Induced-seismicity geomechanics for controlled CO2 storage in the North Sea (IGCCS)

The aim of the current study, IGCCS (2017–2020), is to evaluate feasibility micro-seismic (MS) monitoring CO2 injection into representative storage candidates in North Sea, based on broad and quantitative characterization relevant subsurface behavior with respect geology, geomechanics seismicity. For this purpose, we first group potential sites Sea three different depths. Then, advanced triaxial rock mechanical tests are performed together acoustic emission (AE) acquisition under loading for formations each depth group, covering shale, mudstone sandstone cores. Our work focuses particularly quantifying effects injected fluid type temperature associated MS response sediments. experiment results show that may behave differently responses injection. Particularly, occurrence detectable events expected increase depth, as combined stiffness contrast between host increasing. In addition, lithology plays an important role terms response, i.e. high AE event rate observed sandstones, while aseismicity shale mudstone. test then scaled up applied coupled flow-geomechanics simulations a synthetic field-scale data study understand micro-seismicity at fracture, reservoir regional scales. numerical simulation scCO2 scenario shows quite stress-strain changes compared brine injection, resulting mainly from thermally-induced behavior. Furthermore, via so-called Cohesion Zone Modeling (CZM) approach strong improve our understanding multiphase-flow-driven fracture propagation. focused slow-earthquake scenario, also suggests sensors sensitivity low frequency might be necessary better signal detection during This manuscript covers main findings insights obtained whole IGCCS, refers publications more details.