Table schema:
CREATE TABLE table_name_8 (assets__billion_ INTEGER, market_value__billion_$_ VARCHAR, industry VARCHAR, rank VARCHAR)

Question: How many Assets (billion $) has an Industry of oil and gas, and a Rank of 9, and a Market Value (billion $) larger than 121.7?
SQL: SELECT SUM(assets__billion_) AS $_ FROM table_name_8 WHERE industry = "oil and gas" AND rank = 9 AND market_value__billion_$_ > 121.7