Success Stories

March 16, 2010

Figure 1: 3D View of the Geothermal Site

Numerical modeling of geothermal processes has received increased attention in recent years. The process of installing geothermal heating systems in residential homes and cottages is one application of numerical models. These systems typically involve drilling between one and three wells on a particular property. Heat exchangers then act as a pump and remove heat from the ground in order to heat the residential structure. Such systems have significant potential benefit in reducing long-term heating costs, but they raise the question of what impact they have on the geothermal systems in the ground over the long term.

Brad Ford recently contacted SoilVision Systems Ltd. to perform numerical modeling of an existing geothermal heating system under an acreage-type property. Known parameters for this scenario included:

  • Six geothermal wells drilled to accommodate the geothermal heat-exchange process
  • Heat pumping rates for each of the wells
  • Air temperature for the area
  • General geo-strata geometry and thermal properties
  • Water table elevations for the area

The site has an overall flow of water in an aquifer across the property and down to a river, which is located a few hundred meters from the property. The aquifer flows through all six drilled geothermal wells and therefore the correct numerical modeling must include the convective heat transfer as the "coldness" surrounding the geothermal wells is carried downstream by flow from the aquifer.

The system may be represented as shown in Figure 1, above, which illustrates the dimensions of the property as well as the direction of flow of the aquifer and the six geothermal wells.

The system was modeled with the coupled SVHeat and SVFlux finite element software packages. These packages offer fully coupled convective and conductive heat flow analysis and can also model the transition between frozen and unfrozen zones. These aspects of numerical modeling are important for this type of application, as the temperature regime around the installed geothermal wells is influenced by both conductive and convective heat movement.

The difficulty with numerical modeling of this type of system are the sharp gradients directly adjacent to each well. These sharp gradients require a significantly refined mesh adjacent to the geothermal wells. Such a system is difficult to model in a finite difference type of structure such as MODFLOW and efforts to model this system in a finite difference system were attempted but were ultimately unsuccessful.

Once the system is set up in the SVHeat / SVFlux coupled software, the model may be run in a steady-state (infinite time) or transient state manner. This would determine if:

  • Enough heat would be drawn from the ground so as to create a permanent frozen zone, and
  • What would be the influence of the flowing aquifer on the thermal zone around the wells.

The 3D plotting of the temperature contours can be seen in Figure 2, below. This model takes into account both conductive and convective heat flow. The iso-surface for a temperature of zero degrees is plotted in the model to show the growth of the freezing front after 50 days. It can be seen that the influx of "warm" aquifer water causes a reduction in the frozen zone deeper in the wells. It is therefore possible to quantify the potential influence of the heat contribution from an aquifer, as opposed to only having ground conductance.


Figure 2: Plot of Temperature Distributions of Convection Transient Analysis

Figure 3 further illustrates the influence of the convective aquifer flow on the thermal regime. "Warm" water from the aquifer flows across the lower portions of the geothermal wells and carries the lower temperature water away from the wells. The aquifer has the net effect of increasing the amount of heat that can be pumped from the ground in this situation.

This application illustrates the use of SVFlux and SVHeat to model geothermal systems. Numerical modeling is a useful tool which can answer the following questions regarding geothermal systems:

  • To what extent will a geothermal system impact the surrounding temperature regime?
  • How will local groundwater flows influence the system?
  • How large of a frozen zone will be created in northern locations?
  • How many wells should there be and what should be the reasonable spacing between wells?

Models similar to the one shown here are available in our free SVOffice 2009 STUDENT version download. They are available in the "GeoThermal" project as WellHeatExchanger_SS_Cond, WellHeatExchanger_T_Cond, WellHeatExchanger_SS_Conv and WellHeatExchanger_T_Conv.


Figure 3: 2D Slice Plot of Temperature Distribution of Convection Transient Analysis

I do think this type of modeling should be more routinely done and until now there has not been an easy way of doing this. Beyond a few hiccups in setting up the model (mostly lack of CAD software experience on my part) and then the subsequent setting up and understanding of physical properties and units (small learning curve) the model ran and calculated quickly with good visual results. I would have no reservations in recommending SVHEAT heat modeling to better understand heat flow into borehole heat exchangers in a residential geothermal installation. This understanding can be applicable to borehole spacing and depth of drilling for any particular ground and aquifers that intersect the boreholes.

