With the rapid development of science and technology and the improvement of people's quality, the demand for oil and gas resources at home and abroad is increasing day by day. The traditional oil and gas exploration technology can no longer meet the needs of the petroleum to explore and develop deep-layer oil and gas, and the exploitation environment encountered is becoming more and more complex with the deepening of the exploration stratum, with the formation pressure about 150 MPa, the temperature reaching about 300 ℃, and the well depth reaching about 10 km, and the content of H2 and CO2 is also increasing. The performance and quality requirements for oil well pipes are becoming increasingly demanding.
Compared with steel drill pipes, titanium alloy drill pipes have a longer life in high temperature and high sulfur environment, and the surface treatment of TC4 titanium alloy can effectively improve the hardness and corrosion resistance of the drill pipes. In addition, based on characteristics of high specific strength and low elastic modulus of titanium alloys, titanium alloy drill pipes are more suitable for small radius wells and horizontal wells, which can greatly reduce the load of equipment, and also reduce the hydraulic loss of joints. Especially for short radius wells, titanium alloy drill pipes can significantly improve the life of drill strings. Titanium alloys have passed properties, pitting, uniform corrosion, hydrogen embrittlement resistance, stress corrosion cracking resistance, sulfide stress corrosion cracking resistance and other tests, and the results show that properties of the titanium alloy meet the technical requirements of pipeline materials. Fig. 1 is a comparison of related parameters of high-performance drill pipes, and the results show that the of Ti-6AL-4V titanium alloy is the best. Fig. 2 is a photo of a titanium alloy oil drill pipe.
