Phase correction and vertical resolution enhancement of seismic data utilizing post stack wavelet extraction from well data

Abstract

The method of post-stack wavelet extraction utilizing well log data has been described by Ramsden and Hobson (1987) and Danielson and Karlson (1984). This paper presents the results of the application of this method to two vintages of vibroseis data from the Eromanga Basin, Queensland, Australia. A perennial problem in the mapping of seismic data, recorded over the same locality, is the character and timing mismatch often found between different vintages of data. Utilizing well logs a post stack wavelet is extracted from each vintage of seismic data, and used to deconvolve each vintage's wavelets to zero phase. In the area of interest it is found that the wavelets on the two datasets are out of phase by approximately 70 degrees. A wavelet deconvolution operator is designed to correct the data to zero phase. This improves the character and timing misties between the different vintages of data and also improves the vertical resolution of the seismic data. The stability of the seismic wavelet over the survey area is demonstrated by extracting the wavelet from the two wells which are separated by approximately 50 kilometres.