东营凹陷滑塌型重力流沉积分布特征及三角洲沉积对其影响

发布时间：2018-11-07 17:34

【摘要】：三角洲沉积为滑塌型重力流的形成提供了物质来源,它对前端滑塌型重力流的沉积分布特征具有重要影响.以东营凹陷洼陷带沙三中亚段三角洲-前端滑塌型重力流沉积为研究对象,综合利用钻井岩心、三维地震、测录井及分析测试等资料,总结不同类型滑塌型重力流沉积特征、识别标志和分布特征,分析三角洲作为物源对滑塌型重力流的形成、沉积类型、沉积特征和分布特征的影响.研究表明,研究区滑塌型重力流沉积主要发育滑动岩、滑塌岩、碎屑流沉积和浊积岩4种类型,不同类型其沉积构造、粒度特征、地球物理特征差异显著.研究区砂质碎屑流沉积最为发育,滑动滑塌沉积次之,浊流沉积和泥质碎屑流沉积少量发育.不同地区重力流沉积发育程度及常见垂向序列存在差异,博兴南坡与辛133区块重力流类型以砂质碎屑流沉积为主,常见多期次砂质碎屑流沉积相邻或相间垂向组合;牛庄南坡与中央隆起带地区类似,由近及远,重力流类型及垂向序列存在较大差异;营11区块以砂质碎屑流沉积和浊流沉积为主,浊流比例相对其他区块较高;丰14区块单井重力流类型整体较单一,为砂质碎屑流沉积或滑塌沉积.三角洲砂泥百分含量控制了滑塌型重力流的沉积类型和沉积特征;三角洲沉积物粒径控制原始前积角大小,前积角越大,滑塌型重力流越发育,但滑移距离相对越近;三角洲的坡折点控制下,滑动滑塌沉积主要分布在斜坡坡脚和同沉积断层附近,浊流沉积主要分布在深水平原,碎屑流沉积在斜坡坡脚-深水平原均有分布;三角洲高的堆积速率通过减小内摩擦力促使滑塌型重力流的形成,其堆积速率与构造沉降速率的差异对滑塌型重力流沉积的垂向叠置和侧向连续性也具有重要影响.
[Abstract]:The delta deposition provides material source for the formation of slumping gravity flow, which has an important influence on the sedimentary distribution characteristics of the front slip gravity flow. Taking the delta-front sloughing gravity flow deposition in the middle part of the third member of Sha 3 in Dongying sag as the research object, using the data of drilling core, 3D earthquake, logging and analysis and testing, this paper summarizes the sedimentary characteristics of different types of sloughing gravity flow. The influence of delta as a material source on the formation, sedimentary type, sedimentary characteristics and distribution of slumping gravity flow is analyzed. The results show that there are four main types of gravity flow deposition in the study area: sliding rock, sloughing rock, clastic flow deposit and turbidite. The sedimentary structure, grain size and geophysical characteristics of different types are significantly different. Sand clastic flow deposits are the most developed in the study area, followed by sliding sloughing deposits, turbidity flow deposits and muddy clastic deposits. There are differences in the development degree and the common vertical sequence of gravity flow in different regions. The gravity flow types in the south slope of Boxing and Xin-133 blocks are mainly composed of sand clastic flow deposits, and the common multi-stage sand clastic flow deposits are adjacent or interphase vertical assemblages. The southern slope of Niuzhuang is similar to the central uplift zone, and the gravity flow type and vertical sequence are different from near to far, the sand clastic flow and turbidity flow are the main deposits in Ying11 block, and the turbidity flow ratio is higher than other blocks. The gravity flow type of single well in Feng14 block is relatively single, which is composed of sand clastic flow deposition or sloughing deposition. The sedimentary types and sedimentary characteristics of the sliding gravity flow are controlled by the percentage content of the sand and mud in the delta, the grain size of the delta sediment controls the size of the original programe angle, and the larger the forward accumulation angle is, the more developed the slip gravity flow is, but the closer the slip distance is. Under the control of the slope break point of the delta, the sliding sloughing deposit mainly distributes near the slope foot and the synsedimentary fault, the turbidite deposit mainly distributes in the deep water plain, and the clastic flow deposit distributes in the slope foot and deep water plain. The high accumulation rate in the delta promotes the formation of the sloughing gravity flow by reducing the internal friction force. The difference between the stacking rate and the tectonic subsidence rate also has an important effect on the vertical superposition and lateral continuity of the deposition of the sliding gravity flow.
【作者单位】：中国石油大学地球科学与技术学院;青岛海洋科学与技术国家实验室海底矿产资源功能实验室;中国胜利油田地质科学研究院;
【基金】：国家重大科技专项(No.2011ZX05009-003) 中央高校基本科研业务费专项资金项目(No.14CX06070A)
【分类号】：P512.2

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