In the drilling process, the failure of drill pipe is a very serious problem. Although the torque, tensile strength, compressive strength, bending stress, etc. of the drill pipe are accurately calculated under ideal conditions before drilling, the corrosion of the drill pipe in the drilling fluid often makes the drill pipe fail beyond expectations in the actual drilling process. In view of the above problems, Sunrise Petro developed tungsten-plating technology and applied it on the drilling pipe.
The failure modes of drill pipe mainly include brittle fracture, fatigue, corrosion fatigue, corrosion damage, etc. Most of them are corrosion fatigue failures. These failure modes often coexist and interact.
Sunrise Petro applied the tungsten plating and electroplating anti-corrosion technology to the oil drill pipe, forming a dense and uniform anti-corrosion and scale inhibition coating on the surface of the original drill pipe, which significantly improved its surface anti-corrosion and scale inhibition performance without reducing the original mechanical properties. Because the tungsten alloy coating has a long-range disordered and short-range ordered structure, without grain boundaries, dislocation and defects, it has good corrosion resistance to H2S, CO2 and other corrosive medium.
Sunrise Petro has developed a new type of nickel tungsten composite plating technology, which is widely used for surface treatment of tungsten-plated drilling pipe. Composite plating is to add insoluble particles (such as ceramic particles) to the plating solution on the basis of electroplating and electroless plating, so that the particles are deposited together with the coating, and the coating has the characteristics of both metal coating and particles.
The following is the metallographic comparison of composite plating (left) and traditional tungsten plating(right).
The following is Sunrise Petro composite plating data sheet.
| Item | Parameter | Standards |
| Thickness | ≥40μm | GB/T11354 |
| Hardness | 450～550HV | GB/T9790 |
| CASS(Copper-accelerated acetic acid salt spray) | no discoloration, pitting, cracks in 96 hours | GB/T10125 |
Features
1) Strong coating and plating adhesion.
2) Finish surface and obvious scale inhibition effect.
3) High anti-corrosion. Ni-W alloy has excellent corrosion resistance which leads the coating has no pinholes and microcracks to increase the protection ability.
4) High wear resistance. The hardness of the coating is 940-1100hv, and the wear resistance of the coating is greatly increased, which is far better than the chromium coating.
Application
The tungsten-plated drilling pipe of Sunrise Petro is especially suitable for the well conditions with high gas content and prone to corrosion and scaling
Sunrise Petro manufactures a variety of drilling pipes for oilfield including the common drilling pipe, Kelly bar, drill collar, anti-corrosion and anti-abrasion drill pipe according to API 5DP and API 7-1.
These drilling pipes have diverse types to fit different environments and applications.
The company has an R & D center with a team composed of domestic authoritative professors and senior engineers to provide users with high-performance and practical products.
