The Minagish reservoir in the Burgan Field has been produced intermittently at relatively low rates since the 1960's. Full development has been delayed because of the relatively high H2S content of the reservoir fluid. A sour service production facility is now being planned. Reservoir pressure has declined over time and it has been recognized that a component of this decline is due to offset production from several other reservoirs in the area sharing an extensive common aquifer. Reservoir simulation has been used in two phases for the reservoir to assess development options as follows:
The first phase of this work, the "fast loop", involved building models of the regional aquifer and producing reservoirs, developing multiple history matched models and using these models to assess the required volume of injection needed to prevent further reservoir decline. The field level history match was highly non-unique. This work identified the need to have water injection available prior to a new sour service production facility being available and to inject at above voidage rates.
A more detailed "slow loop" simulation model has been developed for the Burgan Minagish reservoir following further geological, geophysical and petrophysical studies. This model has been used to perform development planning studies and, in particular, to plan water injection in the period up to the new production facilities being available. The simulation model has been used as one of the inputs to planning for reservoir management and data acquisition in this period.
The integration between these two models uses a novel methodology. This paper describes how the "fast loop" and "slow loop" studies are linked so as to include the effect of the regional aquifer in conditioning the "slow loop" model to historical data, and using it for predicting future development scenarios performances.