"Two or three years is enough to decide whether to continue with the work," a senior geologist with PetroChina said, adding that risk exploration is about accumulating information and making decisions in the course of exploring.
PetroChina, one of China's top oil and gas producer, has been working with Shell in southwest China since early this year and their first well successfully extracted shale gas in October.
For foreign oil firms eager to join China's game, Sino-foreign cooperation, especially that with big state-controlled companies, has long been a good solution to securing mineral rights.
China's Law of Mineral Resources stipulates that enterprises with exploration rights will be given privileged access to mining rights in the area they have explored, but private and foreign companies are usually daunted by lengthy administrative approval procedures.
"Wording like 'privileged access' does not suffice to protect the rights of the investors," said Zhang Libin, an energy consultant and partner at the Chinese law firm Broad and Bright.
Cumquat market in S China's Guangxi