Abstract: Well Lengke-1,located in No.5 block,Lenghu of Chaidam Basin,is a key scientific investigation well of CNPC.The.drilling depth is 5200m,and 139.7mm production casing was set to the depth of 4854.63m.The cementing interval is from the casing shoe to the wellhead.The mud density is 1.80g/cm3.The bottomhole circulating temperature is 120℃.The two stage cementing method is succeeded with high quality,after measures such as the enhanced displacement efficiency,channeling prevention and high density slurry method are used in high temperature,high pressure and long-distance cementing interval.