渤海湾盆地临南洼陷高硫干酪根油气生成模式研究

PETROLEUM GENERATION MODEL OF A SULFUR—RICH KEROGEN FROM THE LINNAN SAG, THE BOHAI BAY BASIN

郭显令 熊敏 曾庆辉 肖贤明

Guo Xianling Xiong Min Zeng Qinhui Xiao Xianming

中国科学院, 广州地球化学研究所, 有机地球化学国家重点实验室, 广州, 510640 2. 中国科学院研究生院, 北京, 100049

State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, Guangdong 510640, China 2. Graduate Institute of Chinese Academy of Science, Beijing 100049, China

渤海湾盆地临南洼陷沙河街组三段—四段暗色页岩和暗色泥岩干酪根中富含有机硫,对这类干酪根的油气生成模式一直未进行深入的研究。应用生烃动力学方法对取自渤海湾盆地临南洼陷沙河街组四段的一块典型富硫干酪根进行了生烃动力学参数及生烃模式研究。结果表明,该干酪根油气生成模式为:生油门限出现在Easy Ro为0.53%,主生油期出现在0.60%～0.75%,生油下限出现在0.85%,对应埋深分别为2 500,2 600～3 250,3 850 m;天然气生成门限出现在EasyRo为1.05%与1.23%,对应埋深分别为4 100 m和4 650 m。与传统生油模式相比,该干酪根具有石油窗范围窄,主生油峰出现较早等特点。该研究成果对该区油气评价与勘探具有重要的指导作用。

Kerogen from some source rocks in the third and forth members of the Sahejie Formation in the Linnan Sag,the Bohai Bay Basin have been reported to be sulfur-rich.However,there has been little knowledge about the petroleum-generating model of this type of kerogen.In this paper,the kinetics method was applied to investigate petroleum generation kinetics parameters and geological model for a typical sulfur-rich kerogen from the sag.The results have shown that the oil-generating threshold of the kerogen occurs at EasyRo of 0.53%,the oil-generating peak range from 0.60% to 0.75% and oil-generating death line at 0.85%,corresponding to burial depths of 2 500 m,2 600～3 250 m and 3 850 m,respectively,and its gas-generating threshold is at EasyRo of 1.05% and main gas generation stage occurs from 1.23%,with a burial depth of 4100m and 4 650 m,respectively.Compared with conventional kerogen petroleum-generating models,this sulfur-rich kerogen is characterized by a narrow oil window and an earlier occurrence of oil-generating peak.This result will provide a guide to the petroleum evaluation and exploration in this area.

中国科学院重点方向项目(KZCX2-YW-114);国家杰出青年基金项目(40625011)

https://doi.org/10.11781/sysydz200803265