Nuclear-magnetic resonance (NMR) measurements provide petrophysicists with porosity distributions that are lithology-independent. Forward modeling allows analyzing NMR, taking into account all data available. Based on the study of distributary bar system, we found that: (1) mouth bar facies studied are characterized by unimodal distribution of T-2, "free-fluid" maximum at 20.0-40.0 ms and a "tail" associated with the chlorite coating and partially dissolved feldspar microporosity at 0.5-3.0 ms; (2) Delta front facies have bimodal distribution with maximums at approximate to 2.0 and approximate to 30.0 ms, a 4.8 ms and approximate to 65 ms cut-off values were established to define clay-bound and free-fluid volumes; and (3) Distal bar sands with calcite cementation have cut-offs of 12.0 ms and 90 + ms. To characterize delta front facies, an additional case has been modeled to illustrate the dependence of clay-bound water cut-off point upon mineralogy: (a) chlorite-mixed layer grain coating have approximate to 5.0 ms cut-off, and (b) kaolinte pore filling has a cut-off value of approximate to 20 ms.