Using a dynamic coupled well-reservoir simulator to optimize production of a horizontal well in a thin oil rim

Stabilization and optimization of production are the key challenges for smart well control. In order to compare the effectiveness of different control strategies, a simulation environment can be used. To study and control the effects of for instance slugging, gas coning and wax deposition, both reservoir dynamics and the dynamics of multi-phase well flow have to be taken into account in such a simulation environment. In this paper we use a dynamic coupled well-reservoir simulator to identify instabilities of a field case and test a control strategy to mitigate gas coning and wax deposition. The dynamic simulation environment has been developed within the research framework of the 'Integrated System Approach Petroleum Production' knowledge center of TNO, TU Delft and Shell. This simulator has been validated with field data of a horizontal well located in a thin oil rim, suffering from gas coning and containing a crude which has a high tendency to wax. With the help of the simulation environment it was possible to understand the production instabilities observed in this well and to determine a control strategy to stabilize and optimize its production. The results of the coupled well-reservoir simulations are presented and the phenomena that are most likely to cause the production instabilities observed in the field are identified. In production optimization the current status is to use separate dynamic well and reservoir models. In case of significant reservoir-well interaction this approach gives a non-realistic production forecast. This project gives a clear indication that, when using a coupled simulation on a real field case, a better understanding of the instabilities and therefore a more accurate production forecast and a better control strategy can be designed. Copyright 2008. Society of Petroleum Engineers.