Well logging assessment of tight sandstone gas reservoirs from the He-1 member of the Permian Lower Shihezi Formation in the Hangjinqi exploration area, Ordos Basin

The present paper gives a detailed description of the controls of lithology on physical properties and the responses of well logs to lithology, physical and electrical properties, and gas potential of the tight sandstone gas reservoirs from the He-1 member of the Permian Lower Shihezi Formation in the Hangjinqi exploration area, northern Ordos Basin. The main factors influencing physical properties and gas potential include quartz contents, grain sizes and pore structures in the sandstones from the study area. The recognition of the tight sandstone gas reservoirs in the He-1 member is based on the cross plot and porosity overlay tachniques, and the assessment of the tight sandstone gas reservoirs in the He-1 member is carried out according to three types of the gas reservoirs, of which the type Ⅱ gas reservoirs are interpreted to be the good gas reservoirs with exploration potential in the He-1 member.