Below is an context that describes a sql query, paired with an question that provides further information. Write an answer that appropriately completes the request.  # noqa: E501
### Context:
CREATE TABLE table_name_7 (rank INTEGER, industry VARCHAR, revenue_in_usd VARCHAR)
### Question:
What is the rank of the petroleum company who has a revenue of $481.7 billion?
### Answer:
SELECT MIN(rank) FROM table_name_7 WHERE industry = "petroleum" AND revenue_in_usd = "$481.7 billion"