Based in Mahone Bay, nova scotia, agile libre is an independent publisher of technical books about the subsurface.  

The last fifteen years

There are only two things in the universe that remain constant over time:

1. Change.
2. Resistance to change.

Perhaps the biggest contribution to interpretative geophysics in the last decade and a half has been Bill Goodway’s introduction of the lambda-mu-rho or LMR formulation for amplitude-versus-offset (AVO) inversion. Dave Cooper likes to say that LMR really stands for ‘Let’s Measure Rocks’. But as with all great ideas, Bill encountered his share of detractors. I used to tell him, ‘That’s proof you are on the right track!’ The naysayers argued that although it opens up the crossplots and makes them easier to interpret, LMR is no more precise than any other AVO method. They failed to recognize the significance of the method.

Every geologist is trained from the outset to differentiate rocks based on their hardness and brittleness, and that’s precisely what lambda and mu are. Few geologists have an intuitive feeling for Poisson’s ratio or Young’s modulus. Bill had formulated AVO in a framework which transcended geophysics, connecting to the disciplines of geology and engineering. More importantly, managers could now understand the AVO crossplots! LMR also removed the difficulty of reconciling static and unbounded laboratory measurements with the dynamic bounded measurements of seismic waves. As Bill has demonstrated many times, most standard equations in anisotropy and geomechanics add more insight when they are expressed in LMR terms.

The Megabin method

Bill also recognized that pre-stack interpretation needed better 3D sampling than was provided by standard orthogonal acquisition methods. He pioneered the use of interpolation as an integrated part of acquisition to achieve better offset and azimuth sampling with his patented Megabin technique. This concept was first proposed by Jon Claerbout in a course that Bill and I took together in 1994, as well as in one of his textbooks. However, to my knowledge, Bill was the first to actually go out and do it. With the arrival of better interpolation techniques, the approach is now a common part of many wide azimuth methods.

The resource play upheaval

It’s not only new tools that have made the last 15 years so exciting. The emergence of the resource play concept has brought about vast changes in interpretive geophysics. Advances in technology are making accessible the huge volumes of hydrocarbons that reside in the tighter reservoirs of the world (the lower end of the resource pyramid). This idea was pioneered by Canadian Hunter in the Deep Basin in the 1970s and by Encana everywhere in North America in the past decade. Almost overnight, seismic interpretation went from being the leading edge of exploration to what some viewed as a lesser development support role. In its wake, this transformation left many a bitter and disillusioned geophysicist, not the least of whom was Bill Goodway. That is until Bill snapped out of it and adapted to the new reality. Now, once again, he is leading the way for the rest of us. You see, it turns out that geology is not one of the universal constants, something the ‘gas factory’ models tend to overlook. There is still a major role for us to play, but it has evolved. The geophysicist of today has to be an expert in the areas of anisotropy and geomechanics, and understand new tools, such as microseismic data.

If there is a lesson for a young geophysicist, it is this: your most important career skill is the ability to adapt to change, instead of resisting it. And this is becoming even more important as we wake up to the third universal constant:

3. The rate of change is increasing!

I have had an extremely satisfying and exciting career. I have walked among and stood upon the shoulders of giants: Claerbout, Robinson, Treitel, Taner, Hampson, Russell, Goodway, to name just a few! However, when I go through that door for the last time, my final thought will be, ‘I wonder what geophysics will be like 40 years from now.’

I guess I’ll have to hang around and find out…  

Why do we have all this stuff anyway?

What is homeomorphy?

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