China has developed an important theory in the field of continental petroleum geology through many years of research and experiment, one that runs parallel to an influential international theory on hydrocarbon formation in marine geology.

This theory has significantly boosted China's oil development, said Shen Pingping, head of the China Petroleum Exploration and Development Academy.

Addressing a seminar on China's Oil Development Strategy in the21st Century, Shen noted that by using this theory China has located 27 large oilfields, each with deposits above 100 million tons, including such well-known oilfields as Daqing in northeast and Renqiu in north China.

The senior expert said that with research and practice, China has also developed technologies of layer-by-layer oil extraction and stabilizing oil reserves with injected water, and has utilized the polymer-drive extraction method, all comparable to advanced methods used around the world.

Other major oilfields in Bohai Bay areas such as Shengli, Liaohe, Zhongyuan, Huabei, and Dagang have developed rolling exploration technology, which has increased oil exploration in the area.

So far, the bay areas of the Bohai Sea have been proven to have oil deposits of nearly 8 billion tons, and an annual crude output of over 60 million tons, making it the second-largest oil and gas production base in China after Daqing, he explained.

In the exploration of complex oil layers, China has come up with a range of thermodynamic technologies to explore thick oil, mainly by the use of steam.

The country also has developed an annual thick oil output of 12million tons, the fourth largest in the world.

To boost oil and gas development in the 21st century, China now is launching a group of petroleum science and technology projects and a series of technological developments nationwide. (Xinhua)