The processes of CNTs bundle formation and insertion/rearrangement inside lipid bilayers, as models of cellular membranes, is described and analyzed in details using simulations on the microsecond scale. Molecular Dynamics simulations employing hybrid particle-field models (MD-SCF) show that during the insertion process lipid molecules coat bundles surfaces. The distortions of bilayers are more pronounced for systems undergoing to insertion of bundles made of longer CNTs. In particular, when the insertion occurs in perpendicular orientation, adsorption of lipids on CNTs surfaces promotes a transient poration. This result suggests mechanism of membrane disruption operated by bundles causing the formation of solvent-rich pockets.