Paper: A1203 BASED METALLOID COATING FOR DOWNLOAD COMPONENTS IN CORROSIVE WELLS

A process is being developed to provide steel downhole tools and components with a proprietary Al2O3 based metalloid coating that appears to provide a barrier to hydrogen embrittlement and other corrosion forms. Laboratory tests of hardened steel specimens, stressed to 96% of the yield strength and complying with NACE TM-01-77 test requirements, resulted in "no 720 hour failures" or "indefinite time to failure" due to hydrogen embrittlement or sulfide stress cracking. Comparable specimens failed in less than five hours. Subsequently, coated high strength pony sucker rods were installed in West Texas wells with aggressive CO2 and H2S environments and pulled after a significant time period. This paper will provide a post-pull review of the condition of those pony rods relative to other sucker rods from the same wells. The coated pony rods performed without spalling or pitting while the uncoated rods showed heavy embrittlement and corrosion damage.