Chevron Corp. is a multinational energy company, a direct descendent of Standard Oil. It operates through Upstream and Downstream segments. The Upstream segment includes exploration, development and production of crude oil and natural gas; liquefaction, transportation and regasification associated with liquefied natural gas; transporting crude oil via major international oil export pipelines; processing, transporting, storage and marketing of natural gas; and a gas-to-liquids plant. The Downstream segment consists of refining crude oil into petroleum products, marketing of crude oil and refined products; transporting crude oil and refined products by pipeline, marine vessel, motor equipment, and rail car; as well as manufacturing and marketing commodity petrochemicals and plastics for industrial uses and fuel and lubricant additives. Following the Standard Oil breakup and before the change to its current name, the company was known as Standard Oil Company of California, with headquarters in San Ramon, California