 leakage. It is very hard to identify these fractures in conventional 3D seismic images because fractures are associated with weak seismic-wave scattering. We have developed a new vector/elastic double-beam method to characterize subsurface fracture networks. It can deliver fracture orientation, density, and mechanical compliance. Such information is useful in GCS site selection and can be used to infer stress state and assess potential seismic hazards caused by fluid injection and migration. Results from both synthetic seismic datasets and field datasets demonstrate that our new method is effective in characterizing fractures. To validate the method for practical applications, we compare the results of the elastic double-beam method with those of shear-wave splitting analysis using a field 9-component seismic dataset acquired in Montana.