Improved Geological Understanding and Exploration Practice of Stratigraphic Traps in Chinese Sedimentary Basins

Wenzhi Zhao¹, Chengzao Jia², and Caineng Zou^1
1PetroChina Research Institute of Petroleum Exploration and Development, Beijing, China
²PetroChina Company Limited, Beijing, China

Recent petroleum exploration strategy in China is characterized by a paradigm shift from structural traps to stratigraphic traps. Favorable geological conditions for forming large-scale stratigraphic traps exist in many Chinese sedimentary basins. Significant variation in lithology appear to be the norm in nonmarine basins and so are gentle structures in small marine cratonic basins. As almost 60% of the remaining petroleum resources in China occur in stratigraphic traps, they have become the focus of current and future exploration activities. Basic geological controls for the development of stratigraphic traps include six lines (pinch out, onlap, erosion, change in lithology, variation in fluid properties and structural contours) and four surfaces (fault planes, unconformity, flooding surface and over-/underlying beds). Large variation in the distribution of stratigraphic traps has been found in four different types of basins (rift, depression, foreland and craton), leading to 14 different stratigraphic play types. Detailed study of the trap elements, structure-sequence combinations and reservoir filling mechanisms is vital to the future petroleum exploration in China. This talk will review the recent advances in the geological theory and exploration practices related to stratigraphic traps in China.

AAPG Search and Discover Article #90078©2008 AAPG Annual Convention, San Antonio, Texas