4. After examining the following formulation, describe the fluid-flow problem and the porous media fully, from these perspectives: (15 points) Flow dimension? Number of phases/components? Is gravity significant? Are there source/sink terms? Is the formation homogeneous/heterogeneous? Do we have isotropy/anisotropy? x(coB0kxkroxp)+Ybq0=ac1t(BoSo)+x(cogcoBokxkroxZ)x(cwBwkxknwxp)+Vbqw=c1t(BwSw)+x(cwgcwBwkxkrwxZ) 4. After examining the following formulation, describe the fluid-flow problem and the porous media fully, from these perspectives: (15 points) Flow dimension? Number of phases/components? Is gravity significant? Are there source/sink terms? Is the formation homogeneous/heterogeneous? Do we have isotropy/anisotropy? x(coB0kxkroxp)+Ybq0=ac1t(BoSo)+x(cogcoBokxkroxZ)x(cwBwkxknwxp)+Vbqw=c1t(BwSw)+x(cwgcwBwkxkrwxZ)