基于流线的聚合物驱热降解数值模拟  

Numerical simulation study of thermal degradation in polymer flooding based on streamlines

作　　者：赵林[1] 姜汉桥[1] 李俊键[1] 陆祥安[1] 张振涛[1] 李金鸿[1] 裴艳丽[1] 

机构地区：[1]中国石油大学(北京)石油工程教育部重点实验室,北京102249

出　　处：《油气地质与采收率》2016年第6期76-81,86,共7页Petroleum Geology and Recovery Efficiency

基　　金：国家"973"计划"陆相致密油高效开发基础研究"(2015CB250900)

摘　　要：聚合物驱是化学驱提高采收率的主要方法之一。热降解是影响聚合物驱效果的重要因素,利用油藏数值模拟进行聚合物驱方案设计时,应考虑聚合物的热降解作用,但目前考虑热降解的聚合物驱数值模拟尚未完善。为此,基于准确反映热降解的粘度衰减模型,利用分时步更新流线及网格—流线场互相映射的方法求解降解时间,实现了聚合物驱热降解数值模拟。该方法物理意义明确,适用性强,计算结果准确,可以准确反映聚合物在流动状态下的热降解过程。利用该数值模拟方法进行了3组模型的研究,结果表明,聚合物驱过程中聚合物的降解时间小于在地层中的传播时间,聚合物驱达到稳定后,降解时间等于传播时间。热降解对地层中聚合物质量浓度分布基本无影响,但会造成聚合物粘度降低,延长聚合物驱见效时间,同时使含水率下降,漏斗变小,驱油效果变差,在聚合物驱方案设计时应充分考虑聚合物的热降解作用。Polymer flooding is an important chemical EOR technology for many Chinese reservoirs. Polymer thermal degradation is an important factor affecting the polymer flooding. It is necessary to consider the polymer thermal degradation when polymer flooding project is designed using reservoir numerical simulation. Currently,numerical simulation of polymer flooding considering polymer thermal degradation is not yet perfect. Based on viscosity attenuation model that can accurately reflect the polymer thermal degradation,method of streamlines updating at each step and mapping between grid and streamline was applied to solve the degradation time,and the numerical simulation of polymer flooding considering polymer thermal degradation can be realized. The method has clear physical meaning,strong applicability and accurate calculation results,reflecting the thermal degradation process of flowing polymer underground accurately. Three models were studied using the new method. The results show that the time of polymer degradation is less than that of propagation in the stratum during polymer flooding process,and equal when the process is stable. Thermal degradation has no effect on polymer concentration,but decreases the viscosity significantly. As a result,the effective time of polymer flooding is prolonged,water cut drop funnel is minified and the effect becomes poor. It is necessary to consider the polymer thermal degradation when designing polymer flooding project.

关 键 词：聚合物驱 热降解 油藏数值模拟 粘度衰减模型 流线 降解时间 

分 类 号：TE357.431[石油与天然气工程—油气田开发工程]