南黄海盆地烃源潜力比较性评价

COMPARATIVE ASSESSMENT OF HYDROCARBON RESOURCE POTENTIAL IN THE SOUTH YELLOW SEA BASIN

南黄海中—新生代盆地经历了中生代印支运动以来的多期构造运动改造,凹陷分隔性强,各凹陷烃源岩发育条件差异大。利用地质调查获得的最新资料,从烃源岩有机质丰度、类型、成熟度以及成熟烃源岩体积参数等方面,重点探讨了中—新生代陆相盆地生烃条件好和较好的7个凹陷的烃源潜力及中—古生界海相烃源岩的演化特征。结果表明,北部坳陷的北部凹陷、东北凹陷以及南部坳陷的南四凹陷属于一类生烃凹陷,北部坳陷的南(西)部凹陷、南部坳陷的南五凹陷属于二类生烃凹陷,而北部坳陷的中—东部凹陷以及南部坳陷的南七凹陷为三类生烃凹陷。印支构造面之下的中—古生界海相层系是盆地内另一套重要烃源岩,其有机质热演化程度分异明显,在中—新生代凹陷间低凸起区最低,坳陷周围的隆起区最高,新生代凹陷区"基底层"内热演化程度介于上述两者之间。

The Mesozoic-Cenozoic of the South Yellow Sea Basin has experienced multi periods of tectonic movements and transformations since Indosinian movement, and the Mesozoic-Cenozoic sags are strongly differentiated with different hydrocarbon source rocks. Based on the latest data obtained through the geological survey, the abundance, type, maturity of the organic matters from hydrocarbon source rocks were studied, focusing on analysis of hydrocarbon generating conditions of the Mesozoic-Cenozoic continental basin and the hydrocarbon source potential of seven better sags in addition to the evolutionary characteristics of the Middle Paleozoic marine hydrocarbon source rocks. Results show that the Northern Depression of the Northern Sag, the Northern and Northeast Depressions ofthe Northern Sag and the South 4 Depressions of the Southern Sag belong to the first-class of hydro- carbon generating depressions and the Southern（Western） Depression of the Northern Sag and the South-5 Depression of the Southern Sag belong to the seconded-class of hydrocarbon generating depressions, while the Mid-East Depression of the Northern Sag and the South-7 Depression of the Southern Sag belong to the third-class of hydrocarbon generating depressions. The marine Paleozoic under the Indosinian surface of the basin is another important source rock, whose thermal evolution degree of organic matter was more distinctly differentiated, as the low uplift zone in the Mesozoic Ce- nozoic depression has the lowest thermal evolution degree, and the area around the uplift zone of the Mesozoic-Cenozoic depressions have highest thermal evolution degree, and the ＂basement layer＂ in the Mesozoic-Cenozoic depression has the thermal evolution degree between the above two.