News of the month

News from the interface between the infinite istropic half-spaces of geoscience and technology. Got tips? 

Matt was at the SEG Annual Meeting in Las Vegas at the beginning of the month. If you didn't make the trip, and even if you did, Don't miss his highlights posts.

Webapp for wells

This is exciting. Subsurfr could be the start of a much-needed and long-overdue wave of rapid web innovation for petrotechnical tools. Much kudos to tiny Wellstorm Development for the bold initiative; it makes you wonder what on earth Halliburton and Schlumberger are up to. Right from your browser, you can fly around the subsurface of North Dakota, see logs, add picks, build surface segments, and provide the creators with feedback. Try it out!

OpendTect gets even awesomer 

OpendTect goes from strength to strength, having passed 100 000 downloads on about 11 November. If you haven't tried it yet, you really should. It's like all those other integrated volume interpretation tools, with the small difference that it's open source-you can read the code. Oh, and it's free. There is that.

Paul de Groot, one of the founders of dGB, told me at SEG that he's been tinkering with code again. He's implemented GLCM-based texture attributes, and it will be in the open source base package soon. Nice.

The next big thing

Landmark's PowerCalculator was good. Geocraft was awesome. Now there's Canopy - Enthought's attempt to bring Python coding to the rest of us. The idea is to provide a MATLAB-like environment for the galaxy of mathematical and scientific computing packs for Python (numpy, scipy, matplotlib, to name a few). It's in beta right now — why not ask for an invite? Even more exiciting for geophysicists — Enthought is developing a set of geoscience plugins, allowing you to load SEGY data, display seismic, and perform other nifty tricks. Can't wait.

More Nova Scotia exploration

BP won licenses in the latest offshore exploration round (NS12–1), in exchange for a $1.05 billion work bid on 4 deep water parcels. This is in line with Shell's winning bid last January of $970 million, and they also added to their acreage — it seems there's an exploration renaissance happening in Nova Scotia. After the award, there were lots of questions about BP's safety record, but the licensing rules only allow for the highest bidder to win — there's no scrutiny of suitability at this stage. Awarding the license and later denying the right to drill seems a bit disingenuous, however. Water depth: up to about 3500 m!

This regular news feature is for information only. We aren't connected with any of these organizations, and don't necessarily endorse their products or services. Except OpendTect and Canopy, because they are awesome and we use them almost every day.

Update on 2012-11-29 13:58 by Matt Hall

Students... take the FIELD challenge!

This news just in (thanks Jesper!) — I knew all about the AAPG Imperial Barrel Award, but hadn't heard of EAGE's equivalent before — the FIELD Challenge. Applications must be in by 15 December. 

Great geophysicists #6: Robert Hooke

Robert Hooke was born near Freshwater on the Isle of Wight, UK, on 28 July 1635, and died on 13 March 1703 in London. At 18, he was awarded a chorister scholarship at Oxford, where he studied physics under Robert Boyle, 8 years his senior. 

Hooke's famous law tells us how things deform and, along with Newton, Hooke is thus a parent of the wave equation. The derivation starts by equating the force due to acceleration (of a vibrating particle, say), and the force due to elastic deformation:

where m is mass, x is displacement, the two dots denote the second derivative with respect to time (a.k.a. acceleration), and k is the spring constant. This powerful insight, which allows us to compute a particle's motion at a given time, was first made by d'Alembert in about 1742. It is the founding principle of seismic rock physics.

Hooke the geologist

Like most scientists of the 17th century, Hooke was no specialist. One of his best known works was Micrographia, first published in 1665. The microscope was invented in the late 1500s, but Hooke was one of the first people to meticulously document and beautifully draw his observations. His book was a smash hit by all accounts, inspiring wonder in everyone who read it (Samuel Pepys, for example). Among other things, Hooke described samples of petrified wood, forams, ammonites, and crystals of quartz in a flint nodule (left). Hooke also wrote about the chalk formations in the cliffs near his home town.

Hooke went on to help Wren rebuild London after the great fire of 1666, and achieved great respect for this work too. So esteemed is he that Newton was apparently rather jealous of him, and one historian has referred to him as 'England's Leonardo'. He never married, and lived in his Oxford college all his adult life, and is buried in Bishopsgate, London. As one of the fathers of geophysics, we salute him.

