Grand challenges, anisotropy, and diffractions

Some more highlights from the two final days of the SEG Annual Meeting in Houston.

Grand challenges

On Friday, I reported on Chevron's take on the unsolved problems in petroleum geoscience. It was largely about technology. Ken Tubman, VP of Geoscience and Reservoir Engineering at ConocoPhillips gave an equally compelling outlook on some different issue. He had five points:

• Protect the base — Fighting the decline of current production is more challenging than growing production.
• Deepwater — Recent advances in drilling are providing access to larger fields in deep water, and compressed sampling in seismic will make exploration more efficient.
• Unconventionals — In regard to the shale gas frenzy, it is not yet obvious why these reservoirs produce the way that they do. Also, since resource plays are so massive, a big challenge will be shooting larger surveys on land.
• Environment and safety — Containment assurance is more critical than pay-zone management, and geophysics will find an expanding role in preventing and diagnosing environmental and safety issues.
• People — Corporations are concerned about maintaining world class people. Which will only become more difficult as the demographic bump of senior knowledge heads off into retirement.

The Calgary crowd that harvested the list of unsolved problems at our unsession in May touched on many of these points, and identified many others that went unmentioned in this session.

Driving anisotropic ideas

In the past, seismic imaging and wave propagation were almost exclusively driven by isotropic ideas. In the final talk of the technical program, Leon Thomsen asserted that the industry has been doing AVO wrong for 30 years, and doing geomechanics wrong for 5 years. Three take-aways:

• Isotropy is no longer an acceptable approximation. It is conceptually flawed to relate Young's modulus (an elastic property), to brittleness (a mode of failure). 
• Abolish the terms vertically transverse isotropy (VTI), and horizontally transverse isotropy (HTI) from our vocabulary; how confusing to have types of anisotropy with isotropy in the name! Use polar anisotropy (for VTI), and azimuthal anisotropy (for HTI) instead.
• λ₁₃ is a simple expression of P-wave modulus M, and Thomsen's polar anisotropy parameter δ, so it should be attainable with logs.

Bill Goodway, whose work with elasticity has been criticized by Thomsen, walked to the microphone and pointed out to both the speaker and audience, that the tractability of λ₁₃ is what he has been saying all along. Colin Sayers then stood up to reiterate that geomechanics is the statistics of extremes. Anisotropic rock physics is uncontestable, but the challenge remains to find correlations with things we actually measure.

Thomas Young's sketch of 2-slit diffraction, which he showed to the Royal Society in 1803.

Imaging fractures using diffractions

Diffractions are fascinating physical phenomena that occur when the conditions of wave propagation change dramatically. They are a sort of grey zone between reflection and scattering, and can be used to resolve fractures in the subsufrace. The question is whether or not there is enough diffraction energy to detect the fractures; it can be 10× smaller than a specular reflection, so one needs very good data acquisition. Problem is, we must subtract reflections — which we deliberately optimized for — from the wavefield to get diffractions. Evgeny Landa, from Opera Geophysical, was terse, 'we must first study noise, in this case the noise is the reflections... We must study the enemy before we kill it.'

Prospecting with plate tectonics

The Santos, Campos, and Espirito Basins off the coast of Brazil contain prolific oil discoveries and, through the application of plate tectonics, explorers have been able to extend the play concepts to offshore western Africa. John Dribus, Geological Advisor at Schlumberger, described a number of discoveries as 'kissing cousins' on either side of the Atlantic, using fundamental concepts of continental margin systems and plate tectonics (read more here). He spoke passionately about big ideas, and acknowledged collaboration as a necessity: 'if we don't share our knowledge we re-invent the wheel, and we can't do that any longer'.

In the discussion session afterwards, I asked him to comment on offshore successes, which has historically hovered around 14–18%. He noted that a step change — up to about 35% — in success occured in 2009, and he gave 3 causes for it: 

• Seismic imaging around 2005 started dealing with anisotropy appropriately, getting the images right.
• Improved understanding of maturation and petroleum system elements that we didn’t have before.
• Access to places we didn’t have access to before.

Although the workshop format isn't all that different from the relentless PowerPoint of the technical talks, it did have an entirely different feeling. Was it the ample discussion time, or the fact that the trade show, now packed neatly in plywood boxes, boosted the signal:noise? Did you see anything remarkable at a workshop last week? 

