Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

New method to prevent undersea ice clogs

12.04.2012
Surface coatings developed by MIT researchers could inhibit buildup of methane hydrates that can block deep-sea oil and gas wells

During the massive oil spill from the ruptured Deepwater Horizon well in 2010, it seemed at first like there might be a quick fix: a containment dome lowered onto the broken pipe to capture the flow so it could be pumped to the surface and disposed of properly. But that attempt quickly failed, because the dome almost instantly became clogged with frozen methane hydrate.

Methane hydrates, which can freeze upon contact with cold water in the deep ocean, are a chronic problem for deep-sea oil and gas wells. Sometimes these frozen hydrates form inside the well casing, where they can restrict or even block the flow, at enormous cost to the well operators.

Now researchers at MIT, led by associate professor of mechanical engineering Kripa Varanasi, say they have found a solution, described recently in the journal Physical Chemistry Chemical Physics. The paper's lead author is J. David Smith, a graduate student in mechanical engineering.

The deep sea is becoming "a key source" of new oil and gas wells, Varanasi says, as the world's energy demands continue to increase rapidly. But one of the crucial issues in making these deep wells viable is "flow assurance": finding ways to avoid the buildup of methane hydrates. Presently, this is done primarily through the use of expensive heating systems or chemical additives.

"The oil and gas industries currently spend at least $200 million a year just on chemicals" to prevent such buildups, Varanasi says; industry sources say the total figure for prevention and lost production due to hydrates could be in the billions. His team's new method would instead use passive coatings on the insides of the pipes that are designed to prevent the hydrates from adhering.

These hydrates form a cage-like crystalline structure, called clathrate, in which molecules of methane are trapped in a lattice of water molecules. Although they look like ordinary ice, methane hydrates form only under very high pressure: in deep waters or beneath the seafloor, Smith says. By some estimates, the total amount of methane (the main ingredient of natural gas) contained in the world's seafloor clathrates greatly exceeds the total known reserves of all other fossil fuels combined.

Inside the pipes that carry oil or gas from the depths, methane hydrates can attach to the inner walls — much like plaque building up inside the body's arteries — and, in some cases, eventually block the flow entirely. Blockages can happen without warning, and in severe cases require the blocked section of pipe to be cut out and replaced, resulting in long shutdowns of production. Present prevention efforts include expensive heating or insulation of the pipes or additives such as methanol dumped into the flow of gas or oil. "Methanol is a good inhibitor," Varanasi says, but is "very environmentally unfriendly" if it escapes.

Varanasi's research group began looking into the problem before the Deepwater Horizon spill in the Gulf of Mexico. The group has long focused on ways of preventing the buildup of ordinary ice — such as on airplane wings — and on the creation of superhydrophobic surfaces, which prevent water droplets from adhering to a surface. So Varanasi decided to explore the potential for creating what he calls "hydrate-phobic" surfaces to prevent hydrates from adhering tightly to pipe walls. Because methane hydrates themselves are dangerous, the researchers worked mostly with a model clathrate hydrate system that exhibits similar properties.

The study produced several significant results: First, by using a simple coating, Varanasi and his colleagues were able to reduce hydrate adhesion in the pipe to one-quarter of the amount on untreated surfaces. Second, the test system they devised provides a simple and inexpensive way of searching for even more effective inhibitors. Finally, the researchers also found a strong correlation between the "hydrate-phobic" properties of a surface and its wettability — a measure of how well liquid spreads on the surface.

The basic findings also apply to other adhesive solids, Varanasi says — for example, solder adhering to a circuit board, or calcite deposits inside plumbing lines — so the same testing methods could be used to screen coatings for a wide variety of commercial and industrial processes.

The research team included MIT postdoc Adam Meuler and undergraduate Harrison Bralower; professor of mechanical engineering Gareth McKinley; St. Laurent Professor of Chemical Engineering Robert Cohen; and Siva Subramanian and Rama Venkatesan, two researchers from Chevron Energy Technology Company. The work was funded by the MIT Energy Initiative-Chevron program and Varanasi's Doherty Chair in Ocean Utilization.

Sarah McDonnell | EurekAlert!
Further information:
http://www.mit.edu

More articles from Earth Sciences:

nachricht Volcanoes and glaciers combine as powerful methane producers
20.11.2018 | Lancaster University

nachricht Massive impact crater from a kilometer-wide iron meteorite discovered in Greenland
15.11.2018 | Faculty of Science - University of Copenhagen

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Nonstop Tranport of Cargo in Nanomachines

Max Planck researchers revel the nano-structure of molecular trains and the reason for smooth transport in cellular antennas.

Moving around, sensing the extracellular environment, and signaling to other cells are important for a cell to function properly. Responsible for those tasks...

Im Focus: UNH scientists help provide first-ever views of elusive energy explosion

Researchers at the University of New Hampshire have captured a difficult-to-view singular event involving "magnetic reconnection"--the process by which sparse particles and energy around Earth collide producing a quick but mighty explosion--in the Earth's magnetotail, the magnetic environment that trails behind the planet.

Magnetic reconnection has remained a bit of a mystery to scientists. They know it exists and have documented the effects that the energy explosions can...

Im Focus: A Chip with Blood Vessels

Biochips have been developed at TU Wien (Vienna), on which tissue can be produced and examined. This allows supplying the tissue with different substances in a very controlled way.

Cultivating human cells in the Petri dish is not a big challenge today. Producing artificial tissue, however, permeated by fine blood vessels, is a much more...

Im Focus: A Leap Into Quantum Technology

Faster and secure data communication: This is the goal of a new joint project involving physicists from the University of Würzburg. The German Federal Ministry of Education and Research funds the project with 14.8 million euro.

In our digital world data security and secure communication are becoming more and more important. Quantum communication is a promising approach to achieve...

Im Focus: Research icebreaker Polarstern begins the Antarctic season

What does it look like below the ice shelf of the calved massive iceberg A68?

On Saturday, 10 November 2018, the research icebreaker Polarstern will leave its homeport of Bremerhaven, bound for Cape Town, South Africa.

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Optical Coherence Tomography: German-Japanese Research Alliance hosted Medical Imaging Conference

19.11.2018 | Event News

“3rd Conference on Laser Polishing – LaP 2018” Attracts International Experts and Users

09.11.2018 | Event News

On the brain’s ability to find the right direction

06.11.2018 | Event News

 
Latest News

Nonstop Tranport of Cargo in Nanomachines

20.11.2018 | Life Sciences

Researchers find social cultures in chimpanzees

20.11.2018 | Life Sciences

When AI and optoelectronics meet: Researchers take control of light properties

20.11.2018 | Physics and Astronomy

VideoLinks
Science & Research
Overview of more VideoLinks >>>