If shell does decide to go for Dancopter's 155 (order and delivery 139 is up to a year now), Dancopter would still need time to mod the aircraft to Shell requirement with crashworthy
fuel tanks. If Shell doesn't require that from Dancopter then they are very hypocrite and measure with two standards.
My guess is they go for a one year extension with Bristow and than maybe go for Dancopter. This way Dancopter would have more time to setup two bases, arrange crew, mod the aircraft or even go for a 139.
I do say maybe, because it could well be that shell will just continue with Bristow, since this would be more logical, commercially and financially i.e. the shell contract also consist s of them operating out of Aberdeen, as far as I know.