用于CCUS地质封存的CO_(2)响应型智能凝胶封窜体系  

CO_(2) Responsive Smart Gel Sealants for CCUS Geological Storage

作　　者：刘琦 赵莉 马忠诚[2] 刘子龙 彭勃[1] LIU Qi;ZHAO Li;MA Zhongcheng;LIU Zilong;PENG Bo(The Unconventional Petroleum Research Institute,China University of Petroleum-Beijing,Beijing Key Laboratory of Greenhouse Gas Storage and CO_(2)-EOR,Beijing 102249,P R of China;State Key Laboratory of Green Building Materials,China Building Materials Academy,Beijing 100024,P R of China;Beijing Key Laboratory of Optical Detection Technology for Oil and Gas,College of Science,China University of Petroleum-Beijing,Beijing 100024,P R of China)

机构地区：[1]中国石油大学(北京)非常规油气科学技术研究院,温室气体封存与石油开采利用北京市重点实验室,北京102249 [2]中国建筑材料科学研究总院,绿色建筑材料国家重点实验室,北京100024 [3]中国石油大学(北京)理学院,油气光学探测技术北京市重点实验室,北京102249

出　　处：《油田化学》2022年第4期623-629,共7页Oilfield Chemistry

基　　金：国家自然科学基金项目“CCUS地质封存中CO_(2)-咸水-地层岩-油井水泥相互作用机理的研究”(项目编号51604288);绿色建筑材料国家重点实验室开放基金项目“CO_(2)-EOR过程中的油井水泥侵蚀机理”(项目编号2019GBM10);中国石油大学(北京)科研基金项目“CCUS地质封存中固井水泥智能响应封窜体系协同调控机制研究”(项目编号ZX20200133)。

摘　　要：为了有效应对封存CO_(2)后可能会发生的泄漏或逃逸,制备了一种注入性优良、封堵效果良好的CO_(2)响应型凝胶,在酸性条件下发生溶胶-凝胶态转变,适用于CCUS地质封存条件以提高井筒完整性。研究了不同的支化聚乙烯亚胺用量(1.5%~3.5%)、κ-卡拉胶用量(0.4%~0.5%)下CO_(2)响应型智能凝胶体系的流变性能、微观结构与封堵性能。研究表明,对于响应前的聚合物体系,剪切黏度随着剪切速率的增加而下降,为假塑性流体,当剪切速率在100~1000 s^(-1)时,黏度为2~100 m Pa·s,表明响应前的聚合物体系具有良好的注入性。该聚合物体系遇到CO_(2)时会发生溶胶-凝胶态转变。响应前聚合物体系在剪切频率为0.01~10 Hz时,模量在10^(-5)~100 Pa范围内;而CO_(2)响应凝胶在剪切频率为0.01~10 Hz时,模量在80~4000 Pa范围内,通入CO_(2)气体后的体系模量大幅度提升。发生响应后,体系具有表面平整、孔径均匀的三维网络骨架结构,使得体系具有较高的强度。岩心驱替实验结果显示F凝胶封窜体系(κ-卡拉胶用量为0.5%,支化聚乙烯亚胺用量为3.5%)对CO_(2)气体的封堵率为79.7%,对后续注入水的封堵率为99.8%,具有良好的封窜性能。本文为未来CO_(2)响应型凝胶封窜剂在CCUS地质封存领域的应用提供了新的技术路线与理论依据。In order to effectively deal with the leakage or escape that may occur after CO_(2) storage,a CO_(2) responsive gel with excellent injectability and good sealing effect was prepared.The sol-gel state transition occurs under acidic conditions,which was suitable for CCUS geological storage conditions and could improve wellbore integrity.The rheological properties,microstructure and sealing performance of CO_(2) responsive gel with different amounts of branched polyethyleneimine (1.5%—3.5%) andκ-carrageenan(0.4%—0.5%)were studied.The study showed that the viscosity of the system before the response decreased with the increase of the shear rate,and the system was a pseudoplastic fluid.When the shear rate was 100—1000 s^(-1),the viscosity was2—100 mPa·s,indicating that the system had good injectability.The polymer system undergoed a sol-gel state transition when it encountered CO_(2).The modulus of the pre-response system was in the range of 10^(-5)—100 Pa when the shear frequency was 0.01—10Hz;while the modulus of the CO_(2) responsive gel was in the range of 80—4000 Pa when the shear frequency was 0.01—10 Hz.The modulus of the system after the introduction of CO_(2) was greatly improved.After the response,the system had a three-dimensional network skeleton structure with smooth surface and uniform pore size,so that the system had high strength.The results of the core flooding experiment showed that the plugging rate of the F system(the amount ofκ-carrageenan was 0.5%,the amount of branched polyethyleneimine was 3.5%)for CO_(2) gas was 79.7%and the plugging rate for the water phase was 99.8%,exhibiting good anti-gas channeling performance.This paper provided a new technical route and theoretical basis for the application of CO_(2) responsive gel channeling agent in the field of CCUS geological storage in the future.

关 键 词：CCUS 智能凝胶 CO_(2)响应 封窜体系 流变性能 

分 类 号：TE357.45[石油与天然气工程—油气田开发工程] TE39