Abstract: Since the 12^th Five-Year Plan, China National Offshore Oil Corporation (hereinafter referred to as CNOOC) has achieved fruitful oil and gas exploration results, such as new records of reserve discoveries in domestic oil and gas exploration, continual successes of exploration expansion in mature regions, and constant exploitation of new exploration areas and fields. The innovation of petroleum geology theories and improvement of exploration technology was the important guarantee for CNOOC’s exploration breakthroughs during the 12th Five-Year Plan. A series of major theories are innovated, including differential hydrocarbon enrichment in active fault belts in Bohai Sea, hydrocarbon accumulation in deepwater at the continental margin of northern South China Sea, and the HTHP (high temperature and high pressure) gas accumulation in western South China Sea. Furthermore, a series of technical innovations are realized in terms of geophysical data acquisition and processing for complex seismogeological conditions of China’s sea area. These theoretical and technical innovations lead to a series of major hydrocarbon exploration breakthroughs of CNOOC in Bohai Sea area, deepwater in northern South China Sea and HTHP strata. During the 13^th Five-Year Plan, CNOOC will continue to deepen its geological understanding and to develop key technologies, so as to make new contributions to the Company’s sustainable development and to ensure national energy security.

Key words: CNOOC, oil and gas exploration, exploration in deepwater of South China Sea, exploration in active fault belts in Bohai Sea, exploration technology in HTHP regions, 12^th Five-Year Plan, 13^th Five-Year Plan