TY - JOUR
T1 - Different effects of temperature and salinity on permeability reduction by fines migration in Berea sandstone
AU - Rosenbrand, Esther
AU - Kjøller, Claus
AU - Riis, Jacob Fabricius
AU - Kets, Frans
AU - Fabricius, Ida Lykke
N1 - Funding Information:
This research was funded by the Danish Council , ( 10-093934 ) for Strategic Research as part of the HeHo project grant. Thanks are due to Bjørn Maribo-Mogensen, DTU, Chemical Engineering for his computer codes to calculate the dielectric permittivity as a function of temperature and NaCl concentration and to Morten Kanne Sørensen, DTU, Civil Engineering, for BET and grain density data. Hector Ampuero Diaz (DTU Environment) prepared polished thin sections. Appendix A
PY - 2015/1
Y1 - 2015/1
N2 - Hot water injection into geothermal aquifers is considered in order to store energy seasonally. Berea sandstone is often used as a reference formation to study mechanisms that affect permeability in reservoir sandstones. Both heating of the pore fluid and reduction of the pore fluid salinity can reduce permeability in Berea sandstone. These effects could be caused by mobilisation of fines by increasing the repulsive electrical double layer forces among sandstone grains and the fines. We investigated the reversibility and the dependence on flow velocity and flow direction of the permeability change by means of flow through experiments and examined thin sections of samples prior to and after tests. A permeability reduction at 20. °C with decreasing salinity was not reversed by restoring the salinity, whereas a permeability reduction due to heating to 80. °C was reversible by restoring the temperature to 20. °C. A reversible permeability increase with increasing flow rate was observed at 80. °C but not at 20. °C. We observed no difference in the distribution of kaolinite clay minerals in thin sections of untested and tested samples. Dissolution of iron bearing carbonates and precipitation of iron hydroxides was observed but no effect on permeability was found. The experimental results suggest that different mechanisms are responsible for permeability reduction depending on temperature and salinity.
AB - Hot water injection into geothermal aquifers is considered in order to store energy seasonally. Berea sandstone is often used as a reference formation to study mechanisms that affect permeability in reservoir sandstones. Both heating of the pore fluid and reduction of the pore fluid salinity can reduce permeability in Berea sandstone. These effects could be caused by mobilisation of fines by increasing the repulsive electrical double layer forces among sandstone grains and the fines. We investigated the reversibility and the dependence on flow velocity and flow direction of the permeability change by means of flow through experiments and examined thin sections of samples prior to and after tests. A permeability reduction at 20. °C with decreasing salinity was not reversed by restoring the salinity, whereas a permeability reduction due to heating to 80. °C was reversible by restoring the temperature to 20. °C. A reversible permeability increase with increasing flow rate was observed at 80. °C but not at 20. °C. We observed no difference in the distribution of kaolinite clay minerals in thin sections of untested and tested samples. Dissolution of iron bearing carbonates and precipitation of iron hydroxides was observed but no effect on permeability was found. The experimental results suggest that different mechanisms are responsible for permeability reduction depending on temperature and salinity.
KW - Berea sandstone
KW - Heat storage
KW - Kaolinite mobilisation
KW - Permeability reduction
KW - Temperature effect
UR - http://www.scopus.com/inward/record.url?scp=84903843617&partnerID=8YFLogxK
U2 - 10.1016/j.geothermics.2014.06.004
DO - 10.1016/j.geothermics.2014.06.004
M3 - Article
VL - 53
SP - 225
EP - 235
JO - Geothermics
JF - Geothermics
SN - 0375-6505
ER -