Paper: Specialty Pumps - Double Displacement and Two Stage

The double displacement type pump is of relatively recent vintage. It was primarily designed to provide an economical method of producing oil under certain conditions. As "slim hole" completions became more and more common, it became obvious that production requirements could not always be met with an insert or tubing pump. This was especially true in areas where water encroachment had become a problem, or a water flood program had become a problem, or a water flood program had been initiated. These pumps are considered a specialty item and as such are somewhat more complicated than the single plunger type pump. Understanding the operation of this pump should encourage its use.