Removal of colloidal precipitation plugging with high-power ultrasound

Liyuan Mo; Wenhuizi Sun; Song Jiang; Xiangzhi Zhao; Hailing Ma; Bingzhi Liu; Li Feng

doi:10.1016/j.ultsonch.2020.105259

Removal of colloidal precipitation plugging with high-power ultrasound

Ultrason Sonochem. 2020 Dec:69:105259. doi: 10.1016/j.ultsonch.2020.105259. Epub 2020 Jul 15.

Authors

Liyuan Mo¹, Wenhuizi Sun², Song Jiang³, Xiangzhi Zhao⁴, Hailing Ma⁵, Bingzhi Liu⁶, Li Feng⁶

Affiliations

¹ School of Civil and Environmental Engineering, University of New South Wales, Sydney, NSW 2052, Australia.
² School of Medicine, Tongji University, Shanghai 200082, China.
³ School of Resources Engineering, Xi'an University of Architecture and Technology, Xi'an, Shaanxi, China.
⁴ key Laboratory Of Environmental Change And Natural Disaster, MOE, Beijing Normal University, Beijing 100000, China.
⁵ Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190, China. Electronic address: hailingma@yeah.net.
⁶ School of Civil and Transportation Engineering, Guangdong University of Technology, Guangzhou 510006, Guangdong, China.

PMID: 32738455
DOI: 10.1016/j.ultsonch.2020.105259

Abstract

Petroleum is a continuous and dynamically stable colloidal system. In the process of oil extraction, transportation, and post-treatment, the stability of the petroleum sol system is easily destroyed, resulting in asphaltenes precipitation that can make pore throat, oil wells, and pipelines blocked, thereby damaging the reservoir and reducing oil recovery. In this paper, removing near-well plugging caused by asphaltene deposition with high-power ultrasound is investigated. Six PZT transducers with different parameters were used to carry out the experimental study. Results show that ultrasonic frequency is one important factor for removing colloidal precipitation plugging in cores, it could not be too high nor too low. The optimum ultrasonic frequency is 25 kHz; Selecting transducers with a higher power is an effective way to improve the removal efficiency. The optimum ultrasonic power is 1000 W. With the increase of ultrasonic treatment time, the recovery rate reaches the maximum and tends to be stable. ultrasonic processing time should be controlled within 120 min. Besides, three methods - ultrasonic treatment alone, chemical injection alone, and ultrasound-chemical method - for removing colloidal precipitation plugging are compared. Results indicate that the ultrasound-assisted chemical method is better than chemical injection alone or ultrasonic treatment alone to remove colloidal sediment in the core. Finally, the mechanism of the ultrasonic deplugging technique is analyzed from three aspects: cavitation effect, the thermal effect, and mechanical vibration.

Keywords: Colloidal precipitation; Plugging; Ultrasound.