Quantitative Determination of the Degree of Heterogeneity Within an Outcropping Reservoir by Magnetic Resonance Imaging

Abstract

Abstract Under certain conditions, petrophysical analysis of outcropping rock units may add significantly to the knowledge of a buried reservoir by providing laterally continuous control of reservoir heterogeneity. We present here the first results of a project to develop cost saving methods to improve the knowledge of reservoir heterogeneity. The study was performed on a carbonate outcropping reservoir, and the sampled rocks can be correlated with oil bearing reservoir discovered some 50 km to the W, in the Southern Apennines. The cores are highly heterogeneous, with a consistent presence of fractures and vugs; therefore standard porosity measurements are difficult to perform. Quantitative Magnetic Resonance Imaging (MRI) was used to measure porosity. About 300 MRI internal images from 46 samples, taken from 8 full-size cores, were analyzed. Quantitative determination of porosity by MRI proved to be reliable to describe the distribution of porosity at different scales, and it was successful in providing information on the lateral continuity of the porosity. P. 485