Hard graft: nanotechnology for hydrocarbon extraction

In Michael Crichton's technological thriller Prey, a cloud of nanoparticles escapes from a laboratory and undergoes evolutionary change far quicker than anything the world has previously experienced. Within a short space of time, the nano-swarm becomes predatory, attacking wild animals first, and human beings shortly after.

Crichton's unease with the power of technology may have some merit - alongside genetic engineering, nanoscience offers humans the ability to radically manipulate matter at the atomic level - but the process of change he describes isn't quite what scientists are used to seeing.

The oil and gas sector is a perfect case in point. The average time for the commercialisation of new technology in the industry is somewhere between 15 and 22 years, with millions spent on investment along the way. Ideas that use nanotechnology can linger in the minds of scientists for years before they reach field testing, let alone commercialisation.

The electronics and consumer products field was among the first to join the nanotechnology revolution, basing a whole generation of products on an understanding of how materials behave at the nano-level. The medical and telecommunication industries also followed suit, using nanoscience to develop new fibre optics and diagnostic techniques.

"Imagine any surface that you are looking at today," says Sergio Kapusta, chief scientist materials at Shell. "Say your computer or your phone. All these surfaces have been modified by special treatment so that, for example, your fingerprints don't attach to the surface and your screen doesn't scratch. All of these things are part of surface modification. Now, we're using the same things in oil and gas. Rather than starting everything afresh, I think we can learn from these other industries and try to adapt quicker and faster.

"Of course, in some cases, we've been quite slow in advancing new technologies. There are many reasons for that, but one key cause is that our projects last for a much longer period of time. It's not like consumer electronics, where people can replace the product every two or three years."

Despite that slowness, few scientists underplay the utility nanoscience could have in helping meet the world's future energy demands. Unconventional hydrocarbon sources like shale gas, shale oil and basin-centred gas have become increasingly important to the industry, as more traditional sources of fuel run out.

One of the most interesting applications nanotechnology could have is transmitting information about these difficult reservoirs, which are several thousand metres below the earth's surface. Without comprehensive information on what these reservoirs actually look like, geologists are forced to play a potentially wasteful guessing game.

This is where the science of the very small comes into play. The rocks in which oil is found have pore spaces typically between 100 and 100,000 nanometres wide. If nano-scale sensors could be built to flow through these rocks, potentially crucial information about the geological make-up of the reservoirs could be acquired.

From lab to field

This isn't just an idea. Lab experiments have already shown that particles can be injected into reservoirs and convey information back when retrieved. All kinds of pertinent information about the reservoir's temperature, pressure and fluid type can be gleaned and, when the oil or gas is commercialised, recovery rates could be dramatically improved.

"Shell has been at the forefront of developing these nano-sensors," Kapusta says. "But for now and, I think, the foreseeable future, these particles will be simple sensors - exploring what happens on the reservoir but without the intelligence to act by themselves. The proof that the particles work is complete; now we have to scale it up from lab to field and that takes quite long."

The exploration process isn't the only side of the upstream sector that nanotechnology could improve. Nano-coatings are also being used to develop the durability and toughness of existing drilling equipment, which tends to break down far too easily in conventional and harder-to-reach reservoirs.

Improving overall oil recovery is also important. The average oil well yields only a third of its total stock. It's not unusual for a field to be abandoned with around 60% of the reservoir's oil still untapped, even after the primary, secondary and tertiary recovery phases have been executed. Research suggests that viscosity levels could be improved and oil recovery enhanced by adding nanoparticles to the displacement fluids used in the recovery process.

"Of course, there's no magic bullet," Kapusta cautions, "for the simple reason that there is no single 'enhanced oil recovery'. Every field is different. But within those limitations we are understanding things at the nano-scale and knowing what would succeed and what wouldn't."

Fact or fiction

Increasing the efficiency of oil and gas production will be crucial if hydrocarbons are to fulfil our expectations as a necessary bridging fuel, but progress remains slow in various areas. Accelerating the development of nanotechnology will require collaboration from all the major parties, according to Kapusta.

"We already participate in a number of joint industry projects," he says. "So we share information with some of our colleagues and competitors in the interests of trying to understand the fundamentals of nanotechnology for oil and gas, and how the product can be created. We collaborate with some of our vendors and suppliers in trying to develop those projects. And, within that, we have a robust research and development programme that involves some of the largest universities and some small companies.

"The whole field is still in its infancy, and, in some cases, we're slow in advancing the technologies we need. But in other areas, where the oil and gas industry needs something, it can be remarkably agile."

Even on optimistic assumptions, renewables will contribute only 30% of the world's future energy mix. And with economic growth remaining elusive, transitioning to a low-carbon economy is hardly a priority for national governments. Whichever way you look at it, oil and gas will remain central to the world's energy supply in the years to come.

Many of nanotechnology's current applications still sound like science fiction. The image of nano-scale robots scoping out an oil reservoir certainly seems closer to a Crichton novel than it does to real life. But while some of these ideas are only theoretically plausibly, many are becoming commercially viable.

That should come as a big boost to the traditional oil and gas industry, whose working environment is becoming harder and harder to negotiate. Using nanotechnology to improve existing production and exploration techniques should be a top priority for the industry as it looks to meet future demand in an efficient and sustainable way.