The number of fields that are being developed, or redeveloped, using multi-lateral wells to enhance the effective drainage from minimal surface facilities is increasing. Some of these types of wells have complex Level 3, or higher, junctions but the vast majority are still Level 1 junctions.
Often drilling and other damage can be imposed on the various exposed leg well bores, as in the case of a Level 1 junction, while the other branches of the well are being drilled. This formation near well bore damage can, in the extreme, lead to a re-evaluation of the field development strategy as there has been no intervention method available to enter the various branches and perform effective stimulation or clean-up and, therefore, achieve the full production potential from the well.
This paper describes a new Bottom Hole Assembly (BHA), enabling a new method to workover multilateral wells using coiled tubing. The BHA and its method of navigating through multi-lateral wells makes the assumption a smart and/or selective entry completion is not installed in the well. Therefore, the onus is on the BHA to intelligently navigate through a junction(s) whether it is an open hole or cased hole. The BHA's operational success however, is dependent on the geometry of the junctions.
Examples from case studies performed in Canada Venezuela will be used to explain how the geometry is critical for successful operation of the tool. In addition, these case studies will explain what type of workovers have been tested and proven and what further possibilities exist.