stroke — Oil & Gas Glossary
In a sucker-rod pump, one complete round of the polished rod (surface stroke). On each stroke, a fixed volume of liquid is lifted. This volume is related to the cross-sectional area of the pump and the length of the stroke.The stroke length at the subsurface sucker-rod pump usually differs from the surface stroke because of the stretching in the upstroke
Detailed Explanation
and the rebounding in the downstroke.