The Investigations & Enforcement Team sits within the NSTA's Regulation Directorate to address disputes between relevant persons and compliance with regulatory obligations.
The NSTA expects regulatory compliance. Some licensees do this voluntarily, others require assistance, direction, (such as through Facilitation or Enhanced Facilitation) or in more serious cases, enforcement action to achieve this.
The Investigations & Enforcement (I&E) Team sits within the NSTA's Regulation Directorate to address disputes between relevant persons and compliance with regulatory obligations.
Matters are often referred to the I&E Team from other teams within the NSTA. Depending on the nature of the issue, some teams will follow a measured escalation process before referring it to the I&E Team; details of the measured escalation process can be found here.
Other matters might involve a potential breach that has already taken place. In such instances, the issue can be referred directly to the I&E Team to consider once the potential breach has been identified.
When a matter is passed to the I&E Team, via any method, the team will carry out an Initial Assessment to decide the next steps.
When considering whether or not to take action using formal powers the NSTA will review that issue alongside its prioritisation criteria which can be found here.
There are various potential outcomes the NSTA can pursue after conducting an Initial Assessment. A summary of the options can be found here.
One outcome is opening a sanctions Investigation. Where the NSTA opens an Investigation, the NSTA will publish brief details of the existence of that Investigation. The NSTA will not generally name the parties who are the subject of the Investigation at that stage, unless the NSTA considers it would be in the public interest to do so.
The NSTA may publish details of any Sanction Notice issued (including the identity of the parties subject to the sanction) subject to the condition that the NSTA may not publish anything that, in the NSTA’s opinion, is commercially sensitive, not in the public interest to publish or is otherwise not appropriate for publication.
The NSTA has published a range of guidance.
Guidance on Disputes over Third Party Access to Upstream Oil and Gas Infrastructure
Following the implementation of the ‘general policy approach to the publication of company specific information’ in July 2025, the NSTA expects to update the case register to name regulated persons under investigation and to confirm that a Sanction Warning Notice (SWN) has been issued. Regulated persons will have the opportunity to comment before a final decision is taken on publication.
Publishing the identity of a regulated person under investigation is not a statement that wrongdoing has been found. The subsequent confirmation of SWN issuance is not a statement that a sanction will in fact be imposed. Any formal finding of a breach would follow a full investigation and is only conclusive once a Sanction Notice has been issued.
| Case ref | Issue | Parties | Case Type | Area of North Sea | Date opened | Status | Case Stage* | Date closed [link to case decision document] |
|---|---|---|---|---|---|---|---|---|
| 2018-00019 | Commercial Transaction – late life assets (right assets right hands) | ConocoPhillips / DNO / Premier / Tullow / BP / Neptune | Sanction investigation | Southern North Sea | February 2018 | Closed | Final Decision | 30 July 2019 Case decision document |
| 2018-00094 | Access to FPO infrastructure (resource progression) | * | Third Party Infrastructure Access Dispute | Central North Sea | Dec 2018 | Closed | Draft Decision, Application later withdrawn | 12 February 2020 |
| 2019-00104 | Dispute over the prioritisation of access to Cygnus capacity in relation to transportation and processing services for gas from the Pegasus field | Owners of Cygnus (Neptune E&P UK Ltd and Spirit Energy) and owners of Pegasus (Spirit Energy and Hague and London Oil BV) | Own initiative Non- Binding Dispute Resolution | Southern North Sea | June 2019 | Closed | Final Decision | 30 August 2019 Summary of Recommendation |
| 2021-00111 | Investigation into the non- compliance of licensing terms for reporting the Vorlich Extended Well Tests | BP Exploration Operating Company Limited | Sanction investigation | Central North Sea | January 2021 | Closed | Final Decision | 26 July 2021 Sanction Notice |
| 2021-00119 | Investigation into behaviours linked to the renegotiation of agreements between the owners of the Fulmar and Flyndre facilities | Repsol North Sea Limited | Sanction investigation | Central North Sea | June 2021 | Closed | Final Decision | 13 November 2024 Sanction Notice |
| 2021-00118 | Investigation into a possible breach of field production consents | Shell U.K. Limited | Sanction investigation | Southern North Sea | August 2021 | Closed | Final Decision | 21 April 2022 Sanction Notice |
| 2021-00117 | Investigation into a possible breach of a flare consent | Equinor U.K. Limited | Sanction investigation | Northern North Sea | August 2021 | Closed | Final Decision | 1 December 2022 Sanction Notice |
| 2021-00121 | Investigation into Exxon Mobil -NEO transaction: Transfer of Interests in the Elgin and Franklin Fields, the SEAL Pipeline and SVT | TotalEnergies E&P UK Limited and E. F. Oil and Gas Limited/Esso Exploration and Production UK Limited/NEO Energy Upstream UK Limited | Sanction investigation | Central North Sea | October 2021 | Closed | Final Decision | 14 April 2022 Press release |
| 2021-00120 | Investigation into a possible breach of field production consents | Spirit Energy North Sea Limited | Sanction investigation | Southern North Sea | December 2021 | Closed | Final Decision | 25 November 2022 Sanction Notice |
| 2021-00128 | Investigation into a possible breach of a flare consent | EnQuest Heather Limited | Sanction investigation | Northern North Sea | December 2021 | Closed | Final Decision | 25 November 2022 Sanction Notice |
