J.D. Clegg, Shell Oil Company
Gas interference continues to be one of the major operating problems in pumping wells. In order to combat this problem effectively, we need a better understanding of what the pump volumetric efficiency should be under various well subsurface conditions Once we know how the pump should perform, it will be possible to select the best setting depth and determine whether a gas anchor is needed. Care must be used in the selection and in the installation of gas anchors, otherwise the results will be disappointing. If free gas is present, not only must an effective gas anchor be used but also must the pump develop a high compression ratio Thus, the type and design pump used is critical. Pumping wells from under a packer and small diameter casing completions are two practices that have increased the gas interference problem. Pump efficiencies and production can often be improved in such type wells.