Lunchbox Geophysics

Pre-stack gathers conditioning for AVO and elastic inversion

Todor Todorov

Todor Todorov

Thursday, April 20th, 2017 – 12:00 PM
Chevron Building +15 Auditorium

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Abstract

AVO analysis and elastic inversion have become important tools in seismic reservoir characterization. Experience is showing that the CMP NMO-corrected gathers, required as an input to the AVO and elastic inversion processes, often require some form of additional processing, known as ‘gathers conditioning’. Different processing workflows may generate slightly different results, however those difference may be of great importance. One should have a good understanding of both, the processing algorithms and the expected AVO behavior to reliably perform the pre-stack gathers conditioning. Common issues that may require attention are high-amplitude noise (ground roll, spiky traces), multiple energy, dipping linear noise, frequency balancing, amplitude scaling, residual NMO-correction (gather flattening). A number of methods have been developed to address some of those issues.

Recently, Todorov and Margrave (CSEG, 2016) have introduced the Borga transform, which is a real-valued time-frequency decomposition of the seismic amplitude. A number of new processing approaches have been developed, which are found to be well applicable to the pre-stack gathers conditioning workflow. By combining those new approaches with more traditional ones, like the Radon transform, one can achieve the goal of AVO ready gathers. Those processing tools should be used with care. There are a number of pitfalls and one should be aware of those. It is important to assign some form of confidence level to the final result, which can be part of the final prospect evaluation.

Biography

Todor Todorov is a Senior Consulting Geophysicist, specializing in seismic inversion and AVO analysis. He holds Master of Science degree in Geophysics from University of Calgary and he is currently pursuing his PhD with Dr. Gary Margrave as a supervisor.

Todor started his career as a project geophysicist for Hampson-Russell Software. Later, he joint Petro-Canada as a Seismic Reservoir Characterization specialist. In April, 2014, Todor started his own consulting company. His research interests include all aspect of seismic data processing and inversion for rock properties. In 2016 he won “Best Oral Presentation” award at the CSEG annual conference.