论渤海湾盆地深层油气勘探

Hydrocarbon Accumulation and Exploration of Deep Zones in Bohaiwan Basin

渤海湾盆地近年来在古近系及以下层系发现并探明31个深层油气藏。分析表明,盆地深层以油藏为主,气藏为辅,盆地西部蕴藏较多的石油,向东部则天然气产量增多,这种分布现象与盆地深层烃源岩干酪根类型和高地温作用有关。讨论了古近系原生油气藏、上古生界煤系烃源岩二次生烃的油气藏、下古生界原生油气藏的成藏机制。认为古近系含油气层系仍是近期深层勘探的主要目标,但应加大上古生界煤系烃源岩层和下古生界海相深层油气的勘探。

During past years, 31 deep reservoirs has been discovered and proved in Paleogene and the lower sequences in Bohaiwan Basin. This study shows that oil reservoirs are major and gas ones are minor in number in deep zones and more gas has yielded in the eastern part of the basin, which indicates that the phenomena of distribution are closely relative with the type of kerogen from the deep source rocks and high geothermal gradient in the basin. The author discusses the mechanism of hydrocarbon migration and accumulation of the Paleogene primary reservoirs, the upper Paleozoic secondary hydrocarbon-generating reservoirs of coal-related source rocks and the lower Paleozoic primary reservoirs. It is suggested that the Paleogene oil and gas reservoir beds are the recent main targets of deep-zone exploration and some great efforts should be made to oil and gas exploration in the upper Paleozoic coal-related strata and the lower Paleozoic deep marine strata.