改性二氧化硅纳米颗粒提高二氧化碳泡沫稳定性的研究  

Enhancement of CO2 Foam Stability with Modified Silica Nanoparticles in High Salinity Brine

作　　者：张旋 张天赐 蒋平[1] 葛际江[1] 张贵才[1] ZHANG Xuan;ZHANG Tianci;JIANG Ping;GE Jijiang;ZHANG Guicai(College of Petroleum Engineering,China University of Petroleum,Qingdao 266580,China)

机构地区：[1]中国石油大学(华东)石油工程学院,青岛266580

出　　处：《高等学校化学学报》2020年第5期1076-1082,共7页Chemical Journal of Chinese Universities

基　　金：国家重点研发计划项目(批准号:2018YFA0702400);国家自然科学基金(批准号:51574266);中央高校基本科研业务费专项资金(批准号:17CX06012)资助.

摘　　要：通过纳米二氧化硅的硅烷化改性,使其在高矿化度盐水中可以稳定存在的前提下,研究了改性纳米颗粒与阳离子表面活性剂十二烷基三甲基氯化铵混合体系的溶液稳定性及协同稳定CO 2泡沫的效果.研究结果表明,无机盐离子对改性纳米颗粒与阳离子表面活性剂间的静电吸引力具有屏蔽作用,且矿化度越高,屏蔽效果越明显,从而混合溶液更易于在高盐水中稳定;纳米颗粒表面的活性剂吸附层受二者浓度的影响,进而影响了颗粒的亲/疏水性;当混合体系中的表面活性剂浓度低于临界胶束浓度(CMC)时,混合溶液与CO 2的界面张力高于单独活性剂溶液,而当活性剂浓度高于CMC时,对CO^2-溶液界面张力几乎无影响,最低界面张力可降至6 mN/m左右;改性纳米颗粒的加入可以进一步提高CO2体相泡沫半衰期一倍以上,但受二者浓度比例的影响;纳米颗粒的加入有效提高了多孔介质中泡沫的表观黏度,最大增幅由20 mPa·s增至55 mPa·s左右,泡沫黏度增加接近3倍,增强了CO2泡沫驱的封堵作用.The liquid phase stability and CO2 foam stability were studied with mixing cationic surfactant and modified nanoparticles(NPs) solutions. It was concluded that inorganic ions screened the electrostatic attraction force between the NPs and cationic surfactant. Moreover,the ratio of surfactant and NPs determined the solution stability in constant salinity brine. From the interfacial tension( IFT) measurement,when the surfactant concentration was higher than its critical micelle concentration,the IFT was similar before and after adding NPs and the lowest IFT was 6 mN/m,whereas it was not as the surfactant concentration was lower than CMC. The bulk foam stability results shown that the NPs enhanced the foam half-life with more than twice time. However,it depended on the concentration ratio. Furthermore,the apparent viscosity of foam stabilized with mixture was increased from 20 mPa·s to 55 m Pa·s,nearly triple higher than that with only surfactant in sand-pack with total injection velocity 2 mL/min and foam quality 70%. In summary,adding NPs to surfactant solution,the foam flooding would be more efficient at specified conditions.

关 键 词：改性纳米颗粒 表面活性剂 二氧化碳泡沫 泡沫稳定性 

分 类 号：O647.2[理学—物理化学]