J.P. Byrd, Consultant
One of the most helpful and convenient aids in the successful application of conventional beam pumping units is the American Petroleum Institute bulletin, 11 L-3, "SUCKER ROD PUMPING SYSTEM DESIGN BOOK". Expanding the work of Sucker Rod Pumping Research Inc. and the Midwest Research Institute, the API produced this set of tables (11 L3) containing literally thousands of different precalculated pumping options, or modes, generated by using a model of the wave equation applied to sucker rod pumping when using conventional beam units. These API tables have been widely accepted, and though certain sections have been questioned, and in some cases revised - in general, they have made a substantial contribution to the petroleum industry in facilitating the application of conventional pumping units. According to these tables, there are twenty API approved sucker rod sizes, eighteen approved stroke lengths, and ten different API plunger diameters. Thus, in lifting a given amount of fluid from a particular depth, with a conventional pumping unit, theoretically there could be some 3600 beam and sucker rod system options, or pumping modes, for a single, artificial lift application - not considering variation in pumping speed.