oa Inherited Uncertainties of Advanced Depth Migrated Images

The process of optimal data preconditioning is a critical framework shaping optimum depth imaging with “accurate” locations. This process serves as input to velocity model building and its qualitative evolution for each of the processing stages. Detailed attention was undertaken to suppress unwanted energy and latest “noise-controlled” deghosting method was applied to the data, ensuring recovery of amplitude and frequency for better demultiple and imaging target zones. The total wave field was decomposed into specular reflection and diffraction data allowing their separated imaging and multi-term surface multiple estimation towards optimal velocity model estimation (FWI and tomographical velocity updates) and focused depth migrated images. Latest advanced FWI was utilized to facilitate inversions of weaker energy of lower frequencies to be modelled and updated. The final derived velocity model was cross checked and validated with measured velocities from 15+ wells with velocity mistie uncertainties below 10% due to ambiguities of the interpreted horizons. Refined horizon picking is critical for gamma analyses for depth uncertainties along the horizons. With these views, justification of each step in the process contributing to uncertainty between seismic depth images and actual geological markers from wells and most importantly away from wells is clarified and further quantified.