济阳坳陷古生界潜山油气成藏新认识与攻关方向

New understanding and research directions of oil and gas accumulation in Paleozoic buried hills,Jiyang Depression

古生界潜山是济阳坳陷油气富集的高产领域之一,也是重要的储量拓展阵地。古生界潜山油气成藏具有独特的石油地质条件,其地层时代老,岩性包括碳酸盐岩和碎屑岩,在漫长的地质演化过程中多期构造、断裂及深部流体活动强烈,导致潜山具有演化叠合性、结构多样性、储层复杂性、油气多源性、成藏差异性等特点。基于“十三五”以来济阳坳陷古生界潜山油气勘探进展和深化研究,从成山、成烃、成储及成藏的内在地质过程出发,揭示断陷盆地古生界潜山油气形成与富集规律,提出了“挤压-拉张-走滑-剥蚀”共控成山机制,古生界潜山具有古近系、石炭系—二叠系双源供烃条件,“沉积-成岩环境、构造-压力耦合、流体-岩石作用”三元控储模式,运移和封堵控制的油气成藏模式以及油藏有序分布规律。以这些认识为指导,实现了济阳坳陷古生界潜山油气藏勘探方向的转变,拓展了潜山勘探空间,为古生界潜山勘探区带评价及圈闭目标优选奠定了基础,并在斜坡部位和负向构造带的隐蔽潜山勘探取得突破。同时基于济阳坳陷古生界潜山不同成藏条件的认识程度和理论发展现状,提出下一步油气勘探攻关方向。

Paleozoic buried hill is one of the high-yield fields of oil and gas enrichment in Jiyang Depression,and it is a critical reserve expansion position.Oil and gas accumulation in Paleozoic buried hills has unique petroleum geology conditions.The strata are age-old,and lithology includes carbonate rock and clastic rock.In the long geological evolution process,multi-stage structures,faults,and deep fluid activities are strong,making the buried hill have the characteristics of evolutionary superposition,structural diversity,reservoir complexity,multi-sources of oil and gas,and accumulation differences.Based on the progress of oil and gas exploration and further research of Paleozoic buried hills in Jiyang Depression since“The 13th Five-Year Plan”,the formation and enrichment of oil and gas in Paleozoic buried hills in faulted basins were revealed from the internal geological process of hill formation,hydrocarbon generation,reservoir formation,and petroleum accumulation.The co-controlled hill formation mechanism of“compression-tension-strike-slip-denudation”was proposed.The Paleozoic buried hills had Carboniferous-Permian and Palaeogene dual-source hydrocarbon supply conditions,ternary control storage mode of“sedimentary-diagenetic environment,structurepressure coupling,and fluid-rock interaction,”oil and gas accumulation mode controlled by migration and plugging,and orderly distribution of reservoirs.Guided by these understandings,the exploration directions of Paleozoic buried hill reservoirs in Jiyang Depression was changed,and the exploration space of buried hills was expanded,laying a foundation for the evaluation of Paleozoic buried hill exploration zones,and the optimization of trap targets and breakthroughs were made in the exploration of hidden buried hills in deep slopes and negative tectonic zones.At the same time,based on the understanding degree and theoretical development status of different accumulation conditions of Paleozoic buried hills in Jiyang Depression,the next research direction of oil and gas exploration was put forward.