China's nascent shale-gas industry is luring US firms well before any product is ready for the market, the Wall Street Journal reports.

China has large reserves of natural gas, trapped within shale, which were allocated to Chinese state-owned companies in several blocks. US oil-field-service companies are investing in local partners, hoping to gain a possible foothold in China's largest energy producers – China National Petroleum Corp. and China Petrochemical Corp., known as Sinopec Group.

US-based giant Schlumberger Ltd. bought a minority share of 20.1%, worth $80 million, in Hong Kong-listed Anton Oilfield Services Group, the main operational services provider of the Sinopec Group. US competitors may follow Schlumberger into China's shale-gas industry but there is still the urge to protect intellectual property and technology holding back US firms.

China's biggest energy producers – CNPC, Sinopec Group, Sinopec Group, and China National Offshore Oil Corp. – have been investing in shale-gas in North America to obtain technology they can use back home. China's state-owned producers told the Journal said that 'drilling know-how' remains firmly owned by oil-services companies.