Abstract: In this study, a quantitative geological knowledge base covering the width of braided channels, as well as the width, length and thickness of river islands in Hanggin Banner was established by determining and analyzing the probability distribution and correlation among various parameters of braided channels and river islands. For this purpose, up-to-date deposition and outcrop data of braided channels as well as drilling data and lateral and in-plane distribution of sedimentation microfacies in the Lower Shihezi Formation of the study area were employed. The knowledge base serves to determine the distribution range of various parameters of the braided river in Hanggin Banner, and to guide the 3D geological modeling and prediction of reservoirs. It also forms the geological foundation for future well positioning. The length, width, and thickness of river islands in Hanggin Banner area were found to be 6 500~8 500 m, 3 000~4 500 m, and mostly 5~14 m, respectively, with a length to width ratio of 1.85~2.30. The width of the braided river is 8 000~18 000 m. The established quantitative parameters of the various microfacies of the braided channels were used to construct a 3D geological sedimentation microfacies model for the Lower Shihezi Formation of the Gin 58 drilling site in Hanggin Banner. This model was used to select favorable drilling areas. Its precision is demonstrated in actual drilling situations.

Key words: Hanggin Banner area, braided river, river island, geological knowledge base, 3D geological model