When some molecules of methane are
trapped within a crystal structure of water,
they form a solid similar to ice.
The name of these ice-like structures
is methane clathrates.
And they are largely responsible for
the initial unsuccessful attempt in containing the oil
spill that rocked the Gulf of Mexico
back in the spring of 2010.
When the explosion on the Deepwater Horizon oil
well occurred, operators tried to funnel the leaking oil
into a pipe to be carried to a tanker ship above,
thus preventing the ongoing leakage into the water.
However, this plan didn’t succeed.
Instead, due to the low temperatures and high pressure
near the sea floor, methane clathrates
built up inside the containment dome
and blocked the outlet pipe, preventing it
from redirecting the flow.
Perhaps if methane clathrates had not been formed,
the containment might have worked.
Now a team of researchers at MIT has come up
with a solution that just may prevent
such a disastrous outcome the next time a leak occurs.
And their new method may also prevent blockages
inside oil and gas pipelines that
are located in environments where methane clathrates can form.
The key to their novel system is the coating inside the pipe.
In previous work by the same group,
they were able to design a way to keep anything
from ketchup to paint from sticking to the container walls
by first creating a textured coating on the walls
and then adding a lubricant that gets trapped by the texture
and prevents content from adhering.
In this case, the lubricant is already
present in the form of oil.
So all they need is a coating on the surface that is chemically
attracted to hydrocarbons present in the petroleum
but repels water.
As long as water is kept away from the pipe wall,
clathrate buildup can be stopped.
In lab tests, which used a proxy chemical for the methane
because actual methane clathrates form
under high-pressure conditions that
are hard to reproduce in the lab,
the system performed very effectively.
The researchers say they didn’t see any hydrates adhering
to the substrates.
Unlike previous methods, such as heating
of the pipe walls, depressurization,
or using chemical additives, which
can be expensive and potentially polluting,
the new method is completely passive.
That is, once in place, it requires no further addition
of energy or material.