Fluid Inclusion Analysis

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Exploration Technique: Fluid Inclusion Analysis

Exploration Technique Information
Exploration Group: Lab Analysis Techniques
Exploration Sub Group: Fluid Lab Analysis
Parent Exploration Technique: Fluid Lab Analysis
Information Provided by Technique
Lithology:
Stratigraphic/Structural:
Hydrological: Fluid composition at a point in time and space
Thermal: The minimum temperature of fluid inclusion formation
Cost Information
Low-End Estimate (USD): 17.571,757 centUSD
0.0176 kUSD
1.757e-5 MUSD
1.757e-8 TUSD
/ sample
Median Estimate (USD): 17.571,757 centUSD
0.0176 kUSD
1.757e-5 MUSD
1.757e-8 TUSD
/ sample
High-End Estimate (USD): 26.782,678 centUSD
0.0268 kUSD
2.678e-5 MUSD
2.678e-8 TUSD
/ sample
Time Required
Low-End Estimate: 2 weeks0.0383 years
336 hours
14 days
0.46 months
/ job
Median Estimate: 2 weeks0.0383 years
336 hours
14 days
0.46 months
/ job
High-End Estimate: 4 weeks0.0767 years
672 hours
28 days
0.92 months
/ job
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Fluid Inclusion Analysis:
Fluid inclusions are microscopic entrapments of fluid (vapor or liquid) and occasionally mineral crystals, that are considered to represent the chemical and physical properties of a hydrothermal fluid at a single point in time and space.
Other definitions:Wikipedia Reegle


 
Introduction
Fluid inclusion analysis is often regarded as an art because it requires painstaking attention to details and locations of microscopic entrapments of fluid and relative textures. Mineral textures are often the only way to determine the timing of one fluid inclusion vs another. There are primary fluid inclusions which occur along crystal growth zonation boundaries, secondary fluid inclusions form after crystal growth and along microfractures, and pseudosecondary fluid inclusions form along microfractures but before the final stages of crystal growth (Goldstein and Reynolds, 1994).
 
Use in Geothermal Exploration
Fluid inclusions can be a valuable tool for characterizing a hydrothermal system’s fluid chemistry, fluid evolution, and temperature.
 
Related Techniques

Fluid Inclusion Stratigraphy
Fluid Inclusion Stratigraphy (FIS) is a patented technology, which provides a means of analyzing organic and inorganic fluid species within fluid inclusions trapped in cuttings, core or outcrop samples. The technology delivers a unique view of petroleum and diagenetic processes operating from basin to reservoir scale.
  • Characteristics and Distribution of Mineral Textures and Fluid Inclusions in the Epithermal Ag-Au Deposits at Guanajuato, Mexico [1]



 
Data Access and Acquisition
Depending on what the fluid inclusion looks like it is possible to determine the approximate conditions in which it formed. If there is a halite crystal within the inclusion at room temperature, it is inferred that the fluid contains more than 26 wt% NaCl. If the vapor bubble is small, it can be assumed that the fluid originated from a liquid-like fluid because of its relatively high density. If the vapor bubble is very large, it can be inferred that the fluid was derived from a vapor-like fluid because of its relatively low density. The conditions of a minimum temperature of formation for a particular fluid inclusion (or assemblage) can be determined by heating the fluid inclusion to its homogenization temperature. The homogenization temperature is a temperature at which the bubble within the fluid inclusion disappears and all that remains is a single phase fluid. At that particular temperature there is an isochore (line of constant density) that can be projected from the liquid-vapor line on a temperature vs pressure phase diagram. If the pressure conditions are well constrained and appropriately estimated then the temperature of entrapment can be found where the isochore crosses the estimated pressure value.
To determine the salinity of the fluid, the fluid inclusion (or assemblage) must undergo freezing, usually below the eutectic temperature. As the temperature of the fluid inclusion drops and eventually freezes completely, the vapor bubble will deform and possibly move slightly. After freezing, the sample is gradually heated, the first melting occurs at the eutectic temperature which is representative of the fluid-salt composition. This can be determined by the vapor bubble “unlocking” from the frozen liquid and returning to its normal shape. Continued heating leads to the last bits of ice to melt, the temperature at which the last ice crystals melt can determine the weight percent of salt in the fluid using a salt vs temperature phase diagram.
 
