莱州湾凹陷烃源岩生烃历史模拟

Simulation of Hydrocarbon Generation History of Source Rocks in Laizhouwan Sag

本文通过运用IES盆地模拟的方法,采用Easy%Ro模型,以单井的热史和生烃史为基础,从剖面和平面两方面研究了莱州湾凹陷两套主力烃源岩沙三段和沙四段在不同时期不同区域生烃状态。研究表明,在明化镇组下段沉积末期(5.1Ma)北洼沙三段烃源岩已广泛进入生烃门限,沙四段烃源岩大范围生排烃;现今北洼沙三段烃源岩大量排烃,沙四段烃源岩排烃范围进一步扩大,北洼中心处已进入生烃高峰。

In this paper, the IES basin modeling method and the model of Easy%Ro are firstly used to analyze the single well thermal history and the hydrocarbon generation history. The third member of Shahejie Formation （Es3） and the fourth member of Shahejie Formation （Es4） are the major source rocks in Laizhouwan Sag. Based on the study of the single well thermal history and the hydrocarbon generation history, the hydrocarbon states of the two major source rocks in different periods and different areas are discussed. It is shown that the 5.1Ma before the third member of Shahejie Formation （Es3m） source rock goes already at the top oil window and the fourth member of Shahejie Formation source rock is in the stage of the hydrocarbon generation and is discharged into the northern sag. Now the two major source rocks are both in the stage of the hydrocarbon generation and are discharge into the northern sag and the fourth member of Shahejie Formation source rock is at the hydrocarbon peak in the center of the Northern sag.