高邮凹陷阜二段沉积微相及沉积演化研究

Study on Sedimentary Microfacies and Sedimentary Evolution of the Second Member of Funing Formation in Gaoyou Sag

摘要: 高邮凹陷是江苏油田油气勘探的一个主要开发地区，由于高邮凹陷在浅层的勘探程度愈来愈高，勘探困难也愈来愈大，因而，下一步的石油勘探方向也已从浅层转入深层，而阜宁组作为深层勘探的重要层位，在阜二段沉积时期，混积环境十分发育，导致该沉积时期的沉积相较为复杂，因此，对其开展沉积微相和沉积演化研究是十分必要的，将为下一步划分有利隐蔽区带提供重要的地质依据。本文通过对高邮凹陷73口井岩心观察，以及测录井数据、单井相、连井相，分析得出，高邮凹陷E₁f₂沉积时期，整体发育湖泊相，包括浅湖、半深湖–深湖亚相，以及混积滩坝、浅湖泥，半深湖–深湖泥3种微相，邵伯地区发育近岸水下冲积扇，包括扇根亚相，以及扇根主水道微相。E₁f₂³亚段沉积时期，在韦庄地区和码头庄地区大面积发育以碳酸盐岩与陆源碎屑岩混合沉积的混积滩坝；E₁f₂²亚段沉积时期，在马家嘴地区、韦庄地区、发财庄地区和码头庄地区小面积发育混积滩坝；E₁f₂¹亚段沉积时期，在码头庄地区和马家嘴地区零星发育混积滩坝。分析得出，E₁f₂沉积时期E₁f₂³亚段和E₁f₂¹亚段，凹陷南部的混积滩坝呈现退积特征。根据E₁f₂沉积时期各亚段沉积演化特征，建立了高邮凹陷阜二段沉积相模式图。

Abstract: Gaoyou Sag is a major development area of Jiangsu oil field oil and gas exploration, as a result of gaoyou Sag in the shallow exploration degree higher and higher, more and more difficult for ex-ploration, thus further petroleum exploration direction is from shallow to deep, and Funing group as an important layer of deep exploration, in the sedimentary period of the Second Member of Funing Formation, mix environment is very well-developed, as a result, the sedimentary facies of this sedimentary period is relatively complex. Therefore, it is very necessary to study the sedimentary microfacies and sedimentary evolution, which will provide an important geological basis for the next step of classifying favorable hidden zones. In Gaoyou Sag is based on core observation, 73 well logging data and test analysis, single well facies and well tie in Gaoyou Sag E₁f₂ lake facies sedimentary period of the overall development, including shallow lake, half deep lake-deep lake sub-facies, and mixed beach dam, shallow lake, half deep lake-deep lake of mud 3 kinds of microfacies, Shao Bo region development nearshore subaqueous alluvial fan, including fan sub-facies, and fan root main channel microfacies. During the deposition of sub-member E₁f₂³, a large area of mixed beach DAMS with carbonate rocks and terrigenous clastic rocks was developed in Weizhuang area and Matouzhuang area. In the depositional period of sub-member E₁f₂₂, mixed beach DAMS were developed in small areas in Majiazui area, Weizhuang area, Facaizhuang area and Matouzhuang area. During the deposition period of E₁f₂₁ sub-members, mixed beach bars developed sporadically in the Quazhuang area and Majiazui area. The analysis shows that E₁f₂³ sub-members and E₁f₂¹ sub-members in the E₁f₂ deposition period, and the mixed beach bars in the south of the depression show the characteristics of retreat. According to the sedimentary evolution characteristics of each sub-member during E₁f₂ deposition, the sedimentary facies model map of the Second Member of Funing Formation member in Gaoyou Sag is established.