Key technology trends in earth science

Yesterday, I went to the workshop entitled, Grand challenges and research opportunities in geophysics, organized by Cengiz Esmersoy, Wafik Beydoun, Colin Sayers, and Yoram Shoham. I was curious if there'd be overlap with the Unsolved Problems Unsession we hosted in Calgary, and had reservations about it being an overly fluffy talkshop, but it was much better than I expected.

Ken Tubman, VP of Geosciences and Reservoir Engineering at ConocoPhillips, gave a splendid talk to open the session. But it was the third talk of the session, from Mark Koelmel, General Manager of Earth Sciences at Chevron, that resonated most with me. He highlighted 5 trends in applied earth science.

Data and information management

Data volumes are expanding with Moore's law. Chevron has more than 15 petabytes of data, by 2020 they will have more than 100PB. Koelmel postulated that spatial metadata and tagging will become pervasive and our data formats will have to evolve accordingly. Instead of managing ridiculously large amounts of data, a better solution may be to 'tag it and chuck it in the closet' — Google's approach to the web (and we know the company has been exploring the use of Hadoop). Beyond hardware, he stressed that new industry standards are needed now. The status quo is holding us back.

Full azimuth seismic data

Only recently have we been able to wield the computing power to deal with the kind of processes needed for full-waveform inversion. It's not only because of data volumes that new processing facilities will not be cheap — or small. He predicted processing centres that resemble small cities in terms of their power consumption. An interesting notion of energy for energy, and the reason for recent massive growth in Google's power production capability. (Renewables for power, oil for cooling... how funny would that be?)

Interpretive seismic processing and imaging

Interpretation, and processing are actually the same thing. The segmentation of seismic technology will have to be stitched back together. Imagine the interpreter working on field data, with a mixing board to produce just the right image for today's work. How will service companies (who acquire data and make images), and operators (who interpret data and make prospects) merge their efforts? We may have to consider different business relationships.

Full-cycle interpretation systems

The current state of integration is sequential at best, each node in a workflow produces static inputs for the next step, with minimal iteration in between. Each component of the sequence typically ends with 'throwing things over the wall' to the next node. With this process, the uncertainties are cumulative throughout, which is unnerving because we don't often know what the uncertainties are. Koelmel's desired future state is one of seamless geophysical processing, static model-building, and dynamic reservoir simulation. It won't reduce uncertainties altogether, but by design it will make them easier to identify and addressed.

Intellectual property

The number of patents filed in this industry has more than tripled in the last decade. I assumed Koelmel was going to give a Big Oil lecture on secrecy and patents, touting them as a competitive advantage. He said just the opposite. He asserted that industries with excessive patenting (think technology, and Big Pharma) make innovation difficult. Chevron is no stranger to the patent processes, filing 125 patents both in 2012 and in 2011, but this is peanuts compared to Schlumberger (462 in 2012) and IBM (6457 in 2012). 

The challenges geophysicists are facing are not our own. They stem from the biggest problems in the industry, which are of incredible importance to mankind. Perhaps expanding the value proposition to such heights is more essential than ever. Geophysics matters.

The future is uncertain

Image: Repsol, SEG. Click for the abstract.

SEG Day 2. In the session entitled Exploration and Uncertainty Analysis, I was underwhelmed with the few talks that I attended, except for the last one of the session entitled, Measuring time-map uncertainty. 

Static uncertainty

It is commonly uttered that different data processing companies will produce different results; seismic processing is non-unique, and so on. But rarely do I get to see real examples of the kind of variances that can occur. Bruce Blake from Repsol showed seismic imaging results that came back from a number of contractors. The results were truly shocking. The example he showed was an extreme case of uncertainty caused by inadequate static solutions caused by the large sand dunes in Libya. The key point for me is exemplified by the figure shown on the right: the image from one vendor suggests a syncline, the image from the other suggest an anticline. Beware!

A hole in the theory

In the borehole sonic session, Xinding Fang, a student from MIT, reinforced a subtle but profound idea: it is tricky to measure the speed of sound in a rock when you drill a hole into it. The hole changes the stress field, and induces an anisotropic stiffness around the circumference of the borehole where sonic tools make their measurements. And since waves take the shortest travel path from source to receiver, speeds that are measured in the presence of an artificial stress are wrong.

