沥青质模型油/MD膜驱剂溶液的ζ电势

Zeta Potential between Asphaltene Model Oil and Aqueous Solution of Molecular Deposition Filming Flooding (MDFF) Agent

从分子沉积(MD)膜驱剂与原油活性组分沥青质模型油的ζ电势出发,考察了水相pH、MD膜驱剂质量浓度、盐浓度、沥青质质量浓度、芳香度等对水包模型油乳状液的ζ电势的影响,并进一步探讨了水包油乳状液的稳定性。结果表明,模型油/MD膜驱剂溶液与模型油/水的ζ电势均随pH增加而降低,等电点由2 8变为3 1;模型油/MD膜驱剂溶液的ζ电势随MD膜驱剂质量浓度的增加而增加,MD膜驱剂具有压缩双电层的作用;盐浓度越大,模型油/MD膜驱剂溶液与模型油/水的ζ电势越高;随沥青质质量浓度的增加,ζ电势均有所降低,但质量浓度达到400mg/L后,ζ电势增加;随对二甲苯体积分数增加,模型油/MD膜驱剂溶液与模型油/水的ζ电势均有增大趋势;从总体看,MD膜驱剂的加入能降低沥青质模型油在水中的分散稳定性。

The oil-water zeta potentials of crude oil active components,asphaltene,from Liaohe Shuguang oilfields were investigated.The water phases include molecular deposition filming flooding (MDFF) agent aqueous solution and deionized water.The influences of pH value,MDFF agent mass concentration,salinity,asphaltene mass concentration and aromaticity on zeta potential were discussed.The oil-water zeta potentials of both model oil/deionized water and model oil/ MDFF agent aqueous solution decrease with increasing pH value,and the isoelectic point changes from 2 .8 to 3 .1.The zeta potential increases when MDFF agent mass concentration and salinity rise,showing that the cations from MDFF agent cause contraction of the electric double layer in aqueous solution.The oil-water zeta potential decreases at first with increasing asphaltene mass concentration,but it increases when asphaltene mass concentration is higher than 400 mg/L.The oil-water zeta potential increases if the volumetric concentration of p -xylene rises.The above results all reveal that the oil-water zeta potential of model oil/MDFF agent aqueous solution is higher than that of model oil/deionized water.Certainly,MDFF agent is contributive to the destabilization of oil-in-water emulsion.