Unsure of the specific circumstances, but after not checking my oil biome for some time I noticed most of the steam I had was lost. On last check I'd had about 1/2 the left side of the biome full of ~30-40kg steam/tile, and it had been stable for over 100 cycles
Steps to Reproduce
run the attached save (cycle 944), observing the 2 steam turbines on the border of the oil biome
This issue has not been confirmed by a developer yet.