The painting of Hooke, by Rita Greer, is licensed under a Free Art License. It's a interpretation based on descriptions of him ("his chin sharp, and forehead large"); amazingly, there are no known contemporary images of him. Hear more about this.

You can read more about the relationship between Hooke's law and seismic waves in Bill Goodway's and Evan's chapters in 52 Things You Should Know About Geophysics. Download their chapters for free!

Units of geological time

I have an exercise in my writing course on scientific units. The last question is about units of geological time, and it always starts a debate. I favour ka, Ma, and Ga for all dates and spans of time, but I've never gone unchallenged. People like Ma BP, mya, m.y., myr, and lots of other things, and I've heard all sorts of rules for when to use which, and why. The sort of rules you can't quite remember the crucial details of.

Twitter isn't for everyone, but I think it has some real strengths — it's a great filter, a reliable connection finder, and a brilliant place to ask questions. So I asked Twitter, and compiled the responses in a storyboard:

The story exposed a useful blog post, an attempt to standardize (Aubry et al., 2009, Stratigraphy 6 (2), 100–105], another attempt [Holden et al., 2011, IUPAC–IUGS recommendation], and a firm rebuttal from Nick Christie-Blick. Many thanks to all my Twitter friends — one of whom I've actually met IRL!

Bottom line — there are regional variations and personal preferences. There's no consensus. Make your choice. Write unambiguously.

You own your brain

I met someone last week who said her employer — a large integrated oil & gas company — 'owned her'. She said she'd signed an employment agreement that unequivocally spelt this out. This person was certainly a professional on paper, with a graduate degree and plenty of experience. But the company had, perhaps unwittingly, robbed her of her professional independence and self-determination. What a thing to lose.

Agreements like this erode our profession. Do not sign agreements like this. 

The idea that a corporation can own a person is obviously ludicrous — I'm certain she didn't mean it literally. But I think lots of people feel confined by their employment. For some reason, it's acceptable to gossip and whisper over coffee, but talking in any public way about our work is uncomfortable for some people. This needs to change.

Your employer owns your products. They pay you for concerted effort on things they need, and to have their socks knocked off occasionally. But they don't own your creativity, judgment, insight, and ideas — the things that make you a professional. They own their data, and their tools, and their processes, but they don't own the people or the intellects that created them. And they can't — or shouldn't be able to — stop you from going out into the world and being an active, engaged professional, free to exerise and discuss our science with whomever you like.

If you're asked to sign something saying you can't talk at meetings, write about your work, or contribute to open projects like SEGwiki — stop.

These contracts only exist because people sign them. Just say, 'No. I am a professional. I own my brain.'

Touring vs tunnel vision

My experience with software started, and still largely sits, at the user end. More often than not, interacting with another's design. One thing I have learned from the user experience is that truly great interfaces are engineered to stay out of the way. The interface is only a skin atop the real work that software does underneath — taking inputs, applying operations, producing outputs. I'd say most users of computers don't know how to compute without an interface. I'm trying to break free from that camp. 

In The dangers of default disdain, I wrote about the power and control that the technology designer has over his users. A kind of tunnel is imposed that restricts the choices for interacting with data. And for me, maybe for you as well, the tunnel has been a welcome structure, directing my focus towards that distant point; the narrow aperture invokes at least some forward motion. I've unknowingly embraced the tunnel vision as a means of interacting without substantial choices, without risk, without wavering digressions. I think it's fair to say that without this tunnel, most travellers would find themselves stuck, incapacitated by the hard graft of touring over or around the mountain.

Tour guides instead of tunnels

But there is nothing to do inside the tunnel, no scenery to observe, just a black void between input and output. For some tasks, taking the tunnel is the only obvious and economic choice — all you want is to get stuff done. But choosing the tunnel means you will be missing things along the way. It's a trade off.

For getting from A to B, there are engineers to build tunnels, there are travellers to travel the tunnels, and there is a third kind of person altogether: tour guides take the scenic route. Building your own tunnel is a grand task, only worthwhile if you can find enough passengers to use it. The scenic route isn't just a casual lackadaisical approach. It's necessary for understanding the landscape; by taking it the traveler becomes connected with the territory. The challenge for software and technology companies is to expose people to the richness of their environment while moving them through at an acceptable pace. Is it possible to have a tunnel with windows?

Oil and gas operating companies are good at purchasing the tunnel access pass, but are not very good at building a robust set of tools to navigate the landscape of their data environment. After all, that is the thing that we travellers need to be in constant contact with. Touring or tunneling? The two approaches may or may not arrive at the same destination and they have different costs along the way, making it different business.

