Abstract: Based on the field geologic survey, core observation and well logging fractural identification, it is shown that in the tight reservoir in Wubaiti gas pool of eastern Sichuan developed structural fractures controlled by local structure. Experimental analysis indicates that petrophysical property, dynamic nature of rocks and stress field intensity of structural deformation are the main geologic factors controlling the fractural development in this area. The fracture in studied area can be divided into diagenetic micro-facture, weathering fracture and structural fracture. According to real geologic situation, the preliminary evaluation of the structural fracture development in the studied area is conducted by means of structural stress simulation method in this paper.

Key words: Sichuan, Carboniferous, Reservoir rock, fracture, origin, distribution