Study of Geomechanical Effects in a Deep Aquifer CO2 Storage
Storage of CO2 has become an important topic in the past few years. This is because excessive CO2 in the atmosphere is considered as the main factor responsible for climate change and green house effect. The emission of CO2 gas is mainly caused by human activities from different sources such as electric power plant, petroleum refinery, transportation and natural gas consumption. Therefore, the increase of CO2 gas in the atmosphere needs be reduced. Currently, CO2 storage in deep saline aquifers is an attractive approach that is being studied extensively. Saline aquifers have large volumes that can handle a large amount of CO2 injection. Furthermore, CO2 can be easily dissolved in brine. However, the above storage may not be secure if the stress and deformation of the aquifer are not analyzed thoroughly.
The main focus of this work is using the coupled code between reservoir flow and geomechanics to study when and where gas leakages may occur through the caprock under different scenarios such as injection methods and orientation of injecting wells. A modified Barton-Bandis model is implemented to compute permeability of fractures that occur in the caprock when its tensile strength is overcome by applied stresses, which then allows free CO2 to escape from the aquifer. Examples are presented to illustrate the workflow in geomechanical risk mitigation of CO2 storage.
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© Copyright 2010. American Rock Mechanics Association
Presented at the 44th U.S. Rock Mechanics Symposium and 5th US-Canada Rock Mechanics Symposium, 27-30 June 2010, Salt Lake City, Utah, USA