稠油热采过程储层中粘土矿物转化研究进展

ADVANCES IN RESEARCH ON CLAY MINERAL ALTERATION IN HEAVY OIL RESERVOIRS DURING THERMAL RECOVERY

综述了稠油热采过程高温高压条件下水-岩反应的3种研究方法,即岩心分析法、实验室模拟法以及流体化学成分研究法;不同温度条件下储层粘土矿物的转化过程及途径不同,即在注汽井井眼附近储层中粘土矿物向膨胀性蒙皂石转化,在远离井眼地区储层中粘土矿物向其它类型矿物发生转化;以及粘土矿物发生转化的2种结构模式-溶解、沉淀型模式和继承型模式。最后探讨了高温高压条件下粘土矿物发生转化的影响因素。改变这些影响因素可使粘土矿物向着将储层伤害降低至最小的方向发生转化,有利于稠油储层保护和提高热采效率。

This paper firstly reviewed advances on the study methods for water-rock interaction in high-temperature and high-pressure environment in heavy oil reservoirs during thermal recovery; core analysis; laboratory simulation and fluid chemical component analysis; secondly alteration processes and means of clay minerals in reservoirs which are altered to smectite having water-swelling characteristics near wellbore and to other minerals far from wellbore; thirdly the two structural modes of clay mineral transformations that are dissolution and precipitation mode and inheritance mode ; finally, decisive factors affecting clay mineral alterations in high-temperature and high-pressure environment were discussed. Clay minerals may be altered to favor minimizing formation damage by adjusting these factors, which can protect heavy oil reservoirs and improve thermal recovery efficiency.