EmphaSeis intelligently tailors sweeps to extend bandwidth while working within all the mechanical constraints of the vibrator. These customized broadband sweeps add both low and high frequencies, including an important extra octave of low-frequency signal, offering better wave penetration, finer images and improved 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 Sercel-equipped vibrator by using customized sweeps designed to build up energy at low and high frequencies while keeping the vibrator operating well within its capabilities.

A shot record is shown (left) with a 20-25 Hz low-pass and a red line to indicate the reflection arrivals.  Conventional sweep data (center) are compared to EmphaSeis data (right) after an FK filter to suppress ground roll and a 3-7Hz low-cut filter to highlight the increased low-frequency content.

Features:

• Additional octave or more of low frequencies with sweeps starting as low as 1 Hz
• Extended high frequency content
• Maximizes overall vibrator energy output
• Intelligently designed vibrator-specific sweep and sweep tapers accounting for:
  • Mass stroke constraint
  • Hydraulic flow constraints
  • Servo-valve constraints
• Combine with HPVA technology to remove slip-sweep harmonic noise
• Compatible with Sercel VE464/432 vibrator electronics

Benefits:

• High-resolution broadband wavelet for easier interpretation
• Better penetration and imaging of deep and shallow targets
• Improved reservoir characterization

Ground Force for a 2-80Hz EmphaSeis sweep (green) and a 5-80Hz conventional sweep (blue).  EmphaSeis adds more than one octave of low frequencies.	Test borehole geophone spectrum comparison showing a 15dB uplift in signal at 3Hz with the EmphaSeis sweep (green).