Abstract:

Based on the analysis of regional tectonic evolution,structural unit division and characteristics of strata development,the reservoirs,hydrocarbon pooling conditions and main controlling factors were studied to set up pool-forming models in the east of the Maichen Sag of the Beibu Gulf Basin.The Paleogene Liushagang and Weizhou formations (El and Ew respectively) are the dominant oil-bearing formations which include four sets of reservoir-seal combinations;the dark mudstone in the El² and the upper El³ are the main source rocks;the El³ and Ew are two important sandstone reservoirs.The traps are mainly faulted nose,faulted block and stratigraphic overlap traps with good timing and spatial configurations.The predominant factors controlling pool-forming could be mature source rocks,reservoirs development,fault features,sealing conditions,configuration of traps and their workable degree.There are three hydrocarbon pooling models,including the inner-slope zone in the deep sag,fault bench in the south,outer-slope and far slope zone.The western part of inner slope zone is the most favorable area for further exploration.

Key words: reservoir, pool-forming characteristics, main controlling factor, Maichen sag, Beibu Gulf Basin