Petroleum Geoscience; April 2003; v. 9; no. 2;
p. 175-183; DOI: 10.1144/1354-079302-517
© 2003 Geological Society of London
Flow characterization of glauconitic sandstones by integrated Dynamic Neutron Radiography and image analysis of backscattered electron micrographs
Mikael Solymar1,
Ida L. Fabricius2 and
Mike Middleton3
1 Department
of Geology, Chalmers University of Technology, S-412 96 Gothenburg,
Sweden (Present address: Statoil ASA, 4035 Stavanger,
Norway; e-mail:
miso@statoil.com)
2 Department of Environment and
Resources, Technical University of Denmark, Building 204, DK-2800
Lyngby, Denmark (e-mail:
ilf@er.dtu.dk)
3 School of Applied Geology, Curtin
University of Technology, Perth, 6845 WA,
Australia(e-mail:
middlem@lithos.curtin.edu.au)
The
effects of porosity and pore geometry on the fluid saturation and
immiscible displacement of greensand reservoir rocks were investigated
on eight samples from the North Sea basin. Dynamic Neutron Radiography
(DNR) was used to image the front stability during displacement
experiments where oil was infiltrating water-saturated samples. The
flow characteristics were related to petrography and pore geometry,
which may be determined by image analysis of backscattered electron
(BSE) micrographs. The fluid saturation observed in each DNR image was
modelled in a corresponding BSE image as a means of evaluating the
effect of pore geometry on front stability. Piston-like displacement
and channelling were observed and these flow patterns were found to
reflect variations in pore geometry. The samples with piston-like
displacement have homogeneous pore space, whereas the samples with
channelling have heterogeneous pore space, with spatial variations in
porosity and pore size. The modelled saturation distribution was
interpreted using results from petrographic and petrophysical analyses.
The results suggest that the micropores of the glauconite grains and
clay minerals contain water, whereas the oil is moving through the
intergranular pore space during the displacement
experiment.
KEYWORDS: greensand, petrography, texture, porosity, immiscible
displacement
Copyright © 2009 by Geological Society of London