A FACTORIAL DESIGN APPROACH TO INVESTIGATE THE EFFECT OF GEOMETRY IN DRILL STRING SCREW CONNECTORS

This paper describes a parametric study of drill string threaded conne ctor design based on a ''factorial design'' method. The study is facil itated by a hybrid model which has been developed, validated, and repo rted previously enabling efficient calculation of load and stress dist ribution along threaded connectors subjected to both axial and bending modes of loading. A parametric equation is produced where stress conc entration factor is defined in terms of various geometrical variables. The equation is then utilized to carry out a constrained optimization within the feasible parameter space, and hence produce an ''optimum'' thread and connector design.