These contracts are made for the most part with the major oil companies authorized to extract oil (such as BP, Chevron, Exxon Mobil, and Shell) or nationally run oil companies of oil-producing countries.
此種期約多與各產油國的國營公司或具有產油權的大型石油公司（如英國石油、雪佛龍、艾克森、殼牌等）訂定。