鄂尔多斯盆地陇东地区长7段沟道型重力流沉积特征研究  

Sedimentary Characteristics of Channel Type Gravity Flow of the Member 7 of Yanchang Formation in the Longdong Area,Ordos Basin

作　　者：付金华[1,2] 罗顺社[3,4] 牛小兵[1,5] 吕奇奇[3,4] 徐黎明[1,5] 冯胜斌[1,5] 李士祥[1,5] 

机构地区：[1]低渗透油气田勘探开发国家工程实验室,西安710018 [2]中国石油长庆油田公司,西安710018 [3]油气资源与勘探技术教育部重点实验室(长江大学),武汉430100 [4]长江大学地球科学学院,武汉430100 [5]中国石油长庆油田公司勘探开发研究院,西安710018

出　　处：《矿物岩石地球化学通报》2015年第1期29-37,1,共9页Bulletin of Mineralogy, Petrology and Geochemistry

基　　金：国家重点基础研究发展计划(2014CB239003);国家自然科学基金项目(41172105);油气资源与勘探技术教育部重点实验室开放基金项目(K2013-19)

摘　　要：致密砂岩目前已成为中国油气勘探开发的重点领域。本文通过野外剖面及岩心观察、测井资料和深水重力流沉积理论对就鄂尔多斯盆地陇东地区长7段重力流沉积特征进行了系统研究,结果表明该区发育砂质碎屑流沉积、浊流沉积及滑塌沉积3种成因类型的重力流沉积砂体。砂质碎屑流沉积由灰色、褐灰色细砂岩构成,厚度均在0.5m以上,多数大于1m,块状层理发育,具有近源分布特征;浊流沉积由灰色、深灰色粉砂岩、泥质粉砂岩构成,单层厚数度从几厘米到十几厘米,具有完整或不完整的鲍马序列,呈远源分布特征;滑塌沉积在研究区发育较少。研究区长7段重力流沉积砂体横向连通性较差,纵向连通性较好,具有带状展布的特征,为沟道型(非扇型)重力流沉积体系。Tight sandstone study has been an important research field in the exploration and development of oil and gas in China. In this paper,the tight sandstone sedimentary characteristics of the Member 7 of Yanchang Formation in the Longdong area,which is believed to have great potential for exploration and development,were studied. The gravity flow sedimentary characteristics in the research area was systematically studied through field profile and core observation,logging data,and deep-water gravity flow deposition theory. Three genetic types of gravity flow deposited sand body were found in this area,including sandy debris flow deposit,turbidite deposit and slump deposit. The sandy debris flow deposit,which develops massive bedding and distributes near its source,is consisted of gray,brown and gray massive fine-grained sandstones with a thickness of more than 0. 5 m,mostly more than 1 m. The turbidite,which normally shows a distal distribution and possesses complete or incomplete Bouma sequences,is made up by gray,dark gray siltstones,argillaceous sand-stones,the thickness of a single turbidite layer is a few centimeters to tens of centimeters. The slump deposit is the least developed sand body in the research area. The gravity flow deposit sand bodies in the Member 7 of Yanchang Formation distributes successively in the longitudinal direction and discontinuously in the horizontal direction. In summary,the gravity flow sand body in the Member 7 of the Yanchang Formation is characterized by zonal distribution and belongs to the channel type（non-fan） gravity flow sedimentary deposition system.

关 键 词：鄂尔多斯盆地 致密砂岩 砂质碎屑流沉积 浊流沉积 沉积模式 

分 类 号：P618.13[天文地球—矿床学]