Field News 行业新闻

Application of titanium alloy in petrochemical industry

Since the discovery of titanium metal, the chemical industry has been the largest use. In the past 12 years, the titanium consumed in the domestic chemical industry has exceeded 15,000 tons per year.

Titanium has higher strength, stronger working capacity, specific strength, 3.5 times of stainless steel, 1.3 times of aluminum alloy, 1.6 times of magnesium alloy, the same weight, can withstand greater impact and pressure; The tensile strength is also 1.5-2 times that of other alloy partners, and it is safer and more durable when drilling underground, especially suitable for drilling operations under complex well conditions such as ultra-deep Wells and short radius Wells in Northwest oilfield.

In recent years, in order to improve oil recovery, reduce the cost of oil and gas field exploitation and extend the development life of oil and gas field, there are more and more complex structure Wells, such as extended reach Wells, short radius Wells and sidetracking horizontal Wells with Windows in old Wells. Conventional drill pipe has encountered some difficult problems in the application of these complex Wells. For example, in ultra-short radius horizontal Wells, the hole curvature is very small (<18m), which causes the conventional drill pipe to produce large alternating stresses. Fatigue fracture of drill pipe caused by alternating stress often occurs, which brings great loss to oil field. In order to solve these problems, foreign countries began to start from new materials, and developed titanium alloy drill pipe, aluminum alloy drill pipe, composite drill pipe, etc., instead of conventional drill pipe.

The laboratory confirmed that when the periodic stress is 30000psi-40000psi, the fatigue life of titanium is 10 times that of ordinary steel, and the elastic coefficient of titanium alloy pipe is about 16.5msi, which is better than that of steel drill pipe and is more suitable for high curvature Wells. At present, the titanium alloy drill pipe with good economy has been produced. The pipe body of Ti-6Al-4V is composed of the butt welding tool joints at both ends after being upset at both ends. The size of the titanium pipe body meets the API standard and the length range is 2 or 3 specified in the API standard. In order to reduce the manufacturing cost, the tool joint is made of steel, the thread of the joint is run through the upper shackle, and the outer diameter of the joint is covered with a welded wear-resistant belt. Titanium alloy drill pipe is also used in ultra-deep Wells and extended reach Wells. Due to the low density of titanium alloy, the hook load can be reduced by 30%, the torque can be reduced by 30-40%, the tension margin and safety factor of the drill tool can be significantly improved, and the complexity of handling accidents can be improved.

In the daily environment, the service life of titanium alloy drill pipe is 10 times that of conventional steel drill pipe of the same specification; 100 times that of conventional steel drill pipe under corrosive conditions.

In addition to drill pipe, offshore oil platform pillars, heat exchangers, pumps, valves, etc., oil production and refining fields are widely used.

For example, the North Sea oil drilling platform in the United States uses 100 titanium heat exchangers; The Heidrum project in Norway used the world's first titanium high-pressure riser shaft.

Titanium is more resistant to corrosion and has a longer operating life

The corrosion of structural parts caused by biological pollution is quite severe in offshore oil exploitation platform. Often makes traditional metal manufacturing equipment "half dead"...

However, the surface of titanium has a naturally formed, dense, inert, rust resistant, corrosion resistant oxide film, without additional anti-corrosion treatment, it can easily resist the corrosion of seawater, sulfuric acid, petrochemical products.

Titanium alloy components can help oil drilling into deeper waters and deeper Wells, including higher temperatures and highly corrosive (i.e., salty) production environments.

With titanium, the rig is just exploring, afraid of nothing!

Most of the natural gas resources in China are sulfur-containing gas fields, such as Tarim and Sichuan basins in Xinjiang. Corrosion prevention and long-term service of pipes with high H2S2 and C2O2 oil and gas fields under high temperature and high pressure conditions are difficult problems in oil and gas development. At present, selecting high-quality corrosion-resistant materials for pipes has become a leading trend. Titanium alloy, with its excellent pitting resistance, is applied to high-sulfur environments, especially in harsh conditions, high Cl and H2S content, generally stainless steel, and even nickel-based alloys are corroded.

Titanium is lighter and more flexible in operation

Although, titanium rods are stronger than steel rods

However, titanium rods are also lighter, weighing almost half as much as steel for the same volume.

Because the titanium rod is lighter, the torque of drilling is reduced by nearly 50%, the load of the top drive on the ground is correspondingly smaller (PS: less force, drilling deeper and more stable), and the equipment is less prone to failure.

Therefore, the titanium rod is strong and lighter, which can save energy, fuel and equipment.