Application Prospect of Titanium Alloy in Petroleum Industry

Titanium alloys are widely used in petroleum. In terms of current economic alternatives, there are mainly the following aspects.

At present, titanium alloy drill pipes of P110 steel grade have been produced in China. Compared with conventional ordinary steel S135 drill pipes, its advantages are as follows:

The large-reach well and horizontal well can be extended farther, and the density of titanium alloy is only 4.5g/cm3. The conventional density of drill pipe with the same wall thickness and length is 1.25g/cm3. The floating weight in the horizontal section of the drilling fluid is only 49% of that of the steel drill pipe. In this case, the frictional resistance is only about 50% of the ordinary drill pipe, and the friction torque of the pipe string is one of the core problems of the extended-reach well technology, which determines the maximum extension of the horizontal displacement, so the titanium alloy drill pipe It can be more beneficial to extended-reach wells and three-dimensional cluster horizontal wells. In the current situation of more and more factory drilling in China, titanium alloy drill pipe is used in a wider range.

Reduce ground equipment load

Due to the light weight of the titanium alloy forged ring the torque is reduced by nearly 50%, which effectively reduces the load of the ground top drive (turntable), which greatly reduces the probability of such damage, and the reduction of the load will also reduce the consumption of diesel.

Reduce hydraulic losses in joints

Titanium alloy drill pipe is light in weight and low in torque, and the processed drill pipe joint does not need to be strengthened like steel drill pipe. Usually, when φ127mm S135 drill pipe is used in horizontal wells, the inner diameter of the joint is reduced from φ82.55mm of G105 drill pipe to φ69. 85mm, titanium alloy drill pipe due to the reduction of torque, 80 steel grade drill pipe can achieve the strength effect of S135 steel grade at the same displacement (due to the 51% reduction in floating weight, the torque will also be reduced by 51%). The inner diameter of the drill pipe joint of X95 steel grade reaches φ88.9mm. The increase in the inner diameter of the joint can significantly reduce the cycle pressure loss.

Compared with the aluminum alloy drill pipe, the titanium alloy drill pipe has very prominent advantages. The performance of the titanium alloy and steel drill pipe joints is very similar, so the joint and the body can be made of the same material. In general, although the aluminum alloy drill pipe also has the characteristics of light weight, because the aluminum alloy is not resistant to wear and has low strength, the joint needs to be strengthened, and the joint is usually made of steel material, which results in a limited reduction in the weight of the drill pipe. Moreover, there is still a certain gap between the strength of aluminum alloy and high-strength steel, which can only reach about 2/3 of that of a complete set of titanium drill pipes. In addition, the material hardness of the aluminum alloy drill pipe is low, which causes serious scratches and wear on the body when the drill pipe collides with the well wall, so it is difficult to use. The titanium alloy drill pipe can effectively avoid this problem because the hardness of the body can be close to that of the steel drill pipe.