Method for Judging the Stability of Asphaltenes in Crude Oil

Ruiying Xiong; Jixiang Guo; Wyclif Kiyingi; Hengshui Feng; Tongcheng Sun; Xiaohui Yang; Qing Li

doi:10.1021/acsomega.0c01779

Method for Judging the Stability of Asphaltenes in Crude Oil

ACS Omega. 2020 Aug 19;5(34):21420-21427. doi: 10.1021/acsomega.0c01779. eCollection 2020 Sep 1.

Authors

Ruiying Xiong¹, Jixiang Guo¹, Wyclif Kiyingi¹, Hengshui Feng¹, Tongcheng Sun², Xiaohui Yang², Qing Li³

Affiliations

¹ Unconventional Petroleum Research Institute, China University of Petroleum, Beijing 102249, China.
² Northwest Oilfield Branch, Sinopec Group, Xinjiang 830011, China.
³ Jiangsu Oilfield Branch Production-2, Sinopec Group, Jiangsu 211600, China.

Abstract

The colloidal instability index (CII) has been widely used for testing the stability of asphaltenes as a classical method. In this study, five oil samples were tested by the CII method; the results obtained greatly differ from the real field results. In our investigation, we combined the Turbiscan LAB stability analyzer and saturate, aromatic, resin, and asphaltene (SARA) analysis to further investigate the asphaltene stability by heptane titration. The results revealed that there exists a threshold volume ratio before the asphaltenes destabilize. The stability of crude oil is related to the saturation solubility of asphaltenes. By testing the CII value of the crude oil in its current state and the CII value of the dissolved asphaltenes in its saturated state, we were able to propose a new way to judge the oil stability.