110ksi-level titanium alloy oil well pipe and production method thereof

The invention provides a 110ksi-level titanium alloy oil well pipe and a production method thereof. The 110ksi-level titanium alloy oil well pipe comprises the following components by mass percent: 3.2% of Nb, 1.9% of Zr, 0.9% of Mo, 1.2% of Cr and the balance of Ti. The production method comprises the following steps of: smelting twice in a vacuum furnace, forging and scalping for many times to form a round blank, heating in an annular furnace to 980-1040 DEG C, and perforating and continuously rolling to obtain a titanium alloy seamless pipe, insulating for 1-1.5 hours at 960-990 DEG C, and then carrying out thermal treatment. The yield strength of the thermally treated titanium alloy oil well pipe conforms to the requirement of 110ksi level of API standard, the ballistic work is greater than 41J, the pipe can be applied to a rigorous corrosion environment with H2S partial pressure of 5Mpa, CO2 partial pressure of 11Mpa, NaCl concentration of 100000ppmCl and the elemental sulfur of 3g/L, and meets the requirement of an oil field in the corrosion environment. The 110ksi-level titanium alloy oil well pipe and the production method thereof have the effect that the yield strength of the titanium alloy oil well pipe conforms to requirement of the 110ksi level of the API standard, has excellent physical and chemical property, operational performance, hydrogen sulfide and carbon dioxide corrosion resistance, and the hydrogen sulfide stress corrosion resisting threshold value reaches 100%SMYS.