辫状河道

扇三角洲沉积体系有扇三角洲平原、扇三角洲前缘、前扇三角洲3个亚相和辫状河道、河漫沼泽、河口坝、远砂坝等微相。

In other system , there are corresponding sub-facies ( fan-delta plain , its former edge and former fan-delta ) and micro-facies ( braid riverbed , marsh , bayou bars and extensive sand bars ) .

每一种沉积体系均已细分到亚相和微相，冲积扇体系有扇根、扇中、扇端3个亚相和河床充填、漫流沉积、辫状河道、沼泽沉积等微相。

There are three sub-facies ( fan-root , fan-middle , fan - terminal ) and four micro-facies ( channel fills , sheet-flood , braid river bed , marsh and so on ) in the alluvial fan system .

通过应用倾角散射程度与沉积环境的关系，对B凹陷沉积特征和物源方向进行了分析，得出B凹陷是受2条主河道控制的扇三角洲前缘辫状河道沉积；

According to the relationship between dip scattering strength and depositional environment , the deposition characteristic and the sand source direction of depression B were analyzed . The depression B is the deposition of a fan delta with braided river course which is controlled by two main rivers .

沼泽沉积环境的辫状河道特征及其识别方法

Braided channel characters in palustrine environment and its identified methods

Ⅱ类流动单元属中孔、中低渗储层，主要分布于辫状河道；

Flow unit ⅱ is characterized by medium porosity and medium to low permeability reservoir , mainly distributed in braided channels .

通过研究表明：厚油层低效无效注采循环部位主要分布在大型曲流河、辫状河道沉积砂体中。

The result shows that inefficient and ineffective injection and recovery circulation mainly lies in the deposit of meandering river and braided channel .

致密砂砾岩夹层和泥岩隔夹层的发育程度和稳定程度从西北向东南逐渐增强，辫状河道微相和水下河道微相夹层少，稳定程度和连通程度低；

The development and stability of tight sand or conglomerate interbed and the shale band are all gradually changing better from the northwest to southeast .

不同微相储层的物性不同，以辫状河道、水下分流河道微相砂体储集物性最好。

Reservoir properties to different microfacies are different . With regard to reservoir properties , the braid-river channel and subaqueous distributary channel are the best .

同时认为，储集层物性随着中期基准面的上升，辫状河道沉积砂体变厚、粒级变粗、砂泥比增大；

Also , with the mid-term datum rising , the braided river channel sand body is thickened , the sand grain size is getting coarser , with sand-shale ratio increasing .

湖水深度、入湖坡降、辫状河道的形态、流量变化率以及粒径大小是影响扇三角洲演化的重要因素。

Deep of lake , slope of accessing lake , formed of braided river course , flow change rate and grain size are importance agent that affecting evolution of fan delta .

由于辫状河道在一定坡度和较高推移速率及悬浮比率下直接进入滨、浅湖，主要由富砾的砂岩相构成骨架相；

Because braided river enters into shore and shallow lake phases directly under certain slope with fairly high traction velocity and a suspension ratio , the main backbone phase are rich conglomeratic in nature ;

高伽马储层的形成不受沉积相控制，可以在三角洲环境下形成，也可以在水下的浊积扇中形成，甚至在辫状河道砂岩中也可见及。

The sedimentary facies is not control the high gamma sandstone formation . It can form in the delta environment , and also can form in the turbidite fan environment , or in the braided channel .

指出扇三角洲平原辫状河道和扇三角洲前缘水下河道具有良好的储集性能和成藏条件，是本区油气勘探的重要领域。

Facies model was established . It is suggested that braided channel of fan delta plain and underwater channel of fan delta front possess better reservoir quality and entrapment condition , thereby the target for oil and gas exploration in this area .

同时，利用时频分析技术，提出了水下辫状河道、河口坝、滩坝等沉积微相具有不同的时频旋回特征，为该区的勘探提供了沉积依据。

At the same time , by using wavelet transform time-frequency analysis technique , this paper proposes sedimentary microfacies such as underwater braided channel , mouth bar and beach bar which have different time-frequency characteristics . It boosts the exploration of this area greatly .

致密砂岩段沉积环境主要以扇三角洲前缘水下分流河道和扇三角洲泛滥平原辫状河道为主，夹有分流河口砂坝和远砂坝及决口扇等沉积环境。

Remote Sensing Explanation and Discussion on Genesis of Crevasse Fan in Jingjiang River Sedimentary environment of the fine sandstone main includes the underwater distributary 's channel of delta frontier , braid channel of flood plain in fan-delta , estuary dam , distal bar and crevasse fan .

层序2的长期基准面上升半旋回呈现由底部充填于切蚀谷的辫状河河道砂砾岩→网状河→曲流河→三角洲序列；

The long-term base-level rising cycle of sequence-2 is composed of basal braided channel sandstone-conglomerate → meandering stream → delta ;

长期基准面上升早期形成的辫状河河道砂岩具连通性好、粒度粗、碎屑含量高、杂基含量低及孔渗条件好等特点，是重要的含矿层。

Sand bodies were provided with good connectedness , coarse granularity , high debris content , low matrix content and good porosity-permeability becoming the most important uranium hosted strata .

统计发现，中砂岩和细砂岩是铀成矿的最佳载体，所以在每个垂向序列单元中，铀矿通常位于辫状分流河道砂体的中下部。

Statistics show that medium-grained and fine-grained sandstone are the best lithologic hosts for uranium mineralization . So , uranium deposits generally exist in the lower-middle part of braided distributary channel sand bodies in each vertical sequence unit .

沙湾组三段为辫状河三角洲平原亚相，细分为辫状河道和河道间湾。

The third member of Shawan Formation was braided-delta plain subfacies , which was divided into braided channel and flood plain .

辫状三角洲体系的平原相基本上由辫状河道沉积组成，三角洲前缘及前三角洲相带则以快速堆积、滑塌及浊流沉积为主。

Braid delta systems mainly consist of braid river deposits in delta plain facies , rapid accumulation deposits , slump deposits and turbidites in delta front and prodelta facies .