Small but mighty

Rapidly depleting hydrocarbon supplies mean scientists are in a race against time to delay the dreaded peak oil scenario. Nanotechnology has been touted by Saudi Aramco and America’s Advanced Energy Consortium as the potential saviour of the industry and a way to revolutionise the exploration process. In this special report Diana Milne investigates why nanotechnology could be the small solution to a very big problem.

“Saudi Arabia is pouring billions of dollars into advanced technologies”
-Dr Abdel Mottaleb

Given the immense scale of the problem facing the world's oil producers, it is ironic that millions of dollars is being spent to develop a solution so microscopic that it is invisible to the naked eye. Nanotechnology may be based on units that measure one-billionth of a metre, but, when applied to oil and gas exploration, its potential is huge. So much so that research projects are underway across the world to develop the technology; most notably at  Saudi Aramco's EXPEC Advanced Research Center (ARC) and the US-based Advanced Energy Consortium, a research body funded by 10 of the world's biggest oil companies at a cost of US$1 million a year each. There are compelling reasons why these companies are funding research into the application of nanotechnology in the oil field - a concept that is still several years from becoming a reality. According to the BP Statistical Review of World Energy, global proven oil reserves fell by three billion barrels in 2008 and the current reserves to production ratio is just 42 years. Meanwhile Faith Birol, the International Energy Agency's Chief Economist has predicted oil production will peak in 2020 and that the world's 800 largest fields are seeing a 6.7 percent annual decline in production.

Big problem, small solution

The days of easily available oil are rapidly running out and oil companies must find ever more ingenious ways of extracting the remaining reserves from minute pores in the rock face. To do this some say the technology they use to access the reserves must shrink. But size isn't the only factor. As exploration goes deeper, already harsh conditions worsen raising the need for more robust equipment and tougher coatings on drilling tools. Finding the oil too is a major challenge; even 3D and 4D seismic still lacks in resolution and the ability to penetrate deeply into the reservoir's lithology. Scientists believe that nanotechnology could address all of these challenges. Sean Murphy is Senior Manager at the Advanced Energy Consortium - one of a team of just four scientists charged with finding out whether nanotechnology really is the oil and gas industry's silver bullet.  He describes why the companies who are funding the project are so keen to find a solution to the incredibly complex challenges they face: "Right now we leave around 60 to 70 percent of the discovered oil in the ground. Even after applying enhanced oil recovery techniques like water and gas flooding technologies, we still don't know how to effectively and economically remove it. Drilling more wells for oil recovery isn't the answer as it can be a multi-million dollar a hole proposition. The oil flows through pores that are not merely microscopic, they are submicron; and the pore throats can be nanometres in scale. Quantifying reservoir characteristics to enable improved recovery processes, like low interfacial tension surfactant flooding or carbon dioxide flooding, is where nanotechnology can really assist in improving total recovery from existing reservoirs."

Nanotechnology, however, exists on a scale small enough to penetrate these pores. And if scientists can produce nanoscale particles or sensors that are able to collection information about oil reserves and deliver the information back the to well or surface these seemingly insurmountable problems could be tackled, delaying the days of peak oil further.

The AEC and Saudi Aramco are both focussing the bulk of their research on two areas: illumination of the reservoir and developing nanosensors that can be injected into oil and gas wells to collect data on the reservoir rock, fluids and physical characteristics then transmit or relay the data back to the surface for use. EXPEC ARC is working on creating what it has dubbed 'resbots' - minuscule nanorobots no bigger one hundredth the width of a human hair.  At O&G's summit in the UAE recently, Saudi Aramco's VP of Exploration, Ibraheem Assaadan, claimed these resbots could be deployed in reservoirs through injected water. Once there, they would be capable of analysing the reservoir pressure, temperature and fluid type and would store this information, effectively mapping the reservoir. The resbots would be retrieved along with crude oil at the producing wells and the reservoir mapping information could then be downloaded. Assaadan believes that resbots could revolutionise the oil and gas industry and the company has already analysed core plugs from existing reservoirs to analyse the maximum size the resbots can be and to understand transport issues.

