TWT → Depth Conversion
for Seismic Profiles
A complete reference for SeisDepth — a browser-based tool that converts seismic two-way travel time to depth using layered interval velocity models, the Dix RMS equation, and real-time uncertainty propagation. No installation required.
Introduction
Seismic reflection surveys image the Earth's subsurface in the time domain. Every seismic section you see displays two-way travel time (TWT) on the vertical axis — the time it takes an acoustic pulse to travel from the surface to a rock boundary and return. While the time domain is useful for mapping structural geometry, it cannot be directly compared to depth-referenced information such as well logs, formation tops, fluid contacts, or pressure data.
Converting seismic data from TWT to true subsurface depth requires a velocity model — a description of how fast acoustic waves travel through each geological layer between the surface and the target. SeisDepth provides a fast, transparent, browser-based environment for building these models and performing the conversion.
Unlike black-box commercial software, every calculation in SeisDepth is grounded in published equations and visible to the user. This documentation explains both what the tool does and the geophysical theory behind each step.
Petroleum geologists, seismic interpreters, exploration geophysicists, and geoscience students who need rapid, auditable TWT–depth conversion without commercial software licences or workstation installations.
Key Features
Core Concepts & Theory
This section explains the geophysical theory underlying every calculation SeisDepth performs. Understanding these concepts allows you to build accurate models and correctly interpret the outputs — including their limitations.
Two-Way Travel Time (TWT)
When a seismic source fires, it generates an acoustic pulse that travels downward through the Earth. At each geological boundary where the acoustic impedance changes, part of the wave is reflected back to the surface and recorded by receivers. The total elapsed time from the shot to the return of that reflected arrival is the two-way travel time.
TWT — quick reference
The TWT is related to depth by the velocity of the subsurface layers. Faster layers (e.g., carbonates, salt) compress a large depth interval into a short TWT interval; slower layers (e.g., unconsolidated sediments) do the opposite. This non-linear TWT–depth relationship is precisely what the velocity model defines and what SeisDepth converts.
RMS Velocity (Vrms)
Seismic velocity analysis of CMP (common midpoint) gathers determines the velocity that best corrects the normal moveout (NMO) of each reflection event — that is, the velocity that makes a curved reflection appear flat when the offset between shot and receiver is varied. This is called the NMO velocity or, more precisely in the context of layered media, the root mean square velocity (Vrms).
Vrms at a given reflector is not the velocity of any single layer. It is a weighted average that "smears" the velocity information from all layers above that reflector into a single number:
Because Vrms averages over the whole column, it increases monotonically with depth for a normally compacting sequence. It is the input to the Dix equation, which "un-averages" Vrms into the individual layer velocities needed for depth conversion.
Interval Velocity (Vint)
The interval velocity is the true seismic P-wave velocity within a specific geological layer — the actual speed at which acoustic energy travels through that rock between two bounding reflectors. It is the fundamental quantity for depth conversion.
Three ways to obtain interval velocities, in order of increasing accuracy:
- Lithology presets — representative published values; useful for reconnaissance models
- Dix equation — derived from seismic Vrms picks; typical accuracy ±5–15%
- Borehole measurements — check-shots or VSP surveys; typical accuracy ±1–3%
The Dix Equation
The Dix equation, published by C. H. Dix in 1955, is the standard method for converting seismic RMS velocity picks into layer interval velocities. It is derived by inverting the definition of Vrms for the innermost layer:
Derivation intuition
If you write out the RMS velocity definition for \(n\) layers and for \(n-1\) layers and subtract, you isolate the contribution of layer \(n\). Taking the square root recovers \(V_{int,n}\). The logic is identical to how you find the speed of one segment of a journey from average speeds recorded at different checkpoints.
Worked example — one Dix step
Given Vrms = 1650 m/s at TWT = 800 ms and Vrms = 2100 m/s at TWT = 1600 ms:
The Dix equation strictly requires horizontal, laterally homogeneous, isotropic layers. It breaks down in areas of structural dip, lateral velocity gradients, anisotropy (e.g., shale with VTI symmetry), or near the flanks of salt bodies. In structurally complex areas, full waveform inversion or tomographic velocity model building is required. Always validate Dix-derived velocities against borehole data.
