1. School of Geosciences, China University of Petroleum (East China), Qingdao, Shandong 266580, China;
2. Geophysical Prospecting Research Institute, Shengli Oilfield Branch Co., SINOPEC, Dongying, Shandong 257022, China
Abstract：We firstly discuss in this paper surface wave suppression which is the most relative with the low-frequency data. Then we analyze respectively influences of low frequency on deconvolution, velocity analysis, NMO, stacking and prestack migration. Finally we carry out model and real data processing tests, and obtain the following observations: ①Surface wave suppression may lose part of low frequency signal. Area filtering is a better method compared with band pass filtering and FK filtering; ②Lack of low frequency signals will lead to false events in deconvolution and primary reflections will be inaccurate; ③Lack of low frequency will affect the accumulation of energy group on velocity spectrum or cause false energy group, which dicreases the velocity field precision; ④The lack of low frequency signal lead the increase of NMO stretching. The lack of low frequency 10 Hz and below will increase NMO stretching up to 20%; ⑤The signal-to-noise ratio will increase after stacking, but the false event caused by low frequency losing is obvious than on prestack gathers; ⑥In view of model data test, lack of low frequency causes smaller influences on migration than that people expect.
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