Development status of titanium alloy drill pipe abroad

      Based on the characteristics of titanium alloy, such as high specific strength and low elastic modulus, titanium alloy drill pipe is more suitable for small radius wells and horizontal wells, which can greatly reduce the load of ground equipment and also reduce the hydraulic loss of joint. Especially for short radius wells, titanium alloy drill pipe can significantly improve the life of drill string. A series of studies have been carried out at home and abroad in the hope that titanium alloy drill pipe can provide more reliable equipment support for deep well and ultra-deep well drilling.   

      Torch drilling technology service company use assembly: PDC bit plus rotary steering drilling tool combination olus Φ 73. 02 mm titanium alloy pipe 4 root with Φ 73. 02 mm PH – 6 steel pipe, in 1999 and 2000 has completed 6 Wells of drilling work, including within 8.5 m long hole, hole Angle from 66. 5 ° gradually rose to 89. 5 °.

      Weatherford’s Grant Pfideco subsidiary and RTI’s Texas subsidiary prepared titanium alloy drill pipe with yield strength of 840 MPa from titanium alloy in the early 21st century. Its fatigue life is 10 times that of steel drill pipe under air medium and 100 times that of steel drill pipe under corrosive medium. In 2000, it was successfully drilled in several high gradient Wells in U. S. States.

      At present, there are hundreds of small curvature wells using titanium alloy drill pipe in a foreign oil field, and good economic benefits have been obtained. Relevant reports show that TC4(GR5)(GR5) and Ti38644, two titanium alloys, have slight crack corrosion in the drilling and completion fluid simulated by CaCl2 + CaBr2, which has a great impact on their fatigue life, etc. Therefore, it is still necessary to strengthen the evaluation and assessment of material application in the material selection process.