Xiong Ruiying, Guo Jixiang, Kiyingi Wyclif, Feng Hengshui, Sun Tongcheng, Yang Xiaohui, Li Qing
Unconventional Petroleum Research Institute, China University of Petroleum, Beijing 102249, China.
Northwest Oilfield Branch, Sinopec Group, Xinjiang 830011, China.
ACS Omega. 2020 Aug 19;5(34):21420-21427. doi: 10.1021/acsomega.0c01779. eCollection 2020 Sep 1.
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.
胶体不稳定指数（CII）作为一种经典方法，已被广泛用于测试沥青质的稳定性。在本研究中，采用CII方法对五个油样进行了测试；所得结果与实际现场结果有很大差异。在我们的研究中，我们将Turbiscan LAB稳定性分析仪与饱和烃、芳烃、树脂和沥青质（SARA）分析相结合，通过庚烷滴定进一步研究沥青质的稳定性。结果表明，在沥青质失稳之前存在一个阈值体积比。原油的稳定性与沥青质的饱和溶解度有关。通过测试原油当前状态下的CII值和其饱和状态下溶解沥青质的CII值，我们能够提出一种判断原油稳定性的新方法。
