Qiandi well4 is a geological survey well of shale gas deployed in the southern section of syncline on Zhuohe dam in the depression fold belt of southeast Chongqing, whole depth coring was required. The well was designed with the depth of 2400m and completed with 2258m. Through the selection of drill rigs and drilling tools (drill bits) and the optimization design of wellbore structure, the maximum lifespan of the drill bit is up to 466m and the drilling efficiency is increased by more than 10%. The average penetration rate of the whole well is 1.78m/h and drilling-month efficiency is 535m, of which the second section drilling-month is 704m, rapid and safe drilling is realized.