When digging through abyssalite in the Oil Biome, if reaching hot Abyssalite, Crude Oil will exchange heat with it and boil into Petroleum / Sour Gas, cooling down the Abyssalite to around 400-500 degrees. I haven't tested other liquids, it seems however to only do that if the transfer causes a state change for the liquid, i.e. it will stop exchanging heat with Petroleum around 500, but will do so again if Crude Oil comes into contact with the same tile.
Steps to Reproduce
Find hot Abyssalite in the Oil Biome, dig to it and have Crude Oil get into contact with it.
This issue has not been confirmed by a developer yet.