摘要：Low-amplitude folds are widely developed in the Upper Paleozoic of the eastern Ordos Basin. In this paper, the developmental characteristics and control factors of structural fractures of tight sandstone in low-amplitude tectonic zone were comprehensively studied through field profile observations and data collections. The results showed that a series of vertical structural fractures in the NW, NNW, NE and NNE directions and a type of horizontal structural fractures are well developed in the Upper Paleozoic sandstone. According to the geometric space classification method, the fractures were divided into Types I, II and III fractures. The top, limb and core areas of the low-amplitude folds are all favorable sites for structural fractures. The channel and tidal flat facies sandstones have a higher fracture linear density, which is generally greater than 3.6 m"1. Finally, the distribution pattern of structural fractures in the Upper Paleozoic tight sandstone of the eastern Ordos Basin was established.
