Relationship between approximate analysis of coal and log parameters and its models

The main indicator of raw coal quality evaluation is approximate analysis. Based on Zhaojiazhai coal field of Xinzheng mine area in Henan province, through the testing and statistical analysis, the relationship between coal approximate analysis and log parameters and its models have been established, and the logging response mechanism of coal quality was studied. The results show that between approximate analysis and log parameters exists an obvious correlation. There is the negative correlation between the moisture content of raw coal and the apparent resistivity and density, and the positive correlation between the moisture content of raw coal and the natural potential and natural gamma. The ash content of raw coal has a positive corelation with density, natural gamma and natural potential respectively, and a negative correlation with apparent resistivity. There is a negative correlation between the volatile of raw coal and apparent resistivity and density, and a positive corelation between the volatile of raw coal and natural potential and natural gamma. The correlation between the coal quality indicators and the log parameters is determined by the content of organic matter and inorganic matter in coal, the coal property, the coal structure, the coalification and other factors. The multi-statistical models were established respectively through logging curves predicting parameters for approximate analysis. In the process of exploring coal and coal bed methane, the purpose of predicting the parameters for approximate analysis can be realized by using logging curves.