Slim Hole Coupling Derating Factors do we need them
Norman W. Hein, Jr.,
NPS-AOT
The history and development of slim hole coupling derating factors will be presented. These date back to the 1960s when Conoco originated the first recommendations. Later these were modified to include the comparison of the strength of the couplings versus the strength of the sucker rod. Normally, while operators may not have had problems in the past with slimhole coupling failures, there is a current concern that old practices may not be the best practices for today's new producing wells that are deeper and producing higher volumes than normal wells. Additionally, new derating factors are provided if non-API higher strength, special grade rods are used. Recommendations are made as to what to do with design, installation, and selection of other potential couplings grades to prevent failures from occurring.