Having obtained a Pc curve, pore throat distributions can now be calculated using the Washburn equations. The imbibition and secondary drainage curves generated by the NMR Pc measurement also allow USBM wettability to be predicted. Both of these calculations are integrated into the software, and follow as a natural consequence of the NMR Pc data. A further added advantage is that the NMR measurement is non-destructive and can use reservoir fluids and reservoir wettability.
Until recently, a high level of expertise and knowledge of the principles and practice of NMR has been needed to perform NMR core analysis. Consequently, NMR core analysis has been confined to a relatively small group of Special Core Analysis Laboratories. Now, a partnership between Oxford Instruments and Green Imaging Technologies brings new hardware and software, with improved performance, to enable any core analysis laboratory to generate the petrophysics values that the industry needs without the requirement that every dataset be analysed by an NMR expert.
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.
Need help finding the right suppliers? Try XPRT Sourcing. Let the XPRTs do the work for you