Depth Conversion Formula
Once interval velocities are established, depth is computed iteratively from the surface downward through the layer stack. SeisDepth applies the standard one-way depth formula at each layer boundary:
Step-by-step derivation of the constant
Worked example — depth at a shale top
Layer: Shale, TWT top = 800 ms, TWT base = 1600 ms, Vint = 3385 m/s. Previous cumulative depth zprev = 660 m.
Layer Thickness
Layer thickness is the change in depth between the top and base of a layer. It follows directly from the depth conversion formula:
Uncertainty Propagation
Every velocity estimate carries uncertainty — from noise in the seismic velocity analysis, lateral variability in the rock, and the inherent resolution limits of the NMO method. SeisDepth propagates this uncertainty through the full depth column using linear error propagation:
Expanded form — showing each layer's contribution
Percentage depth error
Worked example — uncertainty to base of shale
Layer 1: Seawater, Δz = 0 m (top layer), δV/V = 0%. Layer 2: Clay (unconsolidated), Δz = 660 m, δV/V = 8%. Layer 3: Shale, Δz = 987.6 m, δV/V = 8%.
Complete Formula Summary
All equations used by SeisDepth, consolidated for reference:
(definition)
Vint from Vrms
(ms → metres)
(iterative)
(linear propagation)
Interface Overview
The SeisDepth interface is organized into four functional areas that update in real time as you modify the velocity model.
Lithology preset selector per layer
Add / remove layers · Dix calculator
Reference lines toggle · Profile labels toggle
Export TWT–Depth function as PNG
Increases downward
Color-coded by lithology
Converted via velocity model
Same color coding
Depth plotted at each TWT step
Exportable as PNG
Global Toolbar
| Button | Action |
|---|---|
| Import CSV | Load TWT / Vrms pairs from a comma-separated file into the Dix calculator text area |
| Export JSON | Save the complete velocity model, all layer settings, and display parameters to a JSON file |
| Import JSON | Restore a previously exported model from a JSON file, replacing the current model |
| My models | Save, recall, or delete named models stored in the current browser session for rapid scenario switching |
Building a Velocity Model
A SeisDepth velocity model is an ordered stack of geological layers from the surface downward. Each layer is defined by the TWT at which it begins (its top reflector), its interval velocity, and an optional velocity uncertainty.
Plan your layer boundaries
Identify the seismic reflections (horizons) you wish to convert. Each boundary between layers corresponds to a picked reflection. For a standard offshore petroleum section this typically includes the sea surface, seafloor, shallow sediments, regional shales, and a target reservoir or carbonate unit.
Configure the surface layer (TWT = 0 ms)
The first row always starts at TWT = 0 ms. For offshore surveys this is the water column (seawater, V ≈ 1500 m/s). Click Apply lithology preset… to auto-populate, or type the velocity directly. Set ±V = 0% for seawater if the value is measured acoustically.
Add deeper layers in TWT order
Click Add to append a new layer. Enter its Top TWT (ms) — the two-way travel time of its upper boundary as picked on the seismic section. Enter the V (m/s) interval velocity and the ±V (%) uncertainty. Repeat for all layers, always maintaining increasing TWT order.
Verify the Converted Horizons Table
The table updates in real time. Check that depths are geologically plausible, layer thicknesses make sense, and the ±Error column reflects your confidence in each velocity. The Max depth indicator updates as you adjust Max TWT.
Export and archive
Use Export JSON to save the model for future sessions. Use Export PNG to capture the TWT–Depth function plot for technical reports. Use My models to name and store the model for quick recall within this session.
Layers must be entered in strictly increasing TWT order. Depth conversion is computed iteratively from the shallowest to the deepest layer. An out-of-order entry produces a negative depth increment for that layer and incorrect cumulative depths for everything below it.
Lithology Presets
SeisDepth provides one-click velocity presets for common geological materials. Selecting a preset from the Apply lithology preset… dropdown fills the velocity field for that layer with a representative published P-wave velocity.
| Preset | V in SeisDepth (m/s) | Published range (m/s) | Primary controls |
|---|---|---|---|
| Seawater | 1500 | 1470 – 1540 | Temperature, salinity, depth (pressure) |
| Clay (unconsolidated) | 1650 | 1000 – 2500 | Water content, burial depth, consolidation |
| Coal | 2469 | 2000 – 3000 | Coal rank, fracture porosity, cleat orientation |
| Shale | 3385 | 2000 – 4500 | Burial depth, compaction, organic content, diagenesis |
| Sandstone | 4056 | 2000 – 6000 | Porosity, cementation, pore fluid, burial depth |
| Salt (halite) | 4442 | 4400 – 4600 | Temperature (narrow range; lab-constrained) |
These values represent midpoints of published ranges. Real formations vary enormously — shale velocity alone can range from 2000 to 4500 m/s depending on depth and diagenesis. For any prospect or drilling decision, calibrate your velocity model against nearby well data (check-shots, VSP, or interval velocities from sonic logs).
