DES+CTAB复配驱油剂体系提高低渗致密砂岩油藏采收率机理  

Mechanism of DES+CTAB composite oil displacement agent system to improve oil recovery of low-permeability tight sandstone reservoirs

作　　者：白佳佳 司双虎 陶磊[1] 王国庆 王龙龙 史文洋 张娜 朱庆杰[1] BAI Jiajia;SIShuanghu;TAO Lei;WANG Guoqing;WANG Longong;SHI Wenyang;ZHANG Na;ZHU Qingjie(School of Petroleum and Natural Gas Engineering,Changzhou University,Changzhou 213164,Jiangsu,China;Shaanxi Key Laboratory of Advanced Stimulation Technology for Oil&Gas Reservoirs,Xi’an Shiyou University,Xi’an 710065,China;School of Petrochemical Engineering,Changzhou University,Changzhou 213164,Jiangsu,China)

机构地区：[1]常州大学石油与天然气工程学院,江苏常州213164 [2]陕西省油气田特种增产技术重点实验室(西安石油大学),西安710065 [3]常州大学石油化工学院,江苏常州213164

出　　处：《岩性油气藏》2024年第1期169-177,共9页Lithologic Reservoirs

基　　金：陕西省油气田特种增产技术重点实验室开放基金项目“页岩渗吸压裂液对甲烷多尺度输运的增益机理研究”(编号:KFJJ-TZ-2022-3)资助。

摘　　要：针对低渗致密油藏注水困难、采收率低等问题,利用尿素基深共晶溶剂(DES)与十六烷基三甲基溴化铵(CTAB)复配的驱油剂体系,对驱油剂在低渗致密油藏中的降压增注和提高采收率机理进行了研究。研究结果表明:①驱油剂体系可以将油水界面张力降低至10^(-3)mN/m以下,大大提高了洗油效率;②驱油剂体系可有效抑制黏土矿物水化,避免了低渗致密砂岩中黏土矿物水化膨胀带来的流体敏感性损害;③驱油剂体系可对砂岩表面进行界面修饰,驱油剂溶液浸泡后样品的油相接触角由25.8°增加至61.4°,亲水性增强,亲油性减弱,有助于吸附在岩石孔隙壁面的油膜脱落;④超前注入驱油剂的注入压力降低率平均为79.64%,采收率平均为50.96%,远大于常规水驱(一次注水→注驱油剂驱→二次注水)的采收率。Aiming at the problems of difficult water injection and low recovery in low-permeability tight reservoirs,an oil displacement agent composed of urea-based deep eutectic solvent(DES)and cetyltrimethylammonium bromide(CTAB)was developed to study the mechanism of reducing pressure and increasing injection and impro-ving recovery in low-permeability tight sandstone reservoirs.The results show that:(1)The oil displacement agent system can reduce the oil-water interfacial tension to below 10^(-3) mN/m,which can greatly improve the oil washing efficiency.(2)The developed oil displacement agent has good clay mineral hydration inhibition,effec‐tively avoiding the fluid sensitivity damage caused by the hydration expansion of clay minerals in low permeability tight sandstone.(3)The oil displacement agent system can modify the interface of sandstone surface.The oil phase contact angle of the samples after soaked by the oil displacement agent system increases from 25.8°to 61.4°,the hydrophilicity increases and the lipophilicity decreases,which contributes to the shedding of the oil film adsorbed on the rock surface.(4)The average reduction rate of injection pressure of advanced injection oil dis‐placement agent is 79.64%,and the average recovery rate is 50.96%,which is much higher than the recovery rate of conventional water flooding(primary water injection→oil displacement agent injection→secondary water injection).

关 键 词：低渗致密砂岩油藏 尿素基深共晶溶剂(DES) 十六烷基三甲基溴化铵(CTAB) 水驱 黏土矿物水化膨胀 表面活性剂 提高采收率 

分 类 号：TE357[石油与天然气工程—油气田开发工程] P618.13[天文地球—矿床学]