This paper describes the modeling of single and dual tubing wells in a full-field reservoir simulator. The tubings associated with each well are modeled in terms of one primary and one or more secondary wells. The multi-segment well modeling techniques incorporated in the simulator have been extended to model multi-tubing systems thereby avoiding the requirement to model special grid blocks representing a wellbore. Wells with two or more tubings present a significant challenge to reservoir simulation where traditionally the coupling of the well with the reservoir, however complex, is solved in terms of a single surface inlet or outlet.
The case studies have been selected to demonstrate that injectors and producers can both be modeled in terms of primary and secondary wells both with targets and constraints. Comparisons are presented showing the differences between single and dual tubing injection and production schemes. An example of a multi-tubing production schemes is also included. These demonstrate that modeling wells with two or more tubings using the multi-segment well approach is practicable for the simulation of hydrocarbon recovery processes.