Near Wellbore Asphaltene Damage Stimulation Using Ultrasonic Technology

Near wellbore asphaltene deposition is one of the major problems in oil and gas industry. Deposition can significantly affected the oil flow towards the wellbore thus decreasing the recovery. There are several factors contributing to asphaltene deposition such as changes in crude oil composition, and changes in reservoir pressure and temperature. In this project, the effectiveness of ultrasonic technology in removing near wellbore asphaltene deposition is studied. It is believed that ultrasonic cleaning is powerful enough to remove tough contaminants (asphaltene), yet gentle enough not to damage the formation. A series of experiments using sandstone core samples and Malaysian light oil is designed and carried out to examine the effect of ultrasonic cleaning on asphaltene deposition. Different stimulation times and temperatures were used in the ultrasonic stimulation in order to investigate the effect of both parameters versus formation permeability improvement. Before that, Dynamic flooding experiment has been introduced to create asphaltene deposition inside the core samples. Asphaltene deposition resulted in reduction of porosity and permeability of core samples, and low asphaltene content in exiting crude oil during CO2 injection. Results show that by increasing the stimulation time and temperature, the permeability also will increase. It is confirmed that ultrasonic cleaning technology is able to disrupt the deposition and dispersed the asphaltene. Besides, the ability of ultrasound to be applied selectively and in a controlled manner gives great advantages to well operators.