부산대학교 도서관

Numerous types of formation damage can occur during hydrocarbon reservoir development. Case studies reveal that the most common cause of formation damage is the rock-fluid interaction that occurs when introduced fluids upset the equilibrium that exists between a formation's pore fluids and minerals such as clays, carbonates, and anhydrite. Clay minerals are particularly sensitive to changes in pore-fluid chemistry. Minerals may swell and disperse during injection of fresh water, whereas during stream injection they typically react to form smectites. Both effects reduce permeability. Clays also may adsorb surfactants or Na/sup +/ and reduce tertiary flooding efficiency. Finally, clays and other fines can be physically mobilized during production, plug pore throats, and reduce permeability. Combined laboratory core flooding and petrographic investigations of exploration and appraisal core are required to predict the damage that may occur during field development. Criteria should be established enabling drilling, completion, injection, and stimulation program design to minimize or avoid damage during field development. Successful predictions on this basis may have an immediate and beneficial impact, reducing development costs and improving recovery efficiency.