引用本文:[点击复制]
[点击复制]
【打印本页】 【在线阅读全文】【下载PDF全文】 查看/发表评论下载PDF阅读器关闭

←前一篇|后一篇→

过刊浏览    高级检索

本文已被:浏览 53次   下载 63 本文二维码信息
码上扫一扫!
基于露头和岩心的深水重力流沉积新认识及其油气地质意义
李建平,廖计华,方勇
0
(中海油研究总院有限责任公司,北京100028)
摘要:
关于深水重力流的流体类型、发育机制及其所形成的砂体内部构成存在诸多争议。基于对南非Karoo盆地二叠系深水沉积露头及意大利Tuscan盆地始新统-渐新统钙质浊积岩露头、英国北海上侏罗统-下白垩统大量深水岩心实物的精细解剖,重新厘定深水重力流沉积类型及其特征,构建深水浊流沉积模式,并进一步探讨其油气地质意义。研究结果表明:深水重力流沉积可划分为块体流沉积和浊流沉积;前者以水下泥石流为主体,垂向上分异不明显,而后者从下至上依次表现为浊流、碎屑流和牵引流沉积,发育大量层理构造,垂向分异性好。受古地貌、物源、构造背景等因素控制,浊流沉积表现为不同的主流态、规模,具有不同的岩性、岩相组成,主要包括沟道、溢岸和朵体3种深水沉积类型。流体性质决定了砂体储层物性、内部非均质性及其勘探价值,浊积沟道中的浊流沉积部分及牵引流沉积部分、朵体核部以及决口扇砂岩储层物性较好,而碎屑流沉积和水下泥石流沉积储层物性差,这也是造成油藏非均质性的主要因素。
关键词:  深水重力流  块体流沉积  浊流沉积  形成机理  露头  沉积模式
DOI:10.13673/j.cnki.cn37-1359/te.2020.06.004
基金项目:“十三五”国家科技重大专项“南海深水区油气资源潜力与大中型油气田勘探方向”(2016ZX05026)。
New understanding of deep-water gravity flow deposition and its significance in petroleum geology based on outcrops and cores
LI Jianping,LIAO Jihua,FANG Yong
(Research Institute of China Offshore Oil Corporation,Beijing City,100028,China)
Abstract:
There are still many controversies about the fluid types,mechanism and the architecture of sand bodies formed by gravity flow in deep water. Based on the detailed analysis of Permian deep-water sedimentary outcrops in Karoo Basin of South Africa,Eocene-Oligocene calcareous turbidite outcrops in Tuscan Basin of Italy and a large number of deep-water cores from Upper Jurassic to lower Cretaceous in the North Sea of England,the sedimentary types formed by deep-water gravity flow and their characteristics are redefined,the deep-water turbidite deposition model is constructed,and its oilgas significance is further discussed. The results show that the deep-water gravity flow deposits can be divided into mass transport deposits(MTD)and turbidite deposits;the former is dominated by underwater mud-supported clast flow with poorly differentiation vertically;and the latter is characterized by turbidity current,debris flow and traction flow deposits from bottom to top,with a large number of bedding structures and well differentiation. Controlled by paleogeomorphology,provenance,tectonic setting,etc.,turbidite deposits show different main flow state and scale,which form different lithology and lithofacies,and they can be divided into gully channel,overflow bank and lobe. Fluid properties determine the physical properties,internal heterogeneity and exploration value of reservoirs. The reservoir quality of turbidite deposits and traction flow deposits in turbidity channel,the core of lobes and crevasse splay reservoir are beneficial,while the debris flow deposit and mud-supported clast flow deposit are poor,which are the main factors that cause reservoir heterogeneity.
Key words:  deep-water gravity flow  mass transport deposits  turbidite deposits  mechanism  outcrop  deposition model

用微信扫一扫

用微信扫一扫