Abstract: An partial stack gather inversion method is put forward. Partial stack data retain original rich information. Restrained by logging and structural interperation results, initial model may be the most close to the actual underground conditions. Through nonlinear optimization theory, using trace by trace extrapolation, more accurate P-wave and S-wave velocity of every point can be inverted simultaneously, and then the P-wave and S-wave velocity ratio and Poisson’s ratio can be obtained, so that provide rich elastic parameters information for reservoir prediction and fluid identification.

Key words: P-wave velocity, S-wave velocity, seismic inversion, hesse matrix, gas identification