NO. 01 · Seismic Methods

Become a 3D Seismic Interpreter

From your first cube to a defended prospect. The craft of seeing geology in seismic: picking, structure, stratigraphy, and the attributes that make subtle things visible.

You can load a 3D volume, pick horizons and faults with defensible QC, read the structural and depositional story, and use attributes to build a prospect case a review panel will take seriously.

20 competencies · 6 interactive widget challenges · 12 to 19 hours of guided study

For geoscientists taking their first interpretation seat

Draws on: 3D Seismic Interpretation

The ground truth

Waves, reflection, refraction

Reflection seismology is two pages of wave physics applied a billion times; own the two pages.

Reads: Waves: amplitude, frequency, wavelength Reflection, refraction, and Snell’s law

Rocks, time, and wells

You interpret geology, not wiggles; rock families, geologic time, and well control are the referees of every pick.

Reads: Rocks 101: the three families we meet Geologic time and sedimentary basins Wells and logs: the other source of truth

How seismic works

The cube and acoustic impedance

Impedance contrast is the only thing the earth ever tells a reflection survey; everything else is inference.

Reads: Welcome: seeing a seismic cube Acoustic impedance and reflection coefficients

The convolutional model and processing

A seismic trace is the wavelet speaking through reflectivity; know the sentence and what processing did to it before you interpret a word.

Reads: The convolutional model From shot to stack: processing at a glance

Migration, time, and depth

Unmigrated data lies about position, and time and depth lie in different ways; an interpreter must know which lie is on screen.

Reads: Migration: why unmigrated data lies Time vs depth: the two domains of seismic

3D volumes and resolution

The wavelength problem decides what you can and cannot see; tuning is where thin beds hide.

Reads: From 2D lines to 3D volumes Resolution and the wavelength problem

The interpreter's toolkit

Reading the volume

Polarity and phase conventions have burned more interpreters than any fault ever has; settle them before the first pick.

Reads: How to look at a 3D volume Polarity, phase, and wavelet conventions

Picking horizonswidget challenge

Horizons are the deliverable; auto-tracking wins and fails in knowable ways, and you should know them.

Reads: Picking horizons: methodology and practice Auto-tracking: when it wins, when it fails

Faults and interpretation QCwidget challenge

Seeing faults in 3D is a skill, and knowing when your own interpretation is wrong is a bigger one.

Reads: Faults in 3D: how to see them, how to pick them QC: when your interpretation is wrong, and how you know

Structural interpretation

Structural styles and fault analysis

Extension, compression, strike-slip, salt, gravity: recognizing the style tells you what the next fault should look like before you see it.

Reads: Structural styles: extension, compression, strike-slip, salt, gravity Fault analysis: throw, heave, dip, and seal

Folds and the structural framework

Folding mechanisms explain why the horizon bends, and the framework turns picks into a 3D model you can defend.

Reads: Folding mechanisms: drape, fault-bend, fault-propagation, detachment Building a structural framework: from picks to 3D model

Salt tectonics and trap geometrywidget challenge

Salt builds the best traps and the worst images; prospect identification is where structural skill becomes money.

Reads: Salt tectonics: diapirs, walls, canopies, and welds Trap geometry and prospect identification

Stratigraphic interpretation

Terminations and sequence stratigraphywidget challenge

Onlap, downlap, toplap, truncation: four words that turn reflection geometry into a history of sea level and sediment.

Reads: Reflection terminations: onlap, downlap, toplap, truncation Sequence stratigraphy: sequences, surfaces, and systems tracts

Depositional systems and channels

Fluvial, deltaic, shoreface, deep-water: each system leaves a signature, and channels are the reservoirs that pay for the survey.

Reads: Depositional systems: fluvial, deltaic, shoreface, carbonate, deep-water Channel systems: meandering, braided, distributary, submarine

Turbidites and seismic geomorphology

Turbidite fans hold the biggest deep-water reservoirs, and geomorphology reads their paleo-landscape straight off the horizon slice.

Reads: Deep-water turbidite fans: anatomy and reservoir architecture Seismic geomorphology: reading paleo-landscapes from 3D volumes

Attributes

Amplitude and spectral attributes

RMS, envelope, and spectral decomposition make the invisible visible, and each one lies in its own characteristic way.

Reads: Amplitude attributes: RMS, envelope, and their friends Frequency attributes: spectral decomposition

Geometric and coherence attributes

Dip, curvature, and coherence see the faults amplitude cannot; this is how modern fault interpretation actually starts.

Reads: Geometric attributes: dip, azimuth, and curvature Coherence and discontinuity attributes: seeing the unseen faults

Combining attributeswidget challenge

RGB blending and classification put three attributes in one image; used with judgment they carry a reservoir story on a single map.

Reads: Attribute combination: RGB blending and classification Attributes for reservoir characterization: putting it together

Case files

Case file: Lula pre-saltwidget challenge

Microbialite carbonates under two kilometers of salt: the case where structural skill, imaging limits, and courage meet.

Reads: Pre-salt carbonate: Lula/Tupi microbialites under 2 km of salt

Case file: Wolfcamp shale

Unconventionals invert the game: no trap, all rock; attributes and geomechanics decide where the lateral goes.

Reads: Unconventional completion design: Wolfcamp shale in the Permian