In order to maximize reservoir contact and improve reservoir productivity， highly deviated wells are used in Chang-7 reservoir， Ba-19 block of Huanjiang Oilfield. In the earlier frac treatment， negligence of the influence of the calcic interbed on fracture height led to a very different actual fracture geometry from the design， resulting in the problems of fracture channeling between wells and high water cut production. With examination of reservoir profile logging characteristics， analysis of the vertical stress distribution based on the subdivision layers， and investigation of the key factors of “the composite layer effect” affecting fracture height extension， the multi-stage fracturing scheme was optimized which produced a better hydraulic fracture geometry and size. The technical modification improved fracturing treatment quality with the good rate of fracture stimulation in Chang-7 reservoir up 100%； Thus， greatly improving the development level in the area.