Analysis of array forming using the Blackfoot high-resolution 3-C data

Brian H. Hoffe, Darren S. Foltinek, Henry C. Bland, Gary F. Margrave, Peter Malcolm Manning

During November 1997 the CREWES Project at the University of Calgary recorded a 3C-2D seismic survey at the Blackfoot field east of Calgary. This survey consisted of recording dynamite shots into a combination of conventional 20 m and high-resolution 2 m receiver intervals. We used this high-resolution data to examine two alternative approaches to array design by simulating 3-C receiver arrays via convolution in the t-x domain. The effectiveness of each approach was then evaluated by analysing the response in both the t-x and f-k domains. The post-stack effect was also compared by analysing the f-x response of both the final P-P and P-S structure stacks produced using these two array design philosophies.

The pre-stack analysis showed that these two approaches were effective in suppressing coherent noise on both the vertical and radial data and performed reasonable well as anti-alias filters. The post-stack analysis revealed that for both the P-P and P-S data neither of the two design approaches improved the quality of the final seismic image over that obtained from non-arrayed data. For the P-P data there was no discernible difference between the final stacked sections, while for the P-S data there was a noticeable deterioration in image quality from the application of arrays. Thus we conclude that, for the Blackfoot area, given the source configuration used, field implementation of 3-C arrays are unnecessary for P-P data acquisition and are certainly detrimental to the recording of P-S data.