Under the licence conditions (model clauses), the licensee is not permitted to commence, suspend or recommence the drilling of any well or to carry out completion or recompletion works, suspend or abandon any well without the consent of the NSTA.

Each application to drill is considered with respect to the fulfilment of specific licence obligations and impact on the environment and other users of the sea. Drilling and petroleum developments offshore are subject to the requirements of the Offshore Petroleum Production and Pipe-lines (Assessment of Environmental Effects) Regulations 1999, which implement the EU Environmental Impact Assessment Directive (PON 15 and PON 16).

On 19 July 2015 the Offshore Installations (Offshore Safety Directive) (Safety Case, etc.) Regulations 2015 (SCR) came into force in the UK, implementing the requirements of EU Offshore Safety Directive 2013/30/EU. This established the Offshore Safety Directive Regulator (OSDR) who is responsible for the regulation of major safety and environmental accident hazards, and their consequences, in the offshore oil and gas sector. This has implications for the approval of drilling operations.

Read more about the Offshore Safety Directive.

Approval process

Licensees must apply for consent to drill and conduct other activities on a well and notify the NSTA of these through the Well Operations and Notifications System. Applications should be submitted at least 28 days in advance. 

All well applications require a well operator to have been appointed under the Offshore Petroleum Licensing (Offshore Safety Directive) Regulations 2015 (2015 licensing regulations). To appoint a wells operator, licensees must notify the NSTA Licensing and Legal Team via email or letter. This may have been done as part of the licence award process. However, if this has not been done, or if the licensees wish to appoint a different well operator, the Offshore Safety Directive requires an application to be made three months before the date of the proposed appointment taking effect.

The diagram below details the E&A well approval process

It can also be downloaded here

Extended Well Tests

Under the model clauses of a licence, the consent of the NSTA is required to undertake extended well tests (EWTs) - extended periods of test production from exploration or appraisal wells prior to development plan authorisation.

Further information on EWTs and the consenting process can be found here: Extended Well Tests guidance

OSDR requirements

All well applications require separate notifications, with supporting information, to be supplied to the OSDR.

Environmental information needs to be submitted to BEIS via the Portal Environmental Tracking System (PETS). Operators need to submit a drilling application via WONS before the well operator can submit data into PETS. The licence operator can initiate this process by submitting a provisional drilling application via WONS if they are not in a position to submit a full initial drilling application.

A full environmental statement may be required for wells determined as likely to have a significant effect on the environment by virtue of their nature, size or location.

The OSDR requires a 21-day notification period for well applications. A 10-day notification period applies to some simpler operations that do not involve drilling. The Offshore Installations and Wells (Design and Construction, etc.) Regulations 1996 are applicable to these activities

See also Regulation 21 and Schedule 9 to the Safety Case Regulations 2015 and further guidance on well applications

Well operators that submit a well notification must also send to the OSDR a copy of their corporate major accident prevention policy (CMAPP), and an adequate description of their Safety and Environmental Management System (SEMS). See further guidance on well notifications.

Data requirements

Data collection starts once a well has been spudded (seabed is penetrated), when the operator submits a spud notification on WONS. The NSTA will issue an official well number via WONS (see PON12), which is to be used for all data and records resulting from the drilling of the well. All well data requirements are set out in the documents PON 9 (offshore) and PON 9b (onshore).

Onshore operators have a statutory obligation to also supply well data to the British Geological Survey (BGS)