The method for low signal-noise ratio seismic data processing in Bachu uplift, Tarim Basin

Abstract：The prospecting extent in the whole Bachu uplift of Tarim Basin is relatively low, which however is a potential area for oil and gas exploration. The poor near-surface shooting conditions, deeply buried target areas and deep geological conditions result in the serious seismic data static correction problem, highly-developed interference wave, difficulties in correct recognition of multiple wave, improvement of the energy of deep reflection wave and accurate obtaining of the velocity and migration imaging. Low S/N ratio data and poor quality have greatly restricted the capability of solving the geological problem by using seismic data. Through an analysis of newly acquired seismic data, the authors accurately built a near-surface model for calculating accurate static values and enhancing pre-stack attenuation. Various amplitude energy compensation methods were used for accurate velocity analysis to improve the precision of the velocity field, and inner mute was adopted in near traces. Integrated application of cascade methods was adopted to eliminate multiple interference, migration method was chosen for improving the imaging quality of deep weak signal and S/N ratio in this low S/N ratio area and, as a result, event continuity and structure imaging quality were greatly enhanced and improved, thus attaining superior applying results.