Transitional source rock and its contribution to hydrocarbon accumulation in superimpose rift-subsidence basin of northern South China Sea:Taking Baiyun Sag of ZhuII Depression as an example
Transitional source rock and its contribution to hydrocarbon accumulation in superimpose rift-subsidence basin of northern South China Sea:Taking Baiyun Sag of ZhuII Depression as an example
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发表时间：
2010
影响因子：
1.8
通讯作者：
Li You-chuan
中科院分区：
文献类型：
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作者：
Li You-chuan
叠合断陷盆地在拉张盆地断陷期充填有陆相、过渡相和海相沉积。叠合断陷盆地的板块构造环境、沉积相和烃源岩与断陷期完全由陆相地层充填的陆相断陷有明显不同。近海沉积了陆相、过渡相和海相三大烃源岩层系。过渡型烃源岩对南海北部朱二坳陷、琼东南盆地等断陷盆地做出了巨大贡献。过渡型地层的生烃时间和成藏期晚于断裂时期沉积的陆相地层。过渡型烃源岩具有陆地植物和海洋生物输入的混合特征。烃源岩生成的油气具有双源性。该类型烃源岩干酪根为II-III型，易产煤型气，但浅层易产油。油气源对比表明，白云凹陷油气来源于恩平组过渡型烃源岩。珠海组海相烃源岩对LW3-1气田有一定贡献。勘探经验表明，过渡型烃源岩是白云凹陷最重要、最有效的烃源岩层系。南海北部目前断陷沉降盆地.
The superimpose rift-subsidence basin is filled with the continental,transitional and marine deposits in the rifting stage of extensional basin.The plate tectonic environment,sedimentary facies and hydrocarbon source rocks of the superimpose rift-subsidence basin are obviously different from those of the continental fault depression exclusively filled with the continental strata in the rift period.Three major hydrocarbon source rock strata of continental,transitional and marine facies were deposited in the offshore rift-subsidence basin of China.The transitional source rocks have great contribution to the rift-subsidence basins such as Zhu Ⅱ Depression and Qiongdongnan Basin in the northern of South China Sea.The hydrocarbon-generation time and hydrocarbon accumulation period of the transitional strata are later than those of the continental strata deposited in the faulted period.The transitional source rocks have the mixed characteristics of the land plant and marine bio-matter inputs.The hydrocarbon generated from the source rocks has the double-source genesis.This type source rock with the kerogen of II-III type is prone to coal-type gas,but it is prone to oil in the shallow layer.The oil-gas-source correlation suggests that oil and gas in the Baiyun Sag was derived from the transitional source rocks of Enping Formation.The marine source rocks of Zhuhai Formation have some contribution to LW3-1 gas field.The explore experience shows that the transitional source rock is the most important and effective to hydrocarbon source rock strata of the rift-subsidence basins in the northern South China Sea at present.