Abstract:

The structural fracture development characteristics of Kuqa depression in Tarim Basin are comprehensively analyzed in
light of the outcrop, core and log data. The characteristics of fractures we overserved consist of properties, attitude, density, intensity, aperture, and filling. The tectonic fractures in this area are mainly the medium-high dip angle shear fractures and include three groups of fractures extending mostly in the N-S direction. The aperture of most outcrop and core fractures is 0~5mm and 0~1mm, respectively. The majority of fractures is unfilled or half-filled, and the filling is mainly calcite. The distribution of each parameter of fracture shows regularity in E-W and N-S direction, respectively. Laterally, the Lower Cretaceous fracture development area is mainly distributed in the Kelasu-Yiqikelike structural belt. Vertically, the fractures are well developed in the Lower Jurassic Ahe Formation in the east Kuqa depression, and the Lower Cretaceous Bashijiqike Formation in the west Kuqa depression. Overall, the structural fracture is very well developed in the Kuche depression, which is beneficial to the improvement of porosity and permeability of tight reservoir, and is also beneficial to the formation of fractured hydrocarbon reservoirs.

Key words: tectonic fractures, development characteristics, distribution regularity, Kuqa depression