Study of Controlling Factors on Productivity of Keshen Gas Field: A Deep Tight Sandstone Reservoir in Kuqa Depression

Abstract

The Keshen gas field in the Kuqa depression of the Tarim Basin with characteristics of deep buried depth, tight matrix and developed fracture, has great differences in gas well productivity within different parts of the structure, which bring difficulties to the gas field development and deployment. Based on the study of the reservoir matrix property, fracture characteristics and individual well productivity of the Keshen ultra-deep gas reservoirs, combined with reservoir geostress research, the difference between high and low efficiency wells in Keshen2 block is analysed, and the main geological factors influencing productivity are revealed. It is found that the effectiveness of reservoir fracture is a necessary condition for high production of gas well. Further study shows that there is a negative correlation between the open flow of gas well and the effective normal stress of fracture. The larger the effective normal stress of fracture is, the more difficult it is to achieve high production with reservoir reconstruction. According to study of the productivity influencing factors of the fractured tight sandstone reservoirs, some suggestions on well deployment and well perforation are given in the paper, which are beneficial to increase production and efficiency of this kind of reservoirs.