孔喉尺度弹性微球运移封堵特性研究

Migration and plugging properties of pore-scale elastic microsphere

贾晓飞 ,雷光伦 ,李会荣, 乔伟刚 ,朱　艳 ,王　冲

Jia Xiaofei  Lei Guanglun  Li Huirong  Qiao Weigang  Zhu Yan  Wang Chong

中国石油大学石油工程学院，山东 青岛 266555

College of Petroleum Engineering, China University of Petroleum, Qingdao 266555, China

为了进一步明确孔喉尺度弹性微球调剖剂的深部液流转向机理，通过进行理论分析，并开展微球在水驱后、聚合物驱后岩心中的运移封堵实验及多测点运移封堵实验，研究了微球在多孔介质中的运移封堵特性。研究表明：微球分子三维网络结构中高分子链的柔性及物理交联点和自由水的可动性是其具有良好的弹性变形能力和运移封堵能力的基础；微球在水驱后、聚合物驱后岩心中的运移均表现出“波动式压力变化”的特征，不同的是在聚合物驱后岩心中压力波动幅度较小，压力的波动变化说明微球在多孔介质中不断运移、封堵、弹性变形、再运移、再封堵，直至岩心深部；微球在多测点岩心中可以运移至末端测点，并可以在运移的全程进行有效封堵。微球良好的运移封堵性能是其实现深部液流转向作用、扩大波及体积并提高油藏采收率的基础；微球对水驱、聚合物驱后油藏的良好适应性，将在各种油藏进行深部调剖提高采收率的进程中发挥更大的作用。

The migration and plugging properties of elastic microsphere in porons medium are studied based on the theoretic analysis and the experiment which includes the core experiments of migration and plugging after water flooding and polymer flooding and the multi-measuring points in order to further make sure the mechanism of deep fluid diversion of pore-scale elastic microsphere. The study indicates that the flexibility of polymer chain in the three-dimensional network structure of microsphere molecule, physical cross-linking points and free water mobility are the basis of having good elastic deformation ability and migration ability. The migration of microsphere in the cores after water flooding and polymer flooding is characterized by fluctuating-style pressure change, which shows that the microsphere goes ahead till the depth through its migration in pores, plugging, elastic deformation, remigration and re-plugging. The difference is that the pressure fluctuation amplitude in core is small after polymer flooding. The microsphere can migrate to the end of measuring point, which proves its good migration and effective plugging property obviously. The function of deep fluid diversion, increasing sweep volume and enhanced oil recovery are based on the good migration and plugging property of microsphere. The pore-scale elastic microsphere is regarded as a good deep fluid diversion agent after water flooding or polymer flooding, which will play an important role in deep profile control and enhanced oil recovery.