What's good for exploration is good for the industry, if we can only figure out what it all means.

One can roam a trade show's exhibit space and find no end to the latest gadgets intended to provide incremental improvements in exploration success.

But talk to technologists at oil companies, and they tend to take a longer-range view. In their estimate, success isn't gauged just by a geophone that picks up crisper signals or a new algorithm that shaves time off of the processing of complex datasets. Success is measured by finding more oil and gas and producing it at a cheaper cost.

"I look at this as a holistic problem, not a specific single incremental development," said Dr. Yoram Shoham, vice president of external technology relations for Shell. "I would like to know more and more about what's under our feet or away from the well bore, especially as it relates to properties of the fluids in the reservoir. Today I can only infer."

Which is not to say that technology doesn't matter. It's just that figuring out which technologies matter, and to what extent, often transcends the traditional boundaries of exploration, drilling and production just as asset teams have blurred the lines between once separate disciplines. And the "not invented here" attitude has no place at these companies-if an aerospace company has developed an imaging technique that, when adapted, provides clearer pictures of the subsurface, by all means it should be employed.

So increasingly it seems that big-picture needs - supply and demand, lowering costs - are driving interest in all aspects of oilfield technology and leading to some extremely creative out-of-the-box thinking. Rather than a laundry list of new stuff, an overview of emerging exploration technologies needs to read more like a flow chart, with all of the elements leading to the final goal of squeezing more hydrocarbons out of the ground.

Dave Bamford, technology vice president of exploration at BP, said that some of the key needs in the industry relate less to specific technologies and more to a suite of technologies that enable this workflow to move smoothly. Among these are a need for more integration from basin to prospect scale, the ability to model hydrocarbon movement around the basin and an integration of exploration data into the drilling process.

Understanding the subsurface

If there's a single overarching theme of emerging exploration technology, it's using everything in the toolbox, often in tandem, to get the clearest picture of what's actually going on down there. This is important not only in finding hydrocarbon reserves but also in avoiding drilling hazards like geopressure, planning the development of the field more effectively and understanding migration patterns to drain the field as well as possible.

Multiple efforts are under way. One area that's seen a tremendous amount of R&D funding recently is in high-resolution imaging. This is partly an acquisition issue, and many of the seismic contractors and equipment manufacturers are developing digital recording systems to provide higher quality data. But more importantly it's a processing issue, and processors are moving away from standard methods and experimenting with different types of waves. Shoham said that traditional acoustic imaging takes into account only a small amount of the information embedded in a seismic trace. Now geophsyicists are working in an elastic framework, studying the elastic properties of rocks to learn more about their permeability, porosity, lithology, fluid content, etc.

Beyond that, he said, is the understanding that fundamentally, rocks are not particularly elastic in nature. "Geotechnical engineers who study the near-surface know a little more about the non-elastic properties of rocks," he said. "But we don't know at all how to calculate or asses these parameters in the subsurface."
To move even into the elastic domain requires multicomponent acquisition, which measures shear waves as well as compressional (P) waves. This is another area of keen interest within the exploration community, but the mastery of multicomponent acquisition, processing and interpretation will have ramifications for drilling and production as well.

Shear waves aren't affected by the fluids in the reservoir, so a comparison of shear and compressional waves provides an additional unique measurement of the physical properties of the reservoir. According to Alan Huffman, formerly with ConocoPhillips, shear wave information might allow for a better determination of the density of the formation, which can be difficult to do with P waves alone.
Increasingly, seismic is not the only card in the exploration deck. The advent of 3-D seismic was apparently so earth-shaking (literally and figuratively) that some explorationists ignored the unique information provided by other techniques such as gravity and magnetics.

Time-lapse seismic

The industry might be getting tired of hearing about the potential benefits of time-lapse, but the fact is that the more it's studied, the greater the promise seems to be.

The original vision of time-lapse was to perform repeat surveys over a field at set intervals to compare the differences in the datasets. While this approach is still being examined, it has some major hurdles to overcome.

The first is getting equivalent images. While several companies argue that surveys acquired with different parameters can effectively be compared, the ideal situation is to have surveys that are as near to identical as possible, difficult on land and implausible at sea.

The second hurdle is making the processing consistent. "If you're not using the exact same algorithm and the exact same people doing the processing and the velocity picking, it makes it more difficult to get the registration right," Huffman said. "In my experience, no two velocity analysts pick their seismic the same way."

Thirdly is the production issue itself. When fluids are produced, they change the reflectivity of the reservoir, and they effect pressure changes within the reservoir. Also, when reservoir pressures are reduced, it has an effect on the seal rocks as well. Current models assume that the surrounding shales don't change.

So the industry has moved toward a different kind of 4-D monitoring that places permanent sensors in the borehole, and ultimately these sensors will monitor continuously, not just during pre-determined survey times. "The goal is to treat the reservoir as a living, breathing creature," Huffman said. "Things don't happen in digital slices. Those are only shapshots of an evolving system."

But who will pay?

Bamford said that many of these research initiatives are being adequately, if not well, funded by the industry. But he's concerned about the flagging seismic industry and its ability to foot part of the bill.
"The seismic contractors are not in good shape," he said, "and it worries me that they're not actively investing in new acquisition and imaging techniques. The whole business feels weak and fragile."

Huffman prognosticated that the super-majors would start to buy up the seismic contractors, returning full-circle to the days when oil companies ran their own crews, as a way to ensure more repeatability in 4-D surveys. Bamford said it was more likely that oil companies would set up long-term relationships with seismic contractors for technology development, depth imaging and perhaps even acquisition, much as they do today with drilling rigs in deepwater development projects, making the oil company a significant player in that contractor's earnings.

Perhaps some of the problem is that there are still a host of technologies vying for the ability to meet a technology need when only one or two might be the best to resolve that challenge in the future. Huffman brings up ocean bottom cable as an example. This is still the best way to record shear waves in marine environments, but it's very expensive, and the technology lags behind the operators' lust for depth in terms of withstanding deepwater temperatures and pressures. Operators don't want to risk the investment, and service companies can't afford to go it alone.

Ultimately, exploration technology will have succeeded when its impact is felt throughout the value chain. That may mean that some of today's widely held beliefs will have to fall by the wayside.
"I feel concern that geophsyicists have provided the industry with enticingly beautiful pictures," Shoham said. "People tend to trivialize geophysics. They think it's a commodity. And they don't take into account what we don't yet know.

"As a matter of fact, the need to achieve super-effectivity in the hyper-competitive E&P market will bring about a renaissance in technologies, many not yet part of our arsenal. Out of this renaissance, a holistic 'smart' operation will emerge, affecting operations all the way from the reservoir through lifting transportation and refining all the way to the market."

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