The effect of injection well arrangement on CO₂ injection into carbonate petroleum reservoir

The injection of CO₂ into the reservoir, during long-term subsurface containment of CO₂, increases the pore pressure, as well as the adsorption induced strains. The associated decrease in permeability causes the transport of the injected CO₂ to decrease to a critical value, after which it becomes impossible to transport the injected carbon dioxide to regions of the reservoir far away from the injection well, regardless of its capacity. This problem initiated the need for multiple injection wells. The present investigation considers a dual porous carbonate reservoir. A new methodology is developed for reducing the pore pressure build-up and increasing the reservoir storage capacity by varying both the number and arrangement of the carbon dioxide injection wells. An equation-based finite element method is utilised for the numerical modelling of various carbon dioxide injection scenarios for Ghawar Arab-D carbonate reservoir. The obtained results demonstrated the significance of changing the number and arrangement of the injection wells and suggested the existence of an optimum arrangement.