The Study On Effective Reservoir Identification Method Of Bedrock In Front Of Aerjin Mountain

The mineral composition of the weathering crust reservoir in the basement buried hill of Dongping area in the front of Altun Mountain in Qaidam Basin is complex,the vertical and horizontal changes are fast,the development degree of fractures and dissolution is uneven,and the evaluation of physical property parameters is difficult,which leads to the uncertainty of the main control factors of the fracture distribution rule and effectiveness of the reservoir.In this paper,based on the conventional logging data,combined with the formation element logging,electrical imaging,nuclear magnetic,array acoustic data,the qualitative identification method of core and electrical imaging image,the quantitative identification standard of Al Si Ca three elements and m-n-gr three variables,the matrix porosity model of variable acoustic skeleton value and sub lithologic acoustic skeleton value are established The fracture porosity model of dual laterolog is reconstructed by core analysis and electrical imaging.Based on the accurate identification of lithology and physical parameters,combined with porotex technology,nuclear magnetic spectrum analysis,fracture and geostress trend analysis,the effectiveness of fracture reservoir is comprehensively evaluated.Finally,by calculating the distance from the top of the bedrock to the fault,calculating the three-dimensional curvature of the stratum and analyzing the weathering and leaching,the main control factors affecting the fracture development and effectiveness of the bedrock reservoir are summarized.The results show that the lithology of the bedrock reservoir in Qaidam area is mainly granitic gneiss,plagioclase gneiss and calcareous gneiss.The comparison effect of fracture porosity and nuclear magnetic porosity calculated by fracture porosity model is good,and the development of fracture is obviously affected by the main control factors.All identification charts and calculation models obtained in this paper are applicable to the effective identification of bedrock reservoir in Dongping area.