Computation of vertical fluid mobility of CO_{2}, methane, hydrogen and hydrocarbons through sandstones and carbonates

Abstract

Over the last decade, there has been an irreversible shift from hydrocarbon exploration towards carbon storage, low-carbon energy generation and hydrogen exploration. Whilst basin modelling techniques may be used to predict the migration of hydrocarbons through sedimentary basins on geological timescales, there remains little understanding of how fluids behave at the basin scale on present-day timescales. We apply the Darcy flow equation to present an algorithm to determine the basin-scale mobilities and maximum vertical velocity, v_{max}, of CO_{2}, methane, hydrogen and hydrocarbons with depth for sandstone and carbonate. v_{max} for CO_{2} and methane are on scales of m/year, whilst values for hydrocarbon fluids are an order of magnitude smaller than for other fluids. Our results indicate that the fluid mobility of subsurface CO_{2} may be sensitive to surface and near-surface temperature variations. v_{max} for hydrogen is approximately 2–10 times greater than hydrocarbon fluids, yielding important consequences for the future use of basin modelling software for determining hydrogen migration for exploration and storage.