薄层稠油蒸汽驱数值模拟研究

Numerical Simulation of Steam Flooding in Thin Heavy Oil Reservoir

为解决林东馆三块薄层稠油油藏转蒸汽驱后老井利用及注采参数优化的问题,利用区块实际地质特征,建立油藏数值模拟模型,研究了薄层稠油油藏蒸汽驱中油、汽、水3相分布规律并优化最佳注汽强度,同时分析薄层和厚层蒸汽驱的不同点及原因。研究表明:薄层稠油油藏蒸汽驱过程中由于顶底盖层热损失严重,与厚层稠油油藏相比,蒸汽超覆不明显,热水驱的影响要远大于蒸汽驱,蒸汽驱段只占30%左右,受水驱影响底部原油也能被动用;为保证蒸汽驱效果,薄层稠油油藏应加大注汽强度;对于林东馆三块油藏,目前老井均位于油藏上部,但蒸汽驱时仍可以继续利用,其最佳注汽强度为2.0 t/(d·hm^2·m),不能直接采用中厚层稠油油藏蒸汽驱经验进行设计。研究成果对薄层稠油油藏转蒸汽驱设计具有重要的借鉴意义。

Field geology data are used to establish a reservoir numerical simulation model to fully utilize old wells and optimize injection-production parameters in Lindong Guan3 Block thin heavy oil reservoir after steam flooding. Steam flooding reservoir numerical simulation is used to study the distributions of oil,steam and water during steam flooding and optimize the steam injection intensity. In addition,the differences and reasons between steam flooding of thin and thick heavy oil reservoirs are also analyzed by this simulation. Research shows that comparing with steam flooding of thick heavy oil reservoir,there is no obvious steam overlap during the steam flooding of thin heavy oil reservoir due to the serious heat loss in bottom and top caprocks.Hot-water flooding is more efficient than that of steam flooding in thin heavy oil reservoir,the steam flooding interval only accounts for 30%. The bottom remaining oil can also be produced due to the effect of waterflooding. The steam injection intensity in thin heavy oil reservoir should be increased to improve steam flooding performance. The available oil wells in Lindong Guan3 Block are all located in the upper part of reservoir,which can also be utilized in steam flooding. The optimum steam injection intensity is 2. 0 t /( d·hm^2·m),which cannot be estimated according to the steaming flooding experience in the heavy oil reservoir with medium-high thickness. Research could provide a reference for the steam flooding design in thin heavy oil reservoir.