Three-parameter AVO inversion based on Gray equation and prediction of CBM enrichment zone

Elastic parameters of coal reservoir can be got directly through AVO inversion to guide the evaluation of reser-voir. Based on the introduction of the Gray approximate equation, the equation is used to study the three-parameter AVO in-version, the density, the bulk modulus and the shear modulus of CBM reservoir can be calculated directly. According to the characteristics of three elastic parameters in CBM enrichment zone, CBM enrichment zone was delineated after comparing the three elastic parameters. Finally,through model and case analysis, the feasibility of the method was verified.