obtain a good estimate of the underground temperature is one
of the indispensable tasks of any geothermal development. There
are several methods to read the underground temperature (Amerada,
thermometer, etc.), but the fluid inclusion thermometry (Fig.3-1)
using homogenization temperature of fluid inclusion (Fig.3-2)
is a technique with the following advantages.
of fluid inclusions is one of the techniques for the analysis
of cores and cuttings that West JEC has developed in collaboration
temperatures can be estimated even as well drilling proceeds
as far as cuttings are recovered.
to other methods, it is possible to estimate the formation
temperature of large lost circulation zones that have been
subject to cooling because of the inflow of drilling fluids.
If such is the case and if geological samples (spot core
or cuttings) are obtained, it is possible to estimate the
formation temperature with high degree of precision (Fig.3-3).
cores and cuttings are taken and preserved, it is possible
to estimate the formation temperature of production or reinjection
wells even if temperature surveys were not taken.
the knowledge of homogenization temperatures, it is possible
to estimate not only formation temperatures but also thermodynamic
phase of the hydrothermal fluids (Fig.3-4).
Measurement in fluid inclusions is one of the techniques for
the analysis of cores and cuttings that West JEC has developed
in collaboration with New Energy Development Organization (NEDO)
for many years. Measurements in fluid inclusions are done with
the three following purposes.
1) determination of the homogenization temperatures of the fluid
inclusions to know subsurface temperature.
2) determination of the ice melting temperature of the fluid
inclusions to estimate the salinity of the fluid inclusion.
3) determination, by Laser Raman micro-spectroscopy, of the
gas composition of the gaseous components in the fluid inclusions.
West JEC continuously is improving the precision of measurements
to develop techniques where the fluid inclusions data is used
for constructing a geothermal model.