Segmentation and decomposition

Day 4 of the SEG Annual Meeting in Las Vegas was a game of two halves: talks in the morning and workshops in the afternoon. I caught two signal processing talks, two image processing talks, and two automatic interpretation talks, then spent the afternoon in a new kind of workshop for students. My highlights:

Anne Solberg, DSB, University of Oslo

Evan and I have been thinking about image segmentation recently, so I'm drawn to those talks (remember Halpert on Day 2?). Angélique Berthelot et al. have been doing interesting work on salt body detection. Solberg (Berthelot's supervisor) showed some remarkable results. Their algorithm:

1. Compute texture attributes, including Haralick and wavenumber textures (Solberg 2011)
2. Supervised Bayesian classification (we've been using fuzzy c-means)
3. 3D regularization and segmentation (okay, I got a bit lost at this point)

The results are excellent, echoing human interpretation well (right) — but having the advantage of being objective and repeatable. I was especially interested in the wavenumber textures, and think they'll help us in our geothermal work. 

Jiajun Han, BLISS, University of Alberta

The first talk of the day was that classic oil industry: a patented technique with an obscure relationship to theory. But Jiajun Han and Mirko van der Baan of the University of Alberta gave us the real deal — a special implementation of empirical mode decomposition, which is a way to analyse time scales (frequencies, essentially), without leaving the time domain. The result is a set of intrinsic mode functions (IMFs), a bit like Fourier components, from which Han extracts instantaneous frequency. It's a clever idea, and the results are impressive. Time–frequency displays usually show smearing in either the time or frequency domain, but Han's method pinpoints the signals precisely:

That's it from me for SEG — I fly home tomorrow. It's tempting to stay for the IQ Earth workshop tomorrow, but I miss my family, and I'm not sure I can crank out another post. If you were in Vegas and saw something amazing (at SEG I mean), please let us know in the comments below. If you weren't, I hope you've enjoyed these posts. Maybe we'll see you in Houston next year!

More posts from SEG 2012.

The images adapted from Berthelot and Han are from the 2012 Annual Meeting proceedings. They are copyright of SEG, and used here in accordance with their permissions guidelines.

Update on 2012-11-09 05:08 by Matt Hall

I just stumbled on another blog post about SEG! Laurent Duval has lots to read on his geophysicsy blog. Add it to your reader.

I was especially pleased to see him writing about Chuck Mosher's talk on the generalized windowed transform, because I was ill-equipped to write about it*, though it seemed 'important'. 

* I know what you're thinking — that doesn't usually stop me.

Brittleness and robovibes

Day 3 of the SEG Annual Meeting was just as rammed with geophysics as the previous two days. I missed this morning's technical program, however, as I've taken on the chairpersonship (if that's a word) of the SEG Online Committee. So I had fun today getting to grips with that business. Aside: if you have opinion's about SEG's online presence, please feel free to send them my way.

Here are my highlights from the rest of the day — both were footnotes in their respective talks:

Brittleness — Lev Vernick, Marathon

Evan and I have had a What is brittleness? post in our Drafts folder for almost two years. We're skeptical of the prevailing view that a shale's brittleness is (a) a tangible rock property and (b) a function of Young's modulus and Poisson's ratio, as proposed by Rickman et al. 2008, SPE 115258. To hear such an intellect as Lev declare the same today convinced me that we need to finish that post — stay tuned for that. Bottom line: computing shale brittleness from elastic properties is not physically meaningful. We need to find more appropriate measures of frackability, [Edit, May 2015; Vernik tells me the following bit is the opposite of what he said, apologies for my cloth ears...] which Lev pointed out is, generally speaking, inversely proportional to organic content. This poses a basic conflict for those exploiting shale plays. [End of public service announcement.]

Robovibes — Guus Berkhout, TU Delft

At least 75% of Berkhout's talk went by me today, mostly over my head. I stopped writing notes, which I only do when I'm defeated. But once he'd got his blended source stuff out of the way, he went rogue and asked the following questions:

1. Why do we combine all seismic frequencies into the device? Audio got over this years ago (right).
2. Why do we put all the frequencies at the same location? Viz 7.1 surround sound.
3. Why don't we try more crazy things in acquisition?

