Abstract:In order to clarify the characteristics of fracture development and its influencing factors, there are many types and complex causes of natural fractures in the low-porosity and low-permeability reservoirs of Chang 63-Chang 71 in the study area. By means of outcrop investigation, core observation and fracture identification by imaging logging, the characteristics and influencing factors of fractures in the study area from Chang 63-Chang 71 were systematically analyzed. The results show that the fractures of Chang 71 are more developed than those of Chang 63 in the study area. The fractures are mainly developed in fine sandstone, and their occurrence is dominated by vertical fractures and high Angle oblique fractures, most of which are unfilled fractures. The development of fractures is mainly affected by regional stress value, formation lithology, petrophysical property, rock layer thickness and mechanical structural plane. The research results provide theoretical basis and support for the deployment plan of water injection for oil recovery and artificial fracturing in low porosity and low permeability reservoirs in the study area.