Constructing and calculating of multistage sucker rod string according to reduced stressстатьяИсследовательская статья
Информация о цитировании статьи получена из
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Дата последнего поиска статьи во внешних источниках: 26 марта 2018 г.
Аннотация:Causes of failures of sucker-rod pumping units, occurring on oil-and-gas production enterprises, include breakages and twist-offs of sucker-rods, which are exposed to static and dynamic loads. Failures of equipment take place due to great values of cyclic loads, pressing forces and friction, which occur in well deviation intervals or as a result of wrong selection and construction of sucker-rod string.
Correct equipment selection is one of the directions of reliability growth of rod strings during operation sucker-rod pumping units. Therefore it is necessary to do strength calculation in the design of rod string. In this article rod string design procedure with differential piston pump NN-2SPxx/xx is regarded. The use of this equipment lets reduce reversal load and increase operational life of this equipment. It is done by design features of differential piston pump.
Calculation of hydraulic load by means of rod diameter regulating in accordance with operating conditions was carried out in this work. Reduced stress in the most strained sucker-rod, maximum and minimum load in rod hanger center were determined and calculated reduced stresses were compared according to strength condition. Recommendations for steel grade of sucker-rods, based on results of reduced stress calculation, were given. Also fiber-glass material for sucker-rods was proposed. The material allows sucker-rod weight decreasing as well as increasing of load and non-corroding cyclic strength.