Brazil, which owns rich resources in Latin America, may become the next investment hotspot for Chinese oil and gas companies trying to establish effective supply chains in overseas market after buying energy assets for years.

"In the future, Latin America will strengthen its external cooperation in oil and gas sector with more bidding offers," said an annual report from the CNPC Economics and Technology Research Institute.

A man walks on the beach past an offshore oil drilling rig in Guanabara Bay in Niteroi, Brazil. Dado Galdieri / Bloomberg

In 2013, Latin America had 35 new oil and gas discoveries, adding new oil reserves of 800 million metric tons and natural gas reserves of 10 billion cubic meters, according to data from the report.

The total oil reserve of the region reached 47.34 billion tons and natural gas of 7.97 trillion cu m by the end of 2013.

The offshore oil and gas development in northeastern Latin America has aroused interests from international players since last year, the institute said.

Brazil, which owns rich deep-water and pre-salt oil and gas resources, is an attractive country for Chinese investors, especially for offshore oil companies who are trying to add more experience by learning from their overseas counterparts.

The pre-salt resource is a geological formation off the coast of Brazil that may hold large amounts of oil.

The oil and gas exploration success ratio is as high as 59 percent in Brazil, far beyond the global average of 30 percent. The exploration success ratio in Brazil's pre-salt oil and gas fields is even higher — reaching 80 percent.

CNOOC Ltd, China's largest offshore oil and gas developer, as part of a consortium comprised of Shell, Total, China National Petroleum Corp and the Brazilian state-owned Petrobras, was awarded a 35-year production-sharing contract last October to develop the Libra pre-salt oil discovery in Brazil's offshore Santos Basin.

The Libra field in Brazil is one of the largest deepwater oil accumulations in the world.

Total investment for the project is $180 billion.

According to CNOOC, it will pay 1.5 billion Brazilian Reals ($629 million) as its 10 percent share of the signing bonus, and the winning consortium will conduct a minimum work program no later than the end of 2017.

Li Fanrong, chief executive officer of CNOOC, said participation in the Libra project not only signifies the milestone of a strategic entry into an ultra-deepwater field for the company, but also aligns with its philosophy of seeking partnerships to expand its global footprint.

"Assets evaluations and feasibility studies are always crucial for overseas investments decision-making," said Li Li, research director at ICIS C1 Energy, a Shanghai-based energy information consultancy. "If the international oil price doesn't drop below $90 a barrel, the Brazil oil and gas assets will keep their attraction for Chinese investors in the years to come."

Li said such investments are about "courage and risks" and that Chinese companies have been playing both "active and cautious".

As China's energy demand increases for its rapid economic growth, Chinese companies have been increasing their interests in Latin American oil and gas resources during their ongoing overseas expansion.

During President Xi Jinping's visit to Latin American countries in May, CNPC signed a $12 billion contract with Ecuador for a refinery project.

China's Sinopec Group is in talks with Petrobras to cooperatively establish a refinery project in the Maranhao state in northeast Brazil.

It is a trend that resource-rich countries are no longer just the sellers of oil and gas, but want investors to bring more technology and projects to their countries to increase jobs and local economic growth.

According to the CNPC Economics and Technology Research Institute, many Latin American countries signed agreements or carried out policies to build new refineries last year.

"They have been continuing to accelerate their crude refining capacities based on the region's advantages in energy resources," the report said.

It added that Brazil's Petrobras had posted a deficit for a few years, which made future investments difficult for them.

In addition, Brazil's deep-water oil and gas projects require huge capital with high risks. Thus, the government hopes to increase domestic employment and economic growth through cooperating with foreign companies in the offshore oil and gas sector, which can also bring advanced technologies.

In May 2013, the Brazilian government provided 142 blocks for the 11th round of oil and gas blocks bidding, which resulted in $3.39 billion of committed investment.