聚合物驱油体系高效络合剂研究

High-Efficiency Complexing Agent for Polymer Flooding System

针对部分水解聚丙烯酰胺在高矿化度条件下增黏能力下降的问题,采用仪器检测和物理模拟等方法,对具有能够去除或屏蔽水中Ca 2+、Mg 2+的络合剂进行筛选、复配和评价,并在此基础上,进行流动性实验和驱油效果实验研究。结果表明,在10种络合剂中,氨基三甲叉膦酸与羟基乙叉二膦酸对部分水解聚丙烯酰胺具有很好的增黏效果,增黏率达到30%左右。综合考虑增黏效果、稳黏效果、反应时间和成本等方面因素,将10种络合剂复配。其中,SY-Ⅰ络合剂提高初始黏度效果明显,SY-Ⅱ络合剂提高黏度稳定性效果明显。与未加络合剂的聚合物溶液相比较,加入络合剂的聚合物溶液分子线团尺寸更大,黏弹性更好,阻力系数和残余阻力系数更大,驱油效果更好。矿场试验表明,加入络合剂的聚合物在驱替过程中注入压力明显提升,采油井的含水明显下降,产油量明显增加,增油降水效果显著。该研究对提高聚合物驱技术经济效益、指导矿场实践应用具有重要意义。

In order to improve the viscosifying performance of some hydrolyzed polyacrylamides in high salinity condition,instrument detection and physical simulation were used to optimize,compound and evaluate the complexing agents which could remove or shield Ca 2+and Mg 2+in water.Flowing and displacement experiments were carried out based on the evaluation.Result indicates that for the tested 10 kinds of complexing agents,the amino trimethyl-phosphonic acid and hydroxyethylidene diphosphonic acid show better performances in viscosifying the partially hydrolyzed polyacrylamide with a viscosifying ratio of about 30%.The SY-I complexing agent shows a favorable performance in viscosifying and the SY-II complexing agent shows a favorable performance in viscosity stabilization.A comprehensive comparison between the polymer solutions with and without 10 kinds of complexing agents was provided by considering viscosifying performance,viscosity-stabilizing performance,reaction time and cost.The polymer solution with complexing agent is featured by larger molecular coil,better viscoelasticity,high resistance coefficient,residual resistance coefficient and favorable displacing performance.Field pilot test reveals that the polymer flooding with complexing agent shows distinct injection pressure increase,water-cut decrease in production well,oil production rate increase and oil increment.This research is of great significance to improve the economic benefits of polymer flooding and guide practical application.