A well pump assembly has an upper plunger and a lower plunger. A working fluidconduit extends between the upper and lower plunger. An upper piston in theworking fluidconduit is connected with the upper plunger. A lower piston in the workingfluid conduit isconnected with the lower plunger. A downstroke working fluid is locatedbetween the upperand lower pistons in the working fluid conduit. An upstroke conduit extendsbetween anupper port in the working fluid conduit above the upper piston and a lowerport in theworking fluid conduit below the lower piston. An upstroke working fluid fillsthe upstrokeconduit and the working fluid conduit above the upper piston and below thelower piston.
展开▼
