Tight sand gas reservoir refers to natural gas that is underground reservoirs with low porosity and low permeability. It is generally accepted that tight sand is less than 1md under reservoir conditions. A number of such fields are in production right now, but in many areas, production with the current technology is hardly economical.Analysis of tight reservoirs is one of the most difficult problems. Many tight formations are extremely complex, producing from multiple layers with permeabilities that are often enhanced by natural fracturing. Therefore, looking for using new physics logging techniques like NMR in individual bases or in combination with conventional logs and building new and advance interpretation methodologies is essential to well define and obtain the representative reservoir characterizations for proper developing decisions. Nuclear magnetic resonance (NMR) logs differ from conventional neutron, density, sonic and resistivity logs because the NMR measurements provide information only on formation fluids and are generally insensitive to matrix properties.