I have discussed the theory relevant for a three phase/two component isothermal gas-water-hydrate fluid flow simulation of hydrate growth and dissociation. Furthermore, I have shown the finite-difference code development for the three dimensional flow problem. The code has been implemented for two dimensions and is currently running correctly in the case of two-phase gas-water flow, with negligible small hydrate saturation for pressures and temperatures that prevent both hydrate growth or dissociation. I have shown the results of a test case simulating the equilibrization of a water over gas system with time. Also, I have discussed the possible future extension of the code to include thermodynamic effects that are crucial in regard to hydrate structures.