Keywords: 
• meandering river /
• high sinuosity /
• quantitative characterization /
• feasibility /
• uncertainty /
• decompaction correction

Abstract: The meandering river sand body reservoir is important continental clastic reservoir type. Based on a series of basic data of modern high sinuosity meandering river, and the idea "past is the key to the present", the hierarchical quantitative knowledge base was established, and underground sand body scale was characterized quantitatively. Feasibility analysis of the quantitative characterization was carried out. The study shows that the meandering river forms when the bank is mainly composed of fine material and the channel gradient ratio reduces by increasing the channel sinuosity and extending the flow path to achieve sediment transport equilibrium and the least energy consumption and. The plane geometry of meandering river channel is derivative sine curve, and the geometry and sand body scale maintain good regularity during the evolution process. Based on uncertainty of sand body scale, combining the hierarchical characterization idea of reservoir architecture theory, multiple sets of empirical formula were built hierarchically and quantitative knowledge base of high sinuosity meandering river was established by fitting the modern sedimentary data with proper confidential level. The compaction of sediment is the main factor of volume decrease of sediment after burial. Quantitative relation between modern sediment and underground sand body was built by decompaction correction. Based on these cognitions, the underground meandering river sand body scale with primary sedimentary state was characterized quantitatively. The results are objective and accurate to be proved by real data.