南海南北陆缘盆地油气成藏条件差异较大,目前南部盆地的油气产量远大于北部盆地。根据储集层和盖层的环境特征,大致可将南海南北陆缘盆地储盖组合划分为4种类型:陆相砂+局部盖层组合,海陆交互相砂+局部/区域性盖层储盖组合,滨浅海碎屑砂体/碳酸盐岩生物礁+浅海相泥岩区域性盖层储盖组合以及深水碎屑岩/浅海砂体+深水泥岩储盖组合。相对于北部盆地,南部盆地的碳酸盐岩+海相泥岩储盖组合发育更加广泛。分析认为,构造活动差异是造成南北陆缘盆地储盖组合特征及其差异的第一控制因素;此外,区域地质和环境背景的演变也是造成这种差异的重要影响因素。
Petroleum geological conditions are obviously different between the northern and southern continental marginal basins of the South China Sea.At present,the oil and gas production of the southern basins are much higher than that from the northern basins.According to their depositional characters,the reservoir/cap assemblages in the northern and southern continental marginal basins of South China Sea can be grouped into four types: continental sandstone + local cap,paralic sandstone +local or regional cap,neritic clastic sandstone/ carbonate/ biological reef + regional cap of neritic shale and clastic rock of deep water/neritic sandstone + cap of shale of deep water.Compared to the north basins,the south basins are extensively dominated by the reservoir-cap assemblage of carbonate + marine facies shale.Results of this study suggest that tectonic activity is the first controlling factor of the differences of reservoir-cap assemblages between the northern and the southern continental marginal basins.Evolution of regional geology and environmental settings are also important.