Static Temperature Survey

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Exploration Technique: Static Temperature Survey

Exploration Technique Information
Exploration Group: Downhole Techniques
Exploration Sub Group: Well Testing Techniques
Parent Exploration Technique: Well Testing Techniques
Information Provided by Technique
Lithology:
Stratigraphic/Structural:
Hydrological:
Thermal: Extrapolate the true temperature of the formation the well penetrates
Cost Information
Low-End Estimate (USD): 0.2525 centUSD
2.5e-4 kUSD
2.5e-7 MUSD
2.5e-10 TUSD
/ foot
Median Estimate (USD): 0.3535 centUSD
3.5e-4 kUSD
3.5e-7 MUSD
3.5e-10 TUSD
/ foot
High-End Estimate (USD): 0.7575 centUSD
7.5e-4 kUSD
7.5e-7 MUSD
7.5e-10 TUSD
/ foot
Dictionary.png
Static Temperature Survey:
Temperature measurements downhole, made over a period of time in a non-flowing well to establish the static (“true”) formation temperature.
Other definitions:Wikipedia Reegle


 
Introduction
Due to the time constraints imposed by the economics of commercial drilling and utilization of geothermal wells, temperature logs are taken in a well during or soon after circulation of drilling fluids has taken place. During drilling operations the drilling mud and circulation of fluids cause the temperature in the well to be influenced by these external fluids, so temperatures in the well may not be at equilibrium. It can take days to several months for a well to reach its static temperature. In many cases waiting for the well temperature to reach static conditions may take too long so the static or “true” temperature of the well can be extrapolated using various numerical methods. The estimation of true formation temperature is affected mainly by the duration of fluid circulation, the process of heat transfer during drilling, and the drilling technology used.[1][2]
 
Use in Geothermal Exploration
In a geothermal well static temperature surveys are conducted to find the static or true temperature of the formation.

 
Field Procedures
Temperature logs are normally collected at various depths in the well either as drilling progresses or after completion of the well.

Static temperature estimation from a well at the Los Humeros geothermal field in Mexico. Temperature logs were taken at three different times (0 hours, 12 hours, and 24 hours) after the well was shut-in. The Line- source Horner method (stars) and the Spherical and radial heat-flow method (circles) were both conducted to estimate the static formation temperature.[2]



 
Best Practices
In order to get temperature measurements that are as close to the static temperature as possible the well must be closed off for some time so that the circulation of fluid is mitigated as much as possible.[1] There are a number of numerical simulators that attempt to reproduce the complete thermal history taking into account the drilling fluid column and surrounding formation. These simulators can be useful for estimating the static temperature without needing to wait for the well to reach equilibrium conditions. The most common numerical method for estimating static formation temperature in the geothermal industry is the line source solution known as the Horner method.[2] Other methods used are the Spherical and radial heat-flow method, and numerical simulations.[2]
 
Potential Pitfalls
Static temperature surveys are expensive and can take a lot of time so they are seldom conducted. Alternatively temperature logs are recorded during the well warm-up phase and used to estimate what the stabilized formation temperature will be.[2]








 
References
  1. 1.0 1.1 Stephen Prensky. 1992. Temperature Measurements in Boreholes: An Overview of Engineering and Scientific Applications. The Log Analyst. 33(3):313-333.
  2. 2.0 2.1 2.2 2.3 2.4 G. Espinosa-Paredes,A. García-Gutiérrez. 2003. Estimation of static formation temperatures in geothermal wells. Energy conversion and management. 44(8):1343-1355.


Page Area Activity Start Date Activity End Date Reference Material
Static Temperature Survey (Cull, 1981) Unspecified


Static Temperature Survey At Blue Mountain Geothermal Area (Fairbank Engineering Ltd, 2003) Blue Mountain Geothermal Area 1996 1997


Static Temperature Survey At Chena Area (Benoit, Et Al., 2007) Chena Area


Static Temperature Survey At Chena Area (Erkan, Et. Al., 2008) Chena Area


Static Temperature Survey At Coso Geothermal Area (1977) Coso Geothermal Area 1977 1977


Static Temperature Survey At Fish Lake Valley Area (Deymonaz, Et Al., 2008) Fish Lake Valley Area


Static Temperature Survey At Fort Bliss Area (Combs, Et Al., 1999) Fort Bliss Area


Static Temperature Survey At Glass Buttes Area (DOE GTP) Glass Buttes Area


Static Temperature Survey At Hot Pot Area (DOE GTP) Hot Pot Area


Static Temperature Survey At Kilauea East Rift Geothermal Area (Rudman & Epp, 1983) Kilauea East Rift Geothermal Area 1983 1983


Static Temperature Survey At Kilauea Summit Area (Keller, Et Al., 1979) Kilauea Summit Area


Static Temperature Survey At Lake City Hot Springs Area (Benoit Et Al., 2005) Lake City Hot Springs Area


Static Temperature Survey At Lassen Volcanic National Park Area (Janik & Mclaren, 2010) Lassen Volcanic National Park Area


Static Temperature Survey At Long Valley Caldera Geothermal Area (Farrar, Et Al., 2003) Long Valley Caldera Geothermal Area 1998 2002


Static Temperature Survey At Long Valley Caldera Geothermal Area (Farrar, Et Al., 2010) Long Valley Caldera Geothermal Area 2005 2007


Static Temperature Survey At Maui Area (DOE GTP) Maui Area


Static Temperature Survey At Medicine Lake Area (Warpinski, Et Al., 2002) Medicine Lake Area


Static Temperature Survey At Medicine Lake Area (Warpinski, Et Al., 2004) Medicine Lake Area


Static Temperature Survey At Molokai Area (Thomas, 1986) Molokai Area


Static Temperature Survey At Newberry Caldera Area (Combs, Et Al., 1999) Newberry Caldera Area


Static Temperature Survey At Reese River Area (Henkle & Ronne, 2008) Reese River Area


Static Temperature Survey At Rio Grande Rift Region (Morgan, Et Al., 2010) Rio Grande Rift Geothermal Region


Static Temperature Survey At San Andreas Region (Williams, Et Al., 2004) San Andreas Geothermal Region


Static Temperature Survey At Steamboat Springs Area (Combs, Et Al., 1999) Steamboat Springs Area


Static Temperature Survey At U.S. South Region (Smith & Dees, 1982) U.S. South Region


Static Temperature Survey At Vale Hot Springs Area (Combs, Et Al., 1999) Vale Hot Springs Area


Static Temperature Survey At Wister Area (DOE GTP) Wister Area


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