离子组成对中低分子量聚合物抗盐行为的影响

Effect of Ion Composition on the Salt-tolerance Behavior of Medium-low Molecular Weight Polymers

王丽莉 梁严 李文宏 袁国伟 曹苗

WANGLili LIANGYan LIWenhong YUANGuowei CAOMiao

中国石油长庆油田公司勘探开发研究院, 陕西 西安 710018 低渗透油气田勘探开发国家工程实验室, 陕西 西安 710018 西南石油大学化学化工学院, 四川 成都 610500 四川光亚聚合物化工有限公司, 四川 南充 637900

Exploration and Development Research Institute, Changqing Oilfield Company, PetroChina, Xi'an, Shaanxi 710018, China National Engineering Laboratory of Low Permeability Oil and Gas Exploration and Development, Xi'an, Shaanxi 710018, China College of Chemistry and Chemical Engineering, Southwest Petroleum University, Chengdu, Sichuan 610500, China Sichuan Guangya Polymer Chemical Co. Ltd., Nanchong, Sichuan 637900, China

针对长庆侏罗系低渗透高矿化度油藏在化学驱中需要优选与油藏匹配性良好且抗盐性好的中低分子量聚合物的现实问题，较为系统地分析了离子浓度和类型对3种不同中低分子量抗盐聚合物抗盐行为的影响规律。通过黏度、松弛时间、荧光与环境扫描电镜等测试表明，与常规抗盐聚合物SAV55和分子量较低的缔合聚合物EY-131相比，分子量和缔合单体含量较高的缔合聚合物BHXF-850有更好的增黏性，但随着Na、Ca和Mg的加入，BHXF-850的黏度保留率、松弛时间、溶液结构数目却是最小的且结构强度也最弱，对溶液微观结构的影响更为显著。同时，一价和二价离子对聚合物的抗盐行为并未产生差异化影响。相关认识可为油藏现场化学驱用中低分子量抗盐聚合物的优选提供参考与借鉴。

In view of the practical problem of choosing the medium-low molecular weight salt-tolerance polymer for Changqing Jurassic reservoir with low permeability and high salinity, this paper systematically analyzed the influence of ion concentration and composition on the salt-tolerance behavior of three different medium-low molecular weight salt-tolerance polymers. The measurement results of viscosity, relaxation time, fluorescence and environmental scanning electron microscopy showed that, compared with the conventional salt-tolerance polymer SAV55 and the associative polymer EY-131 with lower molecular weight, the associative polymer BHXF-850 with higher molecular weight and associative monomer content had better viscosifying capacity. However, with the addition of Na, Ca and Mg, the viscosity retention rate, relaxation time and solution structure number of BHXF-850 were the lowest and the structural strength was also the weakest, and the solution microstructure was significantly affected by the addition of ions. At the same time, the salt-tolerance behavior of the polymer had no obvious difference between the addition of mono-valent and divalent ions. The findings can provide reference for the optimization of medium-low molecular weight salt-resistant polymers used for chemical flooding in reservoir fields.

10.11885/j.issn.1674-5086.2020.10.10.02