Reservoir Simulation Explains Production Problems in Nile Delta Gas Field

This paper provides a case study of how detailed reservoir modeling and simulation helped to explain existing production problems and to subsequently optimize reservoir management for a gas field in the Nile Delta. In this example the complex geology of a fluvial deltaic system was modeled using the concepts of sequence stratigraphy to build the basic reservoir architecture for the Abu Madi Formation. Then seismic attributes were used to characterize the detailed facies and permeability distribution and the interplay of sands and shale in the reservoir intervals. This allowed a representative three dimensional reservoir simulation model to be built that could more accurately reproduce the water influx and gas water contact movement that had happened in the reservoir as a result of historical production conditions. In addition it confirmed that the different reservoir intervals had different reservoir drive mechanisms and thus needed to be managed differently. This was not fully understood using conventional techniques due to the relatively low well density.

This paper will include the specific lessons learnt for three gas wells in a small Upper Abu Madi fluvial channel in the Nile Delta Field where production conditions caused rapid water influx, water production from coning and gas blocking between wells which was not recognized without the detailed geological and dynamic understanding. In addition it will document the development optimization scenarios that were performed for all reservoir levels to maximize recovery. It shows that even for relatively small reservoirs the use of reservoir modeling and simulation can be cost effective by allowing the optimization of production conditions, improved recovery and the prevention of unproductive well interventions.