摘要
将页岩复杂裂缝网络假设为一簇具有分形特征的迂曲二叉树裂缝网络,基于Cubic流量定律推导得到其克氏渗透率模型、表观气体渗透率模型和滑脱因子表达式,利用相关数据对滑脱因子表达式进行验证;对渗透率模型开展敏感性分析,明确影响页岩复杂裂缝网络渗透率与滑脱因子的关键参数。研究结果表明:滑脱因子与裂缝最大初始开度和迂曲度分形维数呈负相关,与裂缝开度分形维数呈正相关;随着地层压力的增加,表观气体渗透率与克氏渗透率的比值先快速减小,再缓慢递减并不断接近于1;克氏渗透率与迂曲度分形维数、裂缝长度比、分叉级数和分叉角度呈负相关,与裂缝最大初始开度呈正相关。
The shale complex fracture network was assumed to be a cluster of tortuous bifurcated tree fracture networks with fractal features,and then the expressions of Klinkenberg permeability model,apparent gas permeability model and slippage factor were derived based on the Cubic flow law.The slippage factor expression was validated using the corresponded experimental data.The sensitivity analysis was conducted to specify the key parameters which influence the permeability and slip factor of the shale complex fracture network.The results show that the slippage factor is negatively correlated with the maximum initial fracture aperture and tortuosity fractal dimension,and positively correlated to the fractal dimension of fracture aperture distribution;the ratio of apparent gas permeability to Klinkenberg permeability decreases rapidly with increasing formation pressure then slowly decreases and keeps approaching 1;Klinkenberg permeability is negatively correlated with tortuosity fractal dimension,fracture length ratio,branch level and branch angle,and positively correlated with the maximum initial fracture aperture.
作者
王付勇
程辉
WANG Fuyong;CHENG Hui(Unconventional Petroleum Research Institute,China University of Petroleum,Beijing 102249,China)
出处
《中南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2020年第12期3454-3464,共11页
Journal of Central South University:Science and Technology
基金
国家自然科学基金资助项目(51874320)。
关键词
页岩
裂缝网络
渗透率
分形
滑脱效应
shale
fracture network
permeability
fractal
slippage effect
