Abstract: There exits obvious limitations by using P-wave data for reservoir characterization alone in Sanhu area, Qaidam Basin, due to energy absorbing and structure distortion caused by underground gas. Affected by many factors, using P-wave data alone may lead to multi-solution problem. This problem could be solved by using multi-wave seismic exploration techniques and converted-wave data, and the accuracy of reservoir forecast and oil-gas detection could be improved a lot. Taking seismic exploration in Sanhu area based on multi-wave data as an example, the converted-wave data processing technique and the interpretation technique combining multiple waves have been improved. Based on making breakthroughs in converted-wave static correction and prestack time migration, and using high-quality multi-wave data, the interpretation technique combining multiple waves has been improved; joint analysis of multi-wave seismic attributes and oil-gas detection have been conducted to confirm lithologic gas reservoirs. Good geological results have been achieved in practical drilling and exploration.

Key words: converted wave, common converted point, prestack time migration of converted wave, P-wave and converted-wave registration, joint inversion, joint attributes analysis