Herbert Smith Freehills has advised PetroChina Company Limited, a subsidiary of state-owned and China's largest oil and gas company China National Petroleum Corporation, on its acquisition of a 25% stake in phase one of the West Qurna field.

PetroChina will acquire the stake from Exxon Mobil, which will separately sell a 10% stake to Indonesia’s Pertamina, leaving it with a 25% interest. Exxon Mobil will remain as the field's operator after the sales.

The West Qurna field is one of Iraq's largest oil fields and is located north of Rumaila field, west of Basra. West Qurna 1is expected to produce around 600,000 barrels of oil per day. The field, launched in 2010, is jointly owned by ExxonMobil (with a majority 60% stake), an Iraqi state-run oil company and Shell.

The Herbert Smith Freehills team was led by Hong Kong partner Hilary Lau. Other members of the team include Doha managing partner Neil Brimson and London partner Isaac Zailer, senior associates Chris Thompson and Aurell Taussig, and associates James Zhang, Natasha Batson and Jie Li.

"PetroChina's acquisition of a West Qurna stake will help it achieve synergies with its other projects in the region," said Hilary. "We are delighted to have been able to provide our long term client PetroChina with the regional support from our network on its bid to develop a larger upstream operations presence in the Middle East."

Earlier this year, Hilary also led a Herbert Smith Freehills team to advise PetroChina on its acquisition of an interest in two Western Australian exploration assets from ConocoPhillips. In August, the firm represented PetroChina's parent company CNPC on another of its major cross-border acquisitions earlier this year, when it acquired a 28.57% stake in Eni East Africa SpA, a wholly owned subsidiary of Eni SpA, for US$4.2 billion.