Document Type: Article
Sharif University of Technology, Tehran, Iran
Chemical and Petroleum Engineering Department, Sharif University of Technology, Tehran, Iran
chemical and petroleum engineering department, sharif university of technology, Tehran, Iran
In this study, application of ultrasound wave for permeability enhancement of reservoir rocks was experimentally examined. In this regards, a specific core holder apparatus was designed with the ability of in-situ exposure of ultrasound to the plug at high-pressure condition, which is a better representative of ultrasound application in real wellbores. The effect of ultrasound power and exposure time as well as probe-plug distance on permeability stimulation was evaluated. The results showed that ultrasound could stimulate the permeability of asphaltene-damaged rocks, in which its efficiency is significant in sandstone rock. Analysis of asphaltene content in the output fluid showed that, as the result of ultrasound exposure, 84% of deposited asphaltenes in the sandstone plug was removed, which is corresponding to 67% of permeability recovery. It was also found that the stimulated permeability increases with increasing exposure time and power while decreases with increasing probe-plug distance, however an optimum value for exposure time and power, after which the permeability recovery is not significantly enhanced, was observed. Analysis of experiments also showed that probe-plug distance has the most prominent effect on recovery of damaged permeability in comparison to ultrasound time and power.