A team of researchers from MIT has developed a new method of preventing icy buildup and leakages in oil and gas pipelines. The new method coats the inside of a pipeline with a layer that helps spread the water-barrier layer along the pipe’s inner surface. The barrier layer will prevent ice particles from adhering to the wall, which eliminates the buildup of clathrates that could slow or block the flow.
Unlike previous methods for preventing buildup and leakages, the researchers’ method is completely passive. Once in place, no additional energy or materials are required. The coated surface attracts liquid hydrocarbons that are already present in the flowing petrol while creating a thin, naturally water-repellant surface layer This process prevents ice from attaching to the pipe’s walls.
According to Kripa Varansi, Current prevention measures, called flow assurance measures, are costly and tend to be detrimental to the environment. However, without these measures, hydrates build up and slow the flow rate, in turn, slowing down the revenues and creating blockages. This could lead to a failure like the explosion that occurred at the Deepwater Horizon oil rig on April 21, 2010.
Blockage problems could increase even more due to methane hydrates, which are abundant in continental shelves and are being referred to as a huge new potential fuel source. The deposits would be even more vulnerable to freezing and plug formation than the existing oil and gas wells. Preventing the buildups depends on stopping the first particles of clathrate from sticking to the pipe.
Varansi’s method is similar to another coating being used in a company he attempted to commercialize his earlier lab work, which creates coatings for containers that prevent contents from sticking to the container walls. This system involves two steps: creating a textured coating on the container walls and adding a lubricant that gets trapped by the texture and prevents contents from adhering.
While the new pipeline system is similar, Varansi emphasizes the use of liquid in the environment itself, instead of the necessity of applying a lubricant to the surface. According to Varansi, the key characteristic in clathrate formation is the presence of water. As long as the water can be kept away from the pipe wall, clathrate buildup can be stopped. If the hydrocarbons in the petroleum cling to the wall due to the chemical affinity to the surface, the coating can effectively keep the water away.
The paper, “Designing Ultra-Low Hydrate Adhesion Surfaces by Interfacial Spreading of Water-Immiscible Barrier Films” was published in the journal ACS Applied Materials and Interfaces and can be read here.