The Importance of Rock Texture in Ultrasonic Well Treatment

Improving the performance and maximizing the productivity of oil wells through cost effective fashion has been received considerable attention in the current economic trends of the petroleum industry. The reduced productivity is sometimes occurred due to the local impairment of formation permeability around the wellbore. Ultrasonic treatment is known as a promising technique to restore the well productivity in a cost effective fashion. Although the potential of ultrasonic waves on flow through porous media and restoration of formation damage has been verified previously; ambiguities on the effectiveness of the treatment implies that the physics of ultrasonic interactions and the effect of reservoir variations is not well understood. This paper is focused on one of the most important reservoir property that affect the treatment results considerably: reservoir rock texture. In this study the effect of ultrasonic treatment on flow behavior and microscopic structure of the rock texture has been studied for Indiana limestone, Oolitic limestone, Grey Dolomite, Berea sandstone and Sister-gray Berea sandstone. The results showed the rock texture plays a critical role in the treatment efficiency. For instance it is found that ultrasonic waves considerably increase the permeability of Oolitic limestone, while Indiana limestone did not expect notable change.