Abstract: The Akekule reservoir of Middle Triassic in AT1well block in Tahe oilfield is a bottom?water reservoir with complex fluid properties controlled by faults and low amplitude structure. At the initial stage of development, the AT1well block was identified as a condensate gas pool by means of PVT data. With the deepening of the development, most of the gas wells were in big drop in gas?oil ratio. And at the beginning of water breakthrough, oil cutting appeared like oil production rise and gas production decline, resulting in poor exploitation effect. By means of the data of PVT, fluid property, oil and gas component analysis, production performance and reserves coefficient, this paper draws a conclusion that the reservoir type in AT1well block belongs to an oil reservoir with condensate gas cap, analyzes the effect of AT1well block development and proposes the countermeasures for this area in high water?cut state, which can be available for reference for type discrimination and development of similar reservoirs