松辽盆地齐家地区高台子致密油层包裹体古流体压力特征及其地质意义

摘要

流体包裹体热动力学(PVTx)模拟应用包裹体组分、均一温度和气液比,结合模拟软件可以恢复包裹体被捕获时的古流体压力,以松辽盆地齐家地区高台子致密油层为例,应用激光共聚焦扫描显微镜、显微荧光和显微测温等分析,划分了油气充注幕次并恢复了各幕次流体古压力,该应用有效区分了不同幕次流体古压力特征.研究结果表明:齐家地区高台子油层存在两期油气充注,第1期发生在晚白垩世嫩江晚期(79 ～ 75 Ma),主要充注发黄色荧光的原油,古流体压力为16.13 ～ 16.97 MPa;第2期发生在晚白垩世明水期(69～65 Ma),主要充注发黄绿色、蓝绿色荧光颜色的原油,古流体压力为22.14～26.13 MPa.研究结果有助于深化勘探区油气成藏规律的认识.%PVTx thermal dynamics simulation of reservoir fluid inclusions has been applied to restore trapping pressures by inclusion component,homogenization temperature and gas liquid ratio combined with simulation software.In Gaotaizi tight reservoir in Qijia area of Songliao Basin,the hydrocarbon charging events and the paleo fluid pressure are divided by CLSM,fluorescence microscopy and microthermometry,through which characteristics of different events of paleo fluid pressure are distinguished.The results indicate two stages of hydrocarbon charging in Qijia Area.The first charging occurred in upper Cretaceous Nenjiang late stage (79 ～75 Ma),with yellow fluorescence color.The second charging occurred in upper Cretaceous Mingshui stage (79 ～75 Ma),with yellow-green and blue-green fluorescence color.The paleo fluid pressures of two stages respectively are 16.13 ～16.97 MPa and 22.14 ～26.13 MPa.All the research findings are of great help to deepen the understanding of hydrocarbon accumulation patterns of the exploration area.