Logging Evaluation Of Coalbed Methane Reservoir In Wuxiang Block Of Qinshui Basin

The Wuxiang block is located in the north-central part of Qinshui basin,which is in the core of Qinshui syncline.In the surrounding area of the Wuxiang block,CBM exploration has achieved certain results,but there are few research results in the Wuxiang Block.Therefore,the completion of the evaluation of coalbed methane reservoirs in the Wuxiang block not only improve the understanding of the CBM reservoir but also provide important scientific basis for the commercial exploitation of the CBM in the Qinshui Basin.The paper takes The NO.3 and The No.15 coal in Wuxiang block as the research object.Based on the logging data and the core test analysis data,the thesis studied the depth and distribution characteristics of the coal seam and the response characteristics of the CBM reservoir,established a prediction model for industrial components,porosity and permeability.By analyzing the influencing factors of gas content,the model for gas content of CBM reservoirs was established.Finally,the article carried out analysis of the mechanical properties of the main coal seam and the rock on the top and bottom..Research has shown that using natural gamma,density,resistivity logging curves,and referencing other curves can identify coal seams and lithology better.Based on the test data and well logging responses,and carried out the correlation analysis between logging data and coal quality parameters,a forecasting model of coal and rock industry component parameters was established.The contour plots of industrial components show that the carbon content in the east is high,the west is low,and the change of ash content is opposite to the carbon content.The evaluation of porosity was carried out for the analysis of the physical properties of coal and the results of previous studies on tight reservoirs.The F-S method was used to evaluate the permeability of coal reservoirs.The distribution characteristics of porosity and permeability of coal reservoirs indicate that the physical properties of the central area of the study area are well developed,and the trend from west to east increases first and then decreases.Through the analysis of the influencing factors of coalbed methane content,combined with the data of this study,we compared the methods of isothermal adsorption,statistical regression,and BP neural network,and finally concluded that the neural network method has the highest evaluation accuracy.The plane distribution characteristics of gas content indicate that the gas content of No.3 coal The plane distribution characteristics of gas content indicate that the gas content of No.3 coal and No.15 coal is becoming higher in the west and lower in the east.The study of the mechanical properties shows that the Young modulus of coal is relatively low,and the range of change is not significant;the elastic parameters and strength parameters of coal and rock are relatively large.The results of this paper improve some support for the evaluation of coalbed methane reservoir in the research area.