黏土对聚合物溶液黏度和渗流特性影响研究——以渤海SZ36-1油田为例

Study on the Influence of Clay Minerals on Viscosity of Polymer Solution and Flowing Characteristics: A Case Study from Bohai SZ36-1 Oilfield

刘文辉 徐国瑞 张云宝 李翔 陈欣 薛宝庆

LIU Wenhui XU Guorui ZANG Yunbao LI Xiang CHEN Xin XUE Baoqing

中海油田服务股份有限公司油田生产事业部, 天津塘沽 300450; 东北石油大学教育部提高油气采收率重点实验室, 黑龙江大庆 163318

Oilfield Production Department, China Oilfield Services Limited, Tanggu Tianjin 300450, China; Key Laboratory of Enhanced Oil Recovery of Ministry Education, Northeast Petroleum University, Daqing Heilongjiang 163318, China

聚合物类调驱剂流经多孔介质时,不可避免地与储层填隙物接触,因水动力学捕集、机械捕集、表面吸附和聚合物分子间的相互作用而产生滞留,这种物理化学作用不仅会影响注入流体的渗流特性,而且会对交联聚合物成胶性能产生影响。以岩石矿物学、物理化学和高分子化学为理论指导,以仪器分析、化学分析和物理模拟为技术手段,以砂岩储层中主要黏土矿物与聚合物间相互作用为研究对象,开展了黏土矿物类型和含量对聚合物凝胶黏度、吸附量和渗流特性实验研究。结果表明,蒙脱土、高岭土和伊利土等三种黏土矿物会不同程度的降低聚合物溶液和凝胶的黏度,原因在于它们表现出的较大吸附能力差异,其中蒙脱土吸附量较大,其次为高岭土,再其次为伊利土,晶层结构差异是产生这种差异的直接原因。与聚合物溶液相比较,黏土矿物对交联聚合物溶液吸附量较小。在进行聚合物浓度取样检测时,容器上层液聚合物浓度通常要比下层液低,但整体水平差异不大。进一步分析发现,黏土矿物吸附作用导致聚合物在孔隙中滞留增加,孔隙过流断面减小,阻力系数和残余阻力系数增大。此外,黏土颗粒在多孔介质内运移和捕集也会造成渗流阻力增大。

When polymer flooding agent flows through porous media, it will inevitably contact with reservoir fillings, and retention will occur because of hydrodynamic trapping, mechaincal trapping, surface adsorption and interaction of polymer molecules. The physical and chemical reactions will not only affect flowing characteristics of injected fluid, but also impact adhesive properties of crosslinking polymer. Based on the theories of rock mineralogy, physical chemistry and polymer materials, by means of instrumental detection, chemical analysis and physical simulation, study has been conducted on the main clay minerals in sandstone reservoir and polymer interaction and experiment study on the influence of clay type and its content on viscosity, adsorption capacity and flow characteristics of polymer gel has been carried out. The results showed that three kinds of clay minerals including montmorillonite, kaolinite and illite could reduce the viscosity of polymer solution and gel in different levels because of great differences in absorption capacity, of which montmorillonite is the largest, followed by kaolinite and illite. The difference of crystal layer structure is the direct reason for this kind of difference. Compared with the polymer solution, the clay minerals is smaller in adsorption capacity of crosslinking polymer solution. During sampling inspection on polymer concentration, polymer concentration in the upper liquid of container is usually lower than that of lower liquid, but the overall level is insignificant. Further analysis has showed that the adsorption of clay minerals has leaded to the increase of polymer retention in pores, reducing the flow section, and increasing in the resistance coefficient and residual resistance coefficient. In addition, migration and trapping of clay particles in porous media might also increase seepage resistance.

国家油气科技重大专项子课题"海上稠油保压热采技术示范"(项目编号2011ZX05057-005-003)

https://doi.org/10.3969/j.issn.1008-2336.2014.04.059