Research On Coal Structure Logging Identification Technology Of Yushe-Wuxiang Block In Qinshui Basin

The Yushe-Wuxiang block is located in the north-central area of the Qinshui Basin,at the core of the Qinshui syncline,and the Anze block in the south of the Qinshui Basin has conducted research on coal body structure identification and achieved certain results.Reservoir exploration has also been carried out in the surrounding blocks of the study area,but no work has been seen in the study of coal body structure in the study area.In order to improve the understanding of the coal structure in the Qinshui Basin,and at the same time help the mining of coalbed methane in the study area,the Yushe-Wuxiang block coal structure identification study was carried out.This thesis takes the 3# coal of Shanxi Formation and 15# coal seam of Taiyuan Formation in Yushe-Wuxiang block as the research object.Based on logging data and core analysis data,the study area is divided and compared,and logging curve preprocessing is carried out.,Coal seam logging curve feature analysis,etc.,completed the log response feature analysis of the coal structure,qualitative identification of the coal structure,established a quantitative identification model of the coal structure based on multiple logging information,and finally carried out the main coal seam Analysis of the distribution characteristics of coal body structure and analysis of problems that need to be paid attention to when mining coalbed methane.Studies have shown that the coal body structure is currently divided into four types:primary coal,fragmented coal,crushed coal,and mylonitic coal,which have a certain impact on coalbed methane mining.After stratigraphic division and comparison,it is found that the main stratigraphic distribution in the study area is stable with little fluctuation.The Smith-Gardner formula method has a good effect on the reconstruction of the acoustic curve in the study area,and the diameter expansion ratio fitting method eliminates the influence of the diameter expansion on the density and the value of the acoustic time difference logging curve.Using natural gamma,density,acoustic wave,and resistivity logging curves can better identify the coal structure.The intersection of GR and AC can clearly distinguish between crushed coal and mylonitized coal.The intersection of GR and RLLD has a better recognition effect on primary coal and crushed coal.The coal body structure distribution of 3# and 15# in the study area shows that the northern primary coal and fragmented coal are thicker,and the southern fragmented coal and mylonitic coal are thicker.Vertically,the primary coal is distributed in the middle of the coal seam.Coal and mylonitic coal are distributed on the top and bottom of coal reservoirs,and fragmented coal is located in the upper and middle lower part of the coal seam.The research results of this paper have a certain supporting effect on the identification of coal body structure and the mining of coalbed methane in the study area.