三水盆地的构造演化及油气地质特征

三水盆地的构造演化主要经历了裂陷、坳陷、沉陷和抬升四个发展阶段,发育了深湖一浅湖-河流三角洲型沉积层序,以泥岩、砂岩为主的沉积地层,具有良好的油气生、储条件.经野外露头剖面勘察和钻井岩性分析,下第三系布心组发育深湖、半深湖相泥岩、碳质泥岩和泥灰岩,是主要的烃源岩;布心组二段为湖泊极盛时期沉积,以暗色泥岩为主夹碳酸盐岩沉积,是盆地内主力生油岩系.根据烃源岩和地质构造特征,主要的含油气系统为布心组生、布心组和西布组储、布心组和西布组盖的生、储、盖组合,为具有一定勘探潜力和开采价值的含油气盆地.

The Tectonic Evolvement and the Petroleum Geological Characteristics in Sanshui Basin

Sanshui Basin is situated in the northwest of Pearl River Delta.It's an important depression of late cretaceous and paleogene in southern China margin.The evolvement had come through four stages,such as splitting,depressing,sinking and uplifting.It has three sediment sequence which includes deep lake facies,shallow lake facies and river delta facies.The mudstone and sandstone are better store stratum for gas and oil.The main source rocks are Buxin and Xibu Formations which sediments are mudstone,shale,carbonaceous mudstone and marl of deep and semi-deep lake facies.The second segment of Buxin Formation(E1-2b) is the most important source rocks which was formed in the largest term of the lake basin.The sediment is mainly dark mudstone and carbonate.The source rocks are matured and in the peak stage of oil generation.According to the oil source and tectonic characteristics,the oil-gas system can be divided into three part.We can found the combination of the oil system which mature oils originated from Buxin Formations,stored up and covered by Buxin-Xibu Formations.It is considered that the Sanshui Basins has great significance for oil exploration in the future.