中文摘要：

南海北部深水区沼泽相煤系烃源岩和海相烃源岩有机质主要来源于陆生高等植物,且含有较丰富的孢子体、角质体、树脂体、壳质体和无定形有机质等富氢组分;热模拟实验结果表明：这类富氢组分较丰富的煤系烃源岩和海相烃源岩属于油气兼生、以气为主的烃源岩,在生油窗内均具有较强的生油能力;热演化程度控制烃源岩的生烃产物特征。生烃史模拟结果表明：①琼东南盆地烃源岩热演化程度明显高于珠江口盆地相应层位烃源岩,以生成高—过成熟的天然气为主;而珠江口盆地主要烃源岩的热演化程度主要处于成熟—高成熟阶段,在生成天然气的同时,还生成较多的油。②烃源岩热演化程度控制油气分布,凹陷边缘烃源岩热演化程度明显低于凹陷中心,如白云凹陷中心主要烃源岩处于高成熟生气阶段,而凹陷边缘主要处于成熟生油阶段。白云凹陷钻探结果表明,凹陷中心已发现油气田和含油气构造中天然气的比例明显高于凹陷边缘。

英文摘要：

In the deepwater region,the northern South China Sea,organic matters in coal-measure source rocks of swamp-facies and marine source rocks are mainly derived from terrestrial higher plants,and are relatively abundant in hydrogen-rich macerals such as sporinite,cutinite,resinite,exinite and amorphous components.The results of thermal simulation have showed that these source rocks with hydrogen-rich organic matters can generate both oil and gas,with gas generation predominated,but will generate much oil if they are in oil window.Therefore,their characteristics of hydrocarbon generation are controlled by their thermal maturities.The modelling efforts of hydrocarbon generation history have indicated that：（1）these source rocks are significantly more thermally mature in Qiongdongnan basin than in Pearl River Mouth basin,with their hydrocarbon generation in the former predominated by high to over mature gas,and both gas and much oil generated in the latter under a mature to high mature stage.（2）Hydrocarbon distribution is also controlled by thermal maturities of these source rocks,with a gas generation period occurring in the central sags,such as Baiyun,where the maturity is much higher than in the marginnal sags,and with a mature period of oil generation occurring in the marginnal sags.According to the drilling results,the fields and hydrocarbon-bearing structures discovered in the central Baiyun sag are much higher in gas-oil ratio than those discovered in the marginal Baiyun sag.