基于渗透率时变的砂岩油藏含水规律表征方法及数模研究

Characterization method and numerical simulation of water-cut law in sandstone reservoirs based on permeability time-change

P油田是渤海最大的陆相多层砂岩油藏,历经十多年的注水开发,油田进入中高含水期,由于储层粉砂岩和泥质含量较高且差异较大,层内、层间、平面三大开发矛盾突出,常规数模单井含水上升规律拟合难度大,对油藏数值模拟拟合与开发指标预测有很大影响。基于油田储层微观结构分析,长期水驱储层微观孔隙结构变化实验研究、现场调整井储层水淹物性变化规律统计分析,结合本油田测井解释孔隙度、渗透率方法,以及水驱油实验、水淹层物性变化规律,建立不同类型储层水驱倍数与渗透率变化比值的关系公式,利用PetrelRE平台和Intersect模拟器实现了注水开发过程局部储层渗透率变大或变小过程,大幅度改善了单井含水上升过程的拟合。

The P Oilfield is the Bohai Sea’s largest continental multilayer sandstone reservoir.After more than ten years of waterflooding development,the oilfield has entered the medium-high water-cut stage.Due to the high and significant differences in the reservoir siltstone and mud content,the three major development contradictions of the intra,inter-,and planar layers are prominent.The conventional digital model is more challenging to fit the rising water-cut law of a single well,which greatly influences the numerical simulation fitting and development index prediction of the reservoir.Based on the analysis of oilfield reservoir microstructure,the relationship formula between the ratio of water drive ratio and permeability change of different types of reservoirs is established by the experimental study of long-term water drive reservoir micro-pore structure change,the statistical analysis of reservoir water-flooded physical property change rule in field adjustment well,and the interpretation of porosity and permeability method by logging in the P Oilfield,as well as water drive oil experiment and water-flooded physical property change rule.The PetrelRE platform and Intersect simulator are used to realize the local reservoir permeability-increasing or decreasing process during waterflooding development,which significantly improves the fitting of the water-cut rise rule in a single well.