The physisorption of methane in idealized bundles of single walled carbon nanotubes (SWCNT) is investigated in detail in this work employing computational. Several aspects related to the possible application of nanotubes as fuel gas containers are analyzed employing molecular dynamics simulations. The influence of the nanotube diameter on the adsorption capacity of the material and the distribution of the adsorbate are examined by considering bundles of carbon nanotubes with different morphologies. An increase of the load capacity with the nanotube diameter is observed, together with a qualitative change in the distribution of the adsorbed molecules. The effect of porosity is also studied from the point of view of the nanotube separation, finding that this leads to a significant increase in storage capacity in the case of bundles made of small diameter nanotubes. The role of temperature as a possible uptake/release triggering variable is also examined.