渤中25-1油田沙三段重力流沉积模式及油气地质意义  

Depositional Models and Petroleum Geological Significance of Gravity Flows Deposits of the Third Member of the Shahejie Formation in Bozhong 25-1 Oil Field,Bohai Sea Area

作　　者：徐伟 李正宇 刘艺萌 刘军钊 王启明 XU Wei;LI ZhengYu;LIU YiMeng;LIU JunZhao;WANG QiMing(CNOOC China Limited,Tianjin Branch,Tianjin 300459,Chin)

机构地区：[1]中海石油(中国)有限公司天津分公司,天津300459

出　　处：《沉积学报》2018年第3期557-569,共13页Acta Sedimentologica Sinica

基　　金：国家科技重大专项(2016ZX05024003)~~

摘　　要：运用最新重力流沉积理论,以钻井岩芯、地震资料为基础,系统研究了渤海海域渤中25-1油田沙三段重力流沉积特征、类型、岩相组合、砂体空间展布特征以及沉积模式。结果表明,研究区主要发育滑塌重力流、砂质碎屑流、浊流3种重力流沉积类型,并构成5种典型的岩相组合,包括湖相细粒沉积与滑塌重力流组合(MS)、砂质碎屑流与滑塌重力流组合(DS)、砂质碎屑流与浊流组合(DT)、浊流与砂质碎屑流组合(TD)、湖相细粒沉积与浊流组合(MT)。研究区重力流沉积具有"源—坡—断—流"联控的"滑塌—砂质碎屑流—浊流"沉积过程与发育模式,其中砂质碎屑流砂体呈舌状体分布,浊流砂体则具有朵状体形态特征。储层综合评价表明,砂质碎屑流砂体粒度粗、宽厚比小、泥质含量低、物性好,是优质的重力流储层类型。对不同重力流类型沉积特征、展布形态以及储层性质的精细研究,对深水优质砂岩储层的预测具有重要的指导意义。By implication of the latest gravity flow theory, the gravity flow deposits of the second member of ShahejieFormation in BZ 25-1 oil field have been systematically studied for their sedimentary characteristics, types, lithofaciescombinations, spatial distribution and depositional models based on corring and seismic data. Three types of gravityflow deposits are recognized as slump, sandy debris flow and turbidity current, which constitute five kinds of lithofa-cies combinations as the followings： 1） lacustrine fine-grained sediments and slump; 2） slump and sandy debris flow;3） debris flow and turbidity current; 4） turbidity current and debris flow; and 5） lacustrine fine-grained sedimentsand turbidity current. The process and depositional models of ＂ slump-sandy debris flow-turbidity current＂ collectivelycontrolled by source, slope, fault activities and fluid characteristics has been established in this paper, and the debrisflows formed tongue-like sediments body while the turbidity current result in fan-shaped patterns. Synthetical evalua-tion of reservoir properties indicates that the debris flow sediments is excellent gravity flow reservoirs normally charac-terized by coarse grains, low width-to-thickness ratio, low mud content and good reservoir quality. It is of great guid-ing significance to high quality reservoir prediction of deep water environment by detailed studies on sedimentary char-acteristics, spatial distribution of sand and reservoir properties.

关 键 词：渤海海域 重力流 砂质碎屑流 浊流 沉积模式 油气地质意义 

分 类 号：P618.13[天文地球—矿床学]