A labelled version of the pump jack diagram.  There are blown up bubbles for the downhole pump and a cross section of the borehole (showing the casing, tubing, sucker rods and annulus). I made it with Inkscape.  It is in png format because the SVG version was not showing the labels properly, if you think you can fix this, you can label the unlabeled version (see below), it is in SVG.
<a href="https://en.wikipedia.org/wiki/en:User:TastyCakes" class="extiw" title="w:en:User:TastyCakes">TastyCakes</a> on English Wikipedia
CC BY 3.0
<span class="int-own-work" lang="en">Own work</span>