| Rich coal and poor oil is the current resource situation in China.As an emerging clean energy,with the development and the need for research,coal-bed methane gradually becomes the main part.Qinshui coalfield belongs to Qinshui Basin of Shanxi Province.It deposits the main coal seams from Carboniferous to Permian.It is an important commercial coalbed methane production area.However,the structure of this area is complex,the seismic multi solution is strong and the vertical and horizontal distribution of reservoirs is uneven,The conventional post stack inversion method can not meet the demand of predicting the gas bearing property of coalbed methane thin layer.Aiming at the difficulties of coalbed methane reservoir prediction in Qinshui coalfield,constrained by logging data,this thesis studies the seismic facies controlled nonlinear random inversion method,and obtains the P-wave velocity data volume with high resolution.In order to supplement the single inversion result of post stack inversion,the prestack inversion method is used to deeply calculate a variety of elastic parameters,and the sensitive parameters reflecting gas bearing property such as Poisson’s ratio and P-wave velocity are found through the results of joint inversion,Then comprehensively analyze and evaluate the distribution of coalbed methane with the coal structure and geological structure of the reservoir in this area.The practice results show that the identification accuracy of thin layers is significantly increased by combining post stack and pre stack inversion,and the coincidence with the logging data not involved in inversion is high,which provides an important basis for the division of coalbed methane dessert in Qinshui coalfield. |
