Geothermal exploration in the Perth Basin, located in Western Australia, focuses on identifying and assessing geothermal resources for potential energy production. The Perth Basin is a significant geological feature that extends from the northern part of Perth to the southern coastal areas, characterized by a series of sedimentary formations that could potentially host geothermal resources.
VEXRAD • ADR Case Study • Geothermal
Australia Geothermal — Perth Basin
Reading a hot sandstone aquifer — and its temperature — from surface at the Jingemia field in the Perth Basin, Western Australia.
EVIDENCE TIER — VALIDATED · WITH A CANDIDATE DEEP TARGETThe result
A reservoir mapped from surface — with an honest line on the deep temperature.
A hot-sedimentary-aquifer play depends on hot, porous and permeable sandstone at depth. Over the Jingemia field, ADR was used to construct a fence of Virtual Boreholes from surface and compare the interpretation with known well and seismic control. The test asked two practical questions: could ADR map the target sandstone formations, and could it estimate temperature at depth?
Calibrated at a tie point associated with the Jingemia-1 petroleum well, the ADR energy fence resolved and correlated the Wagina Formation across the survey from JT-0 to JT-800, in agreement with the seismic top-Wagina interpretation. The depth-temperature model showed a strong fit within its calibrated interval.
The brief
Can a geothermal reservoir — and its temperature — be read from surface?
The geological problem
The geothermal prospect centres on the High Cliff Sandstone at roughly 3 km. The nearby Jingemia-1 petroleum exploration well recorded porosities above 20% and a corrected temperature of approximately 123 °C — characteristics relevant to a hot-sedimentary-aquifer play.
The ADR approach
ADR uses coherent pulsed electromagnetic measurements and analyses energy, frequency and dielectric responses to construct depth-referenced subsurface interpretations. A Virtual Borehole at the Jingemia location provided a tie point to known lithology and temperature information.
Fieldwork and analysis were originally carried out under Adrok. The ADR technology, associated data and intellectual property are now carried forward and developed by VEXRAD.
What we did
A fence of Virtual Boreholes, tied to a well.
Acquisition used ADR Virtual Boreholes along a fence of stations, supported by wide-angle reflection and refraction (WARR) scans. Existing seismic supplied time-to-target control and an interpreted top of the Wagina Formation against which the ADR fence could be assessed.
Temperature was evaluated in two stages: a calibration relationship connected depth and temperature at the tie point, and that relationship was then used as a predictive model for temperature associated with ADR-picked layer depths.
Depth–temperature model
The reported relationship is tight within the calibrated interval to approximately 600 m (R² 0.9995). The approximately 3 km High Cliff estimate lies outside that training interval and is therefore treated as an extrapolation.
ADR energy fence & stratigraphy
Energy responses were interpreted against the Kockatea and Carynginia shales and the Wagina Formation across the Virtual Borehole fence. The deeper High Cliff Sandstone remained the geothermal target requiring confirmation.
Findings
Assessed against the well and the seismic.
Each finding is assigned the evidence tier supported by the available independent information.
| Finding | Evidence | Tier |
|---|---|---|
| Wagina Formation resolved and correlated across JT-0 to JT-800 | Compared with the seismic top-Wagina interpretation and the Jingemia-1 tie point | VALIDATED |
| Kockatea and Carynginia shales picked | E-ADR energy responses correspond with logged shale intervals across the fence | VALIDATED |
| Depth-temperature model within the calibrated range | Strong reported fit at the tie point: R² 0.9995, 97 d.f., p<0.001 | GROUNDED |
| High Cliff temperature at ~3 km (~123 °C target) | Extrapolated beyond the approximately 600 m training range and not independently drilled by this survey | CANDIDATE |
Honest limitations
What this case study does not claim.
- This was an early applicability test tied to a single well and seismic control; calibration contributes materially to the strength of the reservoir-mapping result.
- The temperature model was trained on relatively shallow intervals, to approximately 600 m. The approximately 3 km estimate is an extrapolation beyond that range.
- No independent deep drilling from this survey confirmed the High Cliff temperature prediction.
- No designed true-negative control was included, so the deep target is classified as Candidate rather than Validated.
- Formation depths shown in reconstructed schematics should be treated as interpretive rather than as independent drilling measurements.
We report these limitations plainly because the value of pre-drill geophysics depends on distinguishing measured evidence, interpretation and subsequent validation.
What it means for geothermal developers
Use subsurface evidence before committing the next well.
A deep geothermal well represents a major commitment to a reservoir that cannot be observed directly from surface. This case study demonstrates an ADR workflow in which reservoir-related sandstone stratigraphy was mapped against existing well and seismic control, while the deeper temperature prediction was deliberately kept at Candidate status.
The commercial opportunity is not to replace drilling. It is to use additional pre-drill evidence to improve target definition, compare locations and decide where the next physical well can create the most value.
Have a geothermal target?
Bring us one target before you drill it.
Show VEXRAD the proposed well location, reservoir target or geological question. We can assess whether ADR and a Virtual Borehole could add useful evidence before further drilling capital is committed.
ADR survey and figures originally developed under Adrok (Vol 4 “Together We Rock”; survey ref GSPA-001, Virtual Borehole VB1 / Jingemia-1, Perth Basin). VEXRAD is the successor company holding the ADR technology, data and copyright. Findings are presented under VEXRAD’s four-tier evidence framework.
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.