Analystical or simple accurate approximate formula of critical load of plunger under its weight and compressive force on the end or hydraulic pressure and compressive force on the end are provided.
给出重力与压载、液压与压载下临界压载的解析公式或简便精确的近似公式。
2
When Wells run at one or some of the above states, and the practical down stroke axial load of the plunger is greater than the critical axial load, the wear of rod string and tubing will take place.