The invention discloses a
full waveform joint inversion method for improving high steep structure
velocity inversion efficiency, and belongs to the
petroleum geophysical exploration field. The method comprises the steps: establishing an
observation system by inputting the initial velocity field, the shot
record and the focus
wavelet; utilizing traditional
reverse time migration to obtain the imaging result which is taken as a
reflection coefficient model, and applying linear forward modeling and linear
wave field back propagation; calculating the gradient directions of two
prism waveforms and adding the gradient directions together to calculate the inverse
gradient direction of the
prism waveform, using the
linear search method or a parabolic fitting method to calculate the updated step, and using the calculated
gradient direction and step to update the velocity; using the conventional
full waveform inversion method to update the velocity again, and determining whether or not to satisfy the error condition; if not, using the updated velocity as the input velocity, and updating the velocity again; and if so, outputting the inversion result. The
full waveform joint inversion method for improving high steep structure
velocity inversion efficiency reduces the dependency about whether the high steep structure information is missing in the initial model, and improves the inversion accuracy and efficiency for the high steep structure.