渤海湾盆地黄骅坳陷石炭系—二叠系烃源岩生烃演化及与中—新生代构造演化的响应关系

Hydrocarbon generation and evolution of Carboniferous—Permian source rocks and their response to Meso—Cenozoic tectonic evolution in Huanghua Depression,Bohai Bay Basin

渤海湾盆地石炭系—二叠系为烃源岩的古生界潜山内幕型原生油气藏认识程度低,勘探难度大,明确石炭系—二叠系烃源岩生烃演化过程及与中—新生代构造演化的响应关系对内幕型原生油气藏勘探具有重要意义。笔者等基于三维地震资料、典型井实测镜质体反射率、流体包裹体等数据资料,进一步采用构造解析、潜山埋藏史分析以及盆地生烃模拟等技术手段,探讨了渤海湾盆地黄骅坳陷中—新生代构造运动及对石炭系—二叠系烃源岩生烃演化的控制作用,明确了生烃时期及有利生烃范围。研究表明,黄骅坳陷中—新生代构造活动经历了“两期裂陷,两期抬升”的四个演化阶段,形成多种类型的埋藏史,构造运动引起的古地温变化使南北地区烃源岩进行差异了生烃演化,裂陷建造作用促进地温上升,有利于有机质生烃,挤压改造作用抑制地温上升,有机质生烃中止。乌马营潜山及歧北潜山具有3次生烃阶段,生烃期为早—中三叠纪、早白垩纪、古近纪,港北潜山具有两次生烃阶段,生烃期为早—中三叠纪、古近纪。黄骅坳陷内早期(即早—中三叠纪)生烃范围局限,晚期(即古近纪)生烃最有利,乌马营地区及歧北地区为原生油气藏有利勘探区。

Objectives:Affected by the multi-stage tectonic movements in Mesozoic and Cenozoic,the Paleozoic buried hill inner primary oil and gas reservoir with Carboniferous Permian as the source rock in Bohai Bay Basin has low understanding and difficult exploration.It is of great significance for the exploration of buried hill inner primary oil and gas reservoir to clarify the hydrocarbon generation evolution process of its source rock and its response relationship with the Mesozoic and Cenozoic tectonic evolution.Methods:Based on three-dimensional seismic data,measured vitrinite reflectance of typical wells,apatite fission track,fluid inclusion and other data,and further using technical means such as structural analysis,buried hill burial history analysis and basin hydrocarbon generation simulation,this paper discusses the Miocene tectonic movement and its control on the hydrocarbon generation evolution of Carboniferous Permian source rocks in Huanghua depression,Bohai Bay basin,The hydrocarbon generation period and favorable hydrocarbon generation range are defined.Results:The research shows that the Meso Cenozoic tectonic activity in Huanghua depression has experienced four evolution stages of " two stages of rifting and two stages of uplift",forming various types of burial history.The paleogeothermal change caused by tectonic movement is the fundamental reason for the differential hydrocarbon generation evolution of source rocks in the north and South regions.Among them,the rift formation promotes the rise of geothermal and is conducive to the hydrocarbon generation of organic matter,The compression transformation inhibited the rise of ground temperature and stopped the hydrocarbon generation of organic matter.Wumaying buried hill and Qibei buried hill have three hydrocarbon generation stages.The hydrocarbon generation stages are early Middle Triassic,early Cretaceous and Paleogene.Gangbei buried hill has two hydrocarbon generation stages.The hydrocarbon generation stages are early Middle Triassic and Paleogene.Conclusions:The hydrocarbon generation range in the early( i.e.early Middle Triassic) is limited,and the late( i.e.Paleogene) is the most favorable,Wumaying buried hill and Qibei buried hill are favorable areas for hydrocarbon generation.