In response to the growing demand for CO₂ mitigation and unconventional natural gas, the oil and gas industry is researching for the viability to enhance shale gas recovery (ESGR) and sequester CO₂ in depleted reservoirs. Previous research has shown that a CO₂-N₂ mixture can be employed as a desired injection fluid to concurrently address both industrial issues. Due to the infancy of ESGR operations, there is no thorough knowledge of field-level optimized strategies using CO₂-N₂ for the ESGR associated with CO₂ sequestration. In this study, the commercial reservoir simulator GEM and CMOST by CMG were adopted to conduct ∼ 120 simulation scenarios based on the Barnett shale formation in order to comprehend the impacts of three dominating operational parameters and propose the corresponding solutions. This study reveals four major findings. Firstly, a larger N₂ concentration corresponds to a better recovery factor of shale gas but a shorter breakthrough time that causes the worse CO₂ storage performance. Secondly, an injection rate is initially proportional to the shale gas recovery and CO₂ storage performance but beyond a threshold rate, it can inversely affect both outcomes. Thirdly, the influence of a soaking period is limited in a short term and negligible in a long term for both ESGR and CO₂ sequestration. Lastly, by selecting an appropriate combination of an injection rate and a CO₂-N₂ ratio, the income of a project can significantly be improved by 22 % under the current carbon tax policy. This study provides shale gas operators with a guideline for implementing large-scale ESGR projects employing CO₂-N₂ mixtures.

为应对 CO ₂减排和非常规天然气日益增长的需求，石油和天然气行业正在研究提高页岩气采收率 (ESGR) 和在枯竭储层中封存 CO _{2的可行性。}先前的研究表明，CO ₂ -N ₂混合物可用作所需的注入流体以同时解决这两个工业问题。_{由于 ESGR 操作尚处于起步阶段，对于使用 CO 2} -N ₂进行与 CO ₂封存相关的 ESGR的现场级优化策略没有全面的了解。在本研究中，商业油藏模拟器GEM采用 CMG 的 CMOST 和 CMOST，基于 Barnett 页岩地层进行了约 120 个模拟场景，以了解三个主要操作参数的影响并提出相应的解决方案。这项研究揭示了四个主要发现。首先，N _{2浓度越大，页岩气采收率越高，突破时间越短，CO 2}封存性能越差。其次，注入速率最初与页岩气采收率和 CO ₂储存性能成正比，但超过阈值速率，它会对这两种结果产生相反的影响。_{第三，浸泡时间对ESGR和CO 2}的影响在短期内是有限的，在长期内可以忽略不计。封存。最后，通过选择合适的注入率和CO ₂ -N ₂比率的组合，在当前碳税政策下，项目的收益可以显着提高22%。_{本研究为页岩气运营商提供了实施使用 CO 2} -N ₂混合物的大型 ESGR 项目的指南。