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 New Study Will Help Find the Best Locations for Thermal Power Stations in Iceland
19.01.2017 | University of Gothenburg

nachricht Water - as the underlying driver of the Earth’s carbon cycle
17.01.2017 | Max-Planck-Institut für Biogeochemie

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>