吐哈盆地WM油田辫状河三角洲前缘砂体分析  

Analysis of Sandbodies in the Braided Delta Front, WM Oilfield, Turpan-Hami Basin

作　　者：周丽清 吴胜和[2] 熊琦华[2] 马晓芬[2] 郭燕华 林双运 

机构地区：[1]石油勘探开发科学研究院海外研究中心,北京100083 [2]石油大学,北京昌平102200

出　　处：《沉积学报》2000年第2期248-252,共5页Acta Sedimentologica Sinica

摘　　要：湖盆可容空间较小时 ,辫状河三角洲相对发育 ,水下分支河道横向迁移频繁 ,易形成席状分布的砂体 (水下分支河道复合体 )。可容空间增大时 ,辫状河三角洲相对不发育 ,水下分支河道延伸不远 ,河道砂体较孤立 ,河口坝相对比较发育。文中根据水流和波浪强弱提出九种水下分支河道与河口坝的关系图 ,基本上总结了吐哈盆地WM油田三间房组河口坝的形态 ;The braided delta front is developed in WM oilfield, Turpan-Hami Basin, which is composed of the underwater distributary channels , mouth bars, distal sands, sheet-like sands, and interchannel muds microfacies. The deposition features of the braided deltas are low sedimentary maturation and abundant current structures caused by the traction current. The underwater distributary channels have an erosion surface in the channel bottom, and are fining upward from conglomerates in the base to fine-sandstones in the top of the channels. They are 2.5m in rhythm, and 4～10 m in complicate rhythms , and are 200～400 meters in width. The parallel bedding are well developed in the sandstones. While the mouth bars are coursing upward from siltstones to sandstones, and are large than 4 m in thickness. The sheet-like sands are mainly sandstones, fine to medium grained, well sorted and rounded, and are mostly coursing upward. They are 3-4m in thickness. The rivers in the braided delta are strong, so that the distributary channels still erode downwards after entering lake ,and forms underwater distributary channels as a result of water flow in the bottom of the lake, The underwater distributary channels can frequently migrate laterally so as to form sheet-like sandbodies (complicated sandbodies of the distributary channels). Some uneroded interchannel muds are scatterd in the inner of complicated sandbodies of the distributay channels, and will be flowing barriers. The volumes of the mouth bars depend directly on the amounts of sediments carried by underwater distributary channels ,while the shapes are partly influenced by the waves of the lake. The mouth bars may be ellipsoid parallel to underwater distributary channels (i.e. perpendicular to the shore of lake),but may become fan-like and even ellipsoid parallel to the shore of the lake by the modification of the waves. The nine kinds of relationship between the underwater distributary channels and the mouth bars are proposed according to the strength of the currents in the

关 键 词：辫状河三角洲 河口坝 沉积模式 油田 砂体 

分 类 号：P512.2[天文地球—地质学] P618.130.2