Graphene nanoribbons help to plug gaps in wellbores

This is the claim of Rice University chemist James Tour and civil and environmental engineer Rouzbeh Shahsavari, who’ve combined the nanoribbons with an oil-based thermoset polymer intended to make wells more stable.

According to Rice, when cured in place with low-power microwaves emanating from the drill assembly, the composite would plug the microscopic fractures that allow drilling fluid to seep through and destabilise the walls.

Results of their study have appeared in ACS Applied Materials and Interfaces.

The researchers said that drillers have formerly tried to plug fractures with mica, calcium carbonate, gilsonite and asphalt with limited success because the particles are too large and the method is not efficient enough to stabilise the wellbore.

In lab tests, a polymer-nanoribbon mixture was placed on a sandstone block, similar to the rock that is encountered in many wells. The team found that rapidly heating the graphene nanoribbons to more than 200 degrees Celsius with a 30W microwave was enough to cause crosslinking in the polymer that had infiltrated the sandstone, Tour said in a statement. The microwave energy needed is just a fraction of that typically used by a kitchen appliance, he said.