Reservoir properties of drill cutting by the nuclear magnetic resonance relaxometry and dielectric spectroscopy data

Abstract

The purpose of the study is to extend the use of nuclear magnetic resonance relaxometry and dielectric spectrometry methods. This is realized through a complex interpretation of the data by the above methods to timely provide additional petrophysical information about the drill cuttings pore space properties and structure. The relevance of the study is that the data on the drill cuttings obtained by the NMR method can be used as prior information in the logging data interpretation before a detailed petrophysical study of the core sample or in case of the core absence in the sampling interval. The objects of study are the drill cuttings samples from the fields of the West Siberian oil-and-gas province. The samples are saturated with different fluids, and their reservoir properties are determined by the nuclear magnetic resonance and dielectric spectrometry methods. As part of the experimental research, nuclear magnetic resonance investigations of the core samples of different discretization degrees have been carried out to determine the reservoir properties of the samples depending on the degree of their particle size reduction. It has been shown that the obtained results do not depend on the particle size of the measured sample and are consistent with the results of the standard petrophysical studies. The relationship between the porosity and the saturating fluid type has been established. Based on the data obtained by the dielectric spectroscopy method, the study has determined the value of the complex dielectric constant that shows how the degree of saturation changes depending on the fluid, and what happens in the pore space. The complex interpretation of the results obtained by the two methods provides additional information on the drill cuttings reservoir properties that can be used as a priori information on the formation properties.