Abstract: The study on the structural fracture development in the faulted anticline in Kelasu tectonic zone,Kuqa Depression,reveals a tensile fracture zone developed in the hinge zone of the faulted anticline.And the flow rate from single-well test in the tensile fracture zone is high,indicating a prolific zone.Therefore,it is of great significance to oil/gas exploration and development to make an in-depth study on the tension fracture zone and its controlling factors.Our previous study reveals that the tensile fracture zone is controlled by neutral surfaces,but the influence of rock mechanics on the zone remains unclear.Then,we build several 2D mechanical conceptual models with different rock mechanical parameters through finite numerical modeling,for analyzing the influence of Young's modulus,Poisson ratio and viscosity ratio on the tensile fracture zone.The results show that:(1) when the Young's modulus is greater than 70 GPa,the maximum strain value grows rapidly with the increasing Young's modulus;both the width and thickness of the zone feature an overall linear growth with the increasing Young's modulus;(2) when the Young's modulus is greater than 40 GPa,the maximum strain value and width of the zone grow progressively with the increasing Poisson ratio;(3) when the viscosity ratio is less than 25,the maximum strain value comes to zero,and the width or thickness of the tensile fracture zone can be neglected;while when the viscosity ratio is greater than 25,the maximum strain value grows greater than zero and increases gradually,and so do the width and thickness of the zone.

Key words: Young's modulus, Poisson ratio, viscosity ratio, tensile fracture zone, 2D mechanics, numerical modeling, faulted anticline, Kuqa Depression