This study investigates the nonlinear dynamics of geometrically imperfect graphene platelet-reinforced metal foam (GPLRMF) fluid-conveying pipes under the 1:1 internal resonance condition. With simply supported boundary conditions, the system is subject to the combined external lateral loads and internal pulsating fluid excitations. The nonlinear dynamic model is established with the Euler-Lagrange equations and then systematically discretized via the Galerkin method. The multi-scale analysis reveals how material properties and geometric imperfections influence the internal resonance. Particular emphasis is placed on elucidating, through the modal energy analysis, the energy exchange mechanisms between the first two vibration modes.