渤中坳陷埕北30潜山储层流体包裹体特征与成藏时间研究

Feature of Fluid Inclusions from Chengbei-30 Buried Hill Reservoir in Bozhong Depression and Dating of Hydrocarbon Emplacement

流体包裹体研究表明,渤中坳陷潜山构造CB302井奥陶系储层中流体包裹体丰富,主要发育有盐水包裹体与石油包裹体。与石油包裹体共生的盐水包裹体均一温度有两组,分别为122￣133℃与130￣140℃,结合石油包裹体特征,认为存在两期油气运聚过程。根据埕北30潜山沉积埋藏史、古地温史及成藏地质背景,推导出这两期油气运聚时间分别出现在5～3Ma与3～1.5Ma。第一期油气可能来源于邻近的黄河口凹陷下第三系沙河街组,烃源岩属局部油气充注;第二期油气来源于渤中坳陷斜坡带东营组二段,对埕北30潜山轻质油油气藏的形成起了主要作用。

The study of fluid inclusions from Well CB302 in Chengbei-30 Buried Hill indicates that abundant brine and oil inclusions develop in the Ordovician reservoir. Two groups of homogenization temperature measured from brine inclusions associated with oil inclusions show respectively at 122～133℃ and 130～140℃, which hints there were two stages of hydrocarbon accumulation processes. Combined with burial history of sediments, paleogeotherm history and petroleum geological settings in this area, it is extrapolated that the two stages occurred respectively during 5～3Ma and 3~l.5Ma. Hydrocarbon that could derive from Paleogene Shahejie Formation in Huanghekou Sag had filled partly into source rock at the first stage whereas the hydrocarbon that could come from the slop belt in Bozhong Depression at the second stage was significant for forming light hydrocarbon reservoir in Chengbei-30.