An Experimental Study of the Effect of the Water Injection Process on Rock Structure and Permeability Reduction

The estimation and assessment of formation damage on reservoir core samples is an important measurement. Laboratory tests were set up to investigate the effects of injection pressure, flow rate, and induced fracture on the rock sample with respect to formation damage. In this research, selected rock samples from one of Iranian giant oil fields were used as the laboratory physical model. Permeability reduction was observed for unfractured samples: however, it was more interesting that no injection pressure buildup was detected in fractured samples. It appears that fractures in sandstones, especially with weak cementation, can play the role of an agent for particle movement and cause damage far from injection wells over a long period of time.