While I've experienced a bug with hot abysalite boiling oil, I've never had it freeze solid before and haven't been able to find anything about it. While trying to expand my oil pool, I accidently dug too close to the abysalite and ended up with sour gas when I noticed chunks of frozen oil and petroleum started forming at the bottom of the pool. After watching it for a bit, it only seems to happen once a block of oil boils into sour gas and for a split second leaves a vacuum behind. It's inside this one tile of vacuum that a chunk of frozen oil/petroleum seems to form. I'm not sure if it's related to Spaced Out, but I've never heard of this happening in the base game. (There was an abysalite leak at the start which is why the entire biome is 300C.) In the photo, the chill is even spreading out to the rest of my oil pool. Seems like a pretty big exploit, but really annoying when it slows down a petroleum boiler. The tiles just keep slowly melting and then freezing again once another vacuum pocket forms.
Have the bottom of a large pool of oil touch hot abysalite and frozen tiles form along with sour gas. Frozen tiles appear to form inside the vacuum pocket left by the sour gas.