Dix Calculator
The Dix calculator converts seismic Vrms picks (pairs of TWT and RMS velocity) into layer interval velocities using the Dix equation. This eliminates the need to look up or guess interval velocities when velocity analysis data are available.
Input Format
Enter picks as comma-separated pairs — one TWT–Vrms pair per line — starting at TWT = 0 ms:
# Format: TWT (ms), Vrms (m/s) # One pick per line. The first line must be TWT = 0. 0,1500 800,1650 1600,2100 2400,2600 3400,3100 4600,3500
This format matches the output of most seismic processing packages (e.g., velocity function ASCII files from Petrel, Kingdom, Hampson–Russell, or OpendTect).
Step-by-Step Usage
Enter or import Vrms picks
Paste TWT–Vrms pairs directly into the calculator text area, or click Import CSV from the toolbar to load them from a file.
Click "Compute interval velocities"
SeisDepth applies the Dix equation to each consecutive pair of picks, computing Vint for every layer interval defined by those picks.
Review the computed Vint values
Verify that derived interval velocities are geologically plausible (roughly 1400–7000 m/s for sedimentary sequences). Values outside this range suggest either noisy velocity picks, cycle-skipping in the velocity analysis, or insufficient picks across a high-velocity layer (which inflates the apparent interval velocity of the adjacent layer).
Review and adjust in the Velocity Model panel
Computed Vint values populate the layer table. Assign ±V (%) uncertainty to each layer before running the full depth conversion.
If Vrms decreases with depth — physically impossible in a normally compacting sequence — the expression inside the Dix square root becomes negative and the calculation fails. This indicates either a data-entry error (transposed Vrms values) or genuine velocity analysis noise. Correct the offending picks before proceeding.
Display Controls
The display panel governs the visualization of your model in the time and depth domains and controls the exported figure.
| Control | Default | Description |
|---|---|---|
| Max TWT (ms) | 8000 ms | Sets the vertical extent of the Time Domain and Depth Domain panels. Increase to show deeper stratigraphy; decrease to zoom in on shallower intervals. The Max depth value in metres is shown in real time directly below this control. |
| Reference lines | On | Toggles horizontal depth gridlines on the TWT–Depth function plot, making it easier to read off depth values at specific TWT positions. |
| Profile layer labels | On | Toggles lithology name and interval velocity annotations displayed within each layer band on the Time Domain and Depth Domain panels. |
| TWT–Depth function labels | On | Toggles numeric depth annotations at each TWT step on the function curve panel. |
| Export PNG (TWT–Depth function) | — | Downloads the TWT–Depth function chart as a PNG image. Suitable for insertion into well prognosis documents, seismic interpretation reports, or technical presentations. |
The depth corresponding to the current Max TWT setting is shown in real time as Max depth: X m. This value changes whenever you adjust the TWT range or modify any layer velocity, making it a useful sanity check on your model's total depth extent.
Uncertainty Analysis
Velocity uncertainty is specified per layer via the ±V (%) field. SeisDepth propagates these values through the cumulative depth computation and reports absolute depth uncertainty (±m) and percentage error for every horizon in the Converted Horizons Table.
Recommended Uncertainty Values
| Scenario | Recommended ±V (%) | Rationale |
|---|---|---|
| Seawater — acoustic profiling | 0 – 1% | Directly measurable; negligible uncertainty |
| Salt (halite) — lab-constrained | 2 – 4% | Narrow published range; temperature is the only variable |
| Shallow layers with check-shot calibration | 2 – 5% | Well data reduce uncertainty below seismic-only estimates |
| Standard seismic velocity analysis (uncalibrated) | 5 – 10% | Typical velocity analysis uncertainty without borehole control |
| Sub-salt or very deep layers | 10 – 20% | Poor seismic illumination; low velocity resolution; no well control |
Reading the Converted Horizons Table
| Column | Formula used | Meaning |
|---|---|---|
| TWT (ms) | — | Top TWT of each layer as entered by the user |
| V (m/s) | — | Interval velocity of that layer |
| Thickness (m) | V · ΔTWT / 2000 | True vertical thickness of the layer in metres |
| Depth (m) | zi = zi−1 + Δzi | Cumulative depth from the surface to the top of this layer |
| ±(m) | Σ Δzk · δVk/Vk | Absolute depth uncertainty propagated from all shallower layers |
| Error % | Δztotal / z × 100 | Depth uncertainty as a percentage of the estimated depth |
Reducing interval velocity uncertainty from ±10% to ±3% via check-shot calibration shrinks a ±300 m depth error at 3000 m to ±90 m. For any drilling decision, well-calibrated velocities are strongly preferred over seismic-only estimates. The ±300 m vs. ±90 m difference can determine whether a proposed well location is commercially viable.
