Reading ZGY file format files to use it inside g-Platform environment.

Theory

ZGY is a proprietary 3D seismic volume format developed by Schlumberger for use in its interpretation platforms such as:

• Petrel
• Studio
• GVERSE/Geoprobe (older support)
• OpendTect (read-only plugins)

It is designed specifically for large 3D seismic datasets, supporting fast access, efficient storage, and smooth visualization.

ZGY stands for:

Z (seismic impedance) + GY (geometry) (an informal historical interpretation — original meaning is not officially public)

Key Features of ZGY Format

1. High-Performance 3D Volume Format

ZGY is optimized for:

• Real-time viewing
• Instant slicing (inline, crossline, arbitrary lines)
• Instant extraction (horizons, time/depth slices)
• Handling massive datasets (100s of GBs to TBs)

It’s far more efficient than SEG-Y for interpretation workflows.

2. Tiled / Bricked Data Storage

ZGY divides the 3D volume into small tiles or bricks, which allows:

• Fast random access
• Only loading needed sub-volumes
• Smooth zoom/pan interaction in Petrel

This is why ZGY scrolls so fluidly compared to SEG-Y.

3. Supports Both Time and Depth Domains

ZGY volumes can store:

• Time (TWT) seismic
• Depth seismic
• Pre-stack attributes
• Post-stack attributes

4. Efficient Compression

Modern ZGY (HDF5-based) supports:

• Lossless compression
• Lossy compression (optional)
• Multi-resolution pyramids (mipmaps)

This dramatically reduces disk space and speeds up display.

5. Metadata Embedded Internally

Unlike SEG-Y, ZGY stores:

• Inline/crossline geometry
• Coordinate reference system (UTM / geographic / custom CRS)
• Vertical sampling (dt / dz)
• Corner points
• Data statistics
• Volume extents
• Units and domain info

Petrel reads this instantly without requiring navigation files.

ZGY Versions

Old ZGY (Legacy ZGY)

• Binary proprietary format
• Petrel pre-2017 versions
• Limited compression
• No HDF5 backend

New ZGY (OpenZGY / HDF5 ZGY)

• Since ~2018
• Built on HDF5
• Open API available (OpenZGY library)
• Supports cloud storage (Azure, AWS)
• Multi-resolution access

ZGY is not a processing format — it is an interpretation and visualization format.

Input data

Input file name

- specify the input data file in ZGY format.

Gather domain { TIME, DEPTH, FREQUENCY } - allows the user to specify the input data domain type. By default, Time. There are additional domain options available from the drop down menu.

Time - Input data is in Time domain

Depth - Input data is in Depth domain

Frequency - Input data is in Frequency domain

Parameters

Parameters tab is disabled. There are any parameters to mention to this module.

Settings

Skip

By default, FALSE(Unchecked). This option helps to bypass the module from the workflow.

Output data

Output DataItem

Output gather

generates the output gather to be used in the g-platform environment.

Information

There is no information available for this module so the user can ignore it.

Examples

Actions

There are no action items available for this module.

Video lesson

YouTube video lesson, click here to open [VIDEO IN PROCESS...]

Related articles

Yilmaz. O., 1987, Seismic data processing: Society of Exploration Geophysicist

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