China National Petroleum Corp, the country's largest oil and gas producer, has pumped the first crude oil through the China-Myanmar oil pipeline and the oil is expected to arrive in China within three weeks, the energy giant said on Wednesday.

Around 1,150 cubic meters per hour of crude began flowing into the pipeline on Tuesday, CNPC said in a statement.

The pipeline is the latest energy cooperation between the two countries, and helps ensure China's energy diversification, the company said.