Using NMR for Fluid Typing

GeoSpec2 instruments fitted with Pulsed Field Gradients (pfg) are able to carry out measurements dependent on the diffusion, flow, or distribution of the fluids within the core sample. One application is for fluid typing. It is possible that different fluids, such as heavy oils and partially bound water, may exhibit similar T₂ values, which makes it difficult to identify which fluid is which using a standard T₂ distribution. However, even if they have similar T₂ values they are unlikely also to have similar diffusion characteristics, so a measurement that collects both T₂ and diffusion data should in principle be able to separate the fluid types.

GIT Systems software, together with a pfg accessory on a GeoSpec2 NMR instrument, enables such measurements to be done. The result is a two-dimensional data map illustrating the relative proportions of the different fluid types in the sample.