Pressure Space: The Key Subsurface Commodity for CCS

Le résumé fourni par la source

Subsurface injection of CO2 into saline aquifers requires displacement of native reservoir brines at rates similar to that of injection. Common practice assumes that most injection sites behave as though they have open boundaries, such that capacity for brine displacement is effectively unlimited. Historically, isolated injection projects has generally validated this assumption but it is likely to break down with multiple, closely spaced projects, such as those now in development on the US Gulf Coast. Pressure interference is likely to create effectively closed boundaries and therefore pressure-limited storage capacity, which may be considerably less than indicated by static capacity calculations that assume open boundaries. Likewise, basin-scale capacity is ultimately the sum of individual projects and basins have edges that often create closed boundaries. We develop the algorithms to estimate basin-scale, pressure-limited capacity and apply them to the example of the Texas coastal Miocene, resulting in ~90% reduction in capacity over previous static estimates (barring water production). CCS is still unlikely to be capacity-limited, but effective regulation, land valuation and project development will require consideration of all projects in pressure communication. We conclude that pressure space, not pore space, is the key subsurface commodity.

Ce résumé expose les affirmations des auteurs. BNTIC ne l’interprète pas comme une validation indépendante des résultats.