Abstract:Peacock block is located in the northeast of Tarim,which is Silurian clastic reservoir and its reservoir properties is poor. Currently It is unable to obtain the continuous production by Vertical well fracturing, however well productivity has been improved greatly using Staged fracturing technique in horizontal well.Therefore, the in-depth research on optimal design of staged fracturing in the horizontal well has important significance.In this paper, the method of UFD based on the purpose to maximize productivity is presented, in which we developed a parameter called "proppant number" .With the parameter,the fracturing scale,and the best conductivity of crack and maximum production index are associated,then in a given gas reservoir geology condition we take the best production index for the target to design the optimal fracture geometry. The goal of UFD is to get a maximum production index by hydraulic fracturing design.Through the fracturing optimization practice, we have found that in the Peacock block all kinds of fracturing schemes on horizontal section failed to achieve economic development, and multi - short crack is not suitable for reforming the low porosity and low permeability gas reservoir, need to find a "dessert" development.