东濮凹陷裂缝性砂岩油气藏主控因素及成藏模式

渤海湾盆地临清坳陷东濮凹陷中央隆起带北部发现三叠系裂缝性砂岩油气藏,油气主要富集在岩石节理、裂缝、缝洞中,基质不含油。通过对油气族组成、稳定碳同位素组成及生物标志化合物进行油气地球化学研究,认为东濮凹陷三叠系砂岩裂缝性油藏原油来源于古近系,油藏类型为新生古储式;天然气来源于石炭-二叠系,气藏类型为古生新储式。在油气地球化学研究的基础上,分析东濮凹陷三叠系砂岩裂缝性油藏成藏条件,认为供烃条件、储集空间、构造部位是油气成藏的主控因素。供烃条件决定油气藏规模、裂缝提供油气储集空间、构造控制油气成藏位置。根据东濮凹陷中央隆起带北部不同地区三叠系储集层构造特征、供烃条件、油气藏特征,总结出东濮凹陷北部三叠系砂岩裂缝性油气藏的3种成藏模式,即:双断双向供烃成藏、单断双向供烃成藏、单断单向供烃成藏。图10表1参15

Key controlling factors and reservoir-forming model of the fractured sandstone reservoirs in Dongpu Sag

Triassic fractured sandstone reservoirs have been found in the north of Central Uplift in Dongpu Sag,Linqing Depression,Bohai Bay Basin.Hydrocarbons accumulate in joints,fractures,and cavities.There is no oil in the matrix.The analysis of group component,stable carbon isotopic compositions and biomarker,and the geochemical characteristics of the oil and gas show that the oil comes from the Palaeogene and the oil reservoir is new bed-generating and old bed-storing;the gas comes from Carboniferous-Permian and...