中文摘要：

根据岩心分析、测井与试油资料,评价了彭阳油田长3段油藏成藏条件,厘定了关键成藏要素与成藏规律。长3段油藏烃源岩为延长组长6、长7段暗色泥岩,在早白垩世末期成熟,由断层、裂缝和延长组顶不整合疏导体系大量进入目的层。油藏经历了4次挤压抬升,三叠纪末期挤压奠定其构造形态,形成了鼻状和低幅度圈闭;后三期挤压使目的层整体抬升,但未破坏油藏圈闭。构造、储层与聚集条件是控制油气成藏的关键因素。长3段构造、构造-岩性圈闭形成早于或同步于油气大量充注时期。受小型三角洲平原分流河道控制,长3段砂体宽度窄、厚度薄,且后期遭受了较强的成岩作用,决定了该油藏规模普遍较小。

英文摘要：

The hydrocarbon accumulation conditions of the sandstone reservoirs of the third member of the Yanchang Formation（ Chang3） in Pengyang Oilfield were evaluated based on core analysis,logging and oil testing data,and the key hydrocarbon accumulation factors and rules were determined. The hydrocarbon in Chang 3 reservoir is mainly from the dark mudstones of Chang 6 and Chang 7 member,it matured in the end of the early Cretaceous and largely entered the Chang 3 reservoir through faults,fractures and the unconformity on the top of the Yanchang Formation. The Chang 3 reservoir had undergone compression and uplift 4 times in the end of Triassic,the early Jurassic,the middle Jurassic and the late Cretaceous respectively. The compression and uplift in the end of the Triassic established a basic monocline with east tendency and E- W striking nose structures and low-amplitude anticlines for Chang 3 member; the later three compressions made the Chang 3 member uplift as a whole,but did not damage the structural traps. Structure,reservoir distribution and hydrocarbon accumulation conditions are the key factors to the hydrocarbon accumulation in Chang 3 member. The structural traps and the structural-lithological traps in the Chang 3 member formed before or at the same time a great deal of hydrocarbon charged the reservoir. Under the control of the small delta plain distributary channel,the width and thickness of the Chang 3 sandbody are small,and the sandbody was subjected to strong diagenesis,which determines that the scale of the Chang 3 reservoir is generally small.