Detection and Distribution of Thief Perm in the Late Albian Mauddud Formation, Sabiriyah and Raudhatain Fields, Kuwait: A Dual Porosity Dual Permeability Methodology for Model Implementation

Abstract

An integrated analysis of a detailed core description, image and open-hole logs, PLT and PTA data, and production history in the late Albian (Early Cretaceous) Mauddud formation of Sabiriyah and Raudhatain fields, North Kuwait reveal the presence of dual perm dual porosity carbonate reservoirs. A methodology was developed to distribute this secondary pore system within the dynamic model and achieve an excellent history match. Early water breakthrough within months of water injection in this high porosity/low permeability reservoir indicated the likely presence of a secondary high perm low volume pore system or "Thief". A thief zone facies log was created and derived from core interpretation, foot by foot PLT spike and permeability logs, well test permeabilities, and high flow production zones. Both object and pixel based descriptions were considered for the history match. It is likely that a high quality history match could be achieved from either description. However, model results indicated a preference for the pixel based more continuous thief zone case. The thief description was iteratively modified during the history matching process as the well performance data provides vital information about thief continuity.