苏北高邮凹陷下第三系生油岩的有机地化特征和生油门槛研究

STUDIES ON ORGANIC GEOCHEMICAL CHARACTERISTICS OF EOGENE SOURCE ROCK IN GAOYOU DEPRESSION AND ITS OIL GENERATION THRESHOLD

汪本善 范善发 史继扬 徐芬芳 张丽洁 洪紫青 吕国英 黄宛平 干一女 王文军

Wang Benshan Fan Shanfa Shi Jiyang Xu Fenfang Zhang Lijie Hong Zhiqing Lu Guoying Huang Wanping Gan Yinu Wang Wenjun

我们对苏北盆地高邮凹陷下第三系阜宁组及戴南组一段生油层进行了有机地球化学研究,通过多种指标综合分析,较可靠地确定了下第三系阜宁组生油岩的生油门槛深度。我国东部地区各新生代盆地由于各自的莫霍面深度、基底岩石导热性、火山活动、地下水动态等方面的不同,地温梯度有明显的差别,下第三系生油门限深度也不尽相同。

Oil generation threshold(OGT)of the Funing Formation(Ef,Eocene series)in Gaoyou depression of Subei Basin is one of the most important research subjects which arouse reseachers' wide interests.In this study,a suit of samples collected from the same source bed(E)but buried at different depths due to the staircase faults are investigated.Based upon the comprehensive studies of various organic geochemistry indices,such as vitrinite reflectance(R°%),odd-even predominance(OEP)of n-alkanes,centents of sterane and terpaneand their configuration parameters(e.g.C-((20S)/(20S+20R))-5α(H),14α(H),17α(H)-sterane,C-moretane/C-hopane ratio,C-((22S)/(22S+22R))-17α(H), 21β(H)-hopane)and the like.The OGT of the Funing Formation has been determined at the depth of ca 2,750m referring to the judging criteria of OGT at home and abroad.In terms of the result,it has been suggested that the Funing Formation in this area only buried at the depth of 2,750m or more is the real source rock of petroleum.Thus provide a prospective evaluation for this oil-bearing basin with effective parameter.

10.11743/ogg19850110