2D Characterization of Geometric Features and Connectivity of Fracture Networks in Shale Formations

Joints,fractures and other weak structural planes can be identified as the fundamental structural features of shale formations.Since effective communication among fractural networks can effectively enhance fractured reservoir volume,the understanding and description of configurations and connectivity of fracture network are of great importance for high-efficiency development of shale oil/gas reservoirs.To obtain accurate representations of the the geometric features,2D characterization and connectivity of natural fracture networks in shale,the fractural geometry and topologic geometry are used as a theoretical foundation to construct a fractural description model for fractural sizes and quantity in shale.In this way,calculation models for fracture node type,number of branches,average connectivity of fractures can be established.In addition,2D simulations have been performed for fracture network connectivity to highlight impacts of fracture dimension,fracture groups and angles to connectivity of fracture network.Research results showed that the quantity and development of natural fractures are subject to fractural dimensions,groups and initial quantity.Generally speaking,natural fractures increase with an increase in fractal dimensions.With other parameters remain unchanged,the average connectivity of fractures and branches is sensitive to fractal dimensions,fracture groups,fracture angles and other parameters.The connectivity may decrease with the increase in fractal dimensions and may increase with the increase in groups and angles.Relevant research results may provide theoretical foundation programs making in shale reservoirs development.