Hostname: page-component-7b7567c8c-fvjsw Total loading time: 0 Render date: 2026-11-15T17:58:56.680Z Has data issue: false hasContentIssue false
  • English
  • Français

Formation Factor Determinations by In-Situ Resistivity Logging

Published online by Cambridge University Press:  21 March 2011

M. Löfgren,
Y. Ohlsson and
I. Neretnieks
M. Löfgren
Affiliation:
Department of Chemical Engineering and Technology, Royal institute of Technology Stockholm, Sweden
Y. Ohlsson
Affiliation:
Department of Chemical Engineering and Technology, Royal institute of Technology Stockholm, Sweden
I. Neretnieks
Affiliation:
Department of Chemical Engineering and Technology, Royal institute of Technology Stockholm, Sweden
Get access

Abstract

Matrix diffusion in bedrock is traditionally studied by laboratory liquid diffusion experiments, which are time consuming and expensive. A new way of studying matrix diffusion is to measure the electrical resistivity of the rock. This could be done either in laboratories or in-situ. A fast method of obtaining a formation factor log, later used in matrix diffusion calculations, for an entire borehole is proposed.

It is a standard procedure in geophysical well logging to measure rock resistivity and there are well-developed tools for this in the oil industry. The SKB, Sweden, uses boreholes with a small diameter (56 mm) and this reduces the options in choosing resistivity tools. Therefore they have so far relied on the Normal log that only gives quantitative measurements in special cases, after corrections are made. Modern tools, such as the slimhole Dual-Laterolog, are accurate with a high vertical resolution.

The pore fluid resistivity is required when obtaining a formation factor log. In previous work the borehole fluid resistivity has been used. A new method measures the resistivity in groundwater from local fractures. These values seem more appropriate to use as new in-situ measurements show that there may be local groundwater resistivity differences.

A preliminary study shows that the conductivity could be obtained in saline Swedish groundwater by measuring the chloride concentration only.

Anomalies in the formation factor log have to be sorted out by using supporting core logging and non-electrical in-situ methods.

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.)

Article purchase

Temporarily unavailable

References

REFERENCES

1. Skagius, K. Diffusion of dissolved species in the matrix of some Swedish crystalline rocks. 1986. PhD. Thesis. Dept. of Chem. Eng. Royal Inst. of Techn., Sweden.Google Scholar
2. Ohlsson, Y., Löfgren, M., Neretnieks, I. Rock matrix diffusivity determinations by in-situ electrical conductivity measurements. Accepted for publication in Journal of Contaminant Hydrology, 2000.Google Scholar
3. Atkins, P. W. Physical Chemistry. Fifth edition. Oxford university press. Pages 834–850.Google Scholar
4. Lehikoinen, J., Muurinen, A., Valkiainen, M. A consistent model for anion exclusion and surface diffusion. Conference paper, MRS Fall Meeting. Boston, USA. 1998.Google Scholar
5. Dakhnov, V.N. Geophysical well logging. Moscow 1959. Translated by Keller, V. 1962. In Quaterly of the Colorado School of Mines. Vol. 57. No. 2, 1962.Google Scholar
6. Desbrandes, R. Encyclopedia of well logging. Graham and Trotman Limited. London 1985.Google Scholar
7. Rouhiainen, P., Pöllänen, J. Difference flow measurements in boreholes KA2865A01, KA3065A02 and KTTX5 at the Äspö HRL, SKB, ITD-99-25.Google Scholar
8. Almén, K-E., Zellman, O. Äspö HRL. Field investigation methodology and instruments used in the pre-investigation phase, 1986-1990. 1991. SKB, Technical Report TR 91-21.Google Scholar
9.SICADA, The SKB Site Characterization Database System.Google Scholar
10. Laaksoharju, M., Tullborg, E-L., Wikberg, P., Wallin, B., Smellie, J. Hydrogeochemical conditions and evolution at the Äspö HRL, Sweden. Applied Geochemistry Vol. 14 No. 2, 1999.Google Scholar