Multiscale characterisation of chimneys/pipes: Fluid escape structures within sedimentary basins

Evaluation of seismic reflection data has identified the presence fluid escape structures cross-cutting overburden stratigraphy within sedimentary basins globally. Seismically-imaged chimneys/pipes are considered to be possible pathways for flow, which may hydraulically connect deeper strata seabed. The properties migration through must constrained enable secure, long-term subsurface carbon dioxide (CO2) storage. We have investigated a site natural active in North Sea, Scanner pockmark complex, determine physical characteristics focused conduits, and how they control flow. Here we show that multi-scale, multi-disciplinary experimental approach is required complete characterisation structures. Geophysical techniques necessary resolve fracture geometry structure (e.g., multi-frequency seismics) parameters sediments controlled source electromagnetics) across wide range length scales (m km). At smaller (mm cm) scales, sediment cores were sampled directly their chemical assessed using laboratory-based methods. Numerical modelling approaches bridge resolution gap, though validity dependent on calibration constraint from field laboratory data. Further, time-lapse acoustic methods capable resolving temporal changes key determining flux. Future optimisation experiment resource use facilitated by installation permanent seabed infrastructure, replacement manual processing with automated workflows. This study can used inform measurement, monitoring verification workflows will assist policymaking, regulation, best practice CO2 storage operations.