The recovery factor from tight gas reservoirs is typically less than 15%, even with multistage hydraulic fracturing stimulation. Such low recovery is exacerbated in tight gas condensate reservoirs, where the depletion of gas leaves the valuable condensate behind. In this paper, three enhanced gas recovery (EGR) methods including produced gas injection, CO₂ injection and water injection are investigated to increase the well productivity for a tight gas condensate reservoir in the Montney Formation, Canada. The production performance of the three EGR methods is compared and their economic feasibility is evaluated. Sensitivity analysis of the key factors such as primary production duration, bottom-hole pressures, and fracture conductivity is conducted and their effects on the well production performance are analyzed. Results show that, compared with the simple depletion method, both the cumulative gas and condensate production increase with fluids injected. Produced gas injection leads to both a higher gas and condensate production compared with those of the CO₂ injection, while waterflooding suffers from injection difficulty and the corresponding low sweep efficiency. Meanwhile, the injection cost is lower for the produced gas injection due to the on-site available gas source and minimal transport costs, gaining more economic benefits than the other EGR methods.

中文翻译：

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加强非常规致密气凝析油藏的采收率和敏感性研究。

即使采用多级水力压裂增产措施，致密气藏的采收率通常也低于15％。在致密的气体冷凝物储层中，如此低的回收率会加剧这种情况，因为气体的耗尽会留下有价值的冷凝物。本文介绍了三种增强型气体回收（EGR）方法，包括注入气，CO ₂为了提高加拿大蒙特尼组致密气凝析油藏的产能，对注入和注水进行了研究。比较了三种EGR方法的生产性能，并评估了其经济可行性。进行了诸如一次生产持续时间，井底压力和裂缝传导率等关键因素的敏感性分析，并分析了它们对油井生产性能的影响。结果表明，与简单的消耗方法相比，随着注入的流体，累积的气体和凝析油产量均增加。与CO ₂相比，产生的气体注入导致更高的气体和冷凝物产生注水，而注水则遭受注入困难和相应的低扫除效率。同时，由于现场可利用的气源和最小的运输成本，生产的气体喷射的喷射成本较低，与其他EGR方法相比，可获得更多的经济利益。