Abstract
For more than one hundred years, sucker rod pumping has been the method used for a large majority of wells requiring artificial lift in the industry. During this time, there have been continual efforts to improve and optimize performance by generations of manufacturers, engineers and field personnel with varying degrees of success. Concepts that have proven effective continue to be used and those that haven't have fallen by the wayside. The industry has not been static, and even good ideas have been improved on over time, either through experimentation or from improvements in technology. This paper will summarize some of the concepts and applications that have led to sucker rod pumping to be one of the most efficient and effective methods of artificial lift.
Rod pumping's principal advantages are relatively high efficiencies and the ability to maximize bottomhole drawdown. The concept of efficient operation with long, slow strokes has been recognized since at least the early 1930's. In 1987, R.H. Gault published a paper (Gault, 1987) that quantified the benefits based on data extracted from API Bull 11L3, a table of pumping system calculations using an analog computer simulation that was a result of an industry supported effort to understand and optimize performance. Using a freely available wave equation design program based on the Everitt-Jennings method, this study was duplicated and found, with some variation in results, they essentially verify Gault's premises. Carrying this evaluation further, the true way to optimize efficient design is to use the largest pump size that fits operating parameters with longer surface strokes and a reduction in the pumping speed. Call it Big and Slow is the Way to Go
