泌阳凹陷下第三系流体包裹体特征及其应用——Ⅱ.泌阳凹陷石油运移初探

CHARACTERISTICS AND APPLICATIONS OF EOGENE FLUID INCLUSIONS FROM THE BIYANG DEPRESSION——Ⅱ.A PRELIMINARY STUDY OF PETROLEUM MIGRATION IN THE BIYANG DEPRESSION

流体包裹体研究结果表明,泌阳凹陷石油运移可划分为三个阶段,早期运移阶段、主要运移阶段和晚期运移阶段。根据流体包裹体的显微测温结果计算出各阶段石油运移的温度、压力和水介质条件。研究还表明:早期运移阶段发生于核二段地层沉积时到渐新世末期,深度为1900—3000m;主要运移阶段伴随着渐新世末的上升运动而开始,深度为1200—2500m;晚期运移阶段发生于渐新世末以后,深度为2600m 开始。主要运移阶段石油组分比早期运移阶段重,斜坡地带主要运移阶段以稠油为特征。根据流体包裹体的分布特征,还对泌阳凹陷碳酸岩地区初次运移的通道、相态和运移方式进行了探讨。

The course of petroleum migration in the Biyang depression could been dividedinto three stages——the early migration stage and the main migration stage andthe late migration stage based on the distribution and composition of organic inclu-sions.The microthermometry data from fluid inclusions were used to determine thetemperatures,pressures and aqueous medium characteristics of petroleum migrationat each of the stages.The results also indicate that petroleum migration at the ea-rly stage occurred during the period from Eh_2 to the end of Oligocene at the depthof 1900—3000m,at the main stage accompanied with uplifting of the depression atthe end of Oligocene at the depth of 1200—2500m and at the late stage after theOligocene at the depth of 2600m.The petroleum at the main stage is compositiona-lly heavier than that at the early stage.The main-stage petroleum in slopes of thedepression is characterized by heavy oil.The channelway,phase and pattern of pri-mary migration of petroleum in the carbonate area of the Biyang depression havebeen investigated in terms of the distribution of fluid inclusions.