Automatic first-arrival picking based on extended super-virtual interferometry with quality control procedure

Abstract

Static correction is a crucial step of seismic data processing for onshore play, which frequently has a complex near-surface condition. The effectiveness of the static correction depends on an accurate determination of first-arrival traveltimes. However, it is difficult to accurately auto-pick the first arrivals for data with low signal-to-noise ratios (SNR), especially for those measured in the area of the complex near-surface. The technique of the super-virtual interferometry (SVI) has the potential to enhance the SNR of first arrivals. In this paper, we develop the extended SVI with (1) the application of the reverse correlation to improve the capability of SNR enhancement at near-offset, and (2) the usage of the multi-domain method to partially overcome the limitation of current method, given insufficient available source-receiver combinations. Compared to the standard SVI, the SNR enhancement of the extended SVI can be up to 40%. In addition, we propose a quality control procedure, which is based on the statistical characteristics of multichannel recordings of first arrivals. It can auto-correct the mispicks, which might be spurious events generated by the SVI. This procedure is very robust, highly automatic and it can accommodate large data in batches. Finally, we develop one automatic first-arrival picking method to combine the extended SVI and the quality control procedure. Both the synthetic and the field data examples demonstrate that the proposed method is able to accurately auto-pick first arrivals in seismic traces with low SNR. The quality of the stacked seismic sections obtained from this method is much better than those obtained from an auto-picking method, which is commonly employed by the commercial software.

We have developed an automatic first-arrival picking method that combines extended super-virtual interferometry with quality control. The field data examples show that the proposed method yields stacked sections of similar quality to those obtained by laborious and costly manual picking.

Key words::

• complex near-surface, first arrival, interferometry, quality control, refraction, static correction.

Acknowledgements

We would like to thank the Tarim Oilfield Co., Xinjiang Korla, China, for providing us with exploration field data for research and publication. This work is supported by National Basic Research Program (2013CB228602), the National High Tech Research Program (2013AA064202) and the National Science and Technology Major Project (2011ZX05004–003) of China. The authors thank Professor Roy E. White and two reviewers for their comments and suggestions to improve the quality of this paper.