Research Progress of the Drill String Hardbanding Materials

*Kai Zhang, Zhenquan Wang and Deguo Wang*

### **Abstract**

Among anti-wear technologies, hardbanding is the most effective measure to reduce the wear of drill pipe and casing. Many new hardbanding materials are introduced constantly, and the varieties of hardbandings are becoming more and more abundant. In this paper, the research history and status quo of the hardbanding materials in tool joint are reviewed. And the advantages and disadvantages of all kinds of wear-resisting materials are introduced. Finally, the development orientation in hardbanding materials in drill joint was pointed out.

**Keywords:** drill string, hardbanding, casing wear, anti-friction, anti-wear

#### **1. Introduction**

The drill pipe joint is an important part of drill pipe, which is used to connect the drill pipe to form a drilling string. It always adopts a larger wall thickness and larger outer diameter, which can increase the drill string strength and protect drill pipe. In the process of drilling, when the inclination of the well is larger or the drill string is subjected to larger lateral force, the drill pipe joint will contact with the borehole wall or the inner wall of the casing, which can cause both the serious drill string wear and the heavy casing wear.

At present, there are lots of anti-wear technologies of the drill pipe joint, such as drill string hardbanding, rubber drill pipe protector, casing pipe blast joint, etc. Among them, hardbanding is the process of bonding the hardbanding alloy with the parent steel of the drill pipe (**Figure 1**), which has the advantages of stable performance, simple operation, and easy maintenance [2]. At the moment, hardbanding is the most effective measure to reduce the wear of drill pipe and casing among these anti-wear technologies [3]. However, with the development of oil and gas exploration and drilling technology, complex well structures, such as deep well, extended reach well, horizontal well, and highly-deviated well, are being used more and more widely. In addition, the formation structures, such as strong abrasive formation, fractured formation, etc., are becoming more and more complex in the process of oil drilling. All of these put forward higher requirements for anti-wear and anti-friction characteristics of hardbandings, so the development of new hardbanding materials has already been the task of top priority [4–6].

With the gradual solution of the problems in the field application of hardbanding materials, many new hardbanding materials are introduced constantly, and the varieties of hardbandings are becoming more and more abundant. For this paper, the development and application of hardbanding materials for drill pipe joints were reviewed. Furthermore, the development of a new hardbanding material

**Figure 1.** *Hardbanding welding process and morphology after welding [1].*

independently developed by our team was reviewed. Finally, the weaknesses and development orientation of hardbanding materials were pointed out.
