东营凹陷青南地区沙四上亚段物源沉积体系与滩坝分布

发布时间：2018-02-26 16:47

本文关键词： 青南地区沙四上亚段物源特征沉积演化滩坝分布　出处：《沉积学报》2017年03期 　论文类型：期刊论文

【摘要】：滩坝砂岩是近年来东营凹陷沙四上亚段油气勘探活跃且成效显著的一类隐蔽岩性地层油气藏,但在青南地区,由于缺乏对物源沉积体系的系统研究,对滩坝的分布范围和规模认识不足,制约了该区的精细勘探和储量升级。通过砂岩重矿物组合和泥岩特征元素比值分布模式的综合物源分析认为,北部物源主要供应方向为西南方向,南部物源主要供应方向为西北方向和正北方向,且南部物源影响范围显著大于北部物源,并将南北物源的混合区域限定在X7井—Wx583井—W58井—W126井—L74井—Wx119井—L108井—L2井—L64井—Lx63井连线一带;通过岩石学和测井研究在研究区划分出冲积扇、三角洲、湖泊、重力流4种沉积体系和近岸水下扇、扇三角洲、河流三角洲、湖泊和深水浊积扇5种沉积相类型;通过物源控制下的沉积相连井对比和不同砂组时期沉积相的平面分布研究,厘清了物源沉积体系的演化特征和各类砂体,特别是滩坝的分布范围和规模,为油田的精细勘探提供依据。青南地区沙四上亚段滩坝主要来自南部物源,其发育规模仅次于河流三角洲,发育层位遍及整个沙四上亚段,单个砂组的发育规模受同时期河流三角洲发育规模的影响较大,受扇三角洲发育规模的影响较小:河流三角洲发育规模较大但扇三角洲不发育的纯下3砂组—纯上4砂组时期,滩坝发育规模较大;河流三角洲发育规模逐渐缩小但扇三角洲发育规模逐渐增大的纯上3砂组—纯上1砂组时期,滩坝发育规模也逐渐减小。
[Abstract]:Tan Ba sandstone is a kind of subtle lithologic reservoir in recent years, which is active in oil and gas exploration in the upper submember of Sha 4 in Dongying Sag. However, in the south of Qingnan area, due to the lack of systematic study on provenance and sedimentary system, The lack of understanding of the distribution range and scale of the beach and dam restricts the fine exploration and reserve upgrading in this area. Through the comprehensive provenance analysis of sandstone heavy mineral assemblage and mudstone characteristic element ratio distribution model, it is concluded that, The main supply direction of the material source in the north is southwest, the main supply direction in the south is the northwest direction and the north direction, and the influence range of the source in the south is significantly larger than that in the north. The mixed zone of the north and south provenances is limited to the line of X7 well -Wx583 well -W58 well -W126 well -W74 well -Wx119 well -L108 well -L2 well -L64 well -Lx63, and the alluvial fan, delta and lake are divided into alluvial fans, deltas and lakes in the study area through petrology and logging. There are four sedimentary systems of gravity flow and five sedimentary facies types of near-shore underwater fan, fan delta, river delta, lake and deep-water turbidite fan, the sedimentary contiguous well correlation under the control of provenance and the plane distribution of sedimentary facies in different sand formation periods are studied. The evolution characteristics of provenance sedimentary system and the distribution range and scale of various sand bodies, especially the beach dam, are clarified, which provides the basis for fine exploration of oil fields. Its development scale is second only to that of river delta, and the developmental horizon is all over the upper submember of Sha 4. The development scale of single sand formation is greatly affected by the development scale of river delta in the same period. The influence of fan delta development scale is small: in the period of pure lower 3 sand formation and pure upper 4 sand formation, the development scale of beach and dam is larger; In the period of pure upper 3 sand formation and pure upper 1 sand formation, the development scale of beach and dam also gradually decreased when the development scale of river delta decreased gradually but the development scale of fan delta gradually increased.
【作者单位】：造山带与地壳演化教育部重点实验室北京大学地球与空间科学学院;北京大学石油与天然气研究中心;中国石化胜利油田地质科学研究院;
【基金】：国家重点基础研究发展计划(973计划)项目(2012CB214801)~~
【分类号】：P618.13

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