TITLE:
Thermo-Physical and Mechanical Properties of Al Hashimiyya Basaltic Rocks, Jordan
AUTHORS:
Sana’a Al-Zyoud
KEYWORDS:
Thermo-Physical Properties, Mechanical Properties, Basalts, Al Hashimiyya, Jordan
JOURNAL NAME:
International Journal of Geosciences,
Vol.10 No.2,
February
28,
2019
ABSTRACT: Geothermal exploration in northern Jordan is in juvenile phase.
North eastern basaltic desert is expected to host, with other rock formations,
a shallow geothermal field. For efficient geothermal potential evaluation, a
complete understanding of thermo-physical properties of deep reservoir rocks is
of utmost importance. Due to the complex technical thermo-physical evaluations of basalts in depth, surficial basalts extending to the west were evaluated. Accordingly, six basaltic sub-flows from Al Hashimiyya were
examined into their thermo-physical and mechanical properties. The flows
represent the western extinction of large olivine basalt eruption. Different
properties were evaluated for oven dried samples: thermal
conductivity, permeability, porosity, density and specific heat capacity. In
addition, basalts mechanical properties were examined: compressional wave velocity, unconfined
compressive strength, indirect tensile strength and point load tests. The
results were correlated in proportional patterns. They indicated that thermal
conductivity of the studied basalts is dependent on porosity and permeability
in parallel with mineral composition. It’s found that mechanical properties are
controlled by porosity and permeability, too. The studied basalt properties
exhibit slight deviation from the continental basalts thermo-physical and
mechanical properties reported in the region. Thermal conductivity ranges
between 1.89 and 1.32 W·m-1·K-1,
whereas the porosity and permeability averages at 10.64% and 9.75899E-15
m2, respectively. Additionally, unconfined compressive strength
averages at 104.9 Mpa and it’s almost 20 times higher than indirect tensile
strength which ranges from 8.73 to 2.21 Mpa. As the samples were tested under
laboratory conditions, in situ conditions will not be reflected by
such values. At greater depth, temperature, pressure and hydrothermal
activities will certainly affect rock properties. Micro fractures, whether it will be filled or not, will
affect basalts properties, too. The results of this work will be used to develop a
comprehensive thermo-physico-mechanical model, and improve the ability to
predict rock properties at greater depths of Jordanian basalts.