Successful Implementation and Optimization of MLT Technology

Abstract

Abstract This paper highlights the successful installation of a MultiLateral Technology (MLT) for the first time in an offshore field 40 km from Abu Dhabi. It will document the deployment of the deepest cemented MLT Level 5 globally, with improvements in well design and operations sequence compared to the conventional design and execution plan. The system is demonstrated as a reliable method to access laterals giving the utmost importance to all operational risks concerning drilling and completion. The design relies on the Latch Coupling (LC) pre-installed with the production casing as the foundation for the successful drilling and cementing of the upper drain liner and for different completion runs. The downhole completion components that are permanently installed provide the capability for future reservoir monitoring and intervention to the laterals via coil tubing, wireline or slickline through the Multilateral Tieback System (MLTBS) completion. The well was completed as the deepest cemented Level 5 System globally with zero NPT on MLT completion operations. The planning phase was extremely meticulous and all risks were properly identified at planning stage and mitigated during execution. The significant developments to multilateral construction are: Optimize well profile, mud system, clean out and milling BHAs to facilitate the deployment of MTLB system. Improve the operations sequence by replacing the Retrievable Bridge Plug (RBP) run with intermediate completion. The assessed amendment has reduced four (4) trips during installation which has been recognized as a global system improvement for MLT Technology. Utilizing a glass device for the well barrier instead of slickline plugs have efficiently reduced the time and simplified the operation's intervention. Selecting to spot Hi-Vis after isolating the lateral instead of the sand has effectively improved the metal recovery and clean wellbore post clean up approach. The challenge of clean out post washover was moderated with fabricating a stinger to pass inside the packer and achieve proper debris cleaning to the seal bore area. The well achieved its objective by providing two integral laterals with mechanical and hydraulic isolation and full accessibility of both drains for better reservoir surveillance through one single well slot. MLT installation strategy was effectively optimized to reduce time, cost and installation's risk against the original plan. The design enhancements were beneficial to achieve multiple global records.