Archive for the ‘PIPELINES’ Category


Monday, April 16th, 2012


As the world’s appetite for oil and gas continues to increase while access to easily accessible reserves decreases, deep-sea oil and gas wells are being positioned in ever-deeper waters. The dangers and difficulties faced in such operations were highlighted in 2010 with the Deepwater Horizon oil spill. While placing a containment dome over a leak and piping the oil to a surface storage vessel had worked on leaks in shallower water, the attempt to do the same on the Deepwater Horizon’s largest leak failed when the formation of methane hydrate crystals blocked the opening at the top of the dome. Now researchers at MIT have developed surface coatings that can inhibit the buildup of these methane hydrates and keep the gas and oil flowing.

Methane hydrate is a solid cage-like compound – or clathrate – that forms under very high pressure in which a large amount of methane is trapped within a crystal structure of water to form an ice-like solid. Although it was originally thought to only occur in the outer reaches of the solar system, it is now estimated that total amount of methane contained in hydrates in the world’s seafloor is much greater than the total known reserves of all other fossil fuels combined.

Much like the buildup of cholesterol and fatty deposits on the inner walls of arteries inside the body, the buildup of methane hydrates – which can freeze upon contact with cold water in the depths of the ocean – inside a well casing or on the inner walls of pipes that carry oil or gas from the ocean depths can restrict or even block the flow of gas or oil. It was this kind of blocking that caused the failure of the containment dome technique attempt on the Deepwater Horizon leak.

Current techniques to prevent this happening include the heating or insulation of the pipes – which is expensive – or adding methanol into the flow of gas or oil – which can harm the environment if it escapes.

An MIT team led by associate professor of mechanical engineering Kripa Varanasi had been looking for a solution to this problem even before the Deepwater Horizon spill and now say they have found it. Having already studied the use of superhydrophobic surfaces to prevent the buildup of ordinary ice on things such as aircraft wings, the team decided to examine whether similar surfaces could be used to keep pipe walls clear of methane hydrates.

Using a simple “hydrate-phobic” coating, Varanasi and his colleagues were able to reduce the adhesion of hydrates in a pipe to one-quarter the amount compared to untreated surfaces.

“The oil and gas industries currently spend at least $200 million a year just on chemicals” to prevent methane hydrate buildups, Varanasi says. However, the total figure for prevention and lost production due to hydrates would be much, much higher. Using passive coatings on the insides of pipes would be much cheaper than current prevention techniques and allow the use of containment domes to capture flows from leaks in much deeper waters than is currently possible.

Additionally, the team says the test system they devised provides a simple and inexpensive way to search for even more effective inhibitors. They say their findings are also applicable to other adhesive solids, such as solder adhering to a circuit board, or calcite deposits inside plumbing lines. The testing methods developed by the researchers could also be used to evaluate coatings for a variety of commercial and industrial processes.

The team’s findings are detailed in a paper published in the journal Physical Chemistry Chemical Physics.

Source: MIT

Published by Henry Sapiecha


Saturday, August 20th, 2011


WASHINGTON — Ranchers from Nebraska, people in car caravans from California and hundreds of others plan to hold daily sit-ins at the White House starting Saturday, protesting against a planned pipeline that would greatly expand the flow of oil from the black sands of western Canada.

Two weeks of protests will raise the question of what the United States should do about climate change, putting the topic back into the spotlight. They’ll pressure President Barack Obama, who must decide whether the pipeline is in the national interest and whether it will be built.

For some participants, the key issues are local matters of land and water conservation. The proposed Keystone XL pipeline from the oil sands of Alberta would run from Canada through Montana, South Dakota, Nebraska, Kansas, Oklahoma and Texas.

It would cross the Ogallala Aquifer, the giant underground water source under much of Nebraska and other Great Plains states. Some Nebraskans have been calling for a different route away from their irrigation source and the state’s Sand Hills, a land of canyons and mountains of grass-covered sand where cattle graze.

For others, the key issue is climate change.

Writer and protest organizer Bill McKibben says it may be the “single clearest decision Obama will make in his first four years because for once he has a clear shot. Congress isn’t in the way. He gets to make the call.”

McKibben said it’s a test to see if Obama stands by his 2008 campaign promise that in his presidency “the rise of the oceans will begin to slow and the planet begin to heal.”

An Obama denial of the permit for Keystone XL would “send an electrifying jolt through his base,” McKibben said. “We’ll be reminded about why we were so enthused when he was running.”

The decision puts the president between his environmentalist supporters and those looking for projects that create jobs immediately. The American Petroleum Institute said the pipeline would create 20,000 direct jobs in the two years it would take to build it.

An existing Keystone pipeline from Canada already brings 591,000 barrels of diluted bitumen, the technical name for the thick oil mixed in the sands, to refineries in Oklahoma and Illinois. The new pipeline would increase the capacity to 1.3 million barrels a day and deliver the crude to refineries on the Gulf Coast.

Protesters argue that the pipeline would be in place for some 50 years, bringing a heavily polluting form of oil. The extra energy needed to mine the oil from the sands of Alberta and to process it creates more greenhouse gas emissions than conventional oil.

NASA climate scientist James Hansen argues that if emissions from coal are phased out in a few decades and unconventional fossil fuels such as the crude from the oil sands are left in the ground, it will be possible to stabilize the climate.

“Phase-out of emissions from coal is itself an enormous challenge. However, if the tar sands are thrown into the mix, it is essentially game over,” Hansen wrote in a paper in June. Hansen in recent years has participated in protests, and organizers say he’ll join this one as well.

The organizers said they expect some arrests. They plan to station people in Lafayette Park across from the White House every day for two weeks.

That means they will be there in a week, when the president and his family return from their vacation on Martha’s Vineyard.

Sourced & published by Henry Sapiecha