稠油重组分对砂岩储层润湿性变化的影响

Effect of Heavy Constituent in Crude Oil on Wettability Change of Sandstone

程亮 施雷庭 叶仲斌 王娟 杨超 钟金银

CHENG Liang SHI Leiting YE Zhongbin WANG Juan YANG Chao ZHONG Jinying

为揭示稠油重组分性质与砂岩岩石润湿性变化之间的关系，用X射线光电子能谱和Zeta 电位测定仪考察了不同产地稠油沥青质、胶质表面官能团及其Zeta 电位，采用改进的岩心润湿定量测定方法研究了稠油重质组分（沥青质、胶质）Zeta 电位与砂岩岩样润湿指数间的关系，分析了盐水中阴阳离子对吸附沥青质岩心润湿性的影响。结果表明，辽河沥青质因含较多的羧酸和钙元素（羧酸钙）而带负电荷，塔河、孤岛、克拉玛依和垦东沥青质及渤海、辽河和克拉玛依胶质带正电荷；沥青质、胶质正电性越强，岩石润湿指数变化程度越大，润湿指数（WR）与沥青质、胶质Zeta 电位（ζ）间存在对数关系：ζ=-2.9508 ln（WR）；盐水中的无机阳离子化合价价数越高，吸附沥青质岩心的润湿指数越小，而无机阴离子对润湿性变化影响甚微。通过润湿指数与沥青质、胶质Zeta 电位间的定量公式可推算砂岩岩层润湿性变化趋势，通过调整注入水组成可控制沥青质沉积造成的润湿性变化程度。图11 表6 参19

In order to reveal the relationship between heavy oil property and sandstone wettability，the functional groups and Zeta potential of asphaltenes and resins from different areas were investigated by X-ray photoelectron spectroscopy and Zeta potential analyzer. The relationship between Zeta potential of heavy constituents in viscous crude oil（asphaltene or resin）and sandstone wettability index was studied by the improved core wettability detection method and the effect of cations and anions in brine on core wettability where asphaltene had been adsorbed was analyzed. The results showed that the asphaltene of Liaohe oilfield carried negative charge because of a high mass fraction of carboxylic acid and carboxylic acid calcium，while asphaltene of Tahe，Gudao， Karamay and Kendong oilfield carried positive charge. The more positive charge of asphaltene and resin，the greater change of wettability index was. As a result，wettability index（WR）and Zeta potential（ζ）of asphaltene and resin constituted logarithmic function relation: ζ=-2.9508 ln（WR）. Once the inorganic cation had a higher valence，there was a lower wettability index，while there was a slight impact of inorganic anion on wettability. The wettability change trend of sandstone rock could be estimated by the quantitative formula between wettability index and Zeta potential of asphaltene or resin，and the change degree of wettability caused by asphaltene deposition could be controlled by adjusting the composition of injection water.

10.19346/j.cnki.1000-4092.2016.06.028