But Aramco is not alone in attempting to meet this challenge. The AEC is in the process of developing what David Chapman, Project Manager for Electronics describes as a "communications enabled robot", an active electronics-based, nano-based device. This would be something that has a physical or chemical parameter sensor built into it and is at least 100 times smaller than those in existence today. We need a telemetry solution that is capable of transmitting data topside, or alternatively some type of on board memory that enables them to store the data and keep track of location so that they can be interrogated when retrieved."

Mission impossible

The notion of a robot built on nanoscale dimensions yet possessing such a high level of sensory, communications and storage capacity remains for now "In the realms of science fiction", admits Murphy.  The process of making this concept a reality is fraught with complication - largely to do with the scale and the functionality of the technology involved. "The key is to shrink the sensor down to a size that enables it to move through the pores and the fractures in the rock; this may require difficult choices and tradeoffs in functionality. For example, sensors might be event-driven, only communicating when a specific physical or chemical parameter is sensed, or communicating at specific time intervals, which would reduce power requirements. Communication is also a huge issue; geolocation and telemetry technology will have to be scaled to overcome the severe attenuation of traditional frequencies. Finally, it's an extremely harsh environment with high temperatures and pressures which are not friendly to electronics, not to mention the mud and drilling fluids, and the saline solutions, waxes and asphaltenes all saturating the heterogeneous clays and rocks."

Dr Mohamed Abdel-Mottaleb is founder of Cairo-based SabryCorp, the Middle East's first nanotechnology consultancy which aims to make the region a world hub for nanotechnology research. He outlines some of the issues that must be overcome before nanorobots can become a reality in the oilfield: "I'm not sure really that the nanorobots, as envisioned, would be successful. Nanorobots would be, basically, a number of sensors with a motion, detection and transmission unit. One of the biggest issues with nanotechnology is the ability to integrate all of these systems together. They would need to have temperature sensors, pressure sensors and some sort of location sensor to be able to pinpoint their exact location. They would also need a power source and the ability to transmit the information back. Each unit in the nanorobot already exists and it has been tested and verified. But a complete integration at that level of sophistication is still a bit far away." Mark Morrison of the UK's Institute of Nanotechnology is also sceptical about scientists' ability to overcome the challenges of developing a fully functional reservoir robot: "Providing power and sensors all in a small particle size that is able to withstand different chemical environments and severe pressure requires concerted effort by a lot of different people. One aspect of the robot might develop more quickly than another. But it's combining all these things onto one platform that will be the big breakthrough."

It's a breakthrough that Murphy says he and his team can't make before they have explored the fundamental science behind the concept - i.e the factors that control the retention and transport of nanoparticles through the pores in the reservoir rock: "We are funding a number of fundamental science projects that are related to understanding what it's going to take to move micro and nanoparticles through reservoir rocks. Some are predictive studies that will produce modelling and simulation tools. Other are more experimental in approach and are underway at petroleum engineering departments. They started with glass beads and sand particles and now they are progressing to constructed permeable media and micro models that are representative of reservoir rocks."

He goes on to say that he and his team are currently figuring out how to get these particles to flow from one end of the rock to the other and whether there are coatings they can use on the particles so that they can flow through more easily. He says that even if his team doesn't succeed in moving onto the next level by creating nano particles equipped with sensors, communications equipment and data storage capacity, simply being able to understand how to create a custom designed nanoparticle that will pass through the reservoir could have major benefits for the oil and gas industry.  He goes on to explain that this is one area where the industry could benefit from biomedical research in that coatings developed to enable pharmaceutical nanoparticles to pass through the body could be used in briny oil fields." Not only do we have to figure out how to pass a nanoparticle through heterogeneous rocks and complex fluids, but we need to find a material that can enhance the resolution of sub-surface lithogies and fluids using viable remote sensing technologies. Questions that need to be answered include; can we discriminate these nano contrast agents from the background noise? What volume of material will we need to use? And can we functionalise them so that they will attach to hydrocarbons preferentially?"

