Tubing Rotator reduces rod pumping failures

The tubing, in a well produces by the mean of a rod pumping system, represents the second largest investment in the well. Every day, every stroke on the pumping unit can cause wear in the tubing. On ever stroke the rods move up and down. Especially for deviated wells, the rods will always tend to lie on the downside of the tubing. So, on every stroke of the pumping unit, the rods are wearing a path into the metal of the tubing, path that will become a hole in the tubing.

Rod-wear track in tubing (from a 1” Spray-Metal coupling rubbing in 2 7/8” tubing)

Tubing Wear:

In a typical pumping well running at 10 strokes per minute, the rods will move against the tubing 14400 times every day. This wear will eventually cause a tubing failure. A common tubing failure is termed a “tubing split” and normally will be thin on one side of the tubing’s internal surface (about 20% of the tubing’s circumference) and can be detected by pinging with a hammer, cutting open the tubing, or running a thumb inside the tubing to feel for the thin area. The outside of the tubing will normally have a “tubing split” where a thin crack 1 to 5 inches long runs along the longitudinal axis of the tubing as shown in the following figure.

Continue reading

Why Rod Lift?

Rod Pumping System is a system of artificial lift using a surface pumping unit to impart reciprocating motion to a string of rods. Rod string then extends to a positive displacement pump placed in well near producing formation. In other words, the primary function of a rod pumping system is to convert the energy supplied at the prime mover into the reciprocating motion of the pumping unit required to transmit energy through the rod pumping to the downhole pump in order to artificially lift the reservoir.

Rod Pumping System:

The rod pumping system is made up of three components:

  • The surface pumping unit: which provides the means of turning the rotating power and motion of the motor into the reciprocating motion at the correct speed needed at the pump.
  • The rod string: that connects the surface unit to the pump and provides the force at the pump to lift the fluid to the surface.
  • The pump: which pumps the fluid to the surface.

The integrity of this pumping system is only as good as each of the links or components.

Continue reading

All what you need to know about sucker rod pumping system

All what you need to know about sucker rod pumping system:

This article will give you a summary of all what you need to know about sucker rod pumping system:

  • Calculate the expected production rate,
  • Understand downhole pump operation,
  • Understand the concept of Fluid Load (Fo) and Pump Intake & Discharge Pressures (PIP/PDP),
  • How to avoid Gas Interference and how to design a downhole gas separator?
  • The concept of dynamometer cards and how to interpret pump card shapes?
  • Understand the causes of incomplete pump fillage,
  • SRP equipment – design considerations,
  • SRP Optimization (during design phase, while pulling the well and during operations & monitoring),
  • Fluid level & Dyno surveys,
  • Concepts of Gas interference (or “Gas Pound”) & Fluid Pound,
  • Rod, Tubing and Casing Specifications,
  • API Nomenclature of Pumping Unit and Pump.

Continue reading