Here is the list of top oil and gas companies

Saudi Aramco: Headquartered in Dhahran, Saudi Arabia, Saudi Aramco is the world’s largest oil and gas producer. It is involved in exploration, production, refining, distribution and marketing of oil and gas. It operates the world's largest single hydrocarbon network, the Master Gas System. It is also the operator of the Ghawar Field and the Safaniya Field, the world’s largest onshore and offshore fields, respectively. For the year 2015, the company earned a revenue of $478bn.











Image: Saudi Aramco's core area which includes the headquarters and office buildings in Dhahran city. Photo courtesy of Eagleamn/Wikipedia.

Sinopec: Based in Beijing, it is a state-owned oil and gas company in China. Its activities include oil and gas exploration, refining, and marketing; and production and sales of petrochemicals, among others. As of 31 December 2015, its oil and gas production stood at 471 million barrels of oil equivalent, while its revenue was $454.99bn. A major part of its oil and gas production comes from domestic fields. The company claims to have significant new discoveries in the Xinjiang Tahe Basin, the Beibu Gulf in Guangxi and the Yin-E Basin in Neimongol, along with new shale gas findings in the Yongchuan block in Sichuan.

China National Petroleum Corporation (CNPC): It is a Chinese state-owned integrated international energy company. It oil and gas assets and interests in 37 countries in Africa, Central Asia-Russia, America, the Middle East, Asia Pacific, and other regions. According to its website, the company’s crude oil production accounts for 52% of China’s total output, while its natural gas production’s contribution stands at 71%. As of December 2015, CNPC’s annual crude and natural gas output in China was 111.43 million tons and 95.48 billion cubic meters, respectively. For the year 2015, it earned a revenue of $428.62bn. It is also one of the world's major oilfield service providers and a global contractor in engineering construction.











Image: The headquarters of China National Petroleum Corporation and PetroChina, outside of Dongzhimen, Beijing – 9 Dongzhimen North Street. Photo courtesy of Charlie fong/Wikipedia.

PetroChina: Headquartered in Dongcheng District, Beijing, PetroChina Company is a listed unit of state-owned China National Petroleum Corporation (CNPC). Its activities related to oil and natural gas include exploration, development, production and marketing. Besides, it is involved in refining, transportation, storage and marketing of crude oil and oil products. Domestically, its crude oil output was 806.3 million barrels in 2015, while its oil and gas equivalent output from overseas operations reached 203.5 million barrels. Its revenue was $367.9bn in 2015.

ExxonMobil: It is a US-based oil and gas corporation with headquarters in Irving, Texas. It was formed in November 1999 following the merger of Exxon and Mobil. The company has presence in both upstream and downstream businesses. The company derives more than two-thirds of its revenue from upstream operations. In the US, its oil exploration and production activities are mainly concentrated in the Permian Basin, Bakken Formation, Woodford Shale, Caney Shale, and the Gulf of Mexico. It earned a revenue of $268.9bn in 2015.

Royal Dutch Shell: Headquartered in the Netherlands and incorporated in the United Kingdom, it is a British–Dutch multinational oil and gas company. Its operations are divided into four businesses such as upstream, integrated gas and new energies, downstream, and projects and technology. In deep water, the company has a major presence in the Gulf of Mexico, Brazil, Nigeria and Malaysia. It also has substantial position in shales in North America and Argentina. With operations in more than 70 countries, its major projects are spread across Australia, Brazil, Kazakhstan, Malaysia and the US. It oil and gas production available for sale 1,078 million barrels of oil equivalent in 2015, while its revenue was $265bn.

Kuwait Petroleum Corporation: It is a Kuwait's national oil company with activities focuses on petroleum exploration, production, petrochemicals, refining, marketing, and transportation. It was founded in 1980 as an umbrella organisation to manage Kuwait’s diversified oil interests. Kuwait Integrated Petroleum Industries Company, Kuwait Oil Company and Kuwait National Petroleum Company are some of its subsidiaries. It earned a revenue of $251.9bn in 2015.











Image: Kuwait Petroleum Corporation (KPC) H.Q. Photo courtesy of radiant guy/Wikipedia.

British Petroleum (BP): Headquartered in London, England, is a British multinational oil and gas company with operations in 72 countries. BP is a major acreage holder and producer of oil and natural gas in the deepwater Gulf of Mexico. The region accounts for about 10% of its global production. According to the company, it has proved reserves of 17,810 million barrels of oil equivalent with new exploration access covering 71,000km2.  Its principal areas of production are Angola, Argentina, Australia, Azerbaijan, Egypt, Iraq, Trinidad, the UAE, the UK and the US. For the year 2015, it earned a revenue of $222.8bn.