Hostname: page-component-78c5997874-fbnjt Total loading time: 0 Render date: 2024-11-02T20:33:27.605Z Has data issue: false hasContentIssue false
  • English
  • Français

Thermogravimetry/evolved water analysis (TG/EWA) combined with XRD for improved quantitative whole-rock analysis of clay minerals in sandstones

Published online by Cambridge University Press:  09 July 2018

D. M. Thornley  and
T. J. Primmer
D. M. Thornley
Affiliation:
BP Exploration, Research and Engineering Centre, Chertsey RdSunbury-on-Thames, Middx, TW16 7LN, UK
T. J. Primmer
Affiliation:
BP Exploration, Research and Engineering Centre, Chertsey RdSunbury-on-Thames, Middx, TW16 7LN, UK
Get access Rights & Permissions [Opens in a new window]

Abstract

Current methods of quantitative whole-rock clay mineral analysis of sandstones often provide little more than an estimate of clay mineral abundances, especially where the total clay mineral content is <10 wt% of the sandstone. More accurate determinations of clay mineral abundance in the whole rock can be made by combining thermogravimetry/evolved water analysis (TG/EWA) and X-ray diffraction (XRD) data. The TGA/EWA system incorporates a purpose built thermobalance linked to a water specific infrared detector which is used to measure quantitatively the clay mineral dehydroxylation water evolved from the whole rock when heated from 250°C to 900°C. This gives a measure of the total hydroxyl content of the clay minerals in the whole rock which, when combined with XRD analysis of a separated clay size-fraction, enables individual clay mineral abundances in the whole-rock sample to be determined. Results on artificial sand/clay mineral mixtures prepared with known amounts of different clay minerals (chlorite, illite and kaolinite) show that the accuracy of the combined method is most influenced by the accuracy of the XRD data. Errors associated with TG/EWA were found to be negligible by comparison. A case study is included in which the technique has been used to determine accurately the illite abundance in the Magnus Sandstone Reservoir, Northern North Sea.

Type
Research Article
Information
Clay Minerals , Volume 30 , Issue 1 , March 1995 , pp. 27 - 38
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1995

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Bloodworth, A.J., Hurst, A. & Morgan, D.J. (1990) Detection and estimation of low levels of kaolinite by evolved water vapour analysis. Mem. Set Geol. Strasbourg 89, 143–148.Google Scholar
Chung, F.H. (1974) Quantitative interpretation of X-ray diffraction patterns of mixtures. II. Adiabatic principle of X-ray diffraction analysis of mixtures. J. Appl. Crystallogr. 7, 526–531.Google Scholar
Emery, D., Smalley, P.C. & Oxtoav, N.H. (1993) Synchronous oil migration and cementation in sandstone reservoirs demonstrated by quantitative description of diagenesis. Phil. Trans. R. Soc, Lond. A, 334, 115–125.Google Scholar
Grabs, R.J. (1965) Error due to segregation in quantitative clay mineral X-ray diffraction mounting techniques. Am. Miner. 50, 741—751.Google Scholar
Hardy, R.G. & Tucker, M.E. (1988) X-ray powder diffraction of sediments. Pp. 191–228 in: Techniques in Sedimentology (Tucker, M.E., editor). Blackwell, London.Google Scholar
Heaviside, J., Langley, G.O. & Pallatt, N. (1983) Permeability characteristics of Magnus reservoir rock. 8th European Formation Evaluation Sym. Paper A, 29 pp.Google Scholar
Johnson, L.J., Chu, C.H. & Hussey, G.A. (1985) Quantitative clay mineral analysis using simultaneous linear equations. Clays Clay Miner. 33, 107–117.Google Scholar
Morgan, D.J. (1977) Simultaneous DTA-EGA of minerals and natural mineral mixtures. J. Thermal Anal. 12, 245–263.Google Scholar
Pallatr, N., Wilson, M.J. & Mchardy, W.J. (1984) The relationship between permeability and the morphology of diagenetic illite in reservoir rocks. J. Petrol. Tech. 36, 2225–2227.Google Scholar
Paterson, E. & Swaffielo, R. (1987) Thermal analysis. Pp. 99–132 in: A Handbook of Determinative Methods in Clay Mineralogy (Wilson, M.J., editor). Blackie, London.Google Scholar
Pierce, J.W. & Siegel, F.R. (1969) Quantification in clay mineral studies of sediments and sedimentary rocks. J. Sed. Pet. 39, 187–193.Google Scholar
Reynolds, R.C. (1989) Principles and techniques of quantitative analysis of clay minerals by X-ray powder diffraction. Pp. 4–37 in: CMS Workshop Lectures, Vol. 1, Quantitative Mineral Analysis of Clays (Pevear, D.R. & Mumpton, F.A., editors). The Clay Minerals Society, Evergreen, Colorado.Google Scholar
Waxman, M.H. & Smits, L.J.M (1968) Electrical conductivities in oil-bearing shaly sands. Soc. Pet. Eng. J. 8, 107–122.Google Scholar
Welton, J.E. (1984) SEM Petrology Atlas, pp. 38–100. American Association of Petroleum Geology, Tulsa, Oklahoma.Google Scholar
Wilson, M.D. & Pittman, E.D. (1977) Authigenic clays in sandstones: recognition and influence on reservoir properties and paleoenvironmental analysis. J. Sed. Pet. 47, 3–31.Google Scholar
Wilson, M.J. (1987) X-ray powder diffraction methods. Pp. 26–98 in: A Handbook of Determinative Methods in Clay Mineralogy (Wilson, M.J., editor). Blackie, London.Google Scholar
Worthington, P.F. (1985) The evolution of shaly-sand concepts in reservoir evaluation. Log Analyst, 26, 23—40.Google Scholar