Formation factor logging by electrical methods - Comparison of formation factor logs obtained in situ and in the laboratory
2003 (English)In: J CONTAM HYDROL, 2003, Vol. 61, no 1-4, 107-115 p.Conference paper (Refereed)
In this paper, a new in situ method for obtaining the formation factor, which is essential for the matrix diffusion, is described and tested in intrusive igneous rock. The method is based on electrical resistivity measurements in rock where the pore water and rock resistivities are essential parameters. The method is based on electromigration instead of diffusion as in traditional diffusion experiments. In previous works, quantitative formation factors of rock have been obtained by electrical methods in the laboratory. Here, a similar approach is used in situ. An in situ logging campaign was performed by SKB during 2000 in the 1700-m-deep borehole KLX02 in Laxemar, Sweden. The rock resistivity was measured with the slimhole Dual Laterolog from Antares. The groundwater resistivity was measured with the Difference Flow Meter from Posiva. A formation factor log was obtained with the maximum vertical resolution of 10 cm. In order to validate the log, 100 rock samples were taken from the bore core, and a formation factor log was obtained by using electrical methods in the laboratory. Both direct current (DC) and alternating current (AC) were used. The measurements on the core confirmed that the in situ log was quantitative, but with a possible systematic error. The in situ formation factors were on average about 1/3 to 1/5 of the laboratory formation factors, depending on depth.
Place, publisher, year, edition, pages
2003. Vol. 61, no 1-4, 107-115 p.
, Journal of contaminant hydrology, ISSN 0169-7722
formation factor, matrix diffusion, in situ, rock resistivity
IdentifiersURN: urn:nbn:se:kth:diva-25385DOI: 10.1016/S0169-7722(02)00117-1ISI: 000181510100010OAI: oai:DiVA.org:kth-25385DiVA: diva2:357688
8th International Conference on Chemistry and Migration Behaviour of Actinides and Fission Products in the Geosphere (Migration 01) BREGENZ, AUSTRIA, SEP 16-21, 2001
QC 201010192010-10-192010-10-192010-10-19Bibliographically approved