Fluid Flow Network Simulation Methods and Systems Employing Two-Phase Envelopes with Interpolated Values

A system that comprises:

• a memory having a simulation program;
• and
• one or more processors coupled to the memory, wherein the simulation program, when executed, causes the one or more processors to:
• model a fluid flow network, the fluid flow network having a surface pipeline network connected between a plurality of well perforation nodes and a common outlet or inlet;
• generate a plurality of two-phase envelopes for the modeled fluid flow network, wherein each phase envelope has at least some interpolated values and corresponds to a section of the fluid flow network with a constant flow composition;
• and
• determine phase equilibrium information for the modeled fluid flow network based at least in part on the generated two-phase envelopes;
• and
• apply the determined phase equilibrium information to production or simulation operations related to the modeled simulation flow network.