柴达木盆地昆北油田路乐河组辫状三角洲沉积特征  

Sedimentary characteristic of braided delta in Lulehe Formation of Kunbei oilfield in Qaidam Basin

作　　者：宫清顺 寿建峰 黄革萍 李森明 王艳清 

机构地区：[1]中国石油杭州地质研究院,浙江杭州310023

出　　处：《地质科学》2012年第1期116-128,共13页Chinese Journal of Geology(Scientia Geologica Sinica)

基　　金：中国石油天然气股份有限公司重大科技专项"柴达木盆地油气勘探开发关键技术研究"子课题"柴西地区富油气凹陷圈闭精细评价及钻探目标选择"(编号:07-01Z-01-02)资助

摘　　要：柴达木盆地昆北油田路乐河组主要为砂砾岩、含砾砂岩、砂岩、粉砂岩及泥岩构成的陆源碎屑岩组合,通过详细的岩心特征和区域地质分析,将其确定为辫状三角洲沉积,其微相包括(水下)分流河道、河口坝、席状砂、泛滥平原、分流间湾和前三角洲泥等,其中以(水下)分流河道沉积为主体。该辫状三角洲的纵向岩石组合序列反映为典型的退积型三角洲,即发育于可容纳空间与沉积物补给速率比值(A/S比值)逐渐增大的湖侵环境。沉积旋回早期发育辫状三角洲平原,旋回中后期发育辫状三角洲前缘和前三角洲。辫状三角洲整体呈自南西向北东的扇形展布,平面上发育两期分支物源体系,分别位于Q6和Q16井区。实验分析测试、试油等资料揭示辫状三角洲(水下)分流河道砂体储集性能较好,它的发育控制路乐河组油气的纵向与平面分布。The Lulehe Formation of Kunbei oilfield in the Qaidam Basin is mainly a set of terrigenous clastics combination,including conglomerate,pebbled sandstones,sandstones,siltstones and mudstones,et al.According to the study on detailed descriptions to rock core and regional geology,a braided delta deposit was recognized.Vertical combination pattern of rock indicated that this braided delta was a retrograde-sequence delta,which was located in a transgression of the lake water body whose A/S（the ratio of available accommodation and sediment flux rate）was continuously increasing.The braided delta plain was well developed in the early of cyclic sedimentation,however,the braided delta front and pre-delta were widely spread in the middle-late of it.Microfacies included（underwater）distributary channel,mouth bar,sand sheet,flood plain,inter-distributary bay,pre-delta clay,et al.Distributary channel and underwater distributary channel were the most important ones of all the microfacies.The braided delta whose areal distribution was spread from south-west to north-east,liking a fan,developed two main branch systems,including Q6 and Q16 well-district.Base on the detailed analysis on well testing data,（underwater）distributary channel that was testified to be of better storage capability controlled the vertical and areal distributions of hydrocarbon in Lulehe Formation.

关 键 词：辫状三角洲 沉积特征 路乐河组 柴达木盆地 

分 类 号：P618.13[天文地球—矿床学] TE121[天文地球—地质学]