ABSTRACT
A strongly coupled well model is described for use in a fully implicit 3-phase reservoir simulator. The model uses three variables for each well, instead of the usual single variable representing the well's bottom hole pressure. The two extra variables describe the contents of the wellbore, and provide a means of modeling crossflow of fluid between reservoir layers through the wellbore.
For each of the standard modes of well control, it is possible to express the well flow rates in terms of the three well variables alone. This provides a convenient means of handling fully implicitly the collective interactions between wells that occur with group and field production rate control and re-injection or voidage replacement operations. An example simulation is presented, to illustrate the capabilities of the fully implicit collective well control algorithm.
