Numerical Modeling

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Exploration Technique: Numerical Modeling

Exploration Technique Information
Exploration Group: Data and Modeling Techniques
Exploration Sub Group: Modeling Techniques
Parent Exploration Technique: Modeling Techniques
Information Provided by Technique
Stratigraphic/Structural: Stress fields and magnitudes
Hydrological: Visualization and prediction of the flow patterns and characteristics of geothermal fluids
Thermal: Thermal conduction and convection patterns in the subsurface
Numerical Modeling:
A computer model that is designed to simulate and reproduce the mechanisms of a particular system.
Other definitions:Wikipedia Reegle

Numerical modeling is a computer based method for computing stresses, strains, deformations, and flows of complex objects. Usually this entails discretizing the object into small subvolumes and as such facilitates the application of the laws of mechanics (solid and fluid) for structural and fluid analysis. Examples of these techniques include finite element and finite difference methods, the former of which can be purchased in a number of prepackage codes that can be used for either linear or non-linear analyses.

The purpose of a numerical model is to reproduce the behavior of a complex system in order to learn how each mechanism affects the others and essentially make predictions about how the system will react to different variables. Numerical models have become a useful tool for modeling many natural systems that are too complex for analytical modeling methods to be used.

Use in Geothermal Exploration
A numerical model can be a very useful tool in geothermal reservoir engineering and utilization of the resource. Numerical models can be used in many aspects of geothermal utilization, a few example are: to predict the generating capacity of a reservoir, predict scaling rates in pipelines, show hydrothermal fluid flow patterns in the subsurface, map the distribution and magnitudes of stress in the subsurface, predict heat transfer in the reservoir, and predict power production based on different plant designs. This information is highly useful for optimizing power production while utilizing a reservoir in a sustainable manner. During the exploration phase of development numerical modeling can be very beneficial when determining where to drill the next production and injection wells and to determine the optimal well spacing.[1]

Data Access and Acquisition
For modeling a geothermal reservoir four main types of data need to be gathered, they are: hydraulic data, thermal data, rock structure and stress data, and chemical data.[2] All these data are related in some way to form a dynamic system and it is important to understand how each parameter affects the others when creating a numerical model. A numerical model can only be as good the data input, so it is very important that high quality and accurate data are gathered. Current up to date data are important as well as historical data for verifying predictions made by the simulation.

Four main types of data which are important to input into a numerical model of a geothermal reservoir. Each type of process and how it affects the others is very important to understand when building the numerical model.[2]

Best Practices
Prior to creating a numerical model, simple analytical models can quickly guide the modeler and determine the inputs and boundaries of the numerical model. When beginning the numerical model it is very important to run a sensitivity analysis to ensure the accuracy of the results and to make sure the results are understood properly. A base model that is properly calibrated to the area being studied should be created and verified with historical data to ensure the model is functioning as expected. High attention to detail and proper parameter calibrations are essential. Most importantly the data used in the model must be accurate; the simulation quality and predictions cannot be accurate if the input data are of poor quality.[3][4][1]
Potential Pitfalls
Relying solely on numerical models without an understanding of the simple analytical models may send the modeling team down the wrong path. Numerical models are very complex and if proper quality controls aren’t applied or unrealistic assumptions are made the simulation model will produce inaccurate results and not be a useful prediction tool. Depending on the scope of the model, the methodology used, and modeling theories, conflicts and errors can occur. In some cases modeling errors can be extremely difficult and time consuming to correct.[3][4]

  1. 1.0 1.1 Karsten Pruess. 1990. Modeling of Geothermal Reservoirs: Fundamental Processes, Computer Simulation and Field Applications. Geothermics. 19(1):3-15.
  2. 2.0 2.1 Mauro Cacace,Björn Onno Kaiser,Yvonne Cherubini. N/A. Numerical Modelling of Geothermal Systems a Short Introduction. N/A. Helmholtz Association. N/Ap.
  3. 3.0 3.1 Thomas J. Santner,Brian J. Williams,William I. Notz. 2003. The Design and Analysis of Computer Experiments. New York: Springer-Verlag. N/Ap.
  4. 4.0 4.1 Jerome Sacks,William Welch,Toby Mitchell,Henry Wynn. 1989. Design and Analysis of Computer Experiments. Statistical Science. .

Page Area Activity Start Date Activity End Date Reference Material
Numerical Modeling At Coso Geothermal Area (1995) Coso Geothermal Area 1995 1995

Numerical Modeling At Coso Geothermal Area (1997) Coso Geothermal Area 1997 1997

Numerical Modeling At Coso Geothermal Area (1999) Coso Geothermal Area 1999 1999

Numerical Modeling At Coso Geothermal Area (2000) Coso Geothermal Area 2000 2000

Numerical Modeling At Coso Geothermal Area (2006) Coso Geothermal Area 2006 2006

Numerical Modeling At Coso Geothermal Area (2007) Coso Geothermal Area 2007 2007

Numerical Modeling At Coso Geothermal Area (2010) Coso Geothermal Area 2010 2010

Numerical Modeling At Dixie Valley Geothermal Area (Benoit, 1999) Dixie Valley Geothermal Area 1986 1986

Numerical Modeling At Dixie Valley Geothermal Area (Iovenitti, Et Al., 2013) Dixie Valley Geothermal Area 2012 2012

Numerical Modeling At Dixie Valley Geothermal Area (McKenna & Blackwell, 2003) Dixie Valley Geothermal Area 2003 2003

Numerical Modeling At Lightning Dock Geothermal Area (O'Brien, Et Al., 1984) Lightning Dock Geothermal Area

Numerical Modeling At Neal Hot Springs Geothermal Area (U.S. Geothermal Inc., 2012) Neal Hot Springs Geothermal Area 2011 2011

Numerical Modeling At Raft River Geothermal Area (1983) Raft River Geothermal Area 1983 1983

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