Seismic acquisition and processing

Description

This course proves an in-depth overview of the main principles and steps of seismic acquisition and processing for exploration purposes:

1.      Seismic reflection method principles: wavefronts and seismic rays in homogeneous media; P and S waves; Snell’s law; arrival-time vs offset equations; acoustic impedance; reflection coefficients; amplitude and frequency of seismic traces; vertical and lateral resolution.

2.      Seismic acquisition: land acquisition (sources, receivers, transmitter, onshore specifics); marine acquisition (towed streamer, wide azimuth, ocean bottom seismic, broadband); wellbore seismic (VSP, check-shot); 4D seismic; from shot-point to common mid-point (fold of coverage, bin).

3.      Pre-processing: 5D regularization; amplitude loss compensation; noise attenuation and removal; source de-signature.

4.      Time-processing: normal move-out principles; velocity scan; stack and its impact on multiples; seismic velocities (average, stacking/normal move-out, root-mean-square, interval).

5.      Migration principles: why migration?; the blind geophysicsist experiences; different types of seismic rays (normal, zero-offset); building the time image from a simple depth model; effects of migration (repositioning and focusing the image).

6.      Time and depth imaging: different times of migration (2D vs 3D, post vs pre-stack); pre-stack time migration vs pre-stack depth migration; velocity model building; migration algorithms (ray based, wave-equation based); anisotropy and full-waveform inversion; seismic acquisition and processing costs.

Compétences requises

Seismology and seismics class covering seismic waves, Snell’s Law, basic refraction and reflection seismology.

Autres contacts

Dominique Amilhon