Good Vibrations

I introduce the common principles for building robust saturated rock physics models, with emphasis upon ways for these models to augment quantitative seismic interpretation (QI). Machine learning and geologically-consistent rock physics modeling workflows are mentioned, I review the hits and misses for the industry pursuing very-low-frequency signals, explain for critical FWI has become in QI workflows, and showcase how smart rock physics workflows enable rapid frontier exploration and prospectivity studies with minimal well control. AVO and AVA Represent What? Most geoscientists who work with seismic data understand how subsurface contrasts in impedance between superimposed geological formations cause seismic reflectivity to vary as a function of angle for incident wavefields (‘Amplitude versus Angle or Offset: AVA or AVO). AVA / AVO information is used at a variety of scales: from screening 3D seismic volumes to identify spatial contrasts in AVO classes, to ‘absolute’ pre-stack simul

Is the modern trend by many corporations to encourage their workforces to be innovative, often forcing groups into brainstorming or scheduled ‘creativity’ sessions, in fact the antithesis of creativity? A small group of academics at the Institute of Personality Assessment and Research (IPAR), University of California, Berkeley in the late 1950s enlisted 40 highly successful and world famous architects for an extraordinary set of tests in a rigorous scientific study which aimed to discover: what makes someone creative? Although all the subjects were male, the study results were of remarkable value nevertheless. Inexplicably forgotten, that study was revived by Pierluigi Serraino in a new book ‘The Creative Architect: Inside the Great Midcentury Personality Study’. Creativity: Being Oneself The Berkeley research team's leader, Donald MacKinnon, commented later, "The process of creativity is not easily come by, nor are all of its phases easy to endure." The architects turned

The means by which 'migrated' seismic images are formed is used to illustrate how easily the final images can be degraded by the seismic migration process itself. I mention a few key considerations to avoid the degradation of seismic image quality and resolution during traditional workflows. The Superposition of Partial Seismic Images The animated illustration below of Kirchhoff migration for one offset plane illustrates how the superposition of 'partial images' from discrete trace locations builds up a seismic image.  Kirchhoff migration of individual seismic traces, each corresponding to a common source-receiver offset (i.e., 'offset plane'), is used to build an increasing higher quality 'summed' image by superimposing each 'partial image' from more closely-spaced traces. As trace spacing decreases (i.e., spatial sampling improves), the reconstructed seismic image more closely represents the subsurface geology. The final result represents a sin

Practitioners in the marine seismic industry have focused upon the benefits of enhanced low-frequency amplitudes in recent years: benefits to improved velocity model building with FWI (full waveform inversion), enhanced quantitative prediction of subsurface rock and fluid properties, and cleaner seismic event character for seismic interpretation. In some sense, the benefits of enhanced high-frequency amplitudes has less prominence, partly because the inescapable effects of absorption and dispersion are seen as insurmountable. I revisit this topic and show some encouraging solutions to enhance high-frequency signal content in seismic images. Temporal Frequency Loss: Attenuation Effects The introductory figure above is an unfortunate reminder that the resolution of seismic images is extremely coarse. At exploration targets in the range of 3 or 4 kilometers below the surface, the dominant seismic wavelength will be several tens of meters, so using a well-known rule-of-thumb that the visib