北黄海盆地东部坳陷油气成藏时间研究

Time of hydrocarbon accumulation in eastern depression of North Yellow Sea Basin

东部坳陷是北黄海盆地唯一发现油流的沉积坳陷,具有较好的油气勘探前景,其油气藏形成时间将决定该区油气勘探思路和油气勘探方向。通过烃源岩的油气生排烃史和油层的砂岩包裹体研究,综合分析推断了东部坳陷油气藏成藏时间。研究表明,东部坳陷中侏罗统烃源岩的主要生烃期和排烃期为渐新世,下白垩统和上侏罗统砂岩储层包裹体的油充注时间为早中新世。结合盆地构造演化史综合分析推断,北黄海盆地东部坳陷的油气藏形成时间为晚渐新世至早中新世。

The eastern depression is the only depression in which petroleum was found with good potential in the North Yellow Sea Basin. The time of petroleum accumulation in this depression will decide the strategy of petrole-um exploration. Based on the studies of petroleum generation and expulsion history as well as sandstone inclusions in oil layers, the accumulation time for reservoirs in the eastern depression was discussed. Hydrocarbon was formed and expulsed from the middle Jurassic source rocks in Oligocene, and the sandstone inclusions in the Lower Cretaceous and the Upper Jurassic reservoirs were filled by oil in the early Miocene. Combined with the tectonic evolution of the basin, it was inferred that petroleum accumulated from the Late Oligocene to the Early Miocene in the eastern depression of the North Yellow Sea Basin.