CO_(2) flooding is a widely recognized method for enhanced oil recovery(EOR).This study aims to develop an accurate prediction method for determining the location and migration pathway of CO_(2) front,which plays an e...CO_(2) flooding is a widely recognized method for enhanced oil recovery(EOR).This study aims to develop an accurate prediction method for determining the location and migration pathway of CO_(2) front,which plays an essential role in designing effective CO_(2) injection schemes and optimizing production strategies.Given the challenges of directly monitoring CO_(2) front movement in subsurface reservoirs,numerical well testing serves as an effective tool for indirectly inferring the location and migration characteristics of the CO_(2) front.This study established a numerical well-testing model based on a compositional framework to characterize interactions among multiple components during CO_(2) flooding.The methodology used in this model involves generating well-testing curves of CO_(2) flooding and then determining their flow stages based on CO_(2) distribution within reservoirs.Accordingly,a new well-testing analysis approach was proposed to determine the CO_(2) zone front and mixing zone front.This approach was applied to a pilot study of a practical oilfield,where it effectively predicted the positions of both fronts.The findings of this study reveal that the CO_(2) zone front and the mixing zone front correspond to the beginning of the first horizontal segment and the endpoint of the upward segment in the pressure derivative curve,respectively.This study introduces a cost-effective and time-efficient method for CO_(2) front monitoring,addressing the challenges of high costs and prolonged durations typically associated with CO_(2)-EOR operations.展开更多
文摘CO_(2) flooding is a widely recognized method for enhanced oil recovery(EOR).This study aims to develop an accurate prediction method for determining the location and migration pathway of CO_(2) front,which plays an essential role in designing effective CO_(2) injection schemes and optimizing production strategies.Given the challenges of directly monitoring CO_(2) front movement in subsurface reservoirs,numerical well testing serves as an effective tool for indirectly inferring the location and migration characteristics of the CO_(2) front.This study established a numerical well-testing model based on a compositional framework to characterize interactions among multiple components during CO_(2) flooding.The methodology used in this model involves generating well-testing curves of CO_(2) flooding and then determining their flow stages based on CO_(2) distribution within reservoirs.Accordingly,a new well-testing analysis approach was proposed to determine the CO_(2) zone front and mixing zone front.This approach was applied to a pilot study of a practical oilfield,where it effectively predicted the positions of both fronts.The findings of this study reveal that the CO_(2) zone front and the mixing zone front correspond to the beginning of the first horizontal segment and the endpoint of the upward segment in the pressure derivative curve,respectively.This study introduces a cost-effective and time-efficient method for CO_(2) front monitoring,addressing the challenges of high costs and prolonged durations typically associated with CO_(2)-EOR operations.
