REMOVAL OF NOISE FROM SEISMIC DATA USING IMPROVED TAU-P FILTERS

摘要

Methods of processing seismic data to remove unwanted noise from meaningful reflection signals are provided for. The seismic data is transformed from the offset-time domain to the time-slowness domain using a Radon transformation. A high-low, preferably a time variant, high low corrective filter is then applied to enhance the primary reflection signal content of the data and to eliminate unwanted noise events. The tau-P filter is defined by reference to the velocity function of the primary reflection signals, and preferably is expressed as: 1 $\frac{1}{v_s\left(1+r_2\right)}\le p\le \frac{1}{v_s\left(1-r_1\right)}$ where r1 and r2 are percentages expressed as decimals. The slowness limits typically are set within ±15% of the velocity function, and r1 and r2 may be set accordingly. After filtering, the enhanced signal content is inverse transformed from the time-slowness domain back to the offset-time domain using an inverse Radon transformation. Suitable forward and reverse Radon transformations incorporating an offset weighting factor x'' and its inverse p'', where 0 2 $\begin{array}{c}u\left(p,\mathrm{tau}\right)={\int }_{-\infty }^{\infty }dx{\int }_{-\infty }^{\infty }dt\end{array}$