普光地区陆相须家河组低渗致密砂岩气藏气层识别

Identification of Low Permeability and Tight Sandstone Gas Reservoirs in Xujihe Formation of Puguang Area

普光地区陆相上三叠统须家河组(T3xj)储层整体致密,为低孔-低渗、特低孔-特低渗储层,气层识别难度大。针对该技术难点,从基本地质特征研究入手,寻找识别气层的关键点。运用常规测井曲线,优选建立对裂缝敏感的图板识别裂缝型储层,进一步结合试气、录井显示等资料建立孔隙型、裂缝-孔隙型储层气层判别标准,对普光陆相T3xj的气层进行识别,现场应用效果较好。

The reservoir of Xujiahe Formation in Puguang Area was tight reservoir with low porosity and low permeability and extra-low porosity and extra-low permeability,gas reservoirs were difficult to be identified.In allusion to the problem stated above and starting from the basic geological characters,the key points for gas reservoirs identification were searched.The optimization of conventional logging curve was used to establish a fracture sensitive chart board to recognize the fractured reservoirs.A criterion is established for identifying pore type and fracture-pore type of reservoirs by further combining with gas test and geologic log data,the criterion is used to identify the gas reservoirs in Xujiahe Formation,and good field application result is obtained.