利用地震属性融合技术研究洪浩尔舒特凹陷下白垩统沉积相特征

Sedimentary characteristics research on lower Cretaceous in Honghaoershute Depression using seismic multi-attribute fusion

地震多属性融合技术的基础是多谱成像原理。文中利用地震多属性融合技术探讨了洪浩尔舒特凹陷阿尔善组和腾一段的沉积特征及其地震反射特征,分别选取均方根振幅、能量加权瞬时频率及相似性三种相互独立的属性对腾一段下部地层切片进行属性融合,属性融合后所蕴含的地质信息更全面,其中具有相同颜色的平面单元称为"同相块",代表具有相近的均方根振幅、能量加权瞬时频率及相似性的组合。相对于传统的单一地震属性解释技术,地震多属性融合技术可以更全面地反映沉积体的地震信息,对同相块的追踪可以准确地确定沉积相的平面展布范围,从而准确描述了洪浩尔舒特凹陷腾一段下部地层的沉积相展布特征。分析表明:在腾一段下部地层沉积时期,在凹陷陡坡侧主要发育滑塌堆积扇相、扇三角洲平原和扇三角洲前缘亚相;缓坡侧主要发育辫状河三角洲前缘亚相及滨浅湖—半深湖相;洼槽区主要发育滨浅湖—半深湖相、湖底扇相、水下扇相;滑塌堆积扇为腾一段下部地层的有利储集相带。

Seismic multi-attribute fusion technology is based on multi-spectral imaging principle.In this paper,we use seismic multi-attribute fusion to probe seismic reflection and sedimentary characteristics of Aershan group and Teng 1 member in Honghaoershute Depression.Three independent attributes,such as root mean square amplitude,energy weighted instantaneous frequency and similarity of the lower Teng 1 member,are selected for fusion.Much more geologic information is obtained in the fusion slices.The plane units with the same color in these attributes slices are named 'similar facies block'.Seismic multi-attribute fusion technology provides more information of sedimentary deposits compared with single attribute.Tracing of 'similar facies block' confirms the plane distribution of sedimentary facies,and precisely describes the sedimentary facies distribution characteristic of the lower Teng 1 member in Honghaoershute Depression.The observation of the deposition of lower Teng 1 member are obtained as follows:① Slump fan,fan delta plain and fan delta front were developed at the steep slope side;② Braid river delta front,shore-shallow lacustrine,and semi-deep lacustrine were developed at the gentle slope;③ Shore-shallow to semi-deep lacustrine,sublacustrine fan and subaqueous fan were developed in the sag;④ Slump fan has been proved as a favorable reservoir facies in lower Teng 1 member.