Abstract: In order to solve reducing WOB stack of horizontal and directional wells,increase the ROP and shorten the period of drilling in Block 40 Linpan Oilfield, an impactor reducing WOB stack has been tested and applied. The feasibility of the impactor in horizontal and directional wells has been verified through the impactor simulation in horizontal wells, and its performance parameters and life evaluation have been tested. The test results showed the impactor had an impact force of 20-160 kN,impact frequency of 8-20 Hz,and working life of more than 120 h. According to the design of the wells, the friction of the drill string was simulated. On this basis, the BHA and drilling parameters were optimized. Field test of three sets of reducing weight stack preventing impactors were conducted in Well Pan 40-Xie 501 with a total footage of 1 080 m, and an effective working life of more than 100 h, and significant friction drag reduction. The results of application showed that the impactor was an effective tool to solve the friction problem in long horizontal section of horizontal and directional wells.