Rapid Mineral Analysis Using the SpecCam Imaging Spectrometer

by Dr. Gavin Hunt, Technical Director, Spectra-Map Ltd

Abstract

Spectra-Map Ltd is a UK based consultancy that provides core and cuttings logging services for mineral identification, using the SpecCam short-wave infrared (SWIR) imaging spectrometer. This portable multi-pixel camera provides continuous (as opposed to point sampling), automated, high-throughput mineral information. The SpecCam can be used at rig site or onshore for near real-time analysis. Logging is non-contact and non-invasive so no sample preparation is required and results may be used to link data from point sampling (e.g. thin-section petrography, SEM and/or XRD), with wireline logs, for improved reservoir characterisation.

SWIR spectroscopy is useful for identifying a range of minerals including phylosilicates and carbonates, but especially for discriminating the detailed clay mineralogy, - e.g. clay types and crystallinity, swelling and non swelling clays, and changes in illite and kaolin polytypes - and as such is complementary to techniques such as XRD. Accurate modal percentage values can be derived due to the large number of data points collected.

The SpecCam system was successfully used on core and cuttings in a recent North Sea project to improve stratigraphic correlations of lithological and diagenetic units from well to well. This and other examples including Brent reservoir studies, improvements in permeability estimates and calibration of wireline gamma and electrical logs will be presented.

Further information is available on www.spectra-map.co.uk.

Gavin Hunt, CV

After completing a PhD in mineral spectroscopy in 1990 Gavin joined Rio Tinto’s R&D group to promote and apply infrared spectroscopy techniques for mineral exploration. In 1998 he left Rio Tinto to found Spectra-Map. The company subsequently won a government award and mining industry funding to develop the SpecCam spectrometer. He is currently the Technical Director of Spectra-Map Ltd, a company - based in the U.K. - providing sales and services in mineral analysis using infrared spectroscopy.