Patent ID: 8995223
Filing Date: 2015-03-31
Classification: G01V

Abstract:
1. A method for removing Scholte waves and similar ground roll type waves from seismic sea bottom data in shallow waters, the method comprising the steps of: acquiring seismic sea bottom data in shallow waters; applying a time-frequency-wave number (t-f-k) transform to the acquired seismic sea bottom data to get a three-dimensional result in a time-frequency-wave number domain; identifying a time-frequency relationship of a surface wave based on a specific wave number; identifying a frequency-wave number relationship of a surface wave based on a specific time; designing a time varying frequency-wave number filter in the time-frequency-wave number domain based on the identified time-frequency relationship and the identified frequency-wave number relationship to separate the surface wave; applying a time varying frequency-wave number filtering process to remove at least some undesired energy; and inversing a filtered record by applying an inverse S-Transform operation and an inverse Fourier Transform operation; wherein the time varying frequency-wave number filtering is performed to filter the time varying seismic waves and to distinguish between signals of the same frequency at different times to extract Scholte waves, interface waves and multiple waves from the ocean bottom seismic data without removing other seismic signals.