Import & Export
CSV Import — Vrms Picks
CSV files loaded into the Dix calculator must contain exactly two columns: TWT in milliseconds and Vrms in m/s. A header row is optional and ignored if present.
# Optional header row (ignored by parser) TWT (ms),Vrms (m/s) 0,1500 800,1650 1600,2100 2400,2600 3400,3100 4600,3500
JSON Export / Import — Complete Model State
The JSON format preserves the entire model: all layer names, top TWT values, velocities, uncertainties, and display settings. This is the recommended format for project archival and sharing.
{
"layers": [
{
"topTWT": 0,
"velocity": 1500,
"uncertainty": 0,
"name": "Seawater"
},
{
"topTWT": 200,
"velocity": 1650,
"uncertainty": 8,
"name": "Clay (unconsolidated)"
},
{
"topTWT": 800,
"velocity": 3385,
"uncertainty": 8,
"name": "Shale"
},
{
"topTWT": 2400,
"velocity": 4056,
"uncertainty": 10,
"name": "Sandstone"
}
],
"displayMaxTWT": 6000
}
My Models — Session Storage
The My models panel saves named models within the current browser session. This allows rapid switching between scenarios (low / mid / high velocity cases) without reloading files. Models in this panel are not persisted across browser sessions — always use Export JSON for permanent storage.
Direct SEG-Y file import and export is planned for a future SeisDepth release. Currently, velocity picks must be imported via CSV or entered manually. See Limitations & Roadmap.
Tutorial 1 — Offshore Sedimentary Basin
A complete walkthrough of TWT–depth conversion for a typical offshore clastic petroleum system with a sandstone reservoir target.
Scenario
You are interpreting 2D seismic data over an offshore shelf basin. Velocity analysis of a CMP supergather at the prospect location has produced the following Vrms picks. The target is a sandstone reservoir at approximately 2600 ms TWT.
| TWT (ms) | Vrms (m/s) | Interpreted Horizon |
|---|---|---|
| 0 | 1500 | Sea surface |
| 200 | 1500 | Seafloor |
| 600 | 1620 | Base unconsolidated clays |
| 1200 | 1950 | Top compact shale |
| 2000 | 2350 | Top mid-shale unit |
| 2600 | 2700 | Top reservoir sandstone |
| 3200 | 2950 | Base reservoir / deeper shale |
Enter Vrms picks in the Dix calculator
Paste the TWT–Vrms pairs into the Dix calculator text area and click Compute interval velocities. SeisDepth will apply the Dix equation to each consecutive pair.
Verify the computed Vint values
The interval velocity of the reservoir sandstone interval (2000–2600 ms) should be significantly higher than the enclosing shales, consistent with a porous, cemented clastic reservoir. Check for any anomalously high or low values that might indicate velocity analysis noise.
Assign velocity uncertainty
Set ±V = 2% for seawater (measured). Set ±V = 3% for the seafloor clay (shallow, accessible). Set ±V = 8% for the shale units (standard velocity analysis). Set ±V = 10% for the reservoir sandstone — greater depth reduces velocity resolution.
Read the target depth from the Converted Horizons Table
The top reservoir sandstone at 2600 ms converts to approximately 3000–3200 m depth (central estimate ±10%). This is the depth prognosis to report for pre-drill well planning.
Apply the depth conversion formula manually to verify
For the reservoir layer (2000–2600 ms), with Vint ≈ 3445 m/s (from the Dix step at those picks) and depth to top of reservoir ≈ 1959 m:
Export model and figure
Click Export JSON to archive the model with your project data. Click Export PNG to save the TWT–Depth function chart for inclusion in the well prognosis or prospect summary document.
