The technology provides new data for exploration risk reduction, field development and production decisions by analyzing frequencies below the range of conventional seismic geophones.

Spectraseis acquires high-quality new recordings of the seismic waves which continuously propagate in the Earth’s crust using arrays of high sensitivity, low noise three-component velocity sensors deployed at the surface over a survey area.

The resulting data is processed to remove unwanted signals. Spectral analysis and attribute calculations are performed to generate profiles and maps indicating likely hydrocarbon-bearing zones within the survey area.

This information can be used as a primary tool for early exploration and field development decisions. It can also be integrated with complementary sources of geological and geophysical data, such as 2D/3D active seismic, borehole and production data, to upgrade an operator’s understanding of the subsurface and improve decision-making throughout the life-cycle of a field.

Sophisticated numerical techniques, such time reverse modeling, can be applied to LF data to localize the source of spectral anomalies originating at the reservoir and thereby image hydrocarbon deposits at depth.

The existence of spectral characteristics in low frequency wavefields correlated with hydrocarbon reservoirs has been established at numerous locations around the world. The precise physical mechanisms at play are still the subject of active research.

LF data was integrated with a conventional seismic velocity profile to image this sandstone oil reservoir. The reservoir is seated on basement rock at a depth of approximately 1700m. A second, more recent oil discovery was also imaged using the same technique. 

Strong candidates include resonant amplification occurring at the pore scale within the reservoir and, at the macro scale, resonant scattering due to complex impedance contrasts between hydrocarbon-bearing rocks and the surrounding media.

LF passive seismic technology is feasible today because of the availability of portable broadband sensors capable of recording rich seismic data as low as 0.001 Hz and advances in signal processing and analysis methods in the low frequency domain pioneered by Spectraseis and its research partners.

Broad adoption by the exploration and production industry can be expected to help save billions of dollars which is currently spent each year on non-productive exploration surveys and drilling dry wells.