聚合物驱剖面返转时机及其影响因素

Influence Factors of Profile Reversal Opportunity during Polymer Flooding

杨晶 朱焱 李建冰 崔世铭 刘国红

YANG Jing ZHU Yan LI Jianbing CUI Shiming LI Guohong

聚合物驱过程中的剖面返转现象会对提高采收率造成不利影响，为进一步提高聚合物驱效果，通过理论分析和室内物理模拟方法，对聚合物驱油效果和聚合物驱剖面返转时机及其影响因素进行研究。结果表明，随岩心渗透率升高，聚合物驱剖面返转时机延后且延后幅度增大，聚合物溶液浓度Cp=1600 mg/L、渗透率级差为4 时，渗透率大于1200×10-3μm2后尤为明显；随渗透率级差和小层厚度比（高渗层/低渗层）增大，即地层系数级差增大，剖面返转时机提前，聚合物溶液浓度CP=1600 mg/L、岩心平均渗透率Kg=300×10-3μm2、地层系数级差10 条件下，剖面返转时机可提前至0.06～0.07 PV。随岩心渗透率升高和地层系数级差增大，采收率增幅呈先增大后减小趋势；聚合物驱剖面返转时机Tp与地层系数级差Dj关系满足方程式Tp=a（Dj-1）-1，随聚合物溶液浓度升高，返转系数a 值减小，剖面返转时机提前。应用该公式可定量描述剖面返转时机与地层系数关系，及时调整注入参数，提高聚合物驱效果。图3表5 参8

In process of polymer flooding，the phenomenon of profile reversal has bad influence on enhancement of oil recovery. In order to further improve effect of polymer flooding，we make some researches on the effect of polymer flooding，the reversal time of polymer profile and its influencing factors through the methods of theoretical analysis and laboratory test. Results showed that with the increase of the core permeability，reversal time of polymer flooding profile would delay and the delay degree would increase. When the concentration of polymer solution was 1600 mg/L，permeability differential was 4 and the core permeability was more than 1200×10-3μm2，this phenomenon became especially obvious. With the increase of permeability differential and thickness ratio of divided layer （high permeability layer /low permeability layer），that was to say，with the increase of formation coefficient differential，the reversal time of polymer flooding profile was advanced. When the concentration of polymer solution was 1600 mg/L，average core permeability was 300×10-3 μm2 and formation coefficient was 10，the reversal time of polymer flooding profile was advanced to 0.06—0.07 PV. With the increase of core permeability and formation capacity differential，the enhancement of oil recovery increased at first and then decreased. The reversal time of polymer flooding Tp and formation capacity differential Dj satisfy the equation Tp=a（Dj-1）-1( here，a was the reversal coefficient），With the increase of the polymer solution concentration，the reversal coefficient decreased，profile reversal time was advanced. Using this equation，the relationship between profile reversal time and formation coefficient differential could be quantitative described，and the injection parameters could be adjusted timely and the effect of polymer flooding could be improved.

10.19346/j.cnki.1000-4092.2016.03.019