黄河口凹陷陡坡带B27构造古近系油气成藏期
——基于流体包裹体的证据

Paleogene accumulation period in B27 Structure of northern steep slope belt, Huanghekou Sag: based on evidence from fluid inclusions

 王波¹ 杨海风² 王孝辕² 刘庆顺²

中海油能源发展股份有限公司工程技术分公司，天津 300452 中海石油（中国）有限公司天津分公司，天津 300452）

基于系统取样和流体包裹体镜下观测与均一温度测试，发现黄河口凹陷北部陡坡带B27构造古近系沙二段发育了两期烃类包裹体，其分布特征、发育数量、形态特征与荧光特征均明显不同。其中：第1期为单一液相烃类包裹体，数量较少，零星发育于石英次生加大边和方解石胶结物内；第2期为单一液相和气液两相烃类包裹体，数量明显多于第1期，呈带状广泛分布在石英（长石碎屑）及其次生加大边、方解石胶结物的微裂隙内。结合该区埋藏史，进一步研究热史，结果表明，研究区沙二段油气充注应当具有“晚期成藏，两期充注，晚期为主”的特点。其中：第1期油气充注时间为6～3 Ma；第2期为油气主要充注期，充注时间为2～0 Ma，充注强度明显较大，展示出该区广阔的勘探前景。

 Based on the systematic sampling and microscope observation and homogenization temperature testing for fluid inclusion, it is shown that there are two period hydrocarbon inclusions which have different distribution, quantity, morphology and fluorescence characteristics in B27 Structure of the 2nd Member of Shahejie Formation in the northern steep slope belt, Huanghekou Sag. Among them, the first period is of a single liquid phase hydrocarbon inclusion, fewer, sporadic development in quartz overgrowth and calcite cements; the second period is of a single liquid phase and gas-liquid hydrocarbon inclusion, significantly more than the number of first period, zonal widely distributed within the quartz(detrital feldspar) and quartz overgrowth, micro cracks of calcite cements. Combined with the burial history and thermal history of the area, further study shows that the oil and gas filling in the 2nd Member of Shahejie Formation has the characteristics of "late hydrocarbon accumulation, two periods of filling and mainly at late stage". The first period of oil and gas filling time is about 6￣3 Ma . The second period is the main hydrocarbon charging stage and the filling time is about 2￣0 Ma. The latter filling intensity is significantly stronger, which shows broad exploration prospect.

10.6056/dkyqt201606003