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Engineering Nanoparticles to Boost Oil

Norwegian scientists are combining nanotechnology with petroleum research to enhance recovery. In the future, even nanoparticles from trees could squeeze out more oil.

Microscope image of reservoir rock. The rock pores (shown in blue) may contain trapped oil, gas and water. Nanoparticles can be used to recover more of the residual oil. Source: Ingrid Anne Munz/Research Council of Norway

The Research Council of Norway’s NANO2021 (Large-Scale Program for Nanotechnology and Advanced Materials) issued its first-ever joint call for proposals in 2013 with PETROMAKS 2 (Large-

Scale Program for Petroleum Research) to enhance oil recovery.

Nanotechnology is a burgeoning science that only began to take off in the late 1990s after the US-led National Nanotechnology Initiative and development of new microscopes capable of seeing things at the nanoscale, according to Aase Marie Hundere, Research Council special adviser. The EU followed up in 2002 with the Sixth Framework Program’s focus on nanotechnology and material research. Since then, nanotechnology research has intensified and widened to more uses: everything from food additives, cosmetics, and more recently, petroleum extraction.

“This has been an emerging field in Norway the last ten years,” said Hundere, who is also part of the NANO2021 secretariat. “Nanotechnology is an industry being formed now because you have the ability to control the processes with more precision. There is an increasing trend internationally toward using nanotechnology in the area of petroleum.”

“It was unanimous that the joint call for proposal was a very positive initiative, which gave added value compared to doing this in one program alone,” adds Tarje Nødtvedt Malme, PETROMAKS 2 program coordinator, pointing to the billions in expected additional revenues per percentage point increased oil recovery.

SPEEDING UP FLOW

WINPA is one of two research projects that have recently received funding under the joint call. The project is hosted by NTNU (Norwegian University of Science and Technology) Nanomechanical Lab in Trondheim in cooperation with NTNU Petroleum, together with oil companies Det norske and Wintershall as industrial partners, and research partner University of Houston.

WINPA stands for “Wettability alternation and Improved flow transport by engineered Nanoparticles for Petroleum Application.” The project aims to speed up the flow of oil by engineering nanoparticles. One way will be by using Janus particles with two different surfaces: one hydrophilic attracting water and the hydrophobic attracted to oil. The nanoparticles will spin on two different spheres and push the oil forward in the reservoir. The other method will be to change the surface charge of the nanoparticles to allow them to slip easier through a reservoir’s oil and rock.

“There are research groups working on the effect of nanomaterials for EOR (enhanced oil recovery), for example Texas A&M University, University of Houston, and others,” said Jianying He, NTNU associate professor leading research project WINPA. “They have been working in this field for around 15 years, but the progress has been slow and always laboratory scale tested. The main challenges in the nano-enabled EOR are the stability of nanoparticles under harsh environment in the reservoir and health, safety and environment issues.”

SLOWING IT DOWN

The other PETROMAKS 2-NANO2021-funded project is Hybrid Nanogels, hosted by SINTEF Petroleum Research, which looks at alternative solutions for plugging errant water paths with new gel systems based on green technology. The system uses silica nanoparticles that have been modified with functional groups to bind polymers together, making it possibly the first time nanoparticles are used as cross-linkers for polymers to form gels.

Together with NTNU, Texas A&M and a number of petroleum companies (Eni Norge, Det Norske Oljeselskap, Lundin Norway and GDF Suez E&P Norge), the project will study how to deactivate the surface of nanoparticles to keep them passive up to several months before being activated to bind the polymers together. The project will also research the possibility of packaging active nanoparticles into larger ones, also known as polyelectrolyte complexes (PEC), which can be released further in the well where they form a gel to plug water paths.

“We hope to develop a chemical system – polymer and cross-linkers – where the constituents are environmentally acceptable and where the gelling reaction can be delayed for a long and controlled time, up to months, thus allowing deep placement of the gel into the oil reservoir in question,” said Torleif Holt, manager for the project at SINTEF. “We will also study transport mechanisms for the constituents thus allowing modeling of the placement process.”

USING TREES TO SQUEEZE

Borregaard has developed microfibrilar cellulose (MFC) made from trees that could be used in amongst other things oil field applications Source: Borregaard

Another project funded by PETROMAKS 2 project, which is a continuation of projects funded by NANO 2021, is looking at nanocellulose from trees to squeeze out more oil from reservoirs in a sustainable manner. Led by the Paper and Fiber Institute in Trondheim, the Green EOR project is working with NTNU Department of Petroleum Engineering and Applied Geophysics and NTNU Ugelstad Laboratory. Together, they are developing a novel series of green fluids for chemical EOR applications based on nanocellulose, either alone or with other EOR components.

Nanocellulose are nanoscaled particles produced from wood that have excellent viscosifying and shear thinning properties, hydrophilic particles, excellent possibilities for chemical modification, and particle character. It is also an abundant green resource. However, the particles (cellulose nanofibrils and cellulose nanocrystals) have to be designed with adequate dimensions and surface chemistry.

In a related breakthrough, Norwegian bio-chemical company Borregaard recently announced plans to build the world’s first commercial plant for microfibrilar cellulose (MFC) production in Sarpsborg, Norway. The NOK 225 million plant is expected to start production of Exilva MFC in the third quarter of 2016. The raw material, specialty cellulose, is split into a complex network of fibrils based on proprietary technology developed by Borregaard.

“The secret behind the excellent performance of Exilva is its unique combination of characteristics from soluble polymers and insoluble particles,” said Mats Hjørnevik, Exilva marketing manager at Borregaard. “In addition, Exilva shows an extreme effect on the flow of materials – high yield stress and easy flow- which can give high control of the flowability of the end products. We believe that these characteristics can be of benefit in oil field applications.”