Evolution of Drilling Programs and Complex Well Profiles Drive Development of Fourth-Generation Hardband Technology
Authors: Chan Alvaro , Hannahs Dan , Jellison Michael J. , Breitsameter Michael , Branagan Daniel , Stone Harvey , Jeffers Greg 
Published: March 2008

Abstract
The evolution of drilling programs and complex well profiles has driven the industry to develop new, more suitable hardband materials. This paper reviews the historical changes in drilling practices, development of drill stem hardbanding materials, and their shortfalls in meeting the industry's needs. Testing, verification, and performance evaluation of hardband materials have followed a similar evolution. Also presented are recent developments in laboratory testing to repeatedly predict hardband/tool joint wear performance. Finally, the development, laboratory testing and field trial of a fourth-generation hardband material is described.
Initially, hardband was designed only to protect drill stem elements from rotational wear and to extend their life. Casing wear was not an issue for vertical holes. As wells became deeper and deviated, the first casing friendly hardbands were developed. Today, water depth is increasing and well target depths and step-outs are being extended. The nature of these ultra-deep, ultra-deep water and ERD well designs is further increasing the time the drill stem is rotating inside casing, increasing the demands on hardband. Today, the focus is on protection of both casing and drill stem components in both cased and open hole conditions.
The result of this 36-month development program is a fourth-generation spall resistant, high-performance hardband. The innovative laboratory testing program surpasses the earlier DEA 42 methodology and provides repeatable and accurate prediction of the hardband's wear performance. The test concludes with field trials.
Advanced nanotechnology and a systematic design approach enabled the manipulation of material properties to yield a spall-resistant hardband that offers superb drill stem wear resistance and casing wear protection while reducing friction. These materials are ideally suited for today's long and complex drilling programs where extended drilling through casing is required.

Introduction
The need to reach deeper more remote hydrocarbon reservoirs has pushed the limits of traditional drilling programs. Today's drilling programs require deeper and more extended reach wells. Since the oil industry's beginnings drill pipe has been used to drill wells and more recently it has had the need to evolve its material requirements, mechanical properties, capabilities, and performance as a direct response to the evolution of the newer drilling challenges. The shallow, easy formations are becoming depleted and the deeper more remote and challenging reservoirs are all that is left to exploit.
The evolution of these complex well designs has brought with it economical challenges to those responsible for exploiting them. In order to reach deeper more remote reservoirs, the wells and casing programs have had to adjust. Longer wells mean longer rotational hours for drill pipe inside casing. With horizontal and extended reach wells, this only means there are more negative factors affecting drill pipe life; wear due to torque, drag, stick-slip, higher RPM, vibrations and high torque down hole motors.