高邮凹陷真武油田成藏期与动态成藏过程分析  

Accumulation Period and Dynamic Accumulation Process Analysis of Zhenwu Oilfield in Gaoyou Sag

作　　者：刚文哲[1] 王勇[2] 高岗[1] 娄国泉[2] 沈霞[3] 田志彬[1] 

机构地区：[1]中国石油大学油气资源与探测国家重点实验室,北京102249 [2]江苏油田分公司物探技术研究院,南京210046 [3]吉林油田分公司勘探开发研究院,吉林松原138000

出　　处：《沉积学报》2011年第3期580-586,共7页Acta Sedimentologica Sinica

摘　　要：真武油田位于苏北盆地东台拗陷高邮凹陷中南部,是苏北盆地目前已发现油田中最大的一个油田,油田开发时间长、含油面积大、油气富集程度高。该油田位于深凹带南部真2断裂下盘,邻近高邮生烃凹陷,油气主要分布在垛一段、戴二段和戴一段三个层段,阜一段也含油;储集层岩性多为细砂岩和不等粒砂岩。利用构造演化、原油特征与烃源岩演化、流体包裹体等方法分析了真武油田的成藏期次,结合各种地质要素分析了其动态成藏过程。构造演化史表明,从戴南组沉积开始到盐城组早期断层活动较为强烈,三垛末期地壳抬升,地层遭到剥蚀,先期形成的油气藏遭受破坏,盐城组早期断层仍然继续活动,油气不断进行运移,凹陷继续接受沉积,到盐城组沉积中后期,断层活动基本停止,油气运移速率减慢。后期沉积的地层厚度较大,对油气的保存有利。烃源岩演化史表明,高邮凹陷烃源岩有两期生烃,三垛晚—末期阜二段烃源岩在凹陷内部处于大量生油阶段,该时期阜四段烃源岩未达到生油高峰,只生成少量的油气,所以,应该是阜二段烃源岩主要的排油时期,但由于受到三垛晚期区域构造运动的影响,形成的油气藏多遭到破坏;盐城组沉积时期,阜二段和阜四段烃源岩二次埋深均达到生油高峰,发生二次生烃。真武油田流体包裹体特征明显,主要发育一期流体包裹体,烃类包裹体及伴生的盐水包裹体多发育在石英次生加大边中,包裹体均一温度只有一个主峰温度区间,与单井地层埋藏史结合发现,油气运移聚集的时期处于垛二段沉积时期,这与构造演化和烃源岩演化反演的成藏期有一定差异。综合各种成藏期分析方法对原油动态成藏过程进行了分析,认为真武油田的油气具有两期成藏,早期主要是阜二段烃源岩在三垛末期之前生油、运移、聚集成藏,但三垛末期的构造抬升破�Zhenwu oilfield, located at the mid-southern part of Gaoyou Sag of Subei basin, is the largest oil field that has been discovered in Subei basin, which has the characteristics of developed long, large oil-bearing area and high enriching-oil degree. The oilfield is located at the downthrow block of Zhen 2 fault in the southern part of the deep sag, and it is to hydrocarbon generating sags. The oil mainly distributes in three layers including the first member of the Sanduo Formation, the first ＆ second member of tile Dainan Formation. Some petroleum also distributed in the first member of the Funing Formation. Reservoir rocks are mostly fine sandstone and anisometric sandstone. Combining with various geological features, the authors analyse accumulation period and the dynamic accumulation process of Zhenwu oil field by ways of structural evolution, crude oil features and fluid inclusion. The structural evolution history shows that fault activity is strong from Dainan Formation deposition to early Yancheng Deposition. Earth crust uplifted and formation eroded resulted in serious destruction of oil reservoir at the late of Sanduo Formation, then fault continued activity and petroleum migration. The sag continued to accept deposition and fault activity stops at the late of Yancheng Formation deposition, and the petroleum migration rate slowed down. It is favorable for petroleum reservation when the formation thickness was big at the late deposition. From the source rock evolution history , there are two times of petroleum generation during which the source rock of the second member of the Funing Formation enter the sag is at a great quantity of petroleum generation at the late and last stage of Sanduo Formation when the source rock of the fourth member of the Funing Formation had not reached oil threshold and only generated a little petroleum, so it was the oil mainly generated by the source rock of the second member of the Funing Formation. But most of the reservoirs were damaged by the influence of the regional t

关 键 词：成藏过程 成藏期 真武油田 高邮凹陷 苏北盆地 

分 类 号：TE12[石油与天然气工程—油气勘探]