Tutorial 2 — Sub-salt Exploration Model
Salt bodies are one of the most challenging velocity modeling problems in exploration seismology. Their high P-wave velocity (≈4480 m/s) relative to surrounding sediments creates a strong velocity contrast that distorts seismic imaging and introduces large depth uncertainty in sub-salt targets.
Scenario
Regional seismic imaging shows a salt body (halite) between approximately 2000 and 3400 ms TWT. A structural closure is interpreted in the sub-salt section at ≈4200 ms. You need to estimate the target depth and its uncertainty before committing to a well location.
| Layer | Top TWT (ms) | Vint (m/s) | ±V (%) | Rationale for uncertainty |
|---|---|---|---|---|
| Seawater | 0 | 1500 | 0 | Acoustic measurement; negligible error |
| Overburden shale (upper) | 200 | 2100 | 8 | Standard velocity analysis accuracy |
| Pre-salt shale | 1200 | 2800 | 10 | Deeper, less well-resolved by NMO |
| Salt (halite) | 2000 | 4480 | 3 | Lab-constrained; very narrow range |
| Sub-salt shale (poorly imaged) | 3400 | 2600 | 18 | Very poor illumination below salt |
| Target sandstone | 4200 | 3800 | 18 | No well control; maximum uncertainty |
Build the model in SeisDepth
Enter each layer with its top TWT and interval velocity. For the salt layer, click Apply lithology preset… and select Salt (halite), then set ±V = 3%.
Observe the velocity contrast at salt boundaries
In the Time Domain and Depth Domain panels, note how the salt layer (4480 m/s) compresses a large depth interval into relatively few milliseconds of TWT. The Depth Domain panel reveals the true geometric extent of each unit.
Compute the sub-salt target depth
Apply the iterative depth formula for each layer. Below is the full calculation chain:
Run a scenario comparison
Save this as Base case using My models. Create a Low velocity case by reducing sub-salt shale to 2200 m/s, and a High velocity case at 3000 m/s. Compare the resulting target depths to bracket the drilling depth uncertainty range: this is your P10/P50/P90 depth spread.
Seismic velocity analysis beneath salt bodies is severely limited by poor wavefield illumination and complex ray paths. The ±18% uncertainty used here is conservative. In practice, full waveform inversion (FWI) or dedicated sub-salt model building is required to constrain sub-salt velocities before any drilling commitment.
Tutorial 3 — Well-Calibrated Depth Conversion
When an offset well with check-shot or VSP data is available, the velocity model can be calibrated to dramatically reduce depth uncertainty. This tutorial demonstrates how to integrate borehole data into a SeisDepth model.
Scenario
An exploration well (Well-A) has penetrated the target formation and provides check-shot interval velocities. A seismic prospect (Prospect-B) lies 8 km along strike. You wish to depth-convert the prospect using the well-calibrated velocity model.
Extract check-shot interval velocities from Well-A
From the check-shot survey, read the interval velocity for each formation penetrated by the well. These are measured as the ratio of depth increment to one-way travel time increment between consecutive receivers — a direct physical measurement, not a processed estimate.
Enter well-derived Vint values in SeisDepth
Replace the Dix-derived or preset velocities with the check-shot interval velocities. Set ±V = 2–3% for calibrated layers, reflecting residual uncertainty from lateral velocity variation between the well and the prospect.
Verify the well depth tie
Check that the converted depth at Well-A matches the known formation tops from the well log exactly (or within 1–2%). Any systematic discrepancy is a well mis-tie and usually indicates lateral velocity change between the well and the CMP used for velocity analysis, or a timing error in the seismic-to-well tie.
Apply to Prospect-B and compare uncertainties
With calibrated velocities, the dominant remaining uncertainty is the lateral velocity change between the well and the prospect location — often modeled as a small percentage per kilometre of distance. Typical calibrated depth errors range from ±1–3% for well-tied models vs. ±8–10% for seismic-only models.
In a fully calibrated workflow, check-shot data provide a direct T–Z (time–depth) function at the well location. This can be used to correct the seismic velocity model interval by interval, ensuring the depth conversion matches the well exactly. T–Z calibration support is on the SeisDepth development roadmap.
