Low Field NMR Applications in Oil Sands Mining and Extraction

ABSTRACT

Previous experience has proven that low field Nuclear Magnetic Resonance (NMR) has considerable potential for the characterization of cores containing oil, for conventional and heavy oil reservoir characterization. In oil sands mining and extraction, fast methods for determining the oil, water and solids content in ores and froths are necessary for plant process control and optimization. Currently the benchmark for such measurements is the Dean Stark extraction, which although fairly accurate is very time consuming (approx. 48 hours turnaround). In this work, NMR based methods are described for the analysis and determination of these constituent fluid and solids fractions. The experimental procedures for NMR characterization of ores and froths consist of a single NMR measurement and a single weight measurement. The nature of the in-situ fluid signals can be inferred based on the properties of the NMR spectra and calibration parameters such as the spectra of pure fluids. A large database of ores and froths has been measured, and some very interesting observations have been made. NMR outputs are water content, bitumen content and solids content. Spectra representative of high fines content have also been identified. Predictions are compared against measured oil, water and solids fractions obtained by Dean-Stark extraction, mostly on sister samples.

The results obtained to date are preliminary but have been encouraging enough to warrant further development, while plant applications have been identified. This work presents a novel application of NMR technology for an industry that can benefit considerably from fast and accurate characterization of ore and froth samples.

A full version of this paper is available on SCA Web Online.