纳米ZnO改性VES压裂液流变特性研究  

Rheological Characterization of Nano ZnO-modified VES Fracturing Fluid

作　　者：仝少凯 岳艳芳 贾栋尧 陈志畅 王治国[2] TONG Shao-kai;YUE Yan-fang;JIA Dong-yao;CHENZhi-chang;WANGZhi-guo(PetroChina Chuanqing Drilling&Exploration Engineering Co.,Ltd.Changqing Downhole Technology&Operation Co.,Xi’an Shannxi 710018,China;College of New Energy,Xi'an Shiyou University,Xi'an Shaanxi 710065,China)

机构地区：[1]中国石油集团川庆钻探工程有限公司长庆井下技术作业公司,陕西西安710018 [2]西安石油大学新能源学院,陕西西安710065

出　　处：《当代化工》2023年第12期2941-2945,2954,共6页Contemporary Chemical Industry

基　　金：川庆钻探公司科技攻关项目“高分辨率导电支撑剂电磁压裂监测技术研究与试验”(项目编号:CQ2022B-Z-164-4);陕西省自然科学基础研究计划资助项目(项目编号:2019JM-268)。

摘　　要：低渗透及非常规油气开采中,传统交联聚合物压裂液对地层伤害较高。黏弹性表面活性剂VES压裂液则具有使用浓度较低、良好的黏弹性等特点。但VES压裂液的耐温性差,在高温下黏度显著降低,导致携砂能力变差。而纳米颗粒的加入可以显著增加VES的微观结构强度,增加其黏弹性。采用质量分数0.7%的十八烷基三甲基氯化铵(OTAC)和质量分数0.14%的水杨酸钠(NaSal)搅拌制备VES压裂液,将质量分数0.1%纳米ZnO颗粒加入其中形成纳米改性VES压裂液。稳态剪切流变测试结果表明,该配方下流体呈现剪切稀释特性,在同样的注入条件下,松弛时间小,其携砂能力强。同时,动态黏弹性测试结果表明,该配方下流体的弹性储能模量均大于黏性损耗模量,弹性占主导地位。运用最小二乘法将稳态剪切流变数据进行拟合,得到Cross本构方程可以更加准确地描述纳米改性VES压裂液的流变特性。Conventional crosslinked polymer fracturing fluids in low permeability and unconventional oil and gas extraction have high formation damage.Viscoelastic surfactant(VES)fracturing fluids,on the other hand,are characterized by lower concentration and good viscoelasticity.However,the temperature resistance of VES fracturing fluid is poor,and the viscosity decreases significantly at high temperatures,resulting in poor sand-carrying capacity.And the addition of nanoparticles can significantly increase the microstructural strength of VES and increase its viscoelasticity.In this paper,mass fraction 0.7%of octadecyltrimethylammonium chloride(OTAC)and mass fraction 0.14%of sodium salicylate(NaSal)were used to prepareVES fracturing fluid by stirring,and 0.1%ZnO nanoparticles were added to form nano-modified VES fracturing fluid.The results of steady-state shear rheology tests showed that the fluid exhibited shear dilution characteristics under this formulation.Under the same injection conditions,the relaxation time wassmall and its sand-carrying capacity wasstrong.Meanwhile,the dynamic viscoelasticity test results showed that the elastic energy storage modulus of the fluid under this formulation wasgreater than the viscous loss modulus,and the elasticity wasdominant.The steady state shear rheology data were fitted using the least squares method to obtain the Cross eigenstructure equation,which couldmore accurately characterize the rheological properties of nano-modified VES fracturing fluid.

关 键 词：纳米改性 黏弹性表面活性剂 流变 

分 类 号：TE357[石油与天然气工程—油气田开发工程]