Lithology Reference Table
Published P-wave velocity ranges for common geological materials, compiled from standard geophysical references (Sheriff & Geldart, 1995; Schlumberger Log Interpretation Charts; Mavko et al., 2009).
| Material | VP Range (m/s) | Representative VP | Primary controlling factors |
|---|---|---|---|
| Air | 330 – 340 | 335 | Temperature; negligible pressure dependence near surface |
| Freshwater | 1430 – 1530 | 1480 | Temperature (strong), dissolved solids |
| Seawater | 1470 – 1540 | 1500 | Temperature, salinity, hydrostatic pressure |
| Ice | 3400 – 3800 | 3600 | Temperature, crystal fabric, brine inclusions |
| Peat / top soil | 300 – 700 | 500 | Water content, organic matter, compaction |
| Sand (dry) | 200 – 1000 | 600 | Grain size, packing density, moisture |
| Sand (water-saturated) | 1500 – 2000 | 1750 | Water saturation, depth, grain contacts |
| Clay (unconsolidated) | 1000 – 2500 | 1650 | Water content, burial depth, overburden |
| Shale | 2000 – 4500 | 3000 | Burial, compaction, organic content, diagenesis |
| Sandstone | 2000 – 6000 | 3500 | Porosity, cementation, pore fluid, burial depth |
| Limestone | 3500 – 6500 | 5000 | Porosity, dolomitization, fractures |
| Dolomite | 3500 – 7000 | 5500 | Porosity, crystal size, diagenesis |
| Anhydrite | 4500 – 6500 | 5500 | Composition; relatively uniform pure mineral |
| Salt (halite) | 4400 – 4600 | 4480 | Temperature (only major variable; narrow range) |
| Coal | 2000 – 3000 | 2500 | Coal rank, fracture porosity, cleat orientation |
| Granite | 5500 – 6200 | 5800 | Mineralogy, fracturing, alteration |
| Basalt | 5000 – 7000 | 6000 | Vesicularity, alteration, fracture density |
| Gabbro / Diabase | 6000 – 7000 | 6500 | Mafic mineral content, alteration |
Sheriff, R. E., & Geldart, L. P. (1995). Exploration Seismology (2nd ed.). Cambridge University Press. · Mavko, G., Mukerji, T., & Dvorkin, J. (2009). The Rock Physics Handbook (2nd ed.). Cambridge University Press. · Schlumberger (2013). Log Interpretation Charts.
Limitations & Roadmap
SeisDepth is a strictly one-dimensional tool. It assumes horizontal, laterally homogeneous layers with no dip, no lateral velocity gradients, and no anisotropy. For structurally complex areas — beneath salt, near faults, on steep dips — a 3D velocity model and dedicated depth migration are required.
| Limitation | Impact | Current workaround |
|---|---|---|
| 1D layered model only | No lateral velocity variation | Build separate models for different structural domains |
| Isotropic velocities assumed | No VTI / HTI anisotropy | Apply Thomsen corrections externally before entry |
| Flat-layer assumption | No dip correction | Apply NMO dip corrections in processing before picking Vrms |
| No SEG-Y support | Cannot read seismic files directly | Import Vrms picks as CSV from processing software |
| No 2D / 3D velocity grids | Point model only | Build multiple models; interpolate depths in GIS software |
| Linear uncertainty propagation | May underestimate correlated errors | Use conservative (high) ±V values to compensate |
| Browser session storage only | My models not persistent across sessions | Always use Export JSON for permanent storage |
Planned Features (Roadmap)
| Feature | Status | Description |
|---|---|---|
| SEG-Y import / export | Planned | Read velocity picks and horizon TWT directly from SEG-Y files |
| Well log integration | Planned | Upload check-shot or sonic log data to calibrate interval velocities |
| T–Z calibration curve | Planned | Import a borehole time–depth function for exact well-tie calibration |
| Lateral velocity gradient | Roadmap | Model linear velocity change with lateral distance for 2D transects |
| Monte Carlo uncertainty | Roadmap | Replace linear propagation with full Monte Carlo depth uncertainty |
| P10 / P50 / P90 scenarios | Roadmap | Side-by-side comparison of low / mid / high velocity depth scenarios |
| VTI anisotropy correction | Roadmap | Apply Thomsen δ parameter correction for shale anisotropy |
Glossary
About the Author
SeisDepth was conceived and developed by Yasir Shahzad as a practical open-access tool to support seismic-to-depth conversion workflows in academic and professional petroleum geoscience. It is entirely normal — and indeed recommended — practice in scientific software documentation to introduce the researcher behind the tool, as it establishes scientific credibility, research context, and a point of contact for the community.
