Abstract
The writer investigated the various style of the Oil-well rod-cperated plunger-displacement pumps used in the Oil-field of Teikoku oil company. More than 2, 000 wells are pumped by common style of plunger pump, and 551 wells pumped by D & B style pump. Present pumping Practices of small yielding cil wells demands much closer study for the cause of down time. The writer pointed out the superiority of D & B style pump, and fully descriebed the construction, materials and other important data concerning sand-cut or corrosion of pump parts.
