二连盆地阿南凹陷腾格尔组一段下部岩石学特征及其石油地质意义

发布时间：2018-03-13 00:30

本文选题：致密储层　切入点：沉凝灰岩　出处：《南京大学》2015年硕士论文　论文类型：学位论文

【摘要】：在近年的石油勘探和开发中,致密油藏倍受重视。二连盆地阿南凹陷也有较好的致密油显示,但该区域致密油勘探程度较低,存在岩石类型不明确、成藏机理不清楚等问题。本文通过钻井岩芯观察、岩石薄片鉴定、电子探针、扫描电镜及稀土元素分析等方法,并结合地球物理资料对二连盆地阿南凹陷腾格尔组一段下部展开了岩石学和石油地质学方面的研究。腾格尔组一段下部地层以深灰色云质泥岩、灰色泥质云岩、灰绿色块状凝灰岩、钙质沉凝灰岩、钙质细砂岩为主,其中钙质沉凝灰岩和钙质细砂岩为储层。和其它岩石样品相比,沉凝灰岩重稀土亏损的特点,这是由凝灰质受地层流体的溶蚀作用所致。地层流体有利于次生孔隙的发育,能够提高沉凝灰岩的储油物性。阿南凹陷腾格尔组一段下部沉积主体为浅湖暗色泥岩,此外还发育有近岸水下扇。沉凝灰岩和河道砂岩即为近岸水下扇沉积。该段地层中等及以上烃源岩发育,但成熟度普遍较低,湖盆中心烃源岩的Ro最高能达0.95%。油气二次运移的主要通道为不整合面和断层面,油气的垂向运移能力较差。沉凝灰岩呈透镜状夹于云质泥岩中,云质泥岩既是生油岩又是盖层,形成了透镜体油藏。河道砂岩主要形成了岩性-地层油藏,上覆泥岩为其盖层,油气主要来自于下部的烃源岩。
[Abstract]:In recent years, dense reservoirs have been paid more attention to in petroleum exploration and development. There is also a good indication of tight oil in Anan sag of Erlian Basin, but the exploration degree of dense oil in this area is relatively low, and the rock types are not clear. The mechanism of reservoir formation is not clear. In this paper, the methods of drilling core observation, rock sheet identification, electron probe, scanning electron microscope and rare earth element analysis are used. Combined with geophysical data, the petrology and petroleum geology of the lower part of Tengger formation in Anan sag, Erlian Basin, are studied. The lower part of the formation is composed of dark gray cloud-like mudstone and gray muddy dolomite. Greyish green tuff, calcareous tuff, calcareous fine sandstone, in which calcareous tuff and calcareous fine sandstone are reservoirs. This is caused by the dissolution of the tuff, which is favorable to the development of secondary pores and can improve the oil storage properties of the tuff. The lower part of the Tengger formation in the Anan sag is composed of shallow lake dark mudstone. In addition, there are also nearshore subaqueous fans. Sedimentary tuff and channel sandstone are subaqueous fan deposits on the shore. The source rocks of medium and above strata are developed in this section, but the maturity is generally low. The maximum Ro energy of source rock in the center of lake basin is 0.95.The main channel of secondary migration of oil and gas is unconformity surface and fault plane, and the vertical migration ability of oil and gas is poor. The sedimentary tuff is lenticular in the dolomite mudstone, which is not only oil source rock but also caprock. The channel sandstone mainly forms lithology-stratigraphic reservoir, the overlying mudstone is its caprock, and the oil and gas mainly come from the source rock of the lower part.
【学位授予单位】：南京大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：P618.13

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