Also in 2013, a consortium of companies including Petrobras, Total, Shell, China National Petroleum Corp and China National Offshore Oil Corp, won a 35-year production sharing contract to develop the Libra pre-salt oil block in Santos Basin.

"Brazil is a resource-rich country, but it is short on technology and capital," said Liu Yijun, professor at China Petroleum University. "And the low crude prices have opened new opportunities for Chinese companies in Brazil."

Meanwhile, oil cooperation between the two countries has been further boosted by the loans granted by Chinese financial institutions to Brazilian oil companies in recent years.

In 2009, the China Development Bank (CDB) agreed to provide loans of 10 billion dollars to Petrobras in 10 years, and opened a representative office in Rio de Janeiro, its first outlet in Latin America.

In April 2015, the CDB signed with Petrobras an investment contract worth $3.5 billion. The cooperation between the two companies was expanded again during Chinese Premier Li Keqiang's visit in May with another contract of 1.5 billion dollars of investment and 2 billion dollars of loans.

Petrobras, which has been undergoing financial difficulties, said the company and the CDB "both confirmed their intention to undertake further cooperation in the near future ... to strengthen synergies between the economies of the two countries."