An American professional trade organization that represents all aspects of the US oil and natural gas industry. It was formed after the First World War (1914–18) as a consortium of oil and gas companies to help the recovery from the war by working together. It was formally established in 1919 as a means of cooperation with the government in all matters of national concern and to develop the wider interests of the petroleum industry. It sets standards and recommends practices, covering (p. 12) all aspects of the industry, and promoting the use of safe, proven, and sound engineering practices.

http://www.api.org/ Official website of the American Petroleum Institute.