ABSTRACT
Despite the importance of trajectory optimization, very few reference papers are available on this subject. In this work, numerical methods are adopted to evaluate the advantages of each possible choice of wellbore trajectory. A key issue is the choice of mechanical variables as an index. According to key references (e.g., Sulak and Danielsen 1989; Sulak 1991), the principal types of casing failure in abnormally high geostress zones and/or in cases in which the casing was subjected to production-induced stresses can be classified as follows: compressive inward collapse, shear failure, axial plastic compressive buckling, and tensile plastic failure in the axial direction.
