The Low-Frequency Seismic Sounding method (LFS) is based on the natural seismic background spectrum analysis at low-frequency range (1-10Hz).
Theory of LFS method is based on mechanics of fluid-saturated, fractured and porous media. Behaviour of microseisms shows monotonous distribution of the seismic energy along the spectrum in homogenous geological environment. Geological inhomogeneities, such as crystalline basement, tectonic faults, hydrocarbon deposits and salt formations, induce re-distribution of the seismic energy in spectrum which occurs of clearly defined peaks in the spectrum.
Spectral peaks of the seismic energy generated by the various geological inhomogeneities have different distinguishing features. Thus, oil-saturated reservoir generates a strong anomaly which enables us to estimate the fluid saturation of a reservoir.
Analysis of seismic energy peaks distribution over the survey area allows us to define zones with different geologic structure.
Stages of LFS method
Low-Frequency Seismic Sounding investigations include field surveys, data processing and interpretation.
Modifications of field surveys:
- line (250 m, 500 m and more)
- grid (250x250 m, 500x500 m and more)
Processing is carried out using our original software involving calculation procedures that enable to effectively extract the signal against anthropogenic and natural noises. The procedures include both classic signal processing algorithms based on Fourier analysis and correlation techniques, as well as methods based on wavelet analysis.
Numerical simulations enable us to forecast behaviour of microseismic field for certain geological conditions and to compare simulated and real spectral curves, increasing the reliability of data interpretation.
LFS survey allows to identify and stratify hydrocarbon deposits in geological section. The LFS signal is calibrated using measurement on nearest wells with known fluid saturation.
The main result of LFS survey is a map of oil & gas potential zones for the surveyed area.
Download LFS technology brochure