Identification of roof and floor lithology of coal measures strata based on double modes inversion method: a case of No.3 coal seam in Sihe mining area

Abstract

In order to improve the classification accuracy of No.3 coal seam roof and floor lithology in Sihe mine, the research of wave impedance and gamma ray pseudo acoustic impedance inversion method of dual mode identifications of coal bearing strata lithology of roof and floor were carried out to analysis well logging response characteristics of No.3 coal seam roof and floor lithology.The qualitative analysis results were used to find out the classifications of two kinds of parameters of roof and floor lithology, wave impedance and gamma ray.Combined with the data of No.3 coal seam in Sihe mining area, wave impedance natural gamma cross plot were used to find out the range of wave impedance and gamma quantitatively.Finally, the roof and floor lithology of common coal seam by wave impedance and natural gamma acoustic impedance double mode inversion method could be classified accurately.The results show that compared with the conventional impedance inversion method, the wave impedance and natural gamma pseudo acoustic impedance dual mode inversion method can accurately classify the top and bottom slate of coal seam.

Keywords

• coal seam
• roof and floor
• impedance inversion
• natural gamma pseudo acoustic inversion