CO2 Enhanced Oil Recovery in Reservoirs with Advanced Wells; Simulations and Sensitivity Analysis
采用CO2提高石油采收率（CO2-EOR）技术，通过将超临界CO2注入油藏来增加剩余油产量。结合CO2储存的CO2-EOR是一种有吸引力的方法，它可以在提高老油田的石油产量的同时减少工业源的碳足迹。在CO2-EOR项目中使用自主流入控制阀（AICVs）有助于更好地在储层中分布CO2，减少水和CO2混合物的生产，从而提高CO2的储存能力。
本研究的主要目标是模拟使用CO2气水交替（CO2 WAG）注入以及配备AICVs的高级井来从油藏中生产石油。此外，还完成了对AICV技术的效果评估和对影响WAG过程的参数的敏感性分析。
模拟结果表明，配备AICV的完井可以在减少水产量的同时保持良好的石油产量，水产量从3e+06 m³减少到9.8e+04 m³，减少了97%。敏感性分析证实渗透率、井位布置和井距对WAG EOR方法的生产力有影响。
研究结果表明，渗透率增加对石油采收率有轻微的增加效果。井距分析表明，增加井之间的距离将增加石油采收率并延迟水突破。最后，井位分析表明，垂直注入混相CO2比水平注入混相CO2产生更多的石油。AICVs限制了CO2和水混合物的生产，从而使CO2在储层中更好地分布。
CMG软件应用情况
本研究中，使用商业软件Computer Modelling Group (CMG)进行了模拟。研究中使用了CMG的不同模块，如Builder、FlexWell和STARS，以实现建模和模拟。通过从不同模拟案例收集的数据，对影响EOR过程的参数进行了敏感性分析。
Abstract
Injection of CO2 for enhanced oil recovery (CO2-EOR) is used in fields with high amount of residual oil. CO2-EOR refers to a technology where supercritical CO2 is injected into an oil reservoir to increase the oil production. CO2-EOR in combination with CO2-storage is an attractive method to increase the oil production from mature oilfields, and at the same time reduce the carbon footprint from industrial sources. Utilizing autonomous inflow control valves (AICVs) in CO2-EOR projects contributes to a better distribution of CO2 in the reservoir, reduction in production of water and CO2 mixture, and thereby increased storage capacity of CO2. The main objective of this study is modelling and simulation of oil production from an oil reservoir using CO2 water alternating gas (CO2 WAG) injection in combination with advanced wells that are completed with AICVs. Furthermore, performance evaluation of the AICV technology and sensitivity analysis of parameters affecting the WAG process are completed. The results from the simulations indicate that well completion with AICV can maintain good oil production while the production of water is decreased from 3e+06 m3 to 9.8e+04 m3 which corresponds to 97% reduction in water production. The sensitivity analysis of the simulation results affirms that permeability, well placement, and well spacing have impact on productivity in terms of both oil recovery and water production in the WAG EOR method. The results indicate that permeability increase has a slight increment effect on oil recovery. The well spacing analysis shows that increasing the distance between the wells will increase the oil recovery and delay the water breakthrough. Lastly the well placement analysis shows that vertical injection of miscible CO2 produces more oil than horizontal injection of miscible CO2. AICVs restrict the production of mixture of CO2 and water, and thereby cause a better distribution of CO2 in the reservoir.
作者单位
挪威东南大学过程、能源和环境技术系
