This industry comprises establishments primarily engaged in operating and/or developing oil and gas field properties and establishments primarily engaged in recovering liquid hydrocarbons from oil and gas field gases. Such activities may include exploration for crude petroleum and natural gas; drilling, completing, and equipping wells; operation of separators, emulsion breakers, desilting equipment, and field gathering lines for crude petroleum and natural gas; and all other activities in the preparation of oil and gas up to the point of shipment from the producing property. This industry includes the production of crude petroleum, the mining and extraction of oil from oil shale and oil sands, the production of natural gas, sulfur recovery from natural gas, and the recovery of hydrocarbon liquids from oil and gas field gases. Establishments in this industry operate oil and gas wells on their own account or for others on a contract or fee basis. Performing oil field services for operators on a contract or fee basis--are classified in Industry 21311, Support Activities for Mining; Manufacturing acyclic and cyclic aromatic hydrocarbons from refined petroleum or liquid hydrocarbons--are classified in Industry 325110, Petrochemical Manufacturing; Refining crude petroleum into refined petroleum and liquid hydrocarbons--are classified in Industry 324110, Petroleum Refineries; and Recovering helium from natural gas--are classified in Industry 325120, Industrial Gas Manufacturing.
