摘要
The researches on core observation,thin section data and the analysis of conventional physical property show that the natural fractures are well developed in Chang 2 reservoir of Panlong Oilfield,Ordos Basin and they are high angle fractures.The fracture filling is mainly calcite and some fractures are not filled with good oil accumulation.Using the abnormal frequency analysis method of permeability,this paper studies the plane variation rules of fractures in Chang 2 reservoir.The result shows that the high yield wells are in the two intervals of the main permeability anomaly values of 5% to 30% and more than 50%.Macroscopic fractures play a bridge role of communicating the effective source rocks of Chang 7 reservoir and Chang 2 reservoir,forming a rich oil accumulation in Chang 2 reservoir.Microfractures can play an important role in matrix pore communication,which is one of the factors of high oil production.