It rarely fails. The usual gush of oil and gas industry news always seems to slow to a mere trickle during the summer months. This summer so far has been no exception. Not that there haven’t been some interesting developments over the last few months. Examples of such stories range from the unexpected—“Delta Air Lines to buy Trainer refinery from Phillips 66” (OGJ Online, May 1, 2012)—to the really unexpected—“CNOOC Ltd. to acquire Nexen Inc. for $15.1 billion” (OGJ Online, July 23, 2012).
Not all noteworthy stories capture the top headlines, however. Sometimes this space is used to showcase such stories. Two examples follow.
What’s old is new again
Findings by engineers at Oregon State University are taking a new look at an old but seldom-used “microbial enhanced oil recovery” technique developed by the oil industry that also could aid in environmental cleanup.
The technology was first developed decades ago, but due to its high cost, inconsistent results, and a poor understanding of what was actually happening underground, drillers lost interest and the technique was largely forgotten.
OSU researchers are discovering more about the technique, such as why it works, how it could be improved, and how it might make a comeback not only for EOR but for environmental cleanup. The findings were published in the Journal of Petroleum Science & Engineering.
“This approach of using microbes to increase oil recovery was used somewhat in the 1980s when oil prices were very high, but the field results weren’t very consistent and it was expensive,” said Dorthe Wildenschild, an associate professor in the OSU School of Chemical, Biological & Environmental Engineering. “It’s seldom used now as a result.”
After a well is drilled, researchers said, and secondary EOR techniques such as water injection are exhausted, a tertiary type of EOR can be used that involves the injection of microbes that are “fed” sugars (such as molasses) to encourage their growth. “This can clog some pores and in others has a ‘surfactant’ effect, loosening the oil from the surface it clings to, much as a dishwasher detergent loosens grease from a pan,” researchers said.
Wildenschild noted, “By clogging up some pores and helping oil move more easily through others, these approaches can in theory be used with water flushing to help recover quite a bit more oil.” The surfactant can be manmade, or microbes can be used to produce it at a lower cost, researchers said. “However, getting a particular culture of microbes to produce the biosurfactant under harsh field conditions is tricky,” they said.
Ryan Armstrong, a recent OSU doctoral graduate, found in experiments that the clogging mechanism is the simplest and most effective approach to use, although combining it with the biosurfactant technology achieved optimal oil recovery.
“A better fundamental understanding of this process—along with higher oil prices that better reward efforts to recover more oil—could lead to renewed interest in the technology on a commercial basis,” the researchers said. “As an extra benefit, the concepts might also work well to help remove or clean up underground contaminants,” they said.
Arctic spill response
Separately, 10 final-year master’s degree students participating a 7-week summer project organized by Det Norske Veritas (DNV) presented the results of their intense work to develop a “realistic and suitable” concept for a yearround Arctic oil-spill response system that included requirements for people, vessels, and equipment.
The oil-spill response system is called the Arctic United Response Operation & Recovery Agreement, or AURORA. The cornerstone of the concept is a multifunctional concept vessel—the Boreast.
The methods of AURORA, which is designed to limit the consequences of an oil spill, are divided into three categories of recovery: mechanical, nonmechanical, and manual.
“The first response is conducted by on-site vessels. The second is conducted by vessels arriving from the closest cold or warm hub. The third, which includes beach clean-up, is a large mobilization by all hubs,” DNV said.
The Boreast vessel, meanwhile, has many onboard solutions including an unmanned aerial vehicle, remote in-situ burning, an autonomous underwater vehicle, towable storage bladders, and an ice-cleaning conveyor belt.
The students presented the concept in two scenarios: a drilling rig blowout and a cargo ship grounding.