The aim of this paper is to study the effect of sodium dodecyl sulfate (SDS) foam on methane formation nuclei process. The experimental data were compared with SDS solution in the absence of foam. Repeat experiments proved that the nucleation rate in the presence of SDS foam was 1.15 x 10(-1) min(-1), which was notably faster than 1.18 x 10(-2) min(-1) in the absence SDS foam. It indicated that the SDS foam can significantly accelerate nuclei process, which thus made the nuclei process instantaneous. The foam surface area, the interior gas pressure of the bubble and foam film were investigated to find out the reasons behind promoting nuclei process by SDS foam. The larger interface area of gas liquid provides more nucleation sites, whereas the effect of interior gas pressure on the nuclei process is not significant due to the negligible pressure variation. The result can be used to prevent the pipeline plugging during the gas well production or the gas transmission. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.