Henry Nickens, BP, James Lea and James C. Cox, Texas Tech University
New results have appeared for downhole pump slippage predictions from fairly recent test data. Additional testing is in progress. A pump with large plunger/barrel clearances will slip more fluid. A pump with smaller clearances will slip or leak less but a tighter fit will tend to increase rod buckling at the pump to a greater degree. Considerations for pump leakage and example calculations are presented using the older and the new pump slippage relationships. Also the effect of pump clearances on possible buckling are studied. Further additional possible causes of rod buckling are presented and discussed and compared. The results will help the reader to decide on how to size pump clearances to provide leakage for lubrication in the pump without losing too much pump efficiency. Several ideas on the source of rod buckling are presented and compared, and the reader should be left with some review of older ideas and some newer concepts on how to combat rod buckling in the operation of a beam pump system.