| Popis: |
The reservoir under consideration, Reservoir A of the Lower Cretaceous age, Kharaib formation is a complex giant carbonate reservoir within an onshore field in Abu Dhabi. Substantial volumes of oil remain to be developed from the Attic area directly underneath the giant gas cap. 4 Attic wells were drilled since 2005 and they have all experienced gas breakthrough. To better manage Attic well production and optimize attic development, one of the attic wells has been selected for a pilot to install Integral Control Valves (ICV). The aims and objectives are for down hole zonal gas production control leading to optimized single well recovery while respecting facilities gas handling constraints. In parallel, two long horizontal wells are being drilled next to the pilot well to test the alternative concept of low production drawdown for gas breakthrough control. This paper presents the design and detailed modelling study carried out for the ICV pilot well and the two long horizontal wells. The ICV pilot completion design is described. The technology include swellable packer, inflow control valve (ICV), fiber optic DTS (Distributed Temperature Sensing). The open hole will be segmented into 3 sections using fed through swellable packer technology to pass fiber optic lines and install one ICV gross each section. The overall aim is to enable well GOR control, reduce project cost, maximize production and minimize any future rig intervention cost of shutoff at specific section. A detailed single well model was developed within the 3D full field model. The well model was history matched, including PLTs and saturation logging. For ICV installation planning, a full range of sensitivity and uncertainty analysis was performed to assess likely impact. In particular, the impact due to potential faulting/sub-seismic faults was assessed. The model was also used to define data acquisition planning post ICV installation The early production performances from the ICV pilot well are presented. For the two long horizontal wells, well design considerations are presented. Plan for continued monitoring of the 3 wells are shown, with the aim of helping to optimize attic oil development. |
