盐浓度对交联聚合物溶液剪切增稠现象的影响

Influence of salt concentration on shear thickening properties of LPS

董朝霞 宋锦宏 林梅钦 李明远

DONG Zhaoxia SONG Jinhong LIN Meiqin LI Mingyuan

中国石油大学提高采收率研究中心，北京　102249

Enhance Oil Recovery Research Center, China University of Petroleum, Beijing 102249, China

交联聚合物溶液（LPS）是一种新型调剖剂，LPS在油藏中的流动特性是影响其调剖效果的关键因素之一。采用奥式黏度计模拟油藏中多孔介质的剪切作用，研究了在不同盐质量浓度范围内，重复剪切作用下LPS流动特性的变化，并结合流变学理论，分析了重复剪切作用下LPS剪切增稠现象与LPS中线团（LPC）分散状态间的关系。实验结果表明，在一定NaCl质量浓度范围内，随着NaCl质量浓度的增加，反应到一定时间的LPS会发生剪切增稠现象，且出现剪切增稠所需的反应时间随NaCl质量浓度的增加而缩短。此现象反映出盐质量浓度的提高增加了聚合物与交联剂间发生分子内交联的比例和LPC的数量，为研究低质量浓度聚合物交联体系的交联过程提供了一种简单可行的新方法。

Linked polymer solution (LPS) is a new type of profile control agent, and its flow behavior in oil reservoirs is one of the key factors influencing profile control effect. The shearing function of porous media in oil reservoirs is simulated using the Ostwald viscosity meter. The variation of LPS flow behavior is studied under different salt concentrations and repeated shearing conditions. Combined with rheology, the correlation between the phenomenon of shear thickening and the dispersion of LPS midline group (LPC) is analyzed. Experimental results show that within a certain concentration range of NaCl, LPS system gets shear thickening at the definite reaction time, with the increase of NaCl concentration, while the reaction time required for shear thickening is shortened. It also shows that the ratio of intramolecular cross-linking of polymer and cross-linking agents and the number of LPC increase with the increase of salt concentration. This provides a new method feasible for the study of cross-linking process of low-concentration polymer cross-linking systems.