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Wavelet-Consistent Reprocessing of Multi-Environment 3D Seismic from Abu Dhabi

By

 Michael P. West1, Erik Kleiss2, Abu Baker Al Jeelani2, Mohamad Samir Al Nahhas2, Constantine Tsingas1

(1) Petroleum Geosciences Services, Cairo, Egypt (2) Abu Dhabi Company for Onshore Oil Operations (ADCO), Abu Dhabi, United Arab Emirates

 A vibroseis survey was reprocessed jointly with an adjacent transition zone survey. Previous HitDataNext Hit of high temporal and lateral resolution, and of good structural and stratigraphic accuracy is required here for mapping of subtle faults and improved reservoir characterization. Accurate statics solutions and reliable wavelets are critical - here 6ms false structure can make the difference of an oil well or one in the water. The older Previous HitdataNext Hit has laterally variable bandwidth, phase and structural errors, resulting from inadequate statics and from unsatisfactory matching of source- and receiver types.

Consistent Previous HitdataNext Hit character requires good wavelet corrections for the various source-receiver combinations. In our reprocessing, partly-deterministic and partly-statistical (PDPA) zero-phasing dealt with these issues. Well-proven deterministic phase corrections were applied to the vibroseis Previous HitdataNext Hit. A statistical deconvolution ("PSW designature") was used for zerophasing the impulsive-source Previous HitdataNext Hit and removing the hydrophone ghosts. This route avoids ad-hoc phase matching of overlapping parts of the Previous HitdataNext Hit. Our method was validated using numerous comparisons of pre-stack and stacked Previous HitdataNext Hit.

All Previous HitdataNext Hit were zero-phased before first-arrival Previous HitpickingNext Hit and refraction statics, ensuring consistency between statics-related and zerophasing-related time shifts. This avoids structural errors resulting from lateral phase variability. Phase-corrected impulsive-source first arrivals were found consistent with those for zero-phased vibroseis.

This approach for matching the various Previous HitdataNext Hit types yields a consistent Previous HitdataNext Hit character across the combined surveys. The easier correlation of first-arrival Previous HitdataTop and absence of any post-statics space-variant phase corrections is expected to improve the structural accuracy.