Optimization of ESP Completion Deployment Procedures in Multilateral Wells: Tractor vs. Other Techniques in High Inclination Wells, Challenges and Advantages

Abstract

Abstract OBJECTIVE/SCOPE Artificial lift systems, such as electrical submersible pumps (ESPs), need to be placed as close to the reservoir as possible to maximize their performance and increase longevity. Horizontal wells require setting of the ESP packer in a highly deviated section, where installation of temporary barriers to facilitate the setting of such a packer is a challenge. A feasible solution to this challenge has been identified in a robotic e-line (tractor) intervention technique. METHODS, PROCEDURES, PROCESSES The problem can be addressed in several ways:–Revise the well trajectory plan to have the ESP tangent section with a lower deviation close to the reservoir so it can be accessed by standard intervention methods.–Run new tools, such as dissolvable balls or plugs to create a temporary pressure barrier.–Access the deviated section via coiled tubing.–Access the deviated section via robotic intervention tools on e-line (Tractor). All these methods will be reviewed in this paper with an economic and operational comparison based on experiences from various oil fields. RESULTS, OBSERVATIONS, CONCLUSIONS All the methods stated above have implications not only in drilling and completion processes, but further into the life of the well. For example, drilling the well with greater deviation leads to an increase in complexity of the drilling process, where higher dogleg severity is required to land the well, and moreover, creates additional challenges to deploy the openhole completion and to achieve the well objectives. Additionally, ESP placement requires a 200 ft tangent section, which will increase the short radius trajectory complexity. The use of dissolvable plugs and balls often adds uncertainty to the timing of a completion process, where any delay in procedures can lead to loss of the barrier; and additional safety factors related to dissolution timing may otherwise lead to preventable non-productive time. Coiled tubing is a robust solution, but it is less mobile and swift in comparison to robotic intervention solutions together with nippleless high expansion plugs. The combined use of a self-anchoring stroker tool with a conveyance tractor enables a toolstring to reach highly deviated sections of the well, offering great flexibility in well design and efficiency during completion the stage, which is attractive economically. The stroker tool offers large push and pull force available in-situ resulting in effective plug retrieval and contingency options. NOVEL/ADDITIVE INFORMATION The paper provides an overview and comparison (operational and economic, with attention to long-term effect) of possible solutions to oilfield challenges as stated above and describes how it has in practice been resolved practically. It should be of interest to a wide range of drilling and workover engineering professionals.