Interpretation of 2D seismic data is often challenging, especially in land data with complex overburden. Out of plane energy, S-wave contamination and low signal to noise ratio often results in a seismic section with considerable levels of uncertainty. A novel, yet often overlooked, method available to an interpreter as part of a processing or re-processing project is the percentage velocity migration scan method whereby velocity fields are perturbed around a centrally picked velocity function and pre-stack migrated to yield a series of differently imaged and stacked sections. These sections, often built from velocity models perturbed to 80-120% from the central velocity field, can then be examined by the interpreter to narrow down levels of uncertainty. Scanning through the sections will potentially enable identification of out of plane energy compared to that in the plane, it may focus events that exhibit unconventional move-out, and can lead to a greater appreciation of event positioning uncertainties. The velocity scanning method is often used as a processing tool (Gong et al. 2018) to help narrow down uncertainty surrounding velocity functions used in the pre-stack migration workflow but is rarely used by a seismic interpreter. With modern computing power and advanced imaging algorithms, this approach can easily be adopted into the seismic interpreter's toolkit. With a delivery from the processing house of up to 20 sections to interpret from, instead of just the one deemed most likely by the processor, this brings uncertainty management into the hands of the interpreter where it can be understood and managed as part of the interpretation flow.

Open-Access Online Publication: May 31, 2023