Introduction

Data Release Rules in the NDR provide a consistent, transparent mechanism for determining:

• When data is protected
• When it becomes eligible for publication

The move to structured release rule metadata ensures:

• Clarity
• Consistency
• Traceability

This supports both operational decision-making and regulatory compliance across the NDR.

Background

The introduction of new Release Rules metadata was discussed at ISC Meeting #004 in September 2025. At that time, work had already begun to reapply Release Rules to seismic (seis) and marine hazard site survey (mhaz) projects.

While the rules themselves were in place, the associated metadata (for both Projects and Files) was inconsistently applied, incomplete, and lacked clarity. To address this, we undertook a programme of improvement to ensure that Release Rule metadata is structured, explicit, and consistently applied.

Clear metadata benefits all users by:

• Providing immediate visibility of which rules have been applied
• Giving certainty on how associated data is handled
• Highlighting where exceptions or special treatments have been applied

Historically, survey metadata included labels such as “proprietary” and “spec”, or was left unpopulated. These labels have no regulatory meaning and did not describe how Release Dates were determined. They have therefore been replaced by formal Release Rule metadata.

Current Status (June 2026)

• Release Rule metadata has now been applied to all existing seismic (seis) and Site Survey (mhaz) projects
• All new seis and mhaz projects receive Release Rule metadata at creation
• Equivalent functionality for well projects is in development and will be introduced during summer 2026
• No well projects currently have Release Rule metadata applied

Release Rule Core Concepts

Release Rules

Each NDR Project has Release Rules applied at the point of creation. These rules are implemented as logic that:

• Uses licence type and relevant dates
• Determines a Release Date

The Release Date is the earliest date until which a project and its associated files remain protected.

Project-level release rule metadata has the format:

[Legislation]–[Licence Type]

If an override is used then format of the release rule will then be:

[Override]_[Legislation]–[Licence Type]

The details and examples of these are explained in the later sections

Protected vs Published Data

• Protected data: Data held within the NDR that has not been published
• Published data: Data made available by the NSTA after the Release Date

Once a project reaches its Release Date, the NSTA may publish associated data at its discretion. Some files may remain protected even after the project Release Date.

Rule Variability

Different rules apply depending on:

• The type of licence
• Whether the data relates to a well or a survey
• The applicable legislation

Legislative Framework

Three legislative regimes determine Release Rules:

Petroleum Act 1998 (PA1998)

Applies to:

• Petroleum licence wells with a Regulatory Completion Date before 1 January 2018
• Petroleum licence surveys acquired before 1 January 2018

Energy Act 2016 (EA2016)

Applies to:

• Petroleum licence wells with a Regulatory Completion Date on or after 1 January 2018
• Surveys where original processing was completed on or after 1 January 2018

Energy Act 2023 (EA2023)

Applies to:

• Carbon storage licence wells and surveys

In Release Rule metadata, legislation is abbreviated as:

• PA1998
• EA2016
• EA2023

Licence Types

The main licence types referenced in NDR are:

Exploration Licences (EXPLOR)

• Typically awarded for seismic acquisition
• Apply only to survey projects (no associated wells)
• Usually have longer protection periods

Format: E### (e.g. E28, E456)

Where the Licence ID isn’t recorded, we use the fallback value: E999

Production Licences (PRODUC)

• Used for hydrocarbon exploration, appraisal, and development
• Apply to all petroleum wells and many surveys

Format: P#### (e.g. P6, P438, P2351)
Where the Licence ID isn’t recorded, we use the fallback value: P9999

Carbon Storage Licences (CSTORE)

• Used for offshore carbon storage projects
• Apply to both wells and surveys

Format: CS### (e.g. CS002, CS022)

The Licence ID is always recorded.

In Release Rule metadata, licence types are abbreviated as:

• EXPLOR
• PRODUC
• CSTORE

Overrides

Overrides take precedence when applied to standard Release Rules to account for specific scenarios. When applied, these add prefixes to the Release Rule metadata. Overrides allowed in NDR are:

4D Seismic Surveys (4DRetained)

Data from a 4D survey sequence is not routinely published until the final survey is eligible. Examples of this override applied to a release rule are:

• 4DRetained_EA2016‑PRODUC
• 4DRetained_PA1998‑PRODUC
• 4DRetained_EA2023‑CSTORE

Relinquished Licences (Relinquished)

Applies where a whole licence or specific licenced acreage has been relinquished or Data is released earlier than standard rules allow. An example of this override applied to a release rule is:

• Relinquished_EA2016‑PRODUC

Early Release (EarlyRelease)

Similar to Reliquished, but this applies where the NSTA and licensee agree to an earlier release date – typically as a condition of the licence, and sometimes when the NSTA has published certain data. Examples of this override applied to a release rule are:

• EarlyRelease_PA1998‑PRODUC
• EarlyRelease_EA2016‑EXPLOR
• EarlyRelease_EA2016‑PRODUC

Includes Exploration Data (IncludesExpl)

This is applied when processed seismic includes commercial seismic data within production licence-related projects.  

The Effect of this override flag is:

• Data remains protected beyond the standard Release Date.
• NSTA is not prompted to publish the data.
• Data cannot be published via the NDR UI.
• Visibility limited to Data Reporting Group and NSTA.

Examples of this override applied to a release rule are:

• IncludesExpl_PA1998‑PRODUC
• IncludesExpl_EA2016‑PRODUC
• IncludesExpl_EA2023‑CSTORE

In Release Rule metadata, override types are abbreviated as:

• 4DRetained
• Relinquished
• EarlyRelease
• IncludesExpl

Release Rule Metadata for Projects

Project-level release rule metadata has the format:  

[Legislation]–[Licence Type]

This combination describes the logic used to calculate the Project Release Date. Examples of these release rules in the project metadata are:

• PA1998‑PRODUC - Seis/mhaz projects linked to production licences before 1 January 2018
• EA2016‑PRODUC - Seis/mhaz projects linked to production licences after 1 January 2018

• EA2023‑CSTORE - Projects linked to carbon storage licences

• EA2016‑EXPLOR - Exploration licence surveys from 1 January 2018 onward (EXPLOR projects are usually only visible to Data Reporting Group and NSTA)

Most seis and mhaz projects follow this basic, standard structure. Approximately 100 projects include overrides, where standard rules are adjusted. The the override the release rule metadata has the format:  

[Override]_[Legislation]–[Licence Type] 

Examples of these release rules with overrides in the project metadata are:

• 4DRetained_EA2016‑PRODUC
• EarlyRelease_EA2016‑EXPLOR

Release Rule Metadata for Files

Files inherit project-level metadata with an additional suffix, which indicates the time period in years that the file remains protected. This time period can vary based on the CTAG assigned to data, this means that different files in the same project can have different release dates. File level release rule metadata has the format:  

[Legislation]–[Licence Type]–[Retention Period in Years]

If the project release rule had an override applied then that is also inherited and the File level release rule metadata has the format:

[Override]_[Legislation]–[Licence Type]–[Retention Period in Years]

This combination describes the logic used to calculate the file release date. Examples of these release rules in the file metadata are:

• IncludesExpl_EA2023‑CSTORE‑10
• PA1998‑PRODUC‑04
• EA2016‑PRODUC‑05

Well Project and File Metadata (Current State)

Well-related files currently use simplified metadata (e.g. EA16, PA98). This means the rules have been applied, but the associated metadata isn’t as descriptive as it could be. 

This will be replaced when full Release Rule metadata is extended to:

• Well projects
• Associated files