Study on well logging identification of coal structure in Anze Block ofsouthern Qinshui Basin

In order to provide convincing theoretical basis for hydraulic fracturing and drainage schedule，identification of coal structure studied by using logging and core data.The results demonstrated that the accuracy of coal core position restoring had been improved by the feature of GR increase caused by gangue.The characteristics of logging in unformaed coal were higher AC，lower DEN and GR.The characteristics of logging in cataclastic coal were lower AC，higher DEN and GR.Compared to unformaed and cataclastic coal，the log response in mylonite and granulated coal were medium.The accuracies of identification using GR-DEN and AC-DEN cross plots were respectively up to 86.8% and 82.8%.Undeformaed coal and cataclastic coal were well identified by using logging cross plots.Lower recovery of coal core，the filling of carbonate minerals in fracture and the existence of mudstone were the major factors which causd mistakes in identification of coal structures.Caliper log and resistivity log were favorable for reducing mistakes effectively.