The phase inversion mechanism of the pH-sensitive reversible invert emulsion from w/o to o/w
Liu Fei,
Wang Yanling,
Li Xiaqing,
Zhang Zhaoxiang,
Dai Xiaodong,
Wang Xuewu,
Xin Yanping,
Liu Kun,
Gao Liang,
Du Dehui,
Xing Chunyu,
Jiang Hong,
Liu Zhihua
Affiliations
Liu Fei
School of Petroleum and Gas Engineering, Shengli College, China University of Petroleum, Dongying, Shandong 257061, P. R. China
Wang Yanling
School of Petroleum Engineering, China University of Petroleum (East China), Qingdao, Shandong 266580, P. R. China
Li Xiaqing
Formation Damage Institute, Petroleum Engineering Technology Research Institute of Shengli Oilfield Company, Sinopec, Dongying, Shandong 257000, P. R. China
Zhang Zhaoxiang
Shandong Key Laboratory of Heavy Oil Production Technology, Petroleum Engineering Technology Research Institute, Shengli Oilfield Company Postdoctoral Research Station, Sinopec, Dongying, Shandong 257000, P. R. China
Dai Xiaodong
School of Petroleum and Gas Engineering, Shengli College, China University of Petroleum, Dongying, Shandong 257061, P. R. China
Wang Xuewu
School of Petroleum and Gas Engineering, Shengli College, China University of Petroleum, Dongying, Shandong 257061, P. R. China
Xin Yanping
School of Petroleum and Gas Engineering, Shengli College, China University of Petroleum, Dongying, Shandong 257061, P. R. China
Liu Kun
School of Petroleum and Gas Engineering, Shengli College, China University of Petroleum, Dongying, Shandong 257061, P. R. China
Gao Liang
School of Petroleum and Gas Engineering, Shengli College, China University of Petroleum, Dongying, Shandong 257061, P. R. China
Du Dehui
School of Petroleum and Gas Engineering, Shengli College, China University of Petroleum, Dongying, Shandong 257061, P. R. China
Xing Chunyu
School of Petroleum and Gas Engineering, Shengli College, China University of Petroleum, Dongying, Shandong 257061, P. R. China
Jiang Hong
School of Petroleum and Gas Engineering, Shengli College, China University of Petroleum, Dongying, Shandong 257061, P. R. China
Liu Zhihua
School of Petroleum and Gas Engineering, Shengli College, China University of Petroleum, Dongying, Shandong 257061, P. R. China
Alteration in the environmental conditions will cause a reversed reaction between o/w emulsion and w/o emulsion that has similar advantages of different liquids form on the reversible invert emulsion. The reversible phase inversion of the emulsion has a benefit of dealing with drilling cutting, so the reversible invert emulsion also can be thought used as a drilling fluid. The phase inversion from w/o emulsion to o/w emulsion can be divided into three stages. They are w/o emulsion, w/o/w emulsion, and o/w emulsion. In the w/o emulsion stage, the structure appeared among water droplets when the percentage of the HCl solution (5%) was less than 0.375%. In the w/o/w emulsion stage, the structure among water droplets existed at the beginning of this stage; however, the internal phase and the external phase can interchange their positions during the process. In the third stage, the structures among droplets of the emulsion would be broken and the degree of the dispersion of the oil droplet in the emulsion would increase. The changes in the microstructure, conductivity, electrical stability, standing stability, and the viscosity of the emulsion, which have edified among droplets in the process from w/o emulsion to o/w emulsion, were studied. The result of the microstructure microscopic observation agrees with the result of the electrical stability and viscosity experiments. Moreover, the internal phase and the external phase can interchange positions during the process.
