大庆扶余油层静态渗吸采油效果及其影响因素

Effect of Static Imbibition Recovery and Its Influencing Factors in Fuyu Reservoir of Daqing Oilfield

王庆国 王婷婷 陈 阳 张宝岩 韩大伟 卢祥国

WANG Qingguo WANG Tingting CHEN Yang ZHANG Baoyan HAN Dawei LU Xiangguo

大庆外围致密油藏原油储量十分丰富， 但由于缺乏有效开发技术手段， 储量动用程度较低。渗吸采油是 （弱）亲水致密油藏高效开发的重要技术措施之一。为获得弱亲水致密油藏的高效开采技术， 本文分别考察了 阴/非离子型表面活性剂 “HLX”、“SYH （石油磺酸盐） +Na2CO3”、 阳离子型表面活性剂 “YANG” 和非离子表面活性 剂 “DCY” 渗吸液对渗透率Kg 2.0×10-3 μm2左右的弱亲水岩心的渗吸采油效果。研究表明， 渗吸采收率与渗吸速 度不仅受油水界面张力影响， 还受岩石孔隙润湿性影响。渗吸采油物理模拟实验结果表明，“YANG” 和 “DCY” 渗吸液兼顾了改变岩石孔隙表面润湿性和降低界面张力两方面功效， 因而渗吸采油效果较好， 采收率增幅较 大。考虑到 “YANG” 为阳离子型表面活性剂， 在储层岩石孔隙内吸附量较大， 渗吸采油效果会因此有所降低， 故 推荐使用 “DCY” 渗吸液体系， 质量分数以0.3%为宜。图10表4参12

The crude oil reserves of tight reservoir in peripheral area of Daqing are very rich. However， the development degree of reserve is low due to the lack of effective technologies. The imbibition recovery is one of the important technical measures which are used to develop efficiently the hydrophilic tight reservoir. In order to devlop the efficence exploitation technology of the weak oil-wet tight reservoir，the imbibition recovery effects of anionic/nonionic surfactants“HLX”，“SYH（petroleum sulfonate）+ Na2 CO3 ”，cationic surfactants“YANG”and nonionic surfactants“DCY”on the weakly hydrophilic cores with the permeability of about 2×10-3μm2 were investigated. The results showed that the recovery efficiency and imbibiton rate of imbibition system were influenced not only by oil-water interfacial tension but also by the wettability of the rock porous surface. The results of the physical simulation experiment of imbibition recovery showed that” YANG”and ” DCY”imbibition system could not only change the wettability of rock pore surface but also reduce oil-water interfacial tension， hence， their ability to enchance the effect of imbibition recovery was better and the enhancement of oil recovery was greater. However， as a cationic surfactant， "YANG" had a larger adsorption capacity in reservoir rock pore， which would lead to a lower enhancement of imbibition oil recovery. As a result， It was recommended to use a "DCY" imbibition system with mass fraction of 0.3%.