冲积扇研究现状及沉积模拟实验——以碎屑流和辫状河共同控制的冲积扇为例

发布时间：2018-11-18 08:11

【摘要】：近年来,对冲积扇复杂沉积机制与沉积过程的研究受到关注,取得了较大进展。从冲积扇的分类及其沉积特点、冲积扇沉积储层构型表征方法及冲积扇沉积机制等方面对冲积扇研究现状进行了详细综述。之后,针对碎屑流与辫状河共同控制下冲积扇水道演化机制不明的情况,利用水槽沉积模拟对冲积扇过程进行了沉积实验模拟。研究表明,冲积扇具有多种分类方案,反映了冲积扇的多样性和复杂性;冲积扇表征技术主要有现代沉积、野外露头、地下密井网解剖和水槽沉积实验模拟等方法;控制冲积扇发育的异旋回因素主要有:构造差异活动、同生断层的组合样式及物源气候的变化等;自旋回因素控制下冲积扇存在多种沉积机制,其决定了冲积扇内部构型单元的分布。通过水槽沉积模拟实验研究发现,对碎屑流与辫状河共同控制下冲积扇沉积过程具有如下特点:1在扇体初始雏形形成后,水携沉积物具有向扇面低势部位堆积的趋势;2扇面辫状水道存在两种重要的迁移方式,单一主水道迁移和分叉式次水道迁移方式。单一主水道的迁移是导致扇体辐向前积增大的主要原因,而分叉式次水道迁移方式是扇体展宽的重要机制;3在构造条件相对稳定的情况下,多期扇体具有明显向源退积的特征。在前述研究基础上,探讨了下一步冲积扇的研究方向。
[Abstract]:In recent years, great progress has been made in the study of complex deposition mechanism and process of alluvial fan. The research status of alluvial fan is summarized in detail from the classification and sedimentary characteristics of alluvial fan, the characterization method of alluvial fan sedimentary reservoir and the sedimentary mechanism of alluvial fan. Then, in view of the unclear evolution mechanism of alluvial fan channel under the control of clastic flow and braided river, the sedimentation experiment simulation of alluvial fan process is carried out by using flume sedimentation simulation. The research shows that the alluvial fan has many classification schemes, which reflects the diversity and complexity of the alluvial fan, and the main techniques of alluvial fan characterization include modern sedimentation, outcrop in the field, anatomy of underground dense well pattern and experimental simulation of flume deposition, etc. The main factors controlling the development of alluvial fan are: tectonic difference activity, syngenic fault combination style and the change of provenance climate, etc. There are many sedimentary mechanisms of alluvial fan under the control of spin-cycle factors, which determine the distribution of the internal configuration units of the alluvial fan. It is found that the deposition process of alluvial fan under the control of clastic flow and braided river is characterized by the following characteristics: (1) after the initial prototype of the fan body is formed, the water-carrying sediment tends to pile up to the low potential area of the fan; 2 there are two important migration modes in sector braided waterway, single main channel migration and branched secondary channel migration. The migration of a single main waterway is the main reason leading to the increase of the forward radiative product of the fan body, and the migration mode of the branched secondary waterway is an important mechanism for the expansion of the fan body. (3) in the case of relatively stable structural conditions, the multi-stage fan body has the characteristic of obvious provenance to the source. On the basis of the above research, the next research direction of alluvial fan is discussed.
【作者单位】：长江大学录井技术与工程研究院;长江大学地球科学学院;中国石油新疆油田分公司勘探开发研究院;
【基金】：国家自然科学基金项目(41502126,41372116) 长江大学青年基金项目(2015cqn55)~~
【分类号】：P618.13

【相似文献】