Alleviation of pore pressure buildup and ground uplift during carbon dioxide injection into Ghawar Arab-D carbonate naturally fractured reservoir

Abstract

The depleted petroleum reservoirs are considered geologically attractive sites for carbon dioxide sequestration. The process of oil recovery is commonly improved by water injection. By the time when the reservoir is shut off, it is nearly filled with water, while the rock matrix is almost depleted of oil. The injection of carbon dioxide into petroleum reservoirs with high water saturation tends to increase the reservoir’s pressure and may result in ground uplift. In the present study, a production well is introduced into the reservoir along with the carbon dioxide injection well to reduce the pore pressure buildup during injection. A fully coupled geomechanical analysis is performed to determine the safe injection parameters for the selected sequestration site of Ghawar field and to analyze the effect of adding a production well on the pore pressure buildup, ground uplift, and reservoir stability. Two scenarios are considered in this study. In the first scenario, CO2 is injected via a central injection well. In the second scenario, a water production well is added at a distance away from the central injection well. The pore pressure and the ensuing ground uplift are calculated for different injection pressures and durations. The effect of the added production well location on the buildup of the pore pressure and subsequently on the stability of the reservoir has been analyzed, and some benchmark results are presented.