Image: Xindang Fang, SEG. Click for the abstract.

The bigger issue here that Xinding has elucidated is that we routinely use sonic logs to make time-depth relationships and tie wells, especially in the absence of a check-shot survey. If it works, it works, but if ever discrepancies exists between seismic and well, the interpreter applies a stretch or a squeeze without much thought. Some may blame the discrepancy on dispersion alone, but that's evidently too narrow. Indeed, we rarely bother to investigate the reasons.

There's a profound point here. We have to drop the assumption that logs are the 'geological' truth upon which to hang an interpretation. We have to realize that the act of making the measurement changes the very thing we want to measure. 

Past, present, future SEG

Today was the first day of the SEG Annual Meeting in Houston. 

Last night we wandered around the icebreaker, still buzzing from the hackathon. The contrast was crushing. The exhibition is gigantic — it's an almost overwhelming amount of marketing. My thoughts on what the exhibition hall is, and what it represents, are not fully formed and might be a bit... ranty, so I will save them for a more considered post. 

As usual, SEG kicked off with a general session — much better attended this year, but also much less ambitious. At least 300 members came to hear outgoing president David Monk's perspective on SEG's future. His address mostly looked backwards, however, at the trends over the last few years. I guess the idea is to extrapolate from there... But maybe we can do even better than recent years? We mustn't forget to do completely new and unexpected things too. 

At the end of his slot, Monk showed some animated renderings of SEG's new building in Tulsa. The movie was accompanied by an almost comically strident anthem — evidently it is a big deal. As well as having a smart new office, the real estate will turn in some smart new revenue from other tenants. Ground was broken on Friday, and the opening is expected to be in December 2014. As you see, the architects understood industrial geophysics quite well, opting for a large black box. 

At the end of the day, Canada strode home to yet another SEG Challenge Bowl victory as the University of Manitoba fought off the Autonomous University of Mexico and Colorado School of Mines to prove that, while Texas might be the home of the industry, Canada is the home of exploration geophysics. 

Where's all the geophysics? Evan is compiling some technical highlights from the day as I type. Stay tuned for that. 

If you're at the conference, tell us what you've enjoyed most about the first 24 hours.

Looking forward to SEG 2013

The SEG Annual Meeting is coming! The program starts tomorrow with the DISC, and continues over the weekend with various other courses. It's not part of the conference, but we're looking forward to the Geophysics Hackathon, obviously. Curious? You're welcome to drop in.

The meeting boasts 124 technical sessions totalling over 1000 PowerPoint presentations. If you haven't looked at the list of expanded abstracts yet, I can't blame you, it's a massive amount of content and the website experience is, er, not optimal — and there's no helpful mobile app this year. [Update: The app came out today! Go get it, it's essential. Thank you Whitney at SEG for letting us know.] I've tried to pick out a few sessions that seem really exciting below.

Worst. App. Ever.Each day at 10:30 am, I will be doing a guest presentation at the Enthought booth, showing some novel geophysics tools that I've been making. They are powered by Python and Enthought's Canopy environment. Come by and I will show you that you can too! However, I need somebody to please go to this exhibition booth 'browser' and show me where the Enthought booth is. Worst. App. Ever.

And each day at 11 am, there's a 2-hour mini-wikithon. Stop by the Press Room for a quick tour of SEG Wiki, and find out how you can help make it better.

Monday

With no technical presentations on Monday morning, it is safe to assume that most delegates will be wandering around the exhibition hall. A few may trickle over to the unenticing Opening Session which Matt and I found was horribly attended last year and the year before. Matt at least will be there, mostly out of morbid curiosity.

Continuing the Hackathon's theme on error and uncertainty, I will be diving into the session on Monday afternoon called

• Exploration and uncertainty analysis

From 3-6 pm be sure to check out the always popular SEG Student Challenge Bowl. The global finals, are hosted by the crowd-pleasing past SEG president (and fellow Canadian) Peter Duncan. Top pairings from Universities across the world duking it out in a button-pushing quiz show. Come out, cheer on the students and test your own geophysics trivia from the audience.

