| http://www.w3.org/ns/prov#value | - However, oil or synthetic fluid-based muds are normally used to drill swelling or sloughing shales, salt, gypsum, anhydrite or other evaporate formations, hydrogen sulfide-containing formations, and hot (greater than about 300 degrees Fahrenheit (?????? F.???)) holes, but may be used in other holes penetrating a subterranean formation as well.
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