Method and apparatus for predicting petrophysical properties from NMR data in carbonate rocks

摘要

An apparatus and method for determining a property of an earth formation using a radial basis function derived from a catalog of rock samples. Parameters of a Thomeer capillary pressure fitting curve are derived and used for analyzing rocks with unimodal or multimodal pore size distributions.

主权项

1. A method of estimating a value of a property of interest of an earth formation, the method comprising:
deriving a radial basis function to estimate the value using an estimate for a pore modality of the earth formation and at least one of: (i) a database comprising a plurality of samples and (ii) an nuclear magnetic resonance (NMR) measurement associated with each sample in the database and related to NMR spin-echo signals; and estimating the value using the NMR spin-echo signals and the radial basis function, the spin-echo signals being acquired using an NMR sensor assembly in a borehole penetrating the earth formation.