Abstract: “LONG AND SLOW” OR “SHORT AND FAST” is NOT the way to go! The way to go is to apply recommended practices to operate your wells, do not operate your wells with incomplete pump fillage more than 2% of the time. When a failure occurs then identify the cause and strive to prevent a repeat occurrence of the failure in the future. The three causes of incomplete pump fillage can be accurately diagnosed by using representative dynamometer and fluid level surveys. The magnitude of the pump loads w/ respect to the zero load line, Fo from the Fluid Level, and the Fo Max Load can be used to identify the cause of incomplete pump fillage. The pressure inside the pump chamber is a function of plunger travel and compressibility of fluid in the pump. Sucker rod pumps intake well fluids through the standing, SV, and discharge fluids into the tubing through the traveling, TV.

Gas pumped into the tubing can be detrimental to the operation of the sucker rod pumping system. No pump action can occur when the tubing fluid gradient becomes too light because too much gas is pumped into the tubing. Low producing efficiency and increased rod-on-tubing wear are common problems created by gas interference. Use of back pressure and/or gas separation may be required to increase tubing fluid gradient in order to maintain pump action. Proper gas separator selection requires that pump displacement not exceed gas separator liquid capacity. Casing size determines the maximum size gas separator than can be installed in a well so that annular gas flow will not reduce the liquid throughput efficiency by restricting liquid inflow into the separator chamber. A specific design and size of a gas separator determines the maximum liquid rate that will not drag gas into the pump intake. This rate is defined as the Separator Liquid Capacity. If the pump displacement exceeds the separator liquid capacity, then gas separation will fail and the producing efficiency of the well will be poor.

Low Pump intake pressure in conjunction with incomplete pump fillage cause the pump plunger to suddenly slow on the down stroke quickly transferring the fluid load opening the TV resulting in shock loads throughout the entire pumping system. The shock loading can cause increased rod-on-tubing wear, pump wear, severe rod loading changes and pumping unit vibration even to the extent that the vibration can be visually observed and oftentimes even heard. These changes in rod loading on the downstroke also affect the pumping unit balance and motor power requirements. Longer equipment life will be experienced by the pump, rods, tubing and pumping unit system if the pump does not operate with incomplete pump fillage more than 2% of the time. Sucker rod lifted wells having a pump capacity which exceeds the production rate of the well would operate more efficiently and at a lower cost with a device that reduces the amount of pumping unit operating time. Operating the pumping system with a pump barrel full of liquid will result in high efficiency and longer equipment life.