According to geologic model of unsteady groundwater flow in heterogeneous medium and adopting the finitedifference solution, the direction and strength of oil gas migration can be quantified.
The finitedifference depth migration equation in space-frequency domain can be derived when the radical expression is approximated by continued fraction.
采用连分式近似，可以得到空间频率域的有限差分深度偏移方程。
3
The key to all-dip wave field migration using finite-difference method lies in the continuation direction of wave field.