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This paper takes the ultra-low permeability sandstone reservoir of Jingbian oilfield in Ordos Basin as the research object, analyzes the petrological characteristics, diagenesis, physical characteristics and pore structure characteristics of the reservoir, and carries out reservoir sensitivity evaluation by using rock casting thin sections, X-ray diffraction, and sensitive flow experiments. The research results show that the ultra-low permeability Chang 6 sandstone reservoir has weak velocity sensitivity, medium-weak water sensitivity, weak salt sensitivity, weak alkali sensitivity and strong acid sensitivity; the damage mechanism of reservoir sensitivity mainly depends on the composition of clay minerals and pore structure after diagenesis. The clay mineral content from high to low is chlorite, illite, a small amount of illite / smectite layer, and kaolinite, of which the chlorite content is as high as 75 %; the reservoir has poor physical properties, the types of small hole-thin throat and small hole-fine throat. The reservoir is prone to blockage such as bridge plugging. Therefore, ultra-low permeability sandstone reservoirs are prone to different degrees of sensitivity. The reservoir characteristics are consistent with the reservoir sensitivity evaluation results.

In view of the frequent occurrence of roof collapse and chipping accidents in the broken surrounding rock roadway in the goaf, grouting reinforcement is applied to the surrounding rock of the ro ent ratio. The field test proves that the selected grouting parameters are reasonable and achieve the purpose of controlling the deformation of the surrounding rock of the roadway.

Stratigraphic sequence contrast and sequence stratigraphic framework are of great significance for the sedimentary phase and sedimentary systems of coal-accumulating basin. In the coal-bearing basin, the variation of the flooding surface controls the migration law of the coal-concentrating centres within the range. Therefore, the sequence comparison work is crucial to find favorable coal-collecting areas. In addition, studying the position of the coal seam in the sequence stratigraphic framework and carrying out the sequence comparison work in the lateral direction can effectively track the change of the position of the coal seam in the sequence stratum and summarize the law of coal seam accumulation and occurrence, which can be better to plan and guide the exploration and development of coal resources in Longdong coalfield.