I've wondered the same thing myself — thinking more about the receiver side than the sources — after hearing about the brilliant sampling strategy the Square Kilometer Array is using at a PIMS Lunchbox Lecture once. But Berkhout didn't stop at just spreading a few low-frequency vibrators around the place. No, he wants robots. He wants an autonomous army of flying and/or floating narrow-band sources, each on its own grid, each with its own ghost matching, each with its own deblending code. This might be the cheapest million-channel acquisition system possible. Berkhout's aeronautical vibrator project starts in January. Seriously.

More posts from SEG 2012.

Speaker image is licensed CC-BY-SA by Tobias Rütten, Wikipedia user Metoc.

Smoothing, unsmoothness, and stuff

Day 2 at the SEG Annual Meeting in Las Vegas continued with 191 talks and dozens more posters. People are rushing around all over the place — there are absolutely no breaks, other than lunch, so it's easy to get frazzled. Here are my highlights:

Adam Halpert, Stanford

Image segmentation is an important class of problems in computer vision. An application to seismic data is to automatically pick a contiguous cloud of voxels from the 3D seismic image — a salt body, perhaps. Before trying to do this, it is common to reduce noise (e.g. roughness and jitter) by smoothing the image. The trick is to do this without blurring geologically important edges. Halpert did the hard work and assessed a number of smoothers for both efficacy and efficiency: median (easy), Kuwahara, maximum homogeneity median, Hale's bilateral [PDF], and AlBinHassan's filter. You can read all about his research in his paper online [PDF]. 

Dave Hale, Colorado School of Mines

Automatic fault detection is a long-standing problem in interpretation. Methods tend to focus on optimizing a dissimilarity image of some kind (e.g. Bø 2012 and Dorn 2012), or on detecting planar discontinuities in that image. Hale's method is, I think, a new approach. And it seems to work well, finding fault planes and their throw (right).

Fear not, it's not complete automation — the method can't organize fault planes, interpret their meaning, or discriminate artifacts. But it is undoubtedly faster, more accurate, and more objective than a human. His test dataset is the F3 dataset from dGB's Open Seismic Repository. The shallow section, which resembles the famous polygonally faulted Eocene of the North Sea and elsewhere, contains point-up conical faults that no human would have picked. He is open to explanations of this geometry. 

Other good bits

John Etgen and Chandan Kumar of BP made a very useful tutorial poster about the differences and similarities between pre-stack time and depth migration. They busted some myths about PreSTM:

• Time migration is actually not always more amplitude-friendly than depth migration.
• Time migration does not necessarily produce less noisy images.
• Time migration does not necessarily produce higher frequency images.
• Time migration is not necessarily less sensitive to velocity errors.
• Time migration images do not necessarily have time units.
• Time migrations can use the wave equation.
• But time migration is definitely less expensive than depth migration. That's not a myth.

Brian Frehner of Oklahoma State presented his research [PDF] to the Historical Preservation Committee, which I happened to be in this morning. Check out his interesting-looking book, Finding Oil: The Nature of Petroleum Geology. 

Jon Claerbout of Stanford gave his first talk in several years. I missed it unfortunately, but Sergey Fomel said it was his highlight of the day, and that's good enough for me. Jon is a big proponent of openness in geophysics, so no surprise that he put his talk on YouTube days ago:

The image from Hale is copyright of SEG, from the 2012 Annual Meeting proceedings, and used here in accordance with their permissions guidelines. The DOI links in this post don't work at the time of writing — SEG is on it. 

Update on 2012-11-20 13:28 by Matt Hall

Dave Hale kindly pointed me to a video he made, highlighting those weird conical faults. I think it's wonderful that it's characters like Jon Claerbout and Dave Hale that are leading a new dimension to our technical conferences. Thanks Dave!

Resolution, anisotropy, and brains

Day 1 of the SEG Annual Meeting continued with the start of the regular program — 96 talks and 71 posters, not to mention the 323 booths on the exhibition floor. Instead of deciding where to start, I wandered around the bookstore and bought Don Herron's nice-looking new book, First Steps in Seismic Interpretation, which we will review some time soon.

Here are my highlights from the rest of the day.

