Preserved Amplitude Processing of Complex Transitional Zone 2-D Seismic

Rodney Blackford*, Ding Yenn Maa, and Abdulaziz Al-Fares
KOC
*[email protected]

This presentation provides a sequence of results on relative amplitude processing and interpretation of complex transitional zone 2-D seismic data in the Arabian Gulf. Interpretation of the previous seismic data revealed dynamic mistie problems, which were caused by phase matching of seismic from several different energy sources, geophones and recording systems, as well as multiples and refraction static corrections. Low-relief structures and stratigraphic traps are the primary targets, and therefore the seismic data needed to be processed while preserving relative amplitude. This would permit inversion processing to image the structures as well as provide wavelet processing for seismic stratigraphy. Dynamite, mud-gun and air-gun sources were phase-matched to vibroseis to approximate zero-phase the data prior to the refraction static evaluation and calculations. A relative amplitude-consistent processing sequence of the data was applied throughout. The minimum amount of noise attenuation was used to achieve a balance between enhancing the signal-to-noise ratio, while preserving amplitude. A surface-consistent, triple-gate, second-zero crossing, predictive gap deconvolution was applied to avoid boosting the amplitude of multiples by whitening effects of a spiking deconvolution. Post-stack time migration (PSTM) was applied for additional enhancement of the signal, which improved the apparent post-stack frequency by reducing wavelet smearing in the stack process. Improved seismic to well log ties will be shown as well as solving the seismic mistie problems in the interpretation of events.

AAPG Search and Discovery Article #90077©2008 GEO 2008 Middle East Conference and Exhibition, Manama, Bahrain