CO_2驱合理注入时机探讨

建立苏北溱潼凹陷草舍油田泰州组油藏的数学模型,运用CMG软件对该油藏开展CO2驱合理注入时机研究。研究认为该油藏越早实施CO2驱越有利于提高采收率,CO2驱最晚注入时机应在不超过含水70%之前,目前泰州组注气仍处于有利时期。在含水70%之前,不同注入时机的最终提高采收率幅度呈线形下降趋势,而在含水70%之后注入CO2,最终提高采收率降幅较大,CO2驱油效果明显降低。

Discussion on proper injecting time for CO2 flooding

This paper sets up the mathematical model of Taizhou Formation Reservoir of Caoshe Oilfield of Qintong Sag in the north of Jiangsu Province, and studies the proper injecting time for CO2 flooding in this reservoir by using CMG software. The study shows that the earlier the reservoir performs CO2 flooding, the more favorable for enhancing oil recovery; the latest injecting time for CO2 flooding is when the water cut is not more than 70%, and Taizhou Formation is still in the favorable stage for gas injection. When the water cut is lower than 70%, the ultimate recovery factor of different injecting time is declining in the linear trend ; but when the water cut is higher than 70 %, the decline of ultimate recovery factor is large and the effectiveness of CO2 flooding is obviously declined.