For the 17th year in a row, Saudi Aramco was last year named the No 1 oil company in the world by the energy trade journal Petroleum Intelligence Weekly (PIW).

Saudi Aramco leads the way among all oil companies as state-owned companies gain strength over the publicly held supermajors.
"Saudi Aramco's latest No 1 ranking among the world's oil companies underscores the continuing top priority the company assigns to reliability in everything we do, year in, year out," said Mustafa A Jalali, vice president of Saudi Aramco Affairs in Dhahran.
"Reliability is especially crucial with rising global demand," Jalali said. "Saudi Aramco is doing everything possible to meet that demand. We're succeeding now, and, with major production and refining expansions under way, we will continue to succeed in the future."
Saudi Arabia holds a quarter of the world's total oil reserves, which are managed by Saudi Aramco.
The company is also fourth internationally in gas reserves, seventh in gas output, ninth in petroleum product sales and ninth in refining capacity.
The company is also the leading exporter of crude oil and natural gas liquids.
PIW says that its latest rankings show that the mega-mergers among the world's largest publicly owned oil companies have run their course and that state-owned companies are making a comeback.
"Initial signs of the turning tide are already apparent in this year's rankings as well as in recent structural shifts in the industry," the journal said.
Contributing to that increasing influence is nationalism in countries such as Russia and Venezuela, and expansion by Chinese firms and others that are partially or wholly state-owned. Russia's Gazprom and Rosneft are expected to rise 10-20 places in the next rankings, PIW said.
On the private side, "The supermajors and other large private sector firms seem to have more limited growth options," PIW said, "especially compared to emerging majors with some state ownership such as PetroChina, Petrobras and Petronas, which all scored solid gains."
PIW bases its Top 50 rankings on six criteria that allow private and state-owned companies to be compared.
These 50 firms account for about three-fourths of global oil and gas supply, the journal said.
The Top 10 with their current rank and previous rank: Saudi Aramco: 1, 1; ExxonMobil: 2, 2; PDV: 3, 4; NIOC: 4, 3; BP: 5, 5; Shell: 6, 5; Total: 7, 8; Chevron: 8, 7; Pemex: 9, 9; PetroChina: 9, 10.