Three-dimensional supervirtual seismic refraction interferometry
- PDF / 5,688,030 Bytes
- 13 Pages / 595.224 x 790.955 pts Page_size
- 62 Downloads / 163 Views
ORIGINAL PAPER
Three-dimensional supervirtual seismic refraction interferometry Paul Edigbue1
· Abdullatif Al-Shuhail1
Received: 2 January 2016 / Accepted: 3 June 2016 / Published online: 29 June 2016 © Saudi Society for Geosciences 2016
Abstract Improved supervirtual interferometry (SVI) method that enhance the signal-to-noise ratio (SNR) of noisy seismic refraction data is presented. This 3D supervirtual algorithm is helpful in removal of side lobes caused by convolution in the conventional 3D SVI method. In this study, we extend the supervirtual seismic refraction interferometry method to 3D geometries commonly used in active seismic exploration. To achieve this objective, synthetic 3D seismic refraction data were created using single patch orthogonal geometry. Simple two-layers velocity model was used. A zero phase wavelet was convolved with the refraction travel time to create the seismic wiggle trace. The refraction arrival is computed using the equation for horizontal refractor case and is not adapted for dipping refractor. Noise of Gaussian distribution with zero mean and 0.25 standard deviation was added to simulate a case of moderate ambient noise. The supervirtual algorithm, consisting of crosscorrelation, alignment, summation, and first arrival calculation is performed. By aligning and summation of all the correlogram, the stationary position of source-receiver pairs as required in the 2D supervirtual method are eliminated in this case. Synthetic data presented in this study shows accurate first arrivals after the application of the 3D SVI and traces with much better SNR than the actual traces.
Paul Edigbue
paul [email protected] 1
Earth Sciences Department, King Fahd University of Petroleum and Minerals, Dhahran, Saudi Arabia
Keywords Supervirtual · Signal-to-noise ratio (SNR) · Crosscorrelation · Convolution
Introduction The quality of near-surface seismic data is expected to improve with modern acquisition design and array of geophones. In spite of the progress made in seismic surveying, seismic data still suffer from poor quality, especially data collected in areas with complex near-surface geology. Such conditions result in data showing improper imaging of geologic structures. This distortion of near-surface seismic signals occurs as a result of complex subsurface topography, varying lateral velocity, and noise traveling within the near surface layer. Areas where this geologic problem occurs pose great challenges to exploration activities. This poor data quality problem damps the effectiveness of traditional processing methods. Therefore, it became imperative to enhance the signal-to-noise ratio (SNR) of data with this peculiar problem before processing and interpretation. Near-surface records resulting from complex overburden can be imaged using the virtual source method (Bakulin and Calvert 2004). Korneev et al. (2008) used virtual source method to image complex overburden and they applied the technique to synthetic data acquired from model typical of Middle East structures. There are
Data Loading...
