关键词: 微相结构, 砂体骨架, 叠加图, 储层预测, 吐哈盆地

Abstract: In the exploration of the found reservoir with thin sand, the seismic data were quite inadequate for reservoir prediction, and the well logs could not be sufficient to deduce a reasonable sand body distribution. But reservoir prediction and evaluation must be done for reducing the risk of exploration. In the progressive exploration of Shengnan Block in Tuha Basin, the detailed micro-facies analysis and superposed graph were used to evaluate the targets. The micro-facies of all the layers in the reservoir were analyzed, and the distribution maps of sand body of each layer were made. The target zone belongs to braided delta deposition, and the distributary channel is the most important sedimentary facies in the sand framework. The subaqueous distributay channels in all layers were predicted on the micro-facies analysis. All the distributary channel sand bodies on a single graph were superposed, and the reservoir frame sand thickness was evaluated with the superposed graph. The favorable traps of developed sand body were fixed on the channel sand thickness, fault sealness, hydrocarbon supply and its migration way. Using the study results, some wells were designed for exploring the found reservoir edge and new small fault blocks. The sand body distribution revealed by drilled wells is coincident with the result of micro-facies analysis.

Key words: micro-facies architecture, sand body framework, superposed graph, reservoir prediction, Tuha Basin