Integrity of Faulted Traps for CO2 Storage

Evaluating the structural integrity of fault-bounded traps for CO2 storage requires a thorough assessment of the likely sealing or non-sealing behavior of faults, in particular, i) will the increase in pressure generated by CO2 injection (or by a CO2 column) trigger fault instability and reactivation, thus leading to loss of CO2 from the trap, and ii) will the fault act as a capillary barrier, thus permitting CO2 to accumulate, and if so what might the likely height of the trapped column be before the fault leaks? The structural integrity of fault-bounded CO2 traps can be evaluated using workflows and predictive algorithms originally developed for the prediction of capillary seal of hydrocarbon, using appropriate CO2 fluid densities. Three-dimensional faulted-framework models are an essential first step in assessing the integrity of a fault-bounded CO2 trap. Fault-plane diagrams are used to investigate the juxtaposition geometry of CO2 bearing reservoir/non-reservoir intervals at the fault plane. Predictive algorithms for fault-sealing, such as Shale Gouge Ratio, and for stress-driven leakage enable a better understanding of the possible fault behavior to be derived.