Sweet-spot prediction for CBM reservoir based on seismic inversion parameters

Accurate prediction of CBM sweet spot would improve the reservoir exploration efficiency.In this paper,based on the definition condition for CBM sweet-spot and took advantage of seismic inversion parameters in physical significance and 3D display,we decided to take the gas content,coal-bed thickness,reservoir depth,tectonic stress,fracture density and coal structure types distribution as the predictors for CBM sweet-spot prediction.By using modified entropy method to calculate the weight of predictors,the prediction result of CBM sweet-spot for target reservoir would be exhibited in layer slice style.The comparative analysis between the prediction values and the daily gas production in whole well position shown that the two values were in good agreement except X2 well with an accuracy rate of 85%.Accordingly,the research result exhibited that the method proposed by modified entropy method based on the six types seismic inversion parameters mentioned above was feasible in CBM sweet spot prediction.