Water availability for injection into oil reservoirs is an effective factor for superiority of water injection project. One of the parameters that cause undesirable effects on reservoir rock injectivity is clay minerals. The different structures of clay minerals will result in undesirable effects on rock permeability. Clay minerals enter into the pores and throats by injected water or they are a part of the structure of the reservoir rocks. Clay swelling from the viewpoint of the clay minerals type and structure can reduce the permeability of reservoir rock. In this study after the effects of clay minerals and their performance mechanisms, some of the rock samples were chosen from one of the field in south of Iran that is injecting water in aquifer.
Then it has been tried with XRD examination to specify the clay minerals type, and to estimate the percentage of each type; however permeability reduction was estimated for each one of core samples in core flooding experiments by injecting distilled water and formation water to the sample and creation of clay swelling. Also results comparison could show their performance and effect in the water injection process to estimate permeability reduction.