For China, the biennial Rio Oil and Gas Expo and Conference held in Rio de Janeiro provided a window to demonstrate its companies' products and served as a platform to increase cooperation in the energy industry.

More than 1,000 exhibitors from dozens of countries and regions attended the Latin America's most important oil and gas professional exhibition on Sept 15-18.

The event has been held every two years since 1982 and is organized by the Brazilian Institute of Petroleum (IBP). It is a platform for the international oil industry to promote new products and services, exchange ideas and discuss technological innovation.

China's oil and gas industry is in the midst of a series of significant reforms and a possible restructuring, according to the 2014 Oil and Gas Reality Check report, released by Deloitte Touche Tohmatsu Ltd (DTTL), a UK-based private company and a Deloitte member firm.

In the beginning of this century, bilateral trade in the oil industry focused on China's imports of Brazilian crude oil. In recent years, China's oil industry began to diversify its investment in Brazil, seeking mergers or cooperation with local companies in areas ranging from natural resources to high technology and oil-related equipment.

Brazil-based Petrotech, a subsidiary of China National Petroleum Corporation's (CNPC) Technology Development Company, took part in this year's exhibition. It has become a driving force in promoting Chinese oil companies' overseas investments, and material and equipment exports to Brazil.

Another exhibitor from China was Baoji Petroleum Machinery Co. As a subsidiary of CNPC, it established a joint venture in Brazil in October 2011 under the name Brazilian Baoji Petroleum Equipment Company. Its business includes project design, equipment manufacturing, sales and services.

Deng Weiliang, the company's general manager, said the Brazilian oil-equipment market is relatively closed and highly specialized, and it is not easy to challenge the long-term dominance of brands from the United States, the UK and Italy.

"But Chinese oil equipment has won the trust of customers in Brazil with good quality, which is not only conducive to the development of the company's overseas strategy, but can also help increase acceptance by overseas markets toward China's brand," he said.