利用地层压力系数分析黄河口凹陷中央隆起带新近系油气输导体系

Using formation pressure coefficient to study hydrocarbon carrier system in the central uplift belt of Huanghekou sag

油气输导体系沟通烃源岩和圈闭,在油气成藏过程中具有关键作用。以黄河口凹陷中央隆起带新近系为研究目的层,基于层序地层发育特征,分析研究区4个油田的实测地层压力系数,进而探讨不同地层压力系数条件下的油气输导体系。研究结果表明,正常地层压力条件下黄河口凹陷中央隆起带新近系发育低地层压力系数—高渗透性储层油气输导体系、高地层压力系数—中等渗透性储层油气输导体系和中等地层压力系数—高渗透性储层油气输导体系。黄河口凹陷中央隆起带的凹陷区—缓坡带的馆陶组与明下段V油组、缓坡带—凸起区的明下段Ⅲ油组以低地层压力系数—高渗透性储层油气输导体系为主,凹陷区—缓坡带的明下段Ⅲ油组以高地层压力系数—中等渗透性储层油气输导体系为主,凸起区以中等地层压力系数—高渗透性储层油气输导体系为主。

Hydrocarbon carrier system is important as“the bridge and vinculum”between the oil sources and traps in hy?drocarbon accumulation process. Based on previous study,the Neogene was taken as the target layer to analyze the mea?sured formation pressure coefficient of four oil fields in the central uplift belt of Huanghekou sag,and then the effect of dif?ferent formation pressure coefficient on oil and gas migration was discussed within the sequence stratigraphic framework.The results obtained show that there were three kinds of hydrocarbon coefficient in the central uplift belt of Huanghekousag under the normal pressure condition. They were low pressure coefficient-high permeability carrier system,high pres?sure coefficient-middle permeability carrier system and middle pressure coefficient-high permeability carrier system. Inthe central uplift belt of Huanghekou sag,the low pressure coefficient-high permeability sandstone reservoir was the maincarrier layer in Guantao and V oil group of lower Minghuazhen Formation in sag-gentle slope belt and inⅢoil group of low?er Minghuazhen Formation in gentle slope-salient area. The high pressure coefficient-middle permeability sandstone reser?voir was the main carrier layer inⅢoil group of lower Minghuazhen Formation in sag-gentle slope belt and the middle pres?sure coefficient-high permeability massive sandstone reservoir was the main carrier layer in salient area.