A simulation method of a hydrocarbon field development configuration comprising: a) providing a computer having one or more parallel graphics processing unit (GPU); b) providing historical data for a hydrocarbon field; c) inputting, into said GPU, the network topography, field layout, fluid description, and reservoir characteristics of one or more field configurations to create a field model; characterized by : d) utilizing object-oriented software, on said GPU, for dividing the flow physics and H 2 S generation mechanisms of one or more fluids for said one or more field configurations into a plurality of individual basic elements of appropriate units for individual calculation so that the behavior of each individual basic element can be analyzed separately, wherein at least one of said basic elements incorporates said historical data; e) wherein said H 2 S generation mechanisms are biological reactions of sulfate reducing bacteria (SRB), natural scavenging reactions, thermal reactions, interaction between H 2 S and hydrocarbons, reactions between H 2 S and water injection, reactions between H 2 S and production equipment, and/or a combination thereof f) defining one or more time scales and/or one or more spatial levels for simulating one or more individual basic elements; g) simulating H 2 S generation and transport and fluid flow for at least one field model and one or more individual basic elements over said time scales and/or spatial level; and, h) displaying the results of said simulating step; and i) comparing simulation results for one or more field configurations; selecting the configuration with the lowest H 2 S generation; and creating a final field development plan, including a water injection scheme and an amount of H 2 S scavenger to stay within defined H 2 S limits; and j) implementing the field development plan. a) providing a computer having one or more parallel graphics processing unit (GPU); b) providing historical data for a hydrocarbon field; c) inputting, into said GPU, the network topography, field layout, fluid description, and reservoir characteristics of one or more field configurations to create a field model; d) utilizing object-oriented software, on said GPU, for dividing the flow physics and H 2 S generation mechanisms of one or more fluids for said one or more field configurations into a plurality of individual basic elements of appropriate units for individual calculation so that the behavior of each individual basic element can be analyzed separately, wherein at least one of said basic elements incorporates said historical data; e) wherein said H 2 S generation mechanisms are biological reactions of sulfate reducing bacteria (SRB), natural scavenging reactions, thermal reactions, interaction between H 2 S and hydrocarbons, reactions between H 2 S and water injection, reactions between H 2 S and production equipment, and/or a combination thereof f) defining one or more time scales and/or one or more spatial levels for simulating one or more individual basic elements; g) simulating H 2 S generation and transport and fluid flow for at least one field model and one or more individual basic elements over said time scales and/or spatial level; and, h) displaying the results of said simulating step; and i) comparing simulation results for one or more field configurations; selecting the configuration with the lowest H 2 S generation; and creating a final field development plan, including a water injection scheme and an amount of H 2 S scavenger to stay within defined H 2 S limits; and j) implementing the field development plan. <EOS>