烃源岩评价是沉积盆地油气地质研究的重要组成部分,尤其对油气勘探初期的战略选区与决策至关重要。南黄海北部盆地东北凹陷的油气勘探程度极低.至今尚无探井揭示烃源岩的发育特征,因此制约了凹陷的油气勘探进程。基于地质类比原理,采用与其相邻类似凹陷——北部凹陷综合对比的方法,应用层序地层、沉积相、地震相分析及含油气盆地动态数值模拟等技术,分析了东北凹陷主要烃源岩层的空间展布和生烃演化特征,并初步形成了一套适用于勘探程度低的地区烃源岩早期预测的方法技术流程。研究表明,南黄海北部盆地东北凹陷发育上白垩统泰州组主力烃源岩系,具有广阔的油气勘探前景。
Source rock evaluation, one of the most important aspects of petroleum geology study of a sedimentary basin, will determine the early strategic electoral district and decision of exploration activity. While the low exploration in the northeast sag in the South Yellow Sea Basin indicates that petroleum exploration activity had been restricted in the depression because no exploration well has disclosured the characteristics of source rocks. Based on the geological comparison, the paper analyses the spatial distribution of the main hydrocarbon rocks and their characteristics of hydrocarbon generation in northeast sag by comprehensive correlation with adjacent homologous depressions, sequence strategraphy, sedimentary facies, seismic facies and dynamic modelling of the oil-gas basin. In addition , it presents a method of early prediction and comprehensive evaluation of source rocks in the low exploration stage of sedimentary basin. This study suggests that the upper Cretaceous Taizhou Formation is the main source rock in northeast sag of the north depression in the South Yellow Sea Basin and so the oil and gas exploration prospect is promising.