NMR Characterizations of Properties of Heterogeneous Media

Abstract

The overall goal of this project is to develop reliable methods for resolving macroscopic properties important for describing the flow of one or more fluid phases in reservoirs from formation measurements. In Stage I, we develop advanced core analysis tools to determine macroscopic properties-the porosity, absolute, and relative permeability-within heterogeneous core samples. In Stage II we use these methods, together with additional NMR spectroscopic measurements, to obtain data for development of predictive methods. In Stage III, we develop improved relations for predicting permeabilities, and test a novel method for predicting relative permeability, from NMR well-log observable properties.During this reporting period, the determination of surface relaxivity from NMR data is investigated. A new method for determining the surface relaxivity from measured data is developed and tested with data obtained from an Exxon sample. The new method avoids the use of a certain mathematical short-time approximation in the data analysis, which has been shown to be unsuitable.Numerical work is in progress to simulate two-phase displacement experiments using all three spatial dimensions when estimating two-phase flow functions (relative permeability and capillary pressure properties). The modification of the computer code is underway with tests of the changes with specific examples.ii