The Seismic Family Tree
When you consider a family tree, you likely envision a primary Root Ancestor accompanied by all their descendants: their children, grandchildren, and even great-grandchildren. We can comfortably visualize how this tree is structured, tracking a family’s lineage from its earliest roots to its newest branches.
This same concept applies to seismic data, but, as we’ll soon discover, it can become very complex quite rapidly. The acquired data acts as the Root Ancestor, and each instance of data processing or reprocessing gives birth to a new offspring. Some versions yield many children, grandchildren, and great-grandchildren, while others may not bear any children at all. Every processing step brings forth more offspring until the final interpretation volume is achieved. Nevertheless, even then, interpreters may decide to employ different versions for their interpretation. Despite these complexities, the subsequent versions never stray far from their Root Ancestor, and the tree can still be navigated.
However, real chaos ensues when interpreters utilize both pre-stack and post-stack volumes to construct additional branches. Acquisition footprints are suppressed. Filters and AGCs are implemented. Attributes of all sorts are calculated. EBCDIC headers are altered (or not written) and might not cite the correct, clean volume utilized as an input. Datasets loaded into workstations are disassociated from EBCDIC, Binary, and Trace headers. They’re clipped or transformed into other formats. Following these alterations, tracing a volume back to the original processed version, let alone the Root Ancestor, might be nearly impossible!
And it doesn’t stop there. Even the parent can be compromised when numerous individual surveys merge into one. A combined survey now signifies a new Root Ancestor, complete with an entirely new family tree. Moreover, not all original traces from each combined survey will be used, due to permit issues and areas of interest.
Are you preserving an accurate seismic family tree? Are you documenting the offspring as they’re born and pinpointing the most productive branches contributing to the final interpretation volumes? This might seem daunting, but armed with the correct technology and processes, you can start to assert control over your seismic ancestry, ensuring it remains accurate, easy to navigate, and well-populated.
—
About Don Robinson
Don Robinson has dedicated over 50 years to software development and seismic analysis. He founded Oklahoma Seismic Corporation in 1980 and co-developed the MIRA interpretation system, later acquired by Landmark Graphics in 1993. He then started Resolve GeoSciences in 1997, where he now leads the development of SeisShow and AnalyzeSE, software for analyzing and correcting SEG-Y seismic data.
Connect on LinkedIn