Best Practices
Only have a qualified fluid inclusionist analyze the samples. Know the samples and the system they came from. Make sure the observations in the fluid inclusion analysis align with what is known of the hydrothermal system.
Plot the data properly so that each fluid inclussion assemblage is discernable, becasue each assemblage represents a different period of fluid evolution.
 
Potential Pitfalls
Having an unqualified fluid inclusionist analyze the sample and generate inaccurate data. It is very easy to misinterpret fluid inclusions and get data that is not representative of the true fluid composition or evolution. It is important to recognize that a fluid inclusion assemblage represents a single fluid’s physical and chemical properties at that particular point in time and space. While a fluid inclusion assemblage immediately adjacent could have very different chemical and physical characteristics representing a different fluid from a different point in the evolution of the hydrothermal system.






 
Additional References
Pressure vs Temperature phase diagram showing a hypothetical fluid inclusion while increasing temperature. The isochore is projected from the homogenization temperature.

Temperature vs NaCl concentration phase diagram. Points 1-4 show the varying concentrations of NaCl and the different phases occurring during the temperature experiment.


Page Area Activity Start Date Activity End Date Reference Material
Fluid Inclusion Analysis (Klein, 2007) Unspecified


Fluid Inclusion Analysis (Norton, 2002) Unspecified


Fluid Inclusion Analysis At Chena Geothermal Area (Kolker, 2008) Chena Geothermal Area 2005 2007


Fluid Inclusion Analysis At Coso Geothermal Area (1990) Coso Geothermal Area 1990 1990


Fluid Inclusion Analysis At Coso Geothermal Area (1996) Coso Geothermal Area 1996 1996


Fluid Inclusion Analysis At Coso Geothermal Area (1999) Coso Geothermal Area 1999 1999


Fluid Inclusion Analysis At Coso Geothermal Area (2002) Coso Geothermal Area 2002 2002


Fluid Inclusion Analysis At Coso Geothermal Area (2003) Coso Geothermal Area 2003 2003


Fluid Inclusion Analysis At Coso Geothermal Area (2004) Coso Geothermal Area 2004 2004


Fluid Inclusion Analysis At Coso Geothermal Area (2004-2005) Coso Geothermal Area 2004 2005


Fluid Inclusion Analysis At Coso Geothermal Area (2005-2006) Coso Geothermal Area 2005 2006


Fluid Inclusion Analysis At Coso Geothermal Area (Norman & Moore, 2004) Coso Geothermal Area 2004 2004


Fluid Inclusion Analysis At Dixie Valley Geothermal Area (Dixon, Et Al., 2003) Dixie Valley Geothermal Area 2003 2003


Fluid Inclusion Analysis At Dixie Valley Geothermal Area (Lutz & Moore, 1998) Dixie Valley Geothermal Area 1998 1998


Fluid Inclusion Analysis At Geysers Area (Moore, Et Al., 2001) Geysers Area


Fluid Inclusion Analysis At Geysers Geothermal Area (1990) Geysers Geothermal Area 1990 1990


Fluid Inclusion Analysis At International Geothermal Area Mexico (Norman & Moore, 2004) International Geothermal Area Mexico


Fluid Inclusion Analysis At Lightning Dock Area (Norman & Moore, 2004) Lightning Dock Area


Fluid Inclusion Analysis At Raft River Geothermal Area (2011) Raft River Geothermal Area 2011 2011


Fluid Inclusion Analysis At Salton Sea Geothermal Area (1990) Salton Sea Geothermal Area 1990 1990


Fluid Inclusion Analysis At U.S. West Region (Laney, 2005) U.S. West Region


Fluid Inclusion Analysis At Valles Caldera - Redondo Geothermal Area (Sasada, 1988) Valles Caldera - Redondo Geothermal Area 1988


Fluid Inclusion Analysis At Valles Caldera - Sulphur Springs Geothermal Area (Sasada & Goff, 1995) Valles Caldera - Sulphur Springs Geothermal Area 1995


Fluid Inclusion Analysis At Valles Caldera Geothermal Region (1990) Valles Caldera Geothermal Region 1990 1990


Fluid Inclusion Analysis At Yellowstone Region (Sturchio, Et Al., 1990) Yellowstone Caldera Geothermal Region


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