鄂尔多斯盆地彭阳油田侏罗系延安组油藏成藏规律  

Hydrocarbon accumulation rules of sandstone reservoirs of Jurassic Yan'an Formation, Penyang oilfield of Ordos basin, China

作　　者：兰朝利[1] 王建国[1] 周晓峰[1] 代金友[1] 杨明慧[2] 崔志员 

机构地区：[1]中国石油大学(北京)石油工程教育部重点实验室,北京102249 [2]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [3]中国石化国际石油勘探开发有限公司,北京100029

出　　处：《油气地质与采收率》2014年第5期45-48,113-114,共4页Petroleum Geology and Recovery Efficiency

基　　金：中国石油天然气集团公司石油科技中青年创新基金项目(04E7023)

摘　　要：鄂尔多斯盆地彭阳油田主要勘探开发层位延安组平面展布特征变化较大,影响了对其油藏成藏规律的认识。在研究区延安组基本成藏条件研究的基础上,总结了延安组油藏成藏规律。延安组油藏原油主要来自延长组长6、长7段炭质泥岩或油页岩;生烃期晚于圈闭形成期,有利于油气聚集;油气在早白垩世末期通过断层、裂缝与延长组顶部不整合输导进入延安组成藏。构造是控制延安组油藏成藏的最重要因素,其次为砂体分布与保存条件;北东向砂体与东西向斜坡配置形成构造-岩性油藏,局部砂体向上超覆尖灭形成地层超覆油藏;研究区北、东部保存条件好,其内部的低幅度背斜、鼻状构造处于最有利成藏位置。The Pengyang oilfield, next to the Xiyuan Thrust-belt of Ordos basin, is located in the south west part of Tianhuan depression with a key target of the seventh, eighth and ninth member of Jurassic Yan'an Formation. Structure of the Yan'an Formation showsa complex NE-SW striking syncline with a saddle in the middle. The Yan'an Formation, unconformbly overlying the Triassic Yan-chang Formation toward southwest, was deposited as sandy braided-river sediment under humid conditions with sandbodies having good lateral continuity, porosity and permeability. The Yan'an Formation reservoirs mainly sourced from carbonaceous mudstones and oil shales of the sixth and seventh member of Yanchang Formation. The source rock became mature since the late Jurassic and approached a climax of hydrocarbon generation during the late Cretaceous. It provided petroleum to the reservoirs by faults, fractures and the unconformity on top of the Yanchang Formation. Structure is the most important control on hydrocarbon accumulation of the Yan'an Formation sandstone reservoirs, followed by sandbody distribution and hydrocarbon preservation conditions. These three controls resulted in structural, structural-lithologic and stratigraphic overlap reservoirs. The northern and the eastern part of the studied area have better hydrocarbon preservation conditions than the other parts, in which low-amplitude anticline and nose are the most favorable areas for hydrocarbon accumulation in the Yan'an Formation.

关 键 词：成藏条件 成藏规律 延安组 彭阳油田 鄂尔多斯盆地 

分 类 号：TE112.31[石油与天然气工程—油气勘探]