| 2022-00125 | Investigation into a possible failure to meet licence obligations | * | Sanction investigation | * | August 2022 | Open | Investigation | |
| 2022-00126 | Investigation into a possible failure to meet licence obligations | * | Sanction investigation | * | August 2022 | Open | Investigation | |
| 2022-00123 | Investigation into a possible failure to meet licence obligations | * | Sanction investigation | Central North Sea | September 2022 | Closed | The investigation is closed: it did not meet with the considerations to pursue the investigation as set out in the NSTA’s Sanction Procedure. | 12 July 2024 |
| 2022-00132 | Investigation into a possible breach of flare and vent consents | Repsol Sinopec North Sea Limited | Sanction investigation | Central North Sea | October 2022 | Closed | Final Decision | 5 December 2023 Sanction Notice |
| 2022-00133 | Investigation into possible commencement of well test activity without consent | * | Sanction investigation | Central North Sea | October 2022 | Closed | The investigation is closed: it did not meet with the considerations to pursue the investigation as set out in the NSTA’s Sanction Procedure. | 22 March 2023 |
| 2023-00135 | Investigation into a possible breach of a field production consent | * | Sanction investigation | Central North Sea | January 2023 | Closed | The investigation is closed: it did not meet with the considerations to pursue the investigation as set out in the NSTA’s Sanction Procedure. | 14 August 2023 |
| 2023-00136 | Investigation into a possible breach of a vent consent | * | Sanction investigation | Northern North Sea | January 2023 | Closed | The investigation is closed: it did not meet with the considerations to pursue the investigation as set out in the NSTA’s Sanction Procedure. | 15 August 2023 |
| 2023-00134 | Investigation into a possible failure to meet licence obligations | * | Sanction investigation | West of Shetland | February 2023 | Closed | The investigation is closed: it did not meet with the considerations to pursue the investigation as set out in the NSTA’s Sanction Procedure. | 28 February 2024 |
| 2023-00137 | Investigation into a possible breach of a vent consent | NEO Energy Production UK Limited | Sanction investigation | Central North Sea | March 2023 | Closed | Final Decision | 10 April 2024 Sanction Notice |
| 2023-00138 | Investigation into a possible breach of a vent consent | Perenco UK Limited | Sanction investigation | Onshore | August 2023 | Closed | Final Decision | 24 April 2024 Sanction Notice |
| 2023-00139 | Investigation into a possible breach of a vent consent | Chrysaor North Sea Limited | Sanction investigation | Central North Sea | December 2023 | Closed | Final Decision | 21 July 2025 Sanction Notice |
| 2023-00140 | Investigation into a failure to have the appropriate consent to plug and abandon | ONE-Dyas UK Limited | Sanction investigation | * | December 2023 | Closed | Final Decision | 4 November 2024 Sanction Notice |
| 2023-00141 | Investigation into a possible breach of a vent consent | CNOOC Petroleum Europe Limited | Sanction investigation | Central North Sea | December 2023 | Closed | Final Decision | 17 December 2024 Sanction Notice |
| 2024-00142 | Investigation into a possible breach of a plug and abandon obligation | * | Sanction investigation | Northern North Sea | July 2024 | Open | Investigation | |
| 2024-00143 | Investigation into a possible breach of a plug and abandon obligation | * | Sanction investigation | Northern North Sea | July 2024 | Open | Investigation | |
| 2024-00144 | Investigation into a possible breach of a plug and abandon obligation | * | Sanction investigation | Central North Sea | July 2024 | Open | Investigation | |
| 2024-00145 | Investigation into a possible breach of a plug and abandon obligation | * | Sanction investigation | Central North Sea | July 2024 | Open | Investigation | |
| 2024-00146 | Investigation into a possible breach of the OGA Strategy | * | Sanction investigation | Northern North Sea | August 2024 | Open | Investigation | |
| 2024-00147 | Investigation into a possible breach of a vent consent | * | Sanction investigation | Northern North Sea | August 2024 | Open | Investigation | |
| 2024-00148 | Investigation into a possible failure to have the appropriate consent to plug and abandon | * | Sanction investigation | * | October 2024 | Open | Investigation | |
| 2025-00149 | Investigation into a possible breach of a production consent | * | Sanction investigation | Southern North Sea | March 2025 | Open | Investigation | |
| 2025-00150 | Investigation into a possible breach of a production consent | * | Sanction investigation | Central North Sea | March 2025 | Closed | The investigation is closed: it did not meet with the considerations to pursue the investigation as set out in the NSTA’s Sanction Procedure. | 24 July 2025 |
| 2025-00151 | Investigation into a possible breach of a vent consent | * | Sanction investigation | Northern North Sea | March 2025 | Open | Investigation | |
| 2025-00152 | Investigation into a possible breach of the OGA Strategy and possible breaches of production consents | * | Sanction investigation | Northern North Sea | March 2025 | Open | Investigation | |
| 2025-00153 | Investigation into a possible breach of a vent consent | * | Sanction investigation | Central North Sea | May 2025 | Open | Investigation | |
| 2025-00154 | Investigation into a possible breach of a production consent | * | Sanction investigation | Northern North Sea | May 2025 | Open | Investigation |
* Investigation; Enforcement: Sanction Warning Notice; Enforcement: Sanction Notice; No further action
Latest update October 2025
On 10 December 2024, the NSTA wrote to all licensees to advise that from 1 January 2025, the starting figure when considering the level of any fine imposed for flaring and venting breaches is £500,000.
