Abstract The Case study Field "A" which is one of the largest offshore oil fields in UAE, managed by the Abu Dhabi National Oil Company (ADNOC). As a mature field with complex carbonate formations, it faces ongoing production challenges due to reservoir heterogeneity. Historically, the field has employed a dual completion design to optimize production from two distinct reservoirs. This approach, enabling simultaneous production from both upper and lower drain reservoirs within a single wellbore, effectively addresses the challenge of limited drilling slots in offshore field. However, the existing dual completion design restricts wellbore accessibility to the upper drain, limiting stimulation options to acid bullheading only. This constraint prevents the execution of coiled tubing acid stimulation in the upper drain. In contrast, the Multilateral Tie-back system (MLTBS) enables the string to extend into the upper drain’s lower completion, allowing for full accessibility (mandated by Shareholders) for segmented coiled tubing acid treatments, well intervention and conformance job. This paper presents the first intervention operation targeting both the Upper and Lower Drains through a Multilateral Tie-Back System (MLTBS) featuring a Level 5 open-hole uncemented junction. The system was specifically engineered to overcome previous accessibility limitations by enabling direct intervention into the upper drain. By adopting the Multilateral Tie-Back System (MLTBS) approach, a transformative shift is introduced in field development strategies As a result, it sets a new benchmark for maximizing hydrocarbon recovery from complex and mature field, offering greater operational flexibility and improved reservoir management Introduction.
Alhosani et al. (Mon,) studied this question.