精细地震成像技术在吐孜阿瓦特地区的应用研究

Applied reserch of fine seismic imaging technology in Tuziawat area

吐孜阿瓦特地区石油地质条件优越,但该区处于克拉苏构造带西端与乌什凹陷结合部位,构造变形复杂,且受地表及地下地质条件的影响,地震资料成像效果较差.本文针对该区特殊的地质构造环境,结合老资料处理的实际情况,为满足高分辨率、高信噪比的地震资料处理要求而成功实验了以叠前预处理、优化速度分析和偏移成像为核心的精细地震成像技术,使各种噪声得到很好的压制,各种波得到准确的归位,从而使得地下地质构造得到更精确的呈现,为该区的高精度构造解释和地质解释提供了可靠保证.

The petroleum geological condition in Tuziawat area is rich, but the region is located at the binding site of Crassus＇ structural belt west end and Wushi Sag, and because of complicated tectonic deformation, and the geological conditions of surface and underground, the seismic data imaging effect is poor. According to the special geological environment, combined with the actual situation of the previous data, and in order to meet the needs of high resolution, high signal to noise ratio of seismic data processing requirements, the paper successfully experimented on the fine seismic imaging technique, including pretreatment before stack, optimal velocity analysis and migration imaging. The core of pretreatment is series deconvolution technique, which includes surface consistent deconvolution and predictive deconvolution, the combination of the two steps make all kinds of noise to be well suppressed and enhances the resolution under the precondition of improving the Signal-to-Noise. Optimal velocity analysis comprises mainly the iterating between velocity analysis and residual static correction, linking constant-velocity scaning with variable-velocity scaning, which make the profile present better imaging effect. After a series of optimizing for velocity, migration imaging make various waves get accurate position. Compared with post-stack migration, prestack depth migration makes imaging more accurate and the underground geological structures be more precise, thus provides a reliable guarantee for the district＇s high precision structural interpretation and geological explanation.