Petronel

This reminds me of the bird species, the petrel.

Petra, Pet, Perry, Penny, Ronnie, Nell/Nelle, Nelly and Nella are potential nicknames.

Reminds me of petrol.

It's a shame that some of the more old-fashioned names aren't used more often, like Annora or Isabeau or Petronel, or some others. They're really good names, and they don't sound pretentious at all.