Hydrodynamic and geomechanical evaluations of underground hydrogen (H 2 ) and carbon dioxide (CO 2 ) storage are performed using a full-field history-matched model of a depleted gas reservoir located in the Southern North Sea (SNS) of the UK Continental Shelf (UKCS). H 2 injection and production (optimised rates 120 MMscf/d and 78 MMscf/d, respectively) in cyclic mode for a period of 9 years following the initial 2-year CO 2 cushion gas injection period resulted in 82 % H 2 recovery in the cyclic scheme. The geomechanical investigations revealed minor vertical displacement (uplift) less than 0.35 ft, low slip tendencies (<0.20), and faults requiring an additional pressure of 1200 to 2450 psi to trigger fault failure, all safely below the thresholds. These comparative novel findings confirm that this UKCS–SNS reservoir can be geomechanically safely repurposed for CO 2 and H 2 storage within the same geological formation, whether deployed separately or sequentially (cyclically). • Geomechanical feasibility of repurposing UKCS SNS depleted gas field for H 2 /CO 2 . • Full-field compositional simulations compare coupled H 2 /CO 2 hydrodynamics and geomechanics. • ∼80 % H 2 recovery demonstrated under peak-shaving cyclic injection–production. • CO 2 storage with cyclic H 2 improves decarbonization value and project ROI. • Geomechanical integrity supports standalone or co-/sequential CO 2 and H 2 storage.
Jadhawar et al. (Tue,) studied this question.