支撑剂在纳米改性VES压裂液中的运移特性  

Transport Characteristics of Proppants in Nano-modified VES Fracturing Fluids

作　　者：王治国[1] 陈志畅 仝少凯 贾栋尧[1] 罗向荣 苏晓辉 WANG Zhi-guo;CHEN Zhi-chang;TONG Shao-kai;JIA Dong-yao;LUO Xiang-rong;SU Xiao-hui(College of Mechanical Engineering,Xi'an Shiyou University,Xi'an Shaanxi 710018,China;Changqing Downhole Technology Operation Company,CNPC Chuanqing Drilling Engineering Co.,Ltd.,Xi'an Shaanxi 710018,China)

机构地区：[1]西安石油大学机械工程学院,陕西西安710065 [2]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

出　　处：《当代化工》2023年第1期193-197,共5页Contemporary Chemical Industry

基　　金：国家自然科学基金项目(项目编号:51974255;51674200);陕西省自然科学基础研究项目(项目编号:2020JM-544)。

摘　　要：在压裂过程中,由于天然裂缝的存在,支撑剂在裂缝内的铺置较为复杂,直接影响了压裂增产的效果。为提高压裂液在裂缝中的携砂能力,在黏弹性表面活性剂(VES)压裂液中添加纳米氧化锌颗粒,形成纳米改性VES压裂液。通过自主研发的平板裂缝实验台对比分析清水与纳米改性VES压裂液的携砂效果。结果发现,纳米改性VES压裂液铺砂更加均匀,效果更好。通过应力旋转流变仪测定纳米改性VES压裂液的流变特性,采用Cross流体本构方程对实验结果进行拟合,得到相应的流变参数,并利用颗粒动力学的方法对支撑剂在纳米改性VES压裂液中的运移特性进行研究。模拟结果表明,随着压裂液砂质量分数的增加,支撑剂之间易于发生团聚,使得更多的颗粒发生沉降,达到砂堤平衡高度的时间减小,平衡高度增加;随着支撑剂颗粒粒径及密度的增大,支撑剂沉降速率增加,砂堤高度增加,且靠近入口,极易出现砂堵的现象。在实际压裂施工过程中,要尽可能选用小粒径、低密度的支撑剂。In the fracturing process,due to the presence of natural cracks,the laying of proppant in the cracks is more complicated,which directly affects the effect of fracturing and production.In order to improve the sand carrying capacity of the fracturing fluid in the fracture,nano-zinc oxide particles were added to the viscoelastic surfactant(VES)fracturing fluid to form a nano-modified VES fracturing fluid.Through the self-developed flat crack test bench,the sand carrying effect of clean water and nano-modified VES fracturing liquid was compared and analyzed.The results showed that the equilibrium bank by nano-modified VES fracturing fluid was easy to form and more uniform.The rheological properties of nano-modified VES fracturing fluids was tested by a stress rotary rheometer.The cross constitutive equations was used to fit the rheology parameters of VES.CFD simulation based on granular kinetic theory were conducted to investigate the transport characteristics of proppants in nano-modified VS fracturing fluids.The simulation results showed that with the increase of the sand mass fraction of fracturing liquid,agglomeration between proppant agents was easy to occur,resulting in more particles settling.As a result,the equilibrium time was reduced,and the height of the sand embankment increased.With the increase of particle size and density,the settling rate of proppant increased,the height of the sand embankment increased,and it was close to the inlet,which was very prone to sand blockage.In the actual fracturing construction process,small particle size,low density proppant should be selected as much as possible.

关 键 词：支撑剂运移 纳米改性 数值模拟 Cross本构方程 

分 类 号：TQ022.4[化学工程]