There is no respite in China’s hunt for energy assets. A month after taking a stake in a British refinery, PetroChina  is paying $5.4bn to buy into  a large Canadian gas field project owned by Calgary-based Encana.

The state-controlled company is taking a 50 per cent in a transaction that dwarfs the two  recent deals totalling $1.3bn by rival CNOOC with US-based Chesapeake Energy for American gas projects. In 2010, Chinese oil groups spent $24bn on foreign acquisitions. Given the flying start to 2011, it could be even more this year.

As Bernard Simon reports from Toronto on ft.com, the focus of these deals is so-called unconventional gas – gas locked into shale and/or coal, which requires new technologies for its development. As well as buying foreign energy reserves, Chinese companies want to acquired know-how for possible use in China, where there are reported to be big reserves of unconventional gas.