INTRODUCTION

• Seismic in the Exploration-Production Workflow
• The main steps of the seismic workflow: Acquisition, Time Processing, Depth Imaging, Interpretation
• Objectives of seismic interpretation:  3D geological model building , volumes, risks and uncertainties, well placement

PRINCIPLES OF THE SEISMIC REFLECTION METHOD

• Reminder of the fundamentals of the seismic signal: Dirac, Fourier transform, f-K filtering, convolution deconvolution, amplitude, frequency, phase,…
• Wavefront and seismic rays in a homogeneous medium
• P and S waves, different types of seismic waves in a stratified medium.
• Geometry of seismic rays propagation, Snell-Descartes law
• “Time of arrival vs. Offset” equation for direct and reflected waves
• Acoustic impedance, reflection coefficients, seismic amplitudes and polarity
• Frequency, wavelength, vertical and lateral seismic resolutions

SEISMIC DATA ACQUISITION TECHNIQUES

• Land acquisition: vibroseis and explosive sources, receivers (geophones), transmitters; Onshore acquisition specifics (static correction, noise,…)
• Marine acquisition: Air guns, hydrophones and streamers, Narrow and Wide Azimuth, Ocean Bottom Cables / Nodes, Broadband,…
• Other types of seismic acquisitions: borehole  (VSP, check-shot), 4D
• From Shot Point (SP) to Common Mid Point (CMP); Multiple coverage, Bin

PRE-PROCESSING

• 5D regularization, bin centering
• Amplitude compensation,
• Attenuation of organized and random noise
• Seismic source designature, deconvolution

TIME PROCESSING – SEISMIC VELOCITIES

• Dynamic Corrections, Normal Move-Out: principles and applications
• Velocity analysis, stack, multiple removal.
• Different types of seismic velocities. Dix formula

PRINCIPLES OF MIGRATION

• Why migrate? The blind geophysicist’s experiment
• Different types of seismic rays (normal, zero offset,…)
• Construction of the time image from a simple geological model in depth
• Effects of migration: repositioning and focusing of the image

TIME & DEPTH IMAGING

• Different types of migration: 2D vs 3D, post vs. pre-stack, Time vs. depth
• Differences between pre-stack Time migration (PSTM)  vs. depth migration (PSDM)
• Velocity model building for PSDM. Tomography
• Migration algorithms: seismic rays, wave equation
• Anisotropy, full waveform inversion (FWI)
• Overview of seismic acquisition and processing costs

BEYOND THE SEISMIC IMAGE: ATTRIBUTES AND INTERPRETATION

• The 3D seismic cube ready for interpretation: geometric  and attributes information
• Structural interpretation and depth mapping
• Stratigraphic interpretation for reservoir characterization (seismic stratigraphy)
• Fluid interpretation for hydrocarbon identification (DHI)