Keywords: 
• overburden basin /
• meandering channel /
• monosandbody /
• lateral accretion body /
• intraformational impermeable thin interbed /
• reservoir architecture

Abstract: Because the interbeds in monosandbody usually are very narrow, thin, unstable, and hard to predict its attitude, scale, distribution, the researches on the underground thin interbed in monosandbody and its architecture are a few and very difficulty. This paper, taking the depositional model and architecture model of meandering channel as a guideline, fully using the core, log, closely well spacing and so on, puts forward the researching methods of thin interbed architecture of meandering channel sandbody in overburden basin, especially the three types and thirteen methods of extract architecture parameters (dip angle, dip, scale) about thin interbeds of lateral accretion mudstone, the researching methods of interbed density and lateral accretion orbit, basing on the distinguishing, restoring, measuring and calculating of lateral accretion mudstone, lateral accretion surface and abandoned channel, the calculation of the channel geometry and river engineering parameter and the theoretical model of channelsandbody architecture. To overcome this difficult problem provides feasible idea and method. Using these technique, establishes the theoretic and practical model of thin interbed architecture of meandering channel sandbody in PⅠ31b unit of Xingnan oilfield in Songliao Basin. 