Brazing technology allows metallurgical joining of dissimilar materials by use of a filler material. In this paper, brazing technology applied to casing connections is presented. The brazing process, or temperature/torque/time (TTT) process, is performed with regular casing connections, a filler material deposited by flame spray, and a flux. Two processes were developed, one for expandable-grade material (VM50) and one for quenched-and-tempered-grade material.
Casing connectors continue to be a potential liability in complex wells that use premium connections or expandable liners. The technology presented in this paper applies brazing to casing connectors to improve leak tightness of American Petroleum Institute or premium connectors, ensure leak tightness after severe plastic deformation, and increase torque capacity.
The casing connector needed to have mechanical and pressure integrity before and particularly after expansion. However, the extreme plastic deformation reduced the critical cross section and the effectiveness of the metal-to-metal sealing mechanisms. This proved to be difficult to solve with only mechanical design considerations.
The bond needed relatively high shear strength and enough ductility to cope with the plastic deformation. Furthermore, the bond needed to be made quickly, should not alter the material properties of the expandable material, and should be compatible with standard rig operations. Multiple technologies were investigated to overcome these difficulties, including welding and gluing. However, among the technologies evaluated, only brazing provided the strength and ductility with the relatively high speed for making the joints approaching that of the standard casing running process....
Improving Casing Integrity by Induction Brazing of Casing Connections
01 June 2017