Comparison of Sucker Rod String Design Methods, Types and Applications

The application of sucker rod systems as a preferred artificial lift method and became even more defined over the years, due to technological advancements and more severe operating conditions, but managed to remain the most widely used type of oil well production all over the world. One of the most vital parts of Sucker Rod Pumping system optimization is the sucker rod string design. The performance of this piece of mechanical equipment has an essential impact on the fluid lifting efficiency. Its failure will unquestionably lead to a total loss of production and have a negative impact on the key performance indicators (KPI). A properly designed rod string not only assures good operating conditions but can significantly reduce overall production costs as well. This Master Thesis will provide an analysis of the most commonly used design methods, as well as a statistical analysis of rod failures in OMV Petrom over the past 3 years. It will also include an overview of design particularities of the special rod types used nowadays – fiberglass rods and continuous rods. The ultimate scope is providing a design method decision matrix that will facilitate the choice between the multiple design methods present on the market, considering the particularities of the well (pump setting depth, inclination, pumping speed) as well as the accuracy and performance of the methods in given conditions.