东濮凹陷构造特征及古生界有利勘探区带评价

利用地震、钻井等资料，对东濮凹陷进行构造解析，并结合煤系源岩高热演化区的生气强度进行了研究区古生界有利勘探区带预测。研究结果表明：①东濮凹陷具有印支—燕山期挤压分区、古近纪拉张成带、沙四—沙三段沉积期断陷控洼、沙二段沉积期走滑成块的演化特征，从而导致古近系具有多断、多凸、多洼的结构特征。②东濮凹陷在多期构造应力叠合作用下形成“棋盘式”含油气系统，各含油气系统内油气普遍具有“上油下气、早油晚气、连续成藏”的特征，总体上发育4类油气藏，建立了弱改造型盆地“近源聚集、连续成藏、断超控富”的油气富集模式。③东濮凹陷中区构造改造弱，油气富集，南北向挤压断层控制着古生界残余地层的分布，是深层煤层气原生油气藏有利区带；在高热演化区以烃源岩为中心，利用多成藏要素叠合可优选出卫城—文留构造带为有利勘探区。

Tectonic characteristics and favorable exploration zones of Paleozoic in Dongpu Sag

Based on seismic and drilling data， the structure of Dongpu Sag was analyzed， and the favorable exploration zones of Paleozoic were predicted by considering gas generation intensity in the high thermal evolution zones of coal measure source rocks. The results show that：（1）The Dongpu Sag has the evolution characteristics of IndosinianYanshanian compressional zone， Paleogene extensional zone，fault-sag controlled sub-sag in the sedimentary period of Es₄-Es₃，and strike-slip block in the sedimentary period of Es₂，resulting in the structure of multiple faults，multiple protrusions and multiple sub-sags in the Paleogene.（2）The“checker-board”petroleum system was formed in Dongpu Sag under the superposition of multi-phase tectonic stress. The oil and gas in each petroleum system generally has the characteristics of“upper oil and lower gas， early oil and late gas， and continuous accumulation” . On the whole， four types of oil and gas reservoirs were developed， and the oil and gas enrichment model of “near source accumulation，continuous accumulation，and fault controlled enrichment”in weakly modified basins was established.（3）The central area of Dongpu Sag is characterized by weak structural transformation，oil and gas enrichment，and the distribution of Paleozoic residual strata is controlled by the NS compression fault，which is a favorable zone for deep coalbed methane primary reservoirs. In the high thermal evolution area with the source rock as the center， Weicheng-Wenliu structural belt can be selected as favorable exploration zones by using the superposition of multiple reservoiring factors.