Abstract: The in-depth analysis is made for the Permian reservoir of Bai-31 Well Block in Baikouquan oilfield, Junggar basin, by using lots of well testing data. The result shows that the reservoir is characterized by homogenous dual porosity,dominated by fracture flow with certain dif-ferences in fractural petrophysical property in plane. The post section of buildup curves is in decline due to disturbance from offset wells, which represent the pressure decline status in the whole oil region. The analysis of the disturbance between production wells by using interference test shows that the reservoir is of characteristics of high permeability, good fractural connectivity and high permeable and fractured system.

Key words: Junggar basin, Baikouquan oilfield, Permian, well testing, percolation, reservoir evaluation