Mike Juenke and Colton Oldham, Liberty Lift
The standard API kickoff procedure for gas-lift wells relies on stepwise injection of lift gas into the casing to displace kill fluid from the annulus and lighten the tubing fluid column. In practice, however, solids present in completion fluids can cause severe erosion of check valves—an issue not adequately represented in current API qualification tests, which require flow testing only with clean water.
To better understand these failures, a major operator initiated a comprehensive evaluation of erosion mechanisms in gas-lift check valves after experiencing multiple downhole washouts and valve malfunctions attributed to solids. By introducing sand slurry into the test fluid, the team replicated field-relevant conditions and rapidly identified erosion patterns that were not evident under standard water-only testing. Although most valves met API water-flow requirements, all designs with 1.0” OD exhibited significant erosion—often within the first 100 barrels—when exposed to slurry.
Liberty Lift’s investigation focused on quantifying the location and extent of erosion, characterizing solids-induced failure modes, and engaging subject-matter experts to guide iterative design improvements. Key challenges included fine solids embedding within the check dart and sealing interfaces, preventing proper closure, and elastomer pad degradation due to solids impregnation. Over a two-year period, five successive design iterations were developed, ultimately resulting in a configuration utilizing tungsten-carbide components and modified geometries to mitigate solids accumulation and extend service life.
This paper documents the full development path, including failure analyses, design decisions, and the collaborative engineering process that led to a more erosion-resistant valve. Field inspections of retrieved equipment are presented to demonstrate performance under actual operating conditions and to highlight the importance of incorporating realistic, solids-laden test protocols that better reflect downhole environments.
As the industry continues to push operational limits, this case study underscores the need for qualification methods that capture real-world failure mechanisms and promote more robust downhole equipment design.