SFD® Technology
Airborne Detection of
Subsurface Fluid Entrapment
Overview
Stress Field Detection (SFD®)
Stress Field Detection (SFD®) is NXT’s patented airborne survey technology. It responds to subsurface conditions associated with fluid entrapment in reservoir rock — providing an independent line of evidence that complements seismic, magnetics, and EM data.
What SFD Detects
What SFD® Responds To
SFD® responds to subsurface stress field perturbations and pore pressure conditions associated with fluid entrapment in porous reservoir rock. The resulting anomaly patterns relate to trap configuration, reservoir quality, and seal presence at prospect scale.
SFD® provides information on changes in subsurface homogeneity relating to fluid entrapment — an independent dataset that complements structural and stratigraphic methods.
How It Works
From Aircraft to Prospect Map
We capture high-resolution SFD data in flight, analyze it through independent pattern recognition, and deliver ranked anomalies with integrated maps to guide exploration decisions.
Fly
The SFD® system is self-contained and compact, deployed aboard a Citation 560 jet. Multiple sensor elements capture data simultaneously across customised grid patterns designed around the client’s exploration objectives.
Analyse
NXT’s team interprets signal patterns across all sensors and flight lines — blind, with no a priori knowledge of subsurface conditions. Anomalies are identified through pattern recognition and correlated against NXT’s global library of signal templates. Target anomaly size: 2–20 km linear extent.
Rank & Deliver
Each identified anomaly is assigned a dual ranking: a trap quality score (1 to 2+) and a reservoir quality grade (C to A+). The final SFD® Recommendations Report includes annotated sensor response curves, anomaly maps, and an integrated prospectivity map of the entire survey area.
The Science
The Science Behind SFD® Detection
SFD® sensors generate continuous wave-based signal patterns as the Citation 560 jet traverses the target area. Analysis of these patterns reveals subsurface conditions associated with:
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Stress field perturbationsChanges in horizontal principal stresses around fluid accumulations
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Pore pressure responseCharacteristic of reservoirs with increasing pore pressure and permeability
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Subsurface homogeneity changesContrasts between fluid-filled porous rock and surrounding formation
These conditions are associated with geological features at reservoir scale — anticlines, fault blocks, carbonate bank edges, channel systems, and overpressured zones.
Exploration Workflow
Where SFD® Fits in the Exploration Workflow
No single geophysical method can resolve the non-uniqueness of earth models alone. SFD® is designed to work alongside seismic, gravity-mag, EM, and well data — adding an independent dataset early in the exploration sequence.
The five critical petroleum system elements are source rock, migration, trap, reservoir, and seal. SFD® survey deliverables provide information relevant to three of these — trap configuration, reservoir quality, and seal integrity — giving explorationists an additional dataset to inform prospect evaluation.
Output & Deliverables
Anomaly Maps, Ranked Lead Areas, Prospectivity Maps
Every SFD® survey concludes with a formal Recommendations Report. You receive anomaly maps, dual-ranked lead areas (trap quality + reservoir quality), and integrated prospectivity maps with hot-to-cold colour grading. All outputs are designed to integrate directly into existing G&G workflows.