First Multilateral Well Drilled in Under Balanced Manner within ADNOC Group with Successful Trials Of UBCTD

Abstract Objectives/Scope Exploring the frontiers of exploration, ADNOC Onshore's ASR Team has pioneered the use of Underbalanced Coiled Tubing Drilling (UBCTD) within the entirety of the ADNOC Group, further extending its application to a multilateral well. This technique reduces reservoir impairment resulting from overbalanced drilling conditions and employs coiled tubing instead of a traditional drill rig. The operation realized a remarkable total drilled footage of 11,422 ft, overcoming the technical and safety challenges associated with drilling in an environment containing sour gas with a concentration of 6% H2S. Methods, Procedures, Process The initiative involved exploiting the UBCTD approach for tapping into sour gas deposits, a first for any ADNOC entity. A multitude of stages such as selecting appropriate sites, intricate engineering planning, optimizing well designs, comprehensive risk assessments, the tendering process, recruitment of services, standard drilling operations, connections, and finally, CT drilling took place. The adoption of UBCTD facilitated a safer and more efficient drilling method, allowing for continuous production testing and directional steering while drilling. By creating triple lateral wells, the project not only enhanced reservoir exposure but also cemented UBCTD's efficacy compared to other examined technologies on these specific gas reservoirs. Results, Observations, Conclusions ADNOC, a dominant force in energy resources, adopted the UBCTD method to access reservoir sections without most conventional logging tools. This innovative drilling technique offers several benefits including reducing formation damage, enhancing well productivity and recovery rates, achieving ideal drainage lengths, decreasing completion times, and elevating net present value. Despite initial apprehensions owing to inexperience and perceived risks, the inaugural implementation of UBCTD within the ADNOC conglomerate signifies a leap forward, particularly for re-entry and new sour gas wells where traditional underbalanced drilling is constrained. Notably, UBCTD is gaining global acceptance for its efficiency in both new wells and revisiting existing ones with the goal of maximum resource extraction. Novel/Additive Information The document will delineate a comprehensive procedure used in orchestrating the unique Multilateral CTUBD venture for ADNOC Group, highlighting operational and HSE factors that contributed substantially to the accomplishment of this groundbreaking project.