EmphaSeisTM intelligently tailors vibroseis sweeps to extend bandwidth while working within the mechanical and hydraulic constraints of the vibrator. These proprietary* customized broadband sweeps can add a combination of low and high frequencies to provide better wave penetration, finer images and improved single- and multi-component reservoir characterization.
The ability of vibroseis sources to produce a controlled, broadband seismic source wavelet is limited by a range of constraints related to the complex behaviour of the mechanical and hydraulic systems of the vibrator and its coupling.
EmphaSeis gets the most from any vibrator by using customized sweeps designed to build up energy at low and high frequencies while keeping the vibrator operating well within its capabilities.
The raw stack (on the left of the images) and the filter panels (3-7;7-14;14-72 Hz) show that the EmphaSeis sweep increases the low frequency content of the stack without reducing the amount of energy in the rest of the bandwidth. Data courtesy of Khalsa Production Company/ Apache.
EmphaSeis was recently deployed in Egypt on an existing vibroseis crew. Using the same equipment and the same sweep length (18 seconds) EmphaSeis was able to deliver an additional octave of low-frequency bandwidth from 4-6 Hz.
Drive Level (kN) vs Time (s) of the Linear sweep (6-72 Hz, in blue) and of the EmphaSeis sweep (4-72 Hz, in green). Note the tapered build-up of the low frequencies on the non-linear EmphaSeis sweep. In this case, the high frequencies were also tapered to reduce vibrations on the gravelly terrain.
The stack images show a subtle increase in the low-frequency energy which is clearly visible on the amplitude spectrum. These low frequencies contribute to the signal recovered from deeper events, improving continuity and coherency for interpretation. They will benefit various processing steps such as statics and noise attenuation and also improve the quality of reservoir models from seismic inversion.
Comparison of the 18 s sweeps showing amplitude spectra of the measured ground force. EmphaSeis adds an additional octave of bandwidth compared to the conventional linear sweep.
Leverage the broad frequency content of your data with low frequencies, free of harmonic noise, for more reliable inversion and interpretation.
Enabling quantitative interpretation with high-quality, high-density and cost-effective seismic. A fully integrated solution for onshore reservoir development.
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