Paper: Laboratory Analysis of The Z-Factor Pressure Theory for Down-Hole Rod-Drawn Oil Well Pumps

The historical parameters, which have been used to calculate the sinker bar weight for artificially lifted rod-pumped wells, have been based on what is called the z-factor. This factor was derived using the physical dimensions of the lapped area of the sealing surface of the seat in the traveling valve of a rod-drawn pump. This paper describes testing which was done recently at EVI Oil Tools, Trico Industries, Inc. location, at San Marcos, Texas in the Hydraulic Test Lab.