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The offshore installations and wells (design and construction etc) regulations 1996



1 This SPC provides information on interpretation and enforcement of the Offshore Installations and Wells (Design and Construction, etc.) Regulations 1996 (DCR). It should be read in conjunction with the published guides L84 and L85.

2 The regulations;

Regulations 13-16 and 18-21 also apply to wells onshore in connection with the extraction of petroleum.



3 Part II imposes a duty to ensure that an installation at all times possesses such integrity as is reasonably practicable, so far as it is relevant to the health and safety of persons. This extends through the life-cycle, from design to dismantlement, with the same dutyholder as in MAR. Integrity is not linked to major hazards.

Design of an installation (regulation 5)

4 The owner or operator of an installation is the only dutyholder for this regulation. In many cases dutyholders rely on contractors to provide design expertise. It is essential that dutyholders have robust management arrangements for the selection and monitoring of these contractors. The regulations do not place any responsibility on contractors, so any contact regarding a particular installation should be via the dutyholder. Where dutyholders have not been involved with the design or building of an installation, they should be able to show that they have taken all reasonably practicable measures to ensure that their duties with respect to the integrity of the installation have been fulfilled. This may include a review of records of previous examinations and inspections, and operational history. There is a defence of due diligence under regulation 22.

Work to an installation (regulation 6)

5 If contractors are used, dutyholders should have management arrangements as described above. HSE intervention should focus on the management systems.

Reporting (regulation 9)

6 The purpose of this regulation is to ensure HSE is informed about any significant threat to the integrity of the installation, which is not reportable under RIDDOR but puts personnel on the installation at risk. The guidance to the regulation (paragraph 62) gives examples. It is unlikely that enforcement action will be appropriate without evidence of an attempt to withhold significant information. Reports received are recorded on COIN and passed to the relevant inspection team. See also SPC/Enforcement/50 regarding reports of mooring failures.

Helideck (regulation 11)

7 The Civil Aviation Authority document CAP 437 details requirements for offshore helicopter landing areas. Obvious infringements of the landing area, for example aerials or other obstructions, should be brought to the attention of the dutyholder for immediate action. The marine and aviation team should be consulted before enforcement action is taken.

Additional requirements (regulation 12)

8 These requirements are in addition to those in other legislation, for example in PUWER regarding maintenance. Exemptions cannot be given to these requirements.

Schedule 1

9 The workplace requirements are about risk to individuals. For example, paragraph 1 relates to risk to individuals brought about by the layout and configuration of the installation, not just by major accident hazards. Paragraphs 1-38 deal with workplaces, defined in regulation 2, and workstations which are not defined. Generally, a workplace is anywhere people work, irrespective of the time they are working there. It may be permanent or temporary.

10 The requirements are designed to protect individual workers rather than the workforce at large. For example, HVAC systems may provide both ventilation of enclosed workplaces and a differential pressure between modules. Only the former purpose is relevant to schedule 1.

11 Accommodation is primarily a welfare issue, but it also concerns safety. Sleep deprivation, tiredness and fatigue can adversely affect safety on the installation.

12 Many of the requirements are not precisely defined, such as paragraph 17 regarding lighting, or are mainly concerned with protecting workers when they are not actually at work, such as paragraphs 39-67. Inspectors should consult the relevant topic team before enforcement.

Paragraphs 59-66 (accommodation)

13 The aim is for continuous improvement of accommodation standards offshore. Matters covered include provision of sufficient beds, overcrowding, storage space, privacy and comfort. The industry was consulted in the preparation of the guidance, and paragraphs 115 and 116 represent good practice. Additional guidance has been published in SPC/ENF/169 and Operations Notice 82.

14 Regulation 12 requires compliance with schedule 1 on an installation while it is 'in use', unless non-compliance would not prejudice the health, safety or welfare of any person. 'In use' means personnel are onboard the installation at its offshore location. An installation with no personnel onboard is not in use. Schedule 1 applies at any time while personnel are onboard an offshore installation, from its initial placement at site until final removal.

15 The caveat in regulation 12(1) is unlikely to apply to accommodation, as in most cases facilities which do not meet the schedule will prejudice the welfare, and possibly the safety and health, of persons involved.

Multiple occupancy

16 The guidance to the schedule (paragraphs 114-116) indicates what is reasonably practicable with regard to numbers of occupants. Providing adequate accommodation requires attention to the following:

17 The requirement for sleeping accommodation is two-berth cabins, with en-suite shower, toilet and washroom facilities shared between two cabins, over the full life-cycle of the installation. In applying DCR, HSE will only consider ‘Short-term Incidents’ and ‘Exceptional Circumstances’ as reasons for non-compliance with the full requirements of DCR. Further advice is in SPC