稠油油藏多相协同蒸汽驱物理模拟实验

Experiment on Physical Simulation of Multi-phase Synergistic Steam Flooding in Heavy Oil Reservoirs

针对稠油油藏蒸汽驱后期纵向矛盾突出、高渗层汽窜严重等问题,以新疆油田九6区稠油油藏为例,开展多介质辅助蒸汽驱物理模拟实验研究,首先评价凝胶的成胶性能和降黏剂的降黏效果,然后使用全直径岩心对多相协同蒸汽驱的组合方式进行优化。结果表明:凝胶成胶封堵高渗层后,后续注入的多相介质可有效进入低渗层,驱动低渗油藏剩余油;注入降黏剂后,再注入N_(2)可有效增强原油的弹性能量和流动性,有助于扩大蒸汽波及体积;调堵—降黏—增压的多相协同蒸汽驱开发模式是最佳的组合方式,可提高采收率23.65个百分点。研究成果可为改善稠油油藏蒸汽驱后期开发效果提供技术借鉴。

In a case study of heavy oil reservoirs in IX6 Well Block,Xinjiang Oilfiled,physical simulation test of multi-media assisted steam flooding was conducted to address such problems as prominent vertical contradiction in the late stage of steam flooding in heavy oil reservoirs and serious steam channeling in the high-permeability layer.Firstly,the gelling performance and viscosity reducing effect of gel were evaluated,and then the combination mode of multi-phase synergistic steam flooding was optimized by full-diameter core.The results show that after the high-permeability layer was plugged by gelling,the subsequently injected multi-phase media effectively entered the low-permeability layer and drove the remaining oil in the low-permeability reservoir.Nitrogen was injected after viscosity reducer injected to effectively enhance the elastic energy and fluidity of crude oil,which was conductive to expanding the sweep volume of steam.The multi-phase synergistic steam flooding development mode of plugging control,viscosity reduction and pressurization is the best combination mode,which can improve the oil recovery rate by 23.65 percentage points.The study results can provide technical reference for the improved late development effect of steam flooding in heavy oil reservoirs.