U.S. oil major Exxon Mobil Corp. (XOM) is in talks with PetroChina Co. (PTR) to jointly explore and develop an unconventional gas block in the resource-rich Ordos basin in north China, a person who has direct knowledge of the matter told Dow Jones Newswires. A successful conclusion to the talks would mark the entry of another global energy major into China's huge but undeveloped shale or tight gas sector, which China hasn't been able to develop due to a lack of technical expertise
U.S. oil major Exxon Mobil Corp. (XOM) is in talks with PetroChina Co. (PTR) to jointly explore and develop an unconventional gas block in the resource-rich Ordos basin in north China, a person who has direct knowledge of the matter told Dow Jones Newswires.

A successful conclusion to the talks would mark the entry of another global energy major into China's huge but undeveloped shale or tight gas sector, which China hasn't been able to develop due to a lack of technical expertise.

The discussions have been under way since Exxon Mobil's upstream team visited Beijing in early June.

If they succeed, the companies will sign a production sharing contract and then drill appraisal wells, the person said, declining to be named.

The unconventional gas block being targeted has tight gas reserves, a second source said, who also declined to be identified.

A PetroChina media official said the company is very interested in developing unconventional gas in China, and noted that there had been great success in the development of unconventional gas in the U.S.

He wouldn't confirm if talks with Exxon Mobil are underway, but said agreements of this sort with foreign partners would only be announced when deals were settled.

The U.S. company is well established in China's downstream sector, including in partnering China Petroleum & Chemical Corp., or Sinopec, the Fujian provincial government and Saudi Aramco in a $4.5 billion refining and petrochemical complex in Fujian province.

In March, Royal Dutch Shell PLC (RDSB) signed a 30-year contract with China National Petroleum Corp., parent company of PetroChina, to jointly develop tight gas reserves in central China's Sichuan Province.

Tight gas is natural gas contained in rock that must be fractured or broken open before it can flow easily to production wells.

France's Total SA (TOT) expects the Chinese government will approve its tight gas joint-venture South Sulige gas project, also in the Ordos Basin, "in a few months", Jean-Marie Guillermou, senior vice president for Asia Pacific, Exploration and Production said in June.

CNPC will be the operator of the field, and Total will have a 45% stake, he said.

Earlier this month, BP PLC (BP.LN) and PetroChina agreed to cooperate in coal-bed methane development at the Sha Erhu block at Tuha basin in Xinjiang Uighur Autonomous Region.

Also, Sinopec Group is working with BP in shale gas resource assessment in China's Guizhou and Jiangsu provinces.

CNPC is keen to gain the know how to develop such gas deposits. In June, it signed an initial agreement with Canada's Encana Corp. (ECA) to develop shale gas reserves in Canada, under which it would "gain an advanced understanding of unconventional natural gas development through an ongoing sharing of technical knowledge," Encana said at the time.

Exxon clearly demonstrated its interest in unconventional gas last year, with its $41 billion purchase of XTO Energy Inc, which has major tight gas assets in the U.S.