Brad Ford, P.Geol.

If you are interested in this type of analysis, please contact us directly for more information.


  • "I would like to thank you for all the support and the interest that I got from your team regarding this matter. I was able to successfully finish my project with the help of your technical support and managed to graduate achieving a high grade on the project I did. The software is extremely helpful and wasn't complicated and I look forward to future for more work and experience with your software. Thank you for your help and support."
  • "I have been using SoilVision's SVOFFICE™ software for research and training purposes for a number of years now. Myself and my colleagues have developed a number of training modules in this software, and have been using these to teach limit equilibrium and flow modeling to undergraduate students in the civil, environmental and mining engineering streams.

    In my opinion, this software is easy to learn and fun to use. The built-in tutorials are sufficient to get one started. With these tutorials, my students were generally able to complete their analyses with minimal involvement on my side.

    Based on my own experience, it takes around a month of full-time use to become reasonably competent with the software (provided that one understands the theoretical underpinnings of this type of analysis) - a short learning curve, compared to other products of similar complexity. The interface is intuitive enough for me to figure out things on my own, and I rarely had the need to ask for help.

    I don't generally like praising anything excessively, and I don't post particularly glowing reviews for anything. Having said that, I must mention the SoilVision support. At some point during my research, I was conducting a number of replication studies for my thesis. In that period, I must have emailed SoilVision's support anywhere from 2 to 5 times a day, with fairly complex (and sometimes very dumb) questions. I always got a response by the end of the day, and a resolution within a couple days at most. In a number of urgent cases (such as during a tutorial session with a classroom of students) I called them directly on the phone and, with senior product engineers involved, had the issue addressed in minutes."
  • "We have allowed our students the choice of using multiple Geotechnical software suites in our Dam Design and other Geotechnical courses. Our students consistently gravitate towards SoilVision software as being the most modern and user-friendly."

  • "I've been a geotechnical engineer for more than 25 years and SoilVision has the best tech support I have ever worked with. I truly appreciate their patience and help over the past year."

  • "Peter Brett Associates have been looking to update our existing slope stability software over the last year. After extensive research and trials, SVSLOPE® developed by SoilVision Systems Ltd. was found to meet all our existing and future design requirements. Its ease of use for modeling simple as well as complex geological and geometrical problems was a critical factor in our assessment as well as the incorporation of design to the Eurocodes. Their customer support has been faultless and their willingness to develop the software to meet our own specific design requirements is a most gratifying added bonus."

    "We love the fact that SVSLOPE® is part of an integrated suite of software and that, if required, 3D analysis can be undertaken. We would recommend this product to other geotechnical consulting firms."

  • "We have been using SVSLOPE® and SVFLUX™ for the past year and have found them to be efficient and productive engineering tools which have allowed us to offer our services in an efficient manner. The capability of automated increased discretization of the mesh is an absolute benefit to our modeling, reducing time and effort. We have found the software quick and easy for our engineers to train and utilize. I would recommend this product to other geotechnical consulting firms."

  • "The software is well documented and comes with number of useful example models. We were able to quickly begin creating models after a short review of the user interface and going through the available on-line webinars. The software offers solid benefits of less conservatism and the ability to model real geometry."

  • "This new software for stability analysis includes a number of state-of-the-art options for probabilistic slope stability analysis. This feature, combined with comprehensive deterministic analyses, will provide new opportunities to build confidence in the results of a site-specific analysis.”

  • "I'm excited to see the release of this new and innovative product. I look forward to and encourage the application of this software on additional geotechnical projects.”

  • "In consulting engineering practice, I am increasingly made aware of the important and beneficial role that modeling the unsaturated soil zone can play in providing the client with the best possible engineered solution. The SoilVision software has made it possible to readily estimate and incorporate unsaturated soil properties into the modeling of saturated / unsaturated soil systems.”

  • "The use of SVSLOPE® software as part of a research project on clay slopes under seismic conditions with the Université de Sherbrooke has been incredibly easy and effective. The continuation of this research with SoilVision is promising, with technical support, which was present at the right time, as well as a passionate geotechnical team supporting the project.”

Our industry defining software will change the game for your firm