Controlling factors analysis of upper Palaeozoic gas well production capacity in Ordos basin

In Ordos basin,gas-bearing layers are visible from Carboniferous Benxi formation to Permian Shiqianfeng formation.He-8 sub-member of lower Shihezi formation and Shan-2 sub-member of Shanxi formation are main gasbearing layersFrom east to west,south to north,the gas layers are of rising trend.The results of drilling,well logging and gas testing indicate gas layers' distribution is strictly controlled by sand body distribution and physical properties,gas layer capacity has positive correlation relationship with storage coefficient and formation coefficient,technological factors has a great influence on gas well productivity,such as fracturing scale,test time,etc.,and the influence of reservoir damage on gas well productivity cannot be ignored.