Friday, June 17, 2005

Preventing Methane Hydrate Buildup In Gas Pipelines

The seabed is apparently not the only place that methane hydrates are formed. They also appear inside natural gas pipelines in the seabed, which eventually restricts flow and causes well abandonment. The Engineer has an article about a novel method of dealing with the problem: introducing chemicals that cause the hydrates to become a slush rather than solid chunks.
‘The principle is to allow the hydrates to form, but to make them transportable,’ said Tohidi. The additives encourage the methane to crystallise into specially tailored hydrates where the size of the crystals is controlled so that they do not stick together.


When hydrates form, methane molecules are trapped individually within a cage-like lattice and can exist much closer together than when in their gaseous form. This means that creating a slurry for transportation will also increase the capacity of pipelines.