The Conventional Pump.

We will start at the bottom of the stroke with a conventional pump. There is a tubular barrel with a sealing plunger, which reciprocates within the barrel. Attached to the bottom of the barrel is the standing valve; attached to the plunger is the traveling valve. As we start the up stroke, the traveling valve on the plunger is closed. The standing valve opens and fluid fills the barrel as the plunger rises. As the down stroke starts, the standing valve closes and the traveling valve opens. The plunger passes down through the static fluid that was loaded in the barrel on the previous up stroke. The fluid is still in the barrel, but now the fluid is above the plunger. As the next up stroke starts, the standing valve opens to fill the barrel again. The closed traveling valve on the plunger lifts the fluid within the barrel and adds it to the tubing string, this in turn, pressures up the tubing causing the check valve on the flow line to open and pushes fluid in the tank. The Conventional Pump lifts and loads on the up stroke and does nothing on the down stroke. It's this lifting and pressure that cause rod stretch and fatigue, gearbox torque, fluid slippage, reduced plunger travel and increased horsepower requirements. And until now you had to live with these inefficiencies. 

The Skillman down stroke down hole sucker rod pump.

Now we will explain the pump cycle of the down stroke pump. There is a tubular barrel with a sealing plunger, which is slightly longer than the barrel. (This means the top of the plunger is always out of the barrel even at the bottom of the stroke). As we start the up stroke, the traveling valve on the plunger is closed. The standing valve opens and fluid fills the barrel as the plunger rises. As we start the down stroke the standing valve closes and the traveling valve opens. As the barrel is being filled with the plunger, the fluid is being displaced from the barrel through the plunger into the tubing string, which pressures up, opening the check valve on the flow line, pushing fluid to the tank. Instead of using horsepower to lift fluid, we're using the weight of the rods to displace it. On the next up stroke the fluid in the tubing is static (no fluid from the barrel is being added to the tubing) all you do is load the barrel. Load on the up stroke and displace on the down stroke. The difference between the Down Stroke Pump and a standard pump is not when the standing and traveling valves open and close, those are the same. The key is when the fluid in the tubing is static (on the down stroke with a conventional pump, and on the up stroke with a Down Stroke Pump) and what you are doing the work with, horsepower or rod weight.

Some of the benefits of the down stroke down hole sucker rod pump can be:

1. Reduced horsepower requirements.
2. Lower electric costs (per barrel produced fluid).
3. Higher pump efficiencies (more fluid than same size conventional pump).
4. Can handle solids (frac-sand, formation sand, iron sulfide and trash) much better than a conventional pump.
5. Better run times.
6. Reduce rod failures.
7. Can be made as insert or tubing pump.