Abstract: In some embodiments, apparatus and systems, as well as methods, may operate to acquire signature data representing a plurality of nuclear magnetic resonance (NMR) echo trains associated with a material comprising a first fluid and a second fluid, force a subset of the signature data associated with the first fluid or the second fluid to correspond to single-peak signatures in the T1 and/or T2 domains, and solve for the first fluid and second fluid saturation. The first fluid may include oil, gas, or water and the second fluid may include oil-based mud filtrate or water-based mud filtrate, among others.