GENNET-M is a Windows program that calculates flow rates, pressures, temperatures, velocity and other related variables in a pipeline network system carrying petroleum gases, liquids, water and multiphase mixtures under Steady-State conditions.
The name "GENNET" is an acronym for GENeral pipeline NETwork program. Thus, GENNET models systems comprised of pipes and Pressure/Temperature-changing equipment (pumps, compressors, heaters, valves, coolers, fittings, etc.) connected together in any configuration. For example, GENNET-M can handle gathering systems, flare systems, distribution systems, fire-loop systems, branched and looped pipelines. GENNET-M (the "M" stands for "Multiphase" mixtures of gas, oil or condensate and water) will handle multiphase fluid Mixtures, single-phase Liquids and single-phase Gases too.
This last feature is probably the most important of all. It is best explained by example. Suppose you had a gathering system that had several sources with known flow rates, flowing into a trunkline that is looped at several locations and eventually to a delivery terminal (sink) where the pressure is known. In GENNET-M, you could specify that the source pressures be calculated that would satisfy the known source flows and the known sink pressure. GENNET-M would also calculate the flows in all non-source pipes (including the loops) and the pressures at all nodes. (Of course, the fluid temperature is calculated everywhere too.)