Research and development: Four enhanced oil recovery game changers
From mushroom biopolymers to aloe vera solutions and rock-heating radio frequencies, these are some innovative techniques for enhanced oil recovery.
Acceleware: The inside-out microwave
Acceleware describes its patent-pending technologies as “an inside-out microwave oven,” and that is essentially how they operate. The Canada-based company’s RF XL and Modular RF technologies leverage radio frequencies (RF) to extract heavy oil from oil sands.
An antenna inside a well bore radiates radio frequency energy into the formation, exciting water molecules that are already present in the oil-bearing formation, turning them into steam and lowering the viscosity of oil. After turning to steam, the particles stop absorbing RF energy, so the RF energy can continue further into the formation to gather more oil.
The RF XL technology retains 97% of useful heat, compared with 70% for Steam-Assisted Gravity Drainage (SAGD), and occupies 67% less land than SAGD.
The company also says the technique has a zero-carbon footprint and requires no costly chemicals, solvents or a solvent recovery process. Since the water is already present in the rock, there is no need for fresh water to be pumped into and out of the ground.
While the principle behind the technique is not new (it was tested and patented in the mid-1900s), it could not be commercialized due to technological limitations of the time.
Acceleware successfully completed an initial field test of the technology in partnership with GE Global Research in 2016, and in July 2018 signed an agreement with Prosper Petroleum to conduct commercial-scale tests for RF XL at its Rigel Oil Sands location.
Wintershall: Organic, biodegradable EOR
BASF subsidiary Wintershall is testing using a common fungus, Schizophyllum commune (commonly known as splitgill mushroom), as a biopolymer for EOR. When this fungus is exposed to oxygen and starch, it creates a totally organic thickening agent.
This gel-like biopolymer thickens water injected into a reservoir, forcing more oil out as the water becomes too thick to flow past it. The fungus grows on dead wood and can be found in most forests.
Because it is biodegradable, it removes concerns about damage to the environment. As such, it could potentially be used in sensitive ecosystems, like the sea. Wintershall notes that the fungus is effective in high temperatures and high salinity; conditions common to the Middle East.
This biopolymer was tested for five years at the Bockstedt oilfield in Northern Germany. To test it, a solution of the biopolymer, reservoir water and a preservative agent is added to the injection well. With just 0.03% biopolymer in the solution, water has become 25 times thicker.
After two years of continuous injection, Wintershall started injected it in short, successive tests. The biopolymer solution was pumped into one well in a period of several days and then pumped back out from the well.
The test demonstrated that the biopolymer was stable when injected in the reservoir, and a brief field test showed it retains stability in an offshore environment.
Dr. Omar Chaalal: High recovery, low toxicity
Dr. Omar Chaalal has always had an interest in reducing carbon dioxide emissions; he invented the EnPro Process, which binds CO2 to the salt in seawater to sequester it. One of his latest attempts: using locally-available plants for green water flooding instead of CO2 EOR, which can sometimes lead to CO2 entering the atmosphere.
“I thought, ‘we can find something that is not harmful to the environment and is cheap,’” Chaalal said, recalling his motivation to begin his research. “I researched for almost 10 years and then I found a combination of two plants from the UAE, I mixed them and put them in water and took the extract, which is injected into the well and has the same recovery as CO2.”
The plant extract mixture has an oil recovery of 96.5% at reservoir temperature using non-toxic, biodegradable materials—Chaalal went so far as to say that he would drink the mixture without worry. A series of core-flood tests using cores from the Abu Hassa field in Abu Dhabi found that some of the plant components, like lipids, fructose, sucrose and proteins, among others, may have a synergistic role in increasing efficiency of oil recovery.
Chaalal is an associate professor of chemical engineering at Abu Dhabi University, which filed a patent for the method in 2016. He expects it to be granted by next month. His green water flooding technique has not yet been tested to scale, but he notes that he has signed an MoU with a leading oil & gas company to begin tests.
Petroteq: Shifting sands
Petroteq’s patented extraction technology is billed as an environmentally-safe way of mining oil sands, which are typically equated with pollution.
The process: Petroteq crushes oil sands into chunks, then mixes the crushed ore with a solvent. In a mixing tank, a centrifuge spins the mixture, separating oil and sand. Sand is then separated from the oil-solvent mixture, which is then heated to separate oil from the solvent. Solvent is then evaporated to be recycled, leaving usable oil.
The components of its solvent are a highly-guarded secret, but Petroteq has disclosed that it consists of hydrophobic, hydrophilic and polycyclic hydrocarbons. The company expects 99% of solvents to be recycled using its patented system, and says that it achieves over 98% of bitumen extraction from oil sands.
It currently operates in Utah, United States, in one of the state’s major oil sands deposits, and it can extract oil for as low as $28 a barrel in high volume settings.