Petroleum adjectives are listed in this post. Each word below can often be found in front of the noun petroleum in the same sentence. This reference page can help answer the question what are some adjectives commonly used for describing PETROLEUM.
american, british, crude, global
heavy, large, largest, light
liquefied, liquid, little, major
more, new, other, owned
refined, russian, strategic, total
Hope this word list had the adjective used with petroleum you were looking for. Additional describing words / adjectives that describe / adjectives of various nouns can be found in the other pages on this website.