Chuck Ursenbach, Arcis

Calgary is the home of seismic geophysics. There's a deep tradition of signal processing, and getting the basics right. Sometimes there's snake oil too, but mostly it's good, honest science. And mathematics. So when Jim Gaiser suggested last year at SEG that PS data might offer as good resolution as SS or PP — as good, and possibly better — you know someone in Calgary will jump on it with MATLAB. Ursenbach, Cary, and Perz [PDF] did some jumping, and conclude: PP-to-PS mapping can indeed increase bandwidth, but the resolution is unchanged, because the wavelength is unchanged — 'conservation of resolution', as Ursenbach put it. Resolution isn't everything. 

Gabriel Chao, Total E&P

Chao showed a real-world case study starting with a PreSTM gather with a decent Class 2p AVO anomaly at the top of the reservoir interval (TTI Kirchhoff with 450–4350 m offset). There was residual NMO in the gather, as Leon Thomsen himself later forced Chao to admit, but there did seem to be a phase reversal at about 25°. The authors compared the gather with three synthetics: isotropic convolutional, anisotropic convolutional, and full waveform. The isotropic model was fair, but the phase reversal was out at 33°. The anisotropic convolutional model matched well right up to about 42°, beyond which only the full waveform model was close (right). Anisotropy made a similar difference to wavelet extraction, especially beyond about 25°.

Canada prevails

With no hockey to divert them, Canadians are focusing on geophysical contests this year. With the Canadian champions Keneth Silva and Abdolnaser Yousetz Zadeh denied the chance to go for the world title by circumstances beyond their control, Canada fielded a scratch team of Adrian Smith (U of C) and Darragh O'Connor (Dalhousie). So much depth is there in the boreal Americas that the pair stormed home with the trophy, the cash, and the glory.

The Challenge Bowl event was a delight — live music, semi-raucous cheering, and who can resist MC Peter Duncan's cheesy jests? If you weren't there, promise yourself you'll go next year. 

The image from Chao is copyright of SEG, from the 2012 Annual Meeting proceedings, and used here in accordance with their permissions guidelines. The image of Herron's book is also copyright of SEG; its use here is proposed to be fair use.

The tepidity of social responsibility

Like last year, the 2012 SEG Forum was the only organized event on the morning of Day 1. And like last year, it was thinly attended. The title wasn't exactly enticing — Corporate and Academic Social Responsibility: Engagement or Estrangement — and to be honest I had no idea what we were in for. This stuff borders on sociology, and there's plenty of unfamiliar jargon. Some highlights:  

• Part of our responsibility to society is professional excellence — Isabelle Lambert
• At least one company now speaks of a 'privilege', not 'license', to operate — Isabelle Lambert
• Over-regulation is harmful, but we need them to promote disclosure and transparency — Steve Silliman
• The cheapest, easiest way to look like you care is to actually care

What they said

Mary Lou Zoback of Stanford moderated graciously throughout, despite being clearly perturbed by the thin audience. Jonathan Nyquist of Temple University was first up, and told how he is trying to get things done with $77k/year grad students using $50k grants when most donors want results not research.

Isabelle Lambert of CGGVeritas (above) eloquently described the company's principles. They actually seem to walk the walk: they were the only corporation to reply to the invitation to this forum, they seem very self-aware and open on the issue, and they have a policy of 'no political donations' — something that undermines a lot of what certain companies say about the environment, according to one questioner. 

Steve Silliman of Gonzaga University, a hydrologist, stressed the importance of the long-term view. One of his most successful projects has taken 14 years to reach its most impactful work, and has required funding from a wide range of sources — he had a terrific display of exactly when and how all this funding came in. 

Finally Michael Oxman, of Business for Social Responsibility, highlighted some interesting questions about stakeholder engagement, such as 'What constitues informed consultation?', and 'What constritutes consent?'. He was on the jargony end of things, so I got a bit lost after that.

What do you think, is social responsibility part of the culture where you work? Should it be? 

A footnote about the forum

"Social responsibility has become a popular topic these days", proclaimed the program. Not that popular, it turned out, with less than 2% of delegates showing up. Perhaps this is just the wrong venue for this particular conversation — Oxman pointed out that there is plenty of engagement in more specific venues. But maybe there's another reason for the dearth — this expert-centric, presentation-driven format felt dated somehow. Important people on stage, the unwashed, unnamed masses asking questions at the end. There was a nod to modernity: you could submit questions via Twitter or email, as well as on cards. But is this format, this approach to engagement, dead?

There's nothing to lose: let's declare it dead right now and promise ourselves that the opening morning of SEG in 2013 will be something to get our teeth into.