1. n. [Drilling Fluids]
A general term for those gases that are acidic either alone or when associated with water. Two sour gases associated with oil and gas drilling and production are hydrogen sulfide, H2S, and carbon dioxide, CO2. Sulfur oxides and nitrogen oxides, generated by oxidation of certain sulfur- or nitrogen-bearing materials, are also in this category but not found in the anaerobic conditions of the subsurface.
Antonyms: sweet gas
See: anaerobic, carbon dioxide, carbonate, hydrogen sulfide, sulfate-reducing bacteria, sulfide
2. n. [Production Testing]
A gas containing hydrogen sulfide, carbon dioxide or mercaptans, all of which are extremely harmful.