Effect Of Makeup And Internal Pressure On The Structural Strength Of Api Buttress And 8 Round Threaded Connections

Abstract

The purpose of the study was to define the variables that effect the limit states of API t? Round and Buttress connectors This work will be incorporated into Load and Resistance Factor Design (LRFD) equations. Connectors are an integral part of any well design program. Therefore, it is vital that they be included in the LRFD design approach. Variables that determine the structural capacity were identified and evaluated, within the API tolerances, using finite element analysis. The indications are that taper, lead, and friction have no significant effect on the structural capacity of API connections. The effect of internal pressure on the tensile strength of API round thread accounted by API Bul. 5C3 [1] was verified. In addition, internal pressure was shown to have a beneficial effect on the capacity of buttress connection. The API joint strength equation, which in its present form, accounts for makeup only through the engaged thread length. However, the true joint strength was found to also be function of makeup interference.