Herve Ohmer

Well construction and completion aspects of a Level 6 multilateral junction

Multilateral applications have been historically constrained by the complex construction process of the junction, and the fact that the overall mechanical integrity and detailed geometry of the junction is not always known and predictable for the lifetime of the producing reservoir. In particular, Level 6 1 junctions, as defined by the Technology Advancement-Multi Laterals (TAML) forum, must provide both mechanical and hydraulic integrity. A pre-formed dual-leg Level 6 junction has been developed The design is based on an integrated geometry that increases the branch/parent diameter ratio compared to a non-formed junction using a novel metal forming technique. The junction construction process starts when a compressed shape dual-leg junction is run in the hole at the bottom of the parent casing. Afterwards, a wireline-conveyed expansion tool post-forms the junction in a fully controlled and closely monitored process. The result of this simple construction process is a junction with an overall mechanical integrity and a known geometry. In this paper we first describe the dual-leg junction and process related system tools, then we provide the full construction process of a multilateral well using the pre-formed dual-leg Level 6 junction, and finally we present the results of the successful first field installation of the system.