Frequency bandwidth enhancement using continuous wavelet transform and random noise attenuation by f-xy filtering technique – a case study from Badin oilfield, Indus basin, Pakistan

Asad Taimur,Sylwia Tomecka-Suchon,Fahad Mehmood,Akinniyi Akinsunmade,Z Pilecki,J Dubiński,J Dec,Z Kalab

doi:10.1051/e3sconf/201913301007

Abstract

Routine seismic data processing does not always meet the quantitative interpreters’ expectations especially in areas like Badin, where prospective thin bed B – sand interval is ambiguous throughout the seismic volume. Continuous Wavelet Transform (CWT) provides detailed description of seismic signal in both time and frequency without compromising on window length and a fixed time-frequency resolution over time-frequency spectrum. We present enhancement of seismic data for effective interpretation using the bandwidth extension technique. Implementing bandwidth extension, the dominant frequency increases from 18 Hz to 30 Hz and the frequency content boosted from 40 Hz to 60 Hz. Noise inclusion by the technique was suppressed by F-XY predictive filter and F-XY deconvolution with edge preserve smoothing. Phase and spectral balancing were applied to partial angle stacks to stabilize the phase rotation across the 3D survey, particularly for far offset stack. Frequency was balanced using surface consistent spectrum balancing, and subjected to trace scaling for amplitudes balance and preservation. Results of the techniques yielded unique improvement on the data resolution and subtle information about the thin sand beds were better delineated. Tuning thickness analysis reveals the usefulness of bandwidth extension, with an increase of 30% in the resolving power of thin beds.

Highlights

Seismic data pre-conditioning was performed on a portion of 3D volume from Badin area dominated by random noise and slightly poor resolution
The frequency bandwidth extension technique was applied to the 3D seismic cube of the Badin study area in Lower Indus Basin, Sindh, Pakistan
As observed from the above figures, it shows that extending the seismic frequency bandwidth has resulted in sharpening of the wavelet, which thereby attenuate wavelet compression and increase in temporal resolution

Summary

Introduction

Seismic data pre-conditioning was performed on a portion of 3D volume from Badin area dominated by random noise and slightly poor resolution. The pre-conditioning of the seismic data showed a remarkable improvement in the continuity of the reflectors, recognition of small faults, improvement in the frequency bandwidth of the data and harmonizing the phase as well as amplitude of the seismic data. This process was applied to both partial and full stack data. The flow chart of the seismic data pre-conditioning is illustrated in (Fig. 1)

Methods

Results

Conclusion