Water • Groundwater • Scotland
Finding known aquifer intervals from the surface.
Terregles, Dumfries · a groundwater case study comparing ADR responses with downhole information over known fracture-controlled aquifer intervals.
VALIDATED AGAINST KNOWN CONTROLused to investigate repeatability across Virtual Boreholes.
used as downhole control.
with reported ADR offset of about 1–2 m.
The question
Could ADR identify known water-bearing fractures?
The Terregles work was designed to test ADR against a groundwater setting where independent borehole information was already available. The site lies in the Dumfries Basin, an important Scottish groundwater resource.
The aquifer system includes the Permian Doweel Breccia and Locharbriggs Sandstone. In the Doweel Formation, low intergranular permeability is accompanied by secondary permeability associated with fractures, making known water-bearing fracture intervals a useful test of the ADR response.
Why this is useful evidence
This was not simply a search for an unknown anomaly. Known downhole information provided a reference against which the surface-acquired ADR response could be compared.
That prediction/control relationship is central to VEXRAD’s evidence-led approach today.
Survey design
Three nearby locations. One aquifer system.
Surface acquisition
ADR data were acquired at three closely linked survey sites at Terregles, Dumfries.
Independent control
Downhole logs supplied information on subsurface water flow and saturation for comparison.
Repeatability test
The interpretation was extended across the other Virtual Boreholes to investigate whether the water-bearing intervals could be correlated laterally.
The result
ADR responses closely matched the known aquifer intervals.
High dielectric responses and peaks in Weighted Mean Frequency were reported close to the known fracture zones and associated aquifers.
Downhole control ↔ ADR response
Reported depth correspondence: approximately 1–2 m around the known fracture/aquifer intervals.
What the project demonstrates
Useful groundwater intelligence is more than a “water detected” claim.
Depth
The comparison tests whether the interpreted response occurs at the depth of known water-bearing intervals.
Repeatability
Multiple nearby Virtual Boreholes allow the interpretation to be investigated across the site rather than at one point alone.
Ground truth
Downhole information provides the physical reference needed to assess whether the interpretation is useful.
Where it sits today
From legacy fieldwork to the VEXRAD evidence standard.
The original fieldwork and analysis were carried out under Adrok. VEXRAD carries the ADR technology and associated methods forward and reports legacy case studies using a clearer evidence standard: what was independently controlled, what was interpreted, and what remains outside the evidence.
Supported here
- Known groundwater/fracture intervals available for comparison
- ADR response correspondence around those intervals
- Multiple nearby survey locations
- Reported ~1–2 m offset around the known intervals
Not claimed here
- Prediction of sustainable borehole yield
- Water-quality determination
- Aquifer resource-volume estimation
- Universal performance in different geological settings
Provenance: legacy Terregles, Dumfries groundwater work carried out under Adrok; ADR technology and methods carried forward and developed by VEXRAD Ltd.
See before you drill
Have a groundwater target?
Start with the geology, existing borehole information and the decision you need to make. VEXRAD can assess whether an ADR Virtual Borehole programme could add useful evidence before drilling.
What could ADR show at your target?
Every geological setting is different. This case study demonstrates evidence from a particular project; it does not guarantee the same result elsewhere.
If you have a target, existing geoscience or a proposed drill location, start with a free VEXRAD Project Fit Check. We will review whether ADR appears technically relevant before recommending further work.
No commitment to a field programme is required to submit a Project Fit Check.