Abstract: High water yield occurs during production test in some horizontal wells in Shiguhao area of Dongsheng gas field, which impacts the productivity construction in the gas field. In order to define gas reservoir type and hydrocarbon distribution, the paper conducts well selection for test by combining with single layer production characteristics, establishes well-logging standards for gas zone and aquifer identification for the Lower Shihezi formation on the basis of crossplot chart analysis and determines the gas and water distribution in He1 and He 2 section. After analyzing the relationship between construction parameter and hydraulic fracture height, it is considered that construction displacement has a significant impact on hydraulic fracture height. The relationship between fracturing scale and hydraulic fracture height in gas reservoirs is established and fracture heights under different fracturing scales can be effectively determined. Combined with electrical parameter, microfracture distribution, fracture height and thickness of reservoir and interlayer etc., 3 reasons causing the high water yield are identified in horizontal wells and a “one measure in one well ”reservoir reformation countermeasure is put forward