1. A method for modeling a hydrocarbon reservoir, comprising: generating a reservoir model comprising a plurality of sub regions, wherein the reservoir model is segmented into the plurality of sub regions that represent different portions of the reservoir model and the reservoir model is utilized to model fluid flow within the hydrocarbon reservoir; obtaining a solution surrogate for at least one sub region of the plurality of sub regions by: searching a database of existing solution surrogates to determine if an approximate solution surrogate exists based on a comparison of physical, geometrical, or numerical parameters of the at least one sub region with physical, geometrical, or numerical parameters associated with the existing solution surrogates in the database; if the approximate solution surrogate exists, then associating one of the existing solution surrogates with the at least one sub region as the solution surrogate; if the approximate solution surrogate does not exist in the database: simulating the sub region using a training simulation of the sub region to obtain a set of training parameters comprising state variables and boundary conditions of the sub region, wherein the training simulation is a reservoir simulation having resolution to represent predetermined physical processes wherein the simulating the sub region comprises generating a set of inputs, a set of desired outputs, and weighting values, w; using a machine learning algorithm to obtain a new solution surrogate based on the set of training parameters wherein the machine learning algorithm calculates a set of computed outputs, compares the set of computed outputs to the set of desired outputs to calculate a value for an objective function between the set of computed outputs and the set of desired outputs, and uses the value of the objective function to alter the weighting values, w, in at least one subsequent iteration of calculating a value for the new solution surrogate; storing the new solution surrogate to the database; and associating the new solution surrogate with the at least one sub region as the solution surrogate; and simulating fluid flow in the hydrocarbon reservoir using the reservoir model comprising the plurality of sub regions and the solution surrogate obtained for the at least one sub region; generating a data representation of a physical hydrocarbon reservoir in a non-transitory, computer-readable, medium based at least in part on the results of the simulation; and causing hydrocarbon to be produced from the hydrocarbon reservoir based, at least in part, upon the results of the simulation.