Abstract: The Shenmu Gas Field located in the east of the Ordos Basin is a major component of the reservoir and production of gas in the Changqing gas zone. A systematic analysis of the reservoir characteristics, the spatial superposition structure, and the applicability of horizontal well development is of significance in the scientific development of the gas field. The experimental analysis shows that the reservoir rocks in Shanxi and Taiyuan Formation in Shenmu Gas Field are mainly lithic quartz sandstone, lithic sandstone, and quartz sandstone. The pores in the rocks are mainly dissolution pores, intercrystalline pores, and intergranular pores. The porosity of the reservoir ranges from 20% to 10.0% with an average value of 6.6%, while the permeability of the reservoir ranges from 0.10 to 1.00 mD with an average value of 0.83 mD. The reservoir can be classified as a low-permeability and tight sandstone reservoir. The results from gas tests show that a porosity of 5%, a permeability of 0.10 mD, and a gas saturation level of 45% is the lower limit of the physical properties for effective reservoir. Based on the dissection of the close well spacing, the effective spatial structure of the sand body is classified into three types:the multi-layer isolated dispersed type, the vertical multi-stage superposition type, and the lateral multi-stage superposition type. The study shows that the Shenmu Gas Field is not suitable for large scale horizontal well development. Local horizontal wells can be deployed in certain regions.

Key words: Shenmu Gas Field, reservoir characteristics, lower limit of the physical properties, effective reservoir structure, horizontal well development