Method of fabrication, tooling and installation of downhole sealed casing connectors for drilling and completion of multi-lateral wells

摘要

Multi-lateral wells include one or more connections between a larger diameter well casing and liner-equipped branch-wells of smaller diameter initiated with a small angle deviation from the casing axis, so as to facilitate the sequential insertion of the directional drilling string and of the liner string, used respectively for drilling and for completing each lateral branch. Each such insertion requires, in the casing string, an elliptical window cutout presenting a vertical axis of more than ten feet and a horizontal axis of only a few inches, corresponding to the diameter of the branch-well.