Developments in Logging Response and Identification Methods of Coal Structure
The precise identification of coal body structure through logging is helpful for the exploration and development of deep coalbed methane and the optimization of horizons.In order to accurately and appropriately use geophysical logging to identify coal structure,this paper reviews relevant domestic achievements,the classification,logging response and identification methods of coal structure.The results showed that the wellbore diameter(CAL)of primary structured coal varies from 14.82 cm to 47.29 cm,density(DEN)ranges from 1.18 g/cm3 to 2.08 g/cm3,natural gamma(GR)is between 8.66 API and 11.45 API,acoustic time difference(AC)ranges from 259.00 μs/m to 681.21 μs/m,neutron(CNL)is between 22.95％and 52.76％,and lateral resistivity(LLD)varies from 39.18 Ω·m to 26 990.50 Ω·m.As the degree of coal structure fragmentation intensifies,the DEN,CNL,and LLD values decrease,while the GR,CAL and AC values increase.Quantitative methods such as cluster analysis,multiple linear regression,Bayesian discriminant analysis,BP neural network,machine learning,and support vector machine can significantly improve the accuracy of logging recognition of coal structure.Finally,it is suggested that the precise identification of coal structure should strengthen the research on curve reconstruction theo-ry,data standardization,systematization and dataization of geophysical logging,and build a visualized,intelligent,cross regional coal structure logging identification data extraction,in-dex optimization and result storage system.
deep coalbed methanecoal structureloggingidentification methodprediction model
NETL
NSTL
万方数据
维普
