浅水湖盆河控三角洲前缘砂体分布特征与沉积模式探讨——以松辽盆地北部永乐地区葡萄花油层为例  

Sandbody Distribution and Sedimentary Model in Shallow Lacustrine Fluvial-dominated Delta Front: A case study from Putaohua oil layer of Yongle area in Songliao Basin

作　　者：孙雨[1,2] 赵丹[1] 于利民[3] 王继平[4] 闫百泉[1] 马世忠[1] 

机构地区：[1]东北石油大学油气藏形成机理与资源评价黑龙江省重点实验室,黑龙江大庆163318 [2]中国地质大学构造与油气资源教育部重点实验室,武汉430074 [3]中国石油吉林油田公司勘探开发研究院,吉林松原138001 [4]中国石油长庆油田分公司苏里格气田研究中心,西安710018

出　　处：《沉积学报》2015年第3期439-447,共9页Acta Sedimentologica Sinica

基　　金：国家自然科学基金项目(批准号:41202102);"构造与油气资源"教育部重点实验室开放基金课题(编号:TPR-2013-15);中国博士后科学基金项目(编号:2014M551212)联合资助

摘　　要：在我国古代的松辽盆地和现代的鄱阳湖等大型坳陷湖盆内发现的浅水湖盆河控三角洲的骨架砂体类型、垂向沉积层序及相带分异等方面与正常三角洲存在很大的差异,需要进一步深入研究。利用野外露头、现代沉积和地下岩芯、测井、地震等资料精细解剖及分析表明,浅水湖盆河控三角洲前缘发育大量、密集、窄的水下分流河道砂体,砂体连续且水下延伸较远,直至消失变成薄的水下薄层砂(河口坝或席状砂)。每支水下分流河道构成了由中心向两侧及前方:水下分流河道→薄层砂核部→薄层砂边缘→水下分流间湾的平面微(能量)相序列,形成三角洲前缘"河控带状体"。浅水湖盆河控三角洲前缘不同的相位空间位置具有不同的沉积模式,由岸向湖依次发育高低水位间过渡带"近岸沉积"模式、近岸浅水带"河控带状体"模式、中岸中等水深带"水下分流河道末端河控薄层砂"模式和远岸深水带"浪控席状砂"模式。In recent years,a special kind of delta was found in ancient Songliao Basin and modern Poyang Lake and other large depression lacustrine in China. It is shallow lacustrine fluvial-dominated delta. It is with great differences between normal deltas,including the skeleton sandbody types,vertical sedimentary sequence and facies differentiation etc. Especially,the characteristics of sandbody in delta front is thin thickness and small scale and diversification,which is compared to quite different with sedimentary model of normal fluvial-dominated delta that it include to large scale and thick debouch bar in delta front. In this context,sandbody distribution and depositional model in shallow lacustrine fluvial-dominated delta front,deserves further study. Through analysis of outcrop,modern sedimentary and cores,logging and seismic data,it is realized that underwater distributary channel sandbody as the framework of shallow lacustrine fluvial-dominated delta front is abundant,closely and narrow. It is continual than original understanding and it extends to the far underwater,until disappearing into thin debouch bar and sheet sand. Debouch bar sandbody is not well preserved and is fluvial-dominated. Debouch bar is located mainly in the underwater distributary channel on both sides and the front. It is consistent with the source direction,and has narrow banded morphology. Characteristics of debouch bar is more similar to thin sand under water. In each of the underwater distributary channel is formed in the center of the sequence of sedimentary microfacies. This sequence is underwater distributary channel→ the core of thin sand→ the edge of thin sand→underwater distributary bay from the center to the edge. The study also found that distribution of sandbody is controlled by the position of sedimentary facies in the front of shallow lacustrine fluvial dominated delta. It can be divided into transition zone between high level and low level,shallow water zone of the nearshore,medium depth zone of the shore and deepwater

关 键 词：浅水湖盆 河控三角洲 沉积模式 砂体分布 水下分流河道 

分 类 号：P618.13[天文地球—矿床学]