可修复循环利用二氧化碳智能响应清洁压裂液构筑及成胶机制  

Construction and gelation mechanism of a reusable carbon dioxide smart response clean fracturing fluid system

作　　者：戴彩丽[1,2] 高明伟 赵明伟[1,2] 孙金声 孙宝江[1,2] 侯健[1,2] 余维初[3] DAI Caili;GAO Mingwei;ZHAO Mingwei;SUN Jinsheng;SUN Baojiang;HOU Jian;YU Weichu(Shandong Key Laboratory of Oilfield Chemistry(China University of Petroleum(East China)),Qingdao 266580,China;Key Laboratory of Unconventional Oil&Gas Development(China University of Petroleum(East China)),Ministry of Education,Qingdao 266580,China;College of Chemistry&Environmental Engineering,Yangtze University,Jingzhou 434023,China)

机构地区：[1]山东省油田化学重点实验室(中国石油大学(华东)),山东青岛266580 [2]非常规油气开发教育部重点实验室(中国石油大学(华东)),山东青岛266580 [3]长江大学化学与环境工程学院,湖北荆州434023

出　　处：《中国石油大学学报（自然科学版）》2020年第5期103-113,共11页Journal of China University of Petroleum(Edition of Natural Science)

基　　金：国家自然科学基金重点项目(51834010);长江学者奖励计划(T2014152);国家杰出青年科学基金项目(51425406)。

摘　　要：针对阳离子清洁压裂液吸附严重、成本高等问题,通过合成非离子CO2智能响应黏弹性表面活性剂(C18AKO),研制一种可修复循环利用CO2智能响应清洁压裂液体系(CO^2-VES,中高温体系0.7%C18AKO/1.0%PtsNa/0.12%CO2;高温体系1.30%C18AKO/1.75%PtsNa/0.23%CO2)。利用流变实验和电镜实验揭示CO^2-VES成胶机制。结果表明C18AKO遇CO2发生质子化(C18AKOH+),C18AKO、C18AKOH+、HCO3-和CO32-组装形成蠕虫胶束,蠕虫胶束相互缠绕形成三维空间网状结构,从而宏观上具有优异的黏弹性;该体系有良好的减阻性(减阻率大于76%)、耐温性(温度高于120℃)、界面活性(界面张力为10-2 mN/m数量级)、耐剪切性、防膨性,储层伤害性低(岩心伤害率小于10%),遇油破胶无残渣;CO^2-VES具有良好的修复循环利用性,反排液补充少量药剂通入CO2即可修复,经3次循环修复,其耐温性、减阻性、储层伤害性满足施工需求。Considering the problems of large amount of adsorption in reservoir and high cost,one nonionic CO^2-smart responsive viscoelastic surfactant(C18AKO)was synthesized.The CO^2-smart responsive clean fracturing fluid system that can be repaired and recycled was developed(CO^2-VES,medium-high temperature system 0.7%C18AKO/1.0%PtsNa/0.12%CO2,high temperature system 1.3%C18AKO/1.75%PtsNa/0.23%CO2).The gelation mechanism of CO^2-VES system was studied by rheological tests and environmental scanning electron microscope tests.The results show that the protonated structure(C18AKOH+)of C18AKO is formed after bubbling of CO2.C18AKO,C18AKOH+,HCO3-and CO32-are self-assembled to form wormlike micelles.Wormlike micelles intertwine to form a three-dimensional space network to increase the viscoelasticity at the macro level.The CO^2-VES fluid has good drag reduction performance(>76%),temperature resistance(>120℃),high interfacial activity(10-2 mN/m order of magnitude),good shear resistance,low reservoir damage properties(<10%)and automatic gel breaking without residue in contact with crude oil.The CO^2-VES also presents good repairing and recycling performance.After adding a small amount of reagent,the fracturing flowback fluid can be recycled by bubbling CO2.The temperature resistance,drag reduction performance and reservoir damage properties of CO^2-VES can meet the requests of fracturing operation after three cycles of restoration.

关 键 词：清洁压裂液 CO2智能响应 蠕虫胶束 循环利用 成胶机制 

分 类 号：TE39[石油与天然气工程—油气田开发工程]