The material world

Nanotechnology's potential in the oil and gas field is not limited to its reservoir mapping capabilities. Nanomaterials are already widely used across a wide spectrum of industries including automobiles and consumer electronics products and scientists believe that nanocoatings, in particular, could have great benefits when applied to drill bits.  Morrison says: "There is a lot of development that could potentially be used in the oil and gas industry and probably is being used and these are things like nano structured ceramic materials which have increased hardness and durability compared with conventional materials which could be used in drill bits." He explains that at the nanoscale, materials can be harder and more sheer resistant making them less susceptible to different forces and able to withstand higher temperatures.  Using this sort of coating could enable oil companies to drill deeper and cut down on lost time through having to replace drill bits. "If you can use a nano structured ceramic material to coat a drill bit then you might have access to oil fields that you wouldn't normally be able to access," says Morrison. "Or you might have a longer time between replacing drill bits or pipes. So it both increases, potentially, your access to different reservoirs, and the amount of time those reservoirs are open compared to being offline."

An even more sophisticated use of nanomaterials in oil and gas reservoirs could be to coat well bore tubulars with material that is able to detect and react against corrosion or leakages. The most common terminology for this is 'smart' or 'intelligent' materials. These materials are aware of the environment around them and  can change their properties accordingly. This - like the use of better coatings for drill bits - could make nanotechnology a way for oil companies to save billions of dollars in costs from well shutdowns and the replacing of equipment, notes Dr Abdel-Mottaleb. "Another thing that is being tested in the lab is the use of smart casing for the bore hole. For that, you need a material that can react to the environment around it so that if there is a leakage it can immediately interact and close it. The point of all this is that the oil industry has to invest in this sort of technology to improve its efficiency and reduce costs."

Money talks

Cutting costs is a major concern for the oil and gas industry - with worldwide demand for oil having plunged by 0.6 percent in 2008.  Despite these financial pressures, however, funding for research into the use of nanotechnology from national and international oil companies has been forthcoming as companies seek to make investments in technology that could result in lower costs and high returns on investment in the long term. The AEC is set to receive US$10 million dollars a year for the next three years from 10 of the world's biggest oil companies, including BP, Halliburton, Shell and Total. This decision by these competing companies to pool their resources builds on approaches developed in the semi conductor electronics sectors, says Murphy; "The miniaturisation challenges facing the development of nanotechnology are parallel to those that faced microprocessor technology. It was an expensive multidisciplinary problem with many companies wanting to move onto the next shrink level but unsure of the exact technology to bet on. In such pre-competitive situations it makes sense to leverage the funding from other companies so you can explore lots of problems and share the results."

While a shared approach indicates co-operation amongst these companies, some have expressed concern about the proportion of funding going to US-based companies. Dr Abdel-Mottaleb wants to ensure that a more international approach is taken: "One of the issues is whether this is going to be led by American companies or European companies or whether it is going to be an integrated effort.  What I've seen so far is that the Americans are very active in this and that they are also looking at the American scientists rather than the Europeans or scientists from elsewhere. I think this is not the right approach. This is an international discipline and they need to be looking at it globally and not excluding solutions that come from outside the US." Nevertheless, he says the Middle East is catching up fast when it comes to research into nanotechnology, led by Saudi Aramco and the Saudi government. "Saudi Arabia is pouring billions of dollars into advanced technologies. The UAE and even Egypt are becoming more active. In 2008 I found out the total amount of funding available in Egypt to get a project complete in the next three years is US$10 million. That is nothing compared to what the US or European governments have come up with but in 2007 we had no funding. So from zero to US$100 million is a significant jump."

Meanwhile, the AEC, in an effort to be more inclusive, recently hosted a workshop in Paris where 80 percent of the participants were from European, Asian and Middle Eastern companies. It is also currently reviewing proposals for its second round of funding and is looking for opportunities worldwide. Abdel-Mottaleb says that it wasn't until last year that companies really started to sit up and take notice of the role nanotechnology could play in the oil and gas industry. Now its full potential has been revealed, however they all want a piece of what could ultimately solve some of the biggest challenges facing the oil and gas industry.

Sean Murphy is reluctant to cite nanotechnology as the oil and gas industry's silver bullet. However, he says that even if this microscopic technology were to make a small difference to the numbers involved - its impact in real terms would be massive. "I wouldn't say it's the saviour of the industry, but it has intriguing potential for being able to retrieve more oil than we can retrieve today. We're talking about billions of barrels of oil that are left in the ground. If we can improve the recovery rate by only a small percentage, that represents an incredible amount of additional energy for the world."