S15 well is located in the southeast of Ahawaz in Iran, which was a sidetracking horizontal well and the first horizontal well by Sinopec in Yada project in Iran. Because of the long open hole section, deep sidetrack points, long horizontal section and large horizontal displacement, the construction was very difficult. In order to ensure the smooth progress of the construction, aimed at the characteristics of drilled formation, through making up the effective trajectory control scheme, selecting the appropriate screw and BHA, taking reasonable drilling parameters and technical measures and meanwhile optimizing the drilling tool structure, the drilling tasks were successfully completed. The matching horizontal well drilling technologies suitable to Yada of Iran were summed up as the reference for the late horizontal wells drilling construction.