Evaluating ICD & MLTBS Applications in Carbonate Reservoirs with Sector Models, to Develop a Green Field Off-Shore Abu Dhabi

Abstract

A green field offshore Abu Dhabi is planned to be developed with slanted-horizontal wells (single and dual drains) and an optimized five spot water injection scheme. Three major carbonate reservoirs (2 Jurassic & 1 Cretaceous) will be targeted. Challenges appear in the field development plan due to the high heterogeneous nature of the carbonate reservoirs and fault /fracture network uncertainty. The main challenges are the early water breakthrough mitigation and well drain accessibility. This will be overcomed by utilizing Inflow Control Devices (ICD) coupled with Sliding Sleeve (SSD) to ensure uniform water front displacement across all reservoir layers and control water breakthrough, and Multi-Lateral Tie Back Systems (MLTBS) to allow Coil Tubing (CT) access to the well upper horizontal drains. This paper describes the workflow that was used to evaluate the benefits of ICD-SSD & MLTBS using sector models, and presents some results. The sector models cover representative areas of the studied reservoirs. History match using the available dynamic & static data acquired during field appraisal was conducted to calibrate the sector models. The data included well test data (Flowing & Build-up tests), zonal contribution from production logging, and MDT reservoir pressures, where available. Faults / fracture network uncertainty was addressed using "what-if" scenarios. The study confirmed the potential significant increase in oil recovery by using ICD equipped with SSD. MLTBS providing CT accessibility to the upper drain of the dual lateral wells was shown to positively impact well productivity and oil recovery.