Abstract: Methods and systems for modeling a reservoir system are described. The method includes constructing a reservoir model of a reservoir system. The reservoir model includes a reservoir and a plurality of wells. Also, one or more material balance groups are constructed with each material balance group having a portion of at least one of the plurality of wells, a portion of the reservoir, and at least one well management algorithm to track material balance within the respective material balance group. Then, fluid flow through the reservoir model is simulated based on the material balance groups by a simulator and the results are reported.

Abstract: A field operating policy for a subsurface region is optimized by setting initial policy parameters for the subsurface region. Fluid flow within a subsurface region is simulated, wherein the simulation includes optimizing an objective function for field operating policy, the objective function corresponding simultaneously to the modeled fluid flow characteristics of one or more wellbores within the subsurface region and relating to at least one production system performance parameter. Optimizing the objective function for field operating policy may include optimizing the initial policy parameters for the subsurface region with an over time optimization technique, wherein the policy parameters are optimized for a predetermined policy period. An enhanced value of the objective function is determined at each timestep within the predetermined policy period.

Abstract: Methods and systems for modeling a reservoir system are described. The method includes constructing a reservoir model of a reservoir system. The reservoir model includes a reservoir and a plurality of wells. Also, one or more material balance groups are constructed with each material balance group having a portion of at least one of the plurality of wells, a portion of the reservoir, and at least one well management algorithm to track material balance within the respective material balance group. Then, fluid flow through the reservoir model is simulated based on the material balance groups by a simulator and the results are reported.