Study On The Method Of Identification Deformed Coal By Logging While Drilling

The deformed coal is the main influence factor for coal mining and Coal Bed Methane(CBM) extraction. Coal and gas outburst accidents restriction the safety production seriously in coal mine. And a certain thickness of deformed coal's existence is the necessary condition of coal and gas outburst. On the other hand, during the process of CBM extraction, it could happen "stuck drill" accident if drilling process meet deformed coal. It will influence the drilling process lightly or cause a drill lost and significant property damage. If it could identify the deformed coal while in drilling, it have great significance to avoid these problems.The papers to find the deformed coal from coal for the purpose. Researched the different physical properties of the undeformed coal and the deformed coal, including conductivity, dielectric properties and density. By the analysis of previous research results and together with practical testing coal sample parameters,consider that the deformed coal has low resistivity and low density values relative to the undeformed coal, But the dielectric constants differ are not big. Analyzed the reasons for the differences physical property of coal rock and influencing factors. Determined the resistivity and density difference in quantity, lay the foundation for distinguishing the deformed coal.Analysed of jiaozuo CBM exploration of coal seam in test well logging data segment of the logging response characteristics, summarized the logging curve response range and modeled the logging curves for the direct. Chose the resistivity logging curve for the priority curve and the gamma gamma logging curve as the auxiliary curve to distinguish the deformed coal, make Matlab7.0 as tools, by using wavelet transform, set the qualitative and the quantitative of the deformed coal to logging curves. Combining the artificial distinguish well logging curves, get the deformed coal thickness finally.