How SFD® Fits Alongside Conventional Geophysical Methods

Reflection seismology uses a controlled source to emit a signal into the earth and an array of receivers to capture reflections from subsurface strata. Processing and modelling produces seismic images and rock property estimates. The industry’s primary subsurface imaging tool — high resolution but high cost and long lead times. SFD® acts as a first-pass reconnaissance tool to focus seismic acquisition on the highest-potential areas, reducing the total seismic programme cost.

Aeromagnetic and Aerogravity

Magnetic and gravity data acquired from an aircraft, typically used in early-stage exploration to map basin architecture. Underlying crystalline basement rocks have higher densities than overlying sedimentary cover; processing and inversion of gravity data determines "depth to basement." Helps develop hydrocarbon source/maturity models and determine where to focus exploration. SFD® operates at a different scale — resolving prospect-level anomalies rather than basin-scale structure.

Magnetometers

Measure magnetic susceptibility of materials to aid in mapping basin architecture. Magnetic data can also map fluid conduits due to associated mineralisation effects. Complementary to SFD® — magnetics maps structure, SFD® maps fluid entrapment potential.

Gravimeters

Use accelerometers (a test mass on a spring) to measure variations in subsurface density based on gravitational acceleration between measurement points. Conventional gravimetry maps large-scale density contrasts across basin and sub-basin scales. SFD® contributes prospect-scale stress-field data that complements the broader structural picture provided by conventional gravimetry.

Uses multiple pairs of accelerometers to measure the derivative of the gravity field in all three principal axes. Measuring derivatives gives higher resolution gravity data but is inherently more sensitive to noise. Processing and inversion can locate prospect-level gravity anomalies. SFD® provides complementary information — while FTG resolves density anomalies, SFD® responds to stress field perturbations associated with fluid entrapment.

Marine surveying method that maps resistive bodies in the subsurface by transmitting a low-frequency electromagnetic signal. EM energy is quickly attenuated in conductive sediments while resistive layers (potentially containing hydrocarbons) show less attenuation. Processing produces subsurface resistivity maps. SFD® provides a different physical measurement (stress-field perturbations rather than resistivity) and operates both onshore and offshore, adding another line of evidence to the exploration programme.

Electromagnetic method imaging the subsurface by measuring natural variations of electrical and magnetic fields at the earth’s surface. Mainly used as a complement to seismic — seismic images structure but cannot detect resistivity changes associated with hydrocarbons. MT detects resistivity variations that can differentiate hydrocarbon-bearing formations. SFD® adds a third independent dataset alongside seismic and MT.