Tuesday

The sessions that look appealing to me on Tuesday are

• Novel systems and acquisition design,
• Seismic interpretation, and
• Attribute assisted seismic interpretation

Wednesday

Agile's good friend Maitri Erwin is the instigator behind the Women's Networking Breakfast. All are welcome; consider yourself lucky to connect with Maitri. As for talks, I will try make an appearance at

• Rock physics, and
• Compressed sensing

The first one I know quite a bit about, but can always use a refresher, and the second one I know very little about, but it's been a hot topic for 3 or 4 years now. If we aren't worn out at the end of the day, we might find some tickets to the Bayou Bash.

Thursday & Friday

There are over a dozen workshops on both Thursday and Friday. As far as I can tell, they are basically more talks, each around a central theme. Don't ask me how this is in any way distinguishable from the technical program, and there is still a full suite of technical sessions conflicting on Thursday morning. It's a shame because I'm curious to attend the session Fractures, shale and well-log characterization but I don't want to miss Workshop 2, Grand challenges, which takes place all day on Thursday. Then on Friday there's Characterizing fractures (Workshop 15).

There are many other events going on, so if you see something good, make sure you tweet the rest of us about it: @EvanBianco, @kwinkunks, @maitri, @toastar, and lots of others — follow hashtag #SEG13. (Not #SEG2013, that's all marketing wonks).

If you'll be at the Annual Meeting, do look out for us, we'd love to meet you. If you won't be there, tell us what you'd like to hear about. News from the exhibition? Our favourite talks? Detailed minutes from the committee meetings? Let us know in the comments.

Ten ways to make a difference

After reading my remarks yesterday about geoscience wikis, perhaps you're itching to share some of what you know. Below are ten quick ways to get started. And if you're going to SEG next week, you're in luck: you'll find a quick way to get started. 

Ten things you can do

First, if you really just want to dive in, here are ten easy things you can do in almost any wiki. Let's use SEG Wiki as an example — but this applies equally well to SubSurfWiki, PetroWiki, or Wikipedia.

1. Read it — find a page or category that interests you, and start exploring the content
2. Edit it — nothing tricky, but if you find a typo or other small error, hit Edit and fix it (you can do this without logging in on Wikipedia, but most other wikis require you to make an account first. This isn't usually a deliberate effort to put you off — allowing anonymous editing results in an amazing amount robot spam. Yes, robot spam.)
3. Share it — like most of the web, wikis need to be shared to survive. When you find something useful, share it.
4. Add a profile — if you're an SEG member, you already have an account on SEG Wiki. Why not add some info about yourself? Go log in to SEG.org then click this link. Here's mine. 
5. Add a sandbox — Edit your user page, add this: [[/Sandbox/]], then save your page. You'll see a red link. Click on it. Try some editing — you can do anything you like here. Again, here's mine — click Edit and copy my code. 
6. Fix equations — most of the equations in the SEG Encyclopedic Dictionary are poorly formatted. If you know LaTeX, you can help fix them. Here's one that's been fixed. Here's a bad one (if it looks OK, someone beat you to it :)
7. Add references — Just like technical papers, wikis need citations and references if they are to be useful and trusted. Most articles in SEG Wiki have citations, but the references are on another page. Here's one I've fixed. 
8. Add a figure — Again, the figures are mostly divorced from their articles. The Q article shows one way to integrate them. Some articles have lots of figures. 
9. Improve a definition — Many of the Dictionary definitions are out of date or unhelpfully terse. Long articles probably belong in the 'main' namespace (that is, not the Dictionary part) — so for example I split Spectral decomposition into a main article, apart from the short dictionary definition.
10. Add an article — This may seem like a big step, but don't be shy. Be bold! We can worry later if the new article needs to be split or combined or renamed or reformatted. The point is to start.

Wiki markup takes a little getting used to, but you can get a very long way with a little know-how. This wiki markup cheatsheet will give you a head start.

One place you can start

At the SEG Annual Meeting next week, I'll be hanging about the Press Room from 11 am till 1 pm every day, with John Stockwell, Karl Schleicher and some other wiki enthusiasts. We'd be happy to answer any questions or help you get started.

Bring your laptop! Spread the word! Bring a friend! See you there!