Boundary Distinction Mark of the Complicated Meander Belt and Stacking Mode between Point-bar Sandbodies within the Belt

Key words: 
• complicated meander belt /
• recognition marks /
• superposition patterns between point bar /
• logging and seismic response characteristics

Abstract: Taking modern deposition as a guide, this paper uses cores, logging geology and seismic geology technology to study the types of sand body on the meander-belt boundary and internal structure characteristics of complex meander belt. The typical feature of complicated meander belt is that the proportion of abandoned channel sand body was between 65%~95% on both sides of the boundary in the meander belt, and this ratio is greater than 85% in the concave side. Through the comparative analysis of the forward model, logging geology section and waveform and amplitude of seismic reflection axis after frequency division, the modes of boundary contact and superposition between point bars was summed up in this study i.e. meander belt:main body of point bar-initial point bar-early river edge, the beginning of point bar-the abandoned channel, the beginning of point bar-the beginning of point bar, abandoned channel-abandoned channel, abandoned channel -the beginning of point bar, the end of the river-point bar, etc. And then, the internal structure model of meander belt was established based on the contact and superposition architectures between point bars.