Well operations, including well drilling, production or completion operations, particularly for oil and natural gas wells, utilize various uphole and downhole well components and tools, particularly rotatable components and tools, which must maintain a high abrasion resistance and a low coefficient of sliding friction under extreme conditions, such as, high temperatures and high pressures for their efficient operation. These include many types of rotatable rotors, shafts, bushings, bearings, sleeves and other components that include surfaces that are in slidable engagement with one another. These high temperatures can be elevated further by heat generated by the components and tools themselves, particularly those that are used in the downhole operations. Mud motors, for example, can generate additional heat during their operation. Materials used to fabricate the various uphole and downhole well components and tools used in well drilling, production or completion operations are therefore carefully chosen for their ability to operate, often for long periods of time, in these extreme conditions.
In order to maintain a high abrasion resistance and a low coefficient of sliding friction these components and tools frequently employ a surface coating, such as various chromium hardcoats. While such coatings are generally effective to provide the desired abrasion resistance and coefficient of sliding friction, they are known to be susceptible to corrosion upon exposure to various well environments, particularly fluids that include chlorides.
Therefore, the development of materials that can be used to form well components and tools having the desired combination of high abrasion resistance and low coefficient of sliding friction, as well as high corrosion resistance, particularly in chloride environments, is very desirable.