By the end of 2011, China had nearly 94 billion tons of provable oil reserves, an increase of 23 percent over 2007, and about 55 trillion cubic meters of provable natural gas reserves, about 56 percent more than in 2007, an oil and gas report released by the Ministry of Land and Resources on Thursday said.

The report said the dramatic growth of the oil and gas reserves across the country is mainly due to the technology development and innovation in exploration and drilling.

According to the ministry's latest statistics, the investment in mining and exploration surged from 22 billion yuan ($3.5 billion) in 2002 to more than 71 billion yuan in 2011.

Peng Qiming, director of the ministry's geological exploration department, said the oil and gas reserves in Northeast China has grown dramatically in energy assessment with provable oil reserves reaching up to 23 billion tons, about 34 percent more than the last assessment in 2007.

By 2011, the natural gas provable reserves in Northeast China increased to 4.5 trillion cu m and the shale gas reserves reached nearly 6 trillion cu m, Peng said.

It is estimated that by 2030, the annual output of oil may exceed 250 million tons and the annual output of natural gas is expected to reach 450 billion cu m.