Asia's biggest oil producer PetroChina Co Ltd will acquire some of US ConocoPhillips' interests in two projects in Western Australia, a move indicating its increasing focus on natural gas resources, according to an agreement reached on Wednesday.

PetroChina will acquire a 20 percent share in ConocoPhillips' Poseidon project in Browse Basin and 29 percent equities of the Goldwyer shale gas project in Australia's Canning Basin, according to ConocoPhilips' announcement.

The two companies also established a Joint Study Agreement to co-research unconventional natural gas resources in China's Sichuan Basin.

All the agreements still need to be approved by related governments and business partners.

"ConocoPhillips is pleased that PetroChina has recognized the significant resource potential and value of the Australian opportunities. Likewise, ConocoPhillips recognizes the Sichuan Basin as having some of the most prospective marine shales in China and looks forward to working with PetroChina," said Don Wallette, executive vice-president, Commercial, Business Development and Corporate Planning of ConocoPhillips.

The new agreements are important parts of PetroChina and ConocoPhillips' global cooperation, which also highlights CNPC's growing efforts to strengthen offshore liquefied natural gas and onshore unconventional natural gas resources in Western Australia.

In December, PetroChina agreed to buy BHP Billiton Ltd's shares in liquefied natural gas project in Western Australia at a cost of $1.63 billion - the biggest overseas acquisition by the company in 2012.

The Chinese oil giant will gain an 8.33 percent interest in the East Browse Joint Venture and a 20 percent interest in the West Browse Joint Venture, located off Western Australia, from BHP.