The role of geological surveys in ground source drilling projects

Ground source energy systems have gotten a lot more popular in recent years. From home owners to industrial operators, they can provide access to sustainable, low-cost heat and even electricity sources.

One of the main costs and logistical complications associated with these kinds of projects is the drilling process. Below, we explore the central role of geological surveys in geothermal ground source drilling projects, from their impact on assessing geological stability to their importance in achieving regulatory compliance.

Assessing geological stability

One of the main factors that a geological survey will assess in the context of ground source drilling projects is the general ground condition. 

An important part of this will lie in identifying the subsurface conditions and the exact material that needs to be drilled through. For example, the drilling team will need to use different drill bits if they’re drilling through clay, compared to granite. 

This will allow the team to optimise the design of the drilling process and loop system, based on how efficient it will be to drill to certain depths. 

Analysing thermal performance

Geological surveys also allow an in-depth analysis of thermal performance. Different ground types and subsurface conditions will have different thermal capacities – certain granites, for example, can be much warmer than gravelly or sandy soils. 

The depth that you’ll need to drill to in order to attain the desired heating output will partially be determined by the findings of these analyses, and it’s important that you have the survey conducted by a knowledgeable team with the right equipment.

Identifying hazards

There are a number of potential hazards associated with borehole drilling, and having a geological survey conducted is necessary to identify and mitigate those hazards.

Potential risks that surveys might help avoid include drilling into unstable soil, unearthing buried toxic waste, or stumbling into an old mine or tunnel network, all of which can result in massive unexpected costs and delays.  

There’s also the risk of running into trapped gas pockets, which can result in mini blowouts or even explosions. Drilling teams will need to take precautions against these events when carrying out the project.

Ensuring regulatory compliance

There are also a number of regulatory frameworks and bodies that govern how boreholes must be planned, located and drilled in England, Wales and Scotland. 

Surveys can be used to detect potential interference and contamination risks with groundwater aquifers, for example, to help meet Environment Agency compliance guidelines.

Depending on what’s found during the course of the survey, different planning applications may need to be submitted to a variety of government bodies. An experienced borehole drilling consultant will be able to advise further on this. 

A geological survey is an absolute must-have for anyone considering investing in a ground source heat pump. Not only are they essential for the safe planning of a borehole drilling project, but they will also result in a more efficient, longstanding ground source heat system with a more predictable long-term output.