A Procedure to Improve Low Frequency Content of a Seismic Trace by Side Lobe Reduction

In a seismic trace the location of a reflector is indicated by a reflection wavelet which consists of a main lobe, surrounded by side lobes which add no extra information. Side lobes are result from the lack of the low frequency content in a reflection wavelet. The aim of the study is to reduce side lobes by using the complex trace envelope and thus improve low frequency content of a seismic trace. The method is based on comparing the energies in the reflection events in a seismic trace. The energies are calculated by summation and subtraction of the seismic trace with its envelope trace and thus a polarity table from proportion of these energies is obtained. The resulting polarity table is multiplied to the envelope trace and the result is an envelope trace that has positive valued reflection events and negative valued reflection events in agreement with the corresponding reflection coefficient. The result is that the main lobe in the seismic trace is increased whereas the side lobes are diminished. Tests are done on synthetic and real data. Consequently, low frequency content is improved and it may be stated that resolution and interpretability of the seismic data are increased.