Abstract: To tackle the fracture failure of casing thread joints when running casing in horizontal tight oil wells in Mahu Oilfield, Xinjiang, numerical simulations of casing thread joints and full-scale experiments on casing were conducted to compare and analyze the connection strength and fatigue life of API-LC long round thread joints and TP-G2 special thread joints during the lifting and lowering process of casing running. The results of simulations and experiments showed that the stress of TP-G2 special thread joints was significantly lower than that of the API-LC long round ones under the same tension or compression forces, and further, the fatigue life of TP-G2 special thread joints was about 6.9 times of that of API-LC long round thread joints under the same cyclic and alternating tensile-compressive load. According to our research, TP-G2 special thread joints can play a better role than API-LC long round thread joints in meeting the technical demands for casing operation in horizontal tight oil wells in Mahu Oilfield, Xinjiang and in improving operation efficiency.