李燕+金振奎+高白水+石良+李桂仔

摘要：分流河道是很多大型油气田的重要储集体，但目前对分流河道内部砂体的系统研究仍较少，在一定程度上制约了油气的开发效果。采用野外实地考察、浅钻孔、探坑、探槽等方法，对赣江三角洲分流河道内发育的砂体类型、沉积特征、砂体规模进行了系统研究。分流河道内发育水道、边滩、汊口滩、并口滩4种砂体，其中汊口滩发育在分流河道的分汊口处，并口滩发育在分流河道的合并处；不同砂体的堆积方式不同，水道为垂向加积，边滩为侧向加积，汊口滩为逆流加积，并口滩为顺流加积。对不同砂体的规模进行测量，建立了分流河道内砂体定量参数地质资料库。上三角洲平原分流河道内边滩、汊口滩的规模普遍大于下三角洲平原，上三角洲平原的边滩长度集中在500～2 000 m之间，边滩宽度集中在100～400 m之间，下三角洲平原边滩长度一般为300～900 m，宽度一般为50～200 m。并口滩的规模较小，长度一般为20～100 m，宽度一般为20～60 m，且仅在下三角洲平原发育。本次研究对油气田开发中预测砂体和寻找新的潜力目标区具有重要的借鉴作用。

关键词：分流河道；定量参数；边滩；汊口滩；并口滩；堆积方式；赣江三角洲；鄱阳湖

中图分类号：P512.2文献标志码：A

Sedimentary Characteristics and Quantitative Parameters of Sand Bodies in Distributary Channel

—A Case Study of Ganjiang Delta in Poyang Lake

LI Yan1，2，3， JIN Zhenkui3， GAO Baishui3， SHI Liang3， LI Guizai3

（1. CNOOC Research Institute， Beijing 100028， China； 2. Postdoctoral Center， China University of Geosciences，

Beijing 100083， China； 3. College of Geosciences， China University of Petroleum， Beijing 102249， China）

Abstract： Distributary channel is important reservoir of many large oilgas fields. Oil and gas development is restricted because few research has paid attention to the sand body in distributary channel in the past. Based on field investigation， shallow borehole， exploration pit and exploration trench， the study on sand body types， sedimentary characteristics and quantitative parameters of sand bodies in distributary channel was carried out in Ganjiang delta. There are four kinds of sand bodies in distributary channel， i.e. waterway， point bar， branch mouth bar and confluence mouth bar. Branch mouth bar develops in the branch site of distributary channel， and confluence mouth bar develops in the confluence site of distributary channel. Stacking manners of the four kinds of sand bodies are different， including waterway with vertical accretion， point bar with lateral accretion， branch mouth bar with countercurrent accretion and confluence mouth bar with downstream accretion. The quantitative parameters of sand bodies in distributary channel were studied. The point bar and branch mouth bar in upper delta plain are bigger than that in lower delta plain. The point bars in upper delta plain are 5002 000 m long and 100400 m wide， while the point bars in lower delta plain are 300900 m long and 50200 m wide. Confluence mouth bars are small in size with the length of 20100 m and the width of 2060 m， and only develop in lower delta plain. The study has great implication for guiding the sand body prediction and searching for new potential area in oil and gas development.

Key words： distributary channel； quantitative parameter； point bar； branch mouth bar； confluence mouth bar； stacking manner； Ganjiang delta； Poyang Lake

0引言

分流河道构成三角洲沉积的骨架，是三角洲重要的储集砂体[15]。目前，国内外学者利用现代沉积、野外露头、地下资料等对三角洲分流河道进行了大量研究[620]，总结了分流河道的平面形态及垂向叠置样式。……