数值模拟分析水气混注的影响因素

Numerical simulation analysis of the influence factors of simultaneous water and gas injection

水气交替注入和水气混注能提高波及系数。因此,水和气混注能够提高衰竭式油藏的采收率。相对于水气交替注入方式来说对水气混注方式了解的不多,本文主要研究的是影响混相水气混注驱油的因素。本文使用油藏数值模拟方法,以固定比例分别注入水和气到两口水平井中。为了得到更好的波及效率并且增加在水气分离前运移的距离,气体注入到油藏的底部。测试了不同位置的注入水效果。还有储层纵向渗透率对储层波及系数和原油采收率的影响。

Injection of water and gas as water alternating gas （WAG） process or simultaneous water and gas （SWAG） process can improve the sweep efficiency. Therefore, oil recovery from depleted reservoirs can be enhanced by combined injection of water and gas. However, SWAG process compare to WAG process is less known. Investigation of factors that effect on miscible SWAG injection is the aim of this study. For this purpose, reservoir simulator is used. Methane （as gas） is injected into an under-saturated reservoir which contained typical Pubei Tuha. Water and gas are injected at fixed rates by two separate horizontal wells. For more sweep efficiency and increase the distance gas and water travel before segregation, gas is injected at the bottom of reservoirs. For water, different locations of injection are tested and the effect of water injection location is studied. We also investigate the effect of well models, and reservoir heterogeneity on sweep efficiency and oil recovery.