Paper: Sandstone Diagenesis As A Factor In Stimulation Design

The presence of clay minerals within a sandstone reservoir is a major factor in the sensitivity of that reservoir to treatment fluids. The exact type of fluid sensitivity (acid, fresh water, etc.) depends on the exact type of clay mineral present in the reservoir. In recent years, X-ray diffraction analysis has been extensively used to determine the type and amount of clay minerals present in reservoir sandstones. There is a problem in designing a well stimulation on the basis of X-ray diffraction analysis or any other type of analysis which evaluates the properties of the reservoir sandstone in bulk. The problem is that clay minerals may be of two distinct origins which produce different distributions of clay minerals within the reservoir and different degrees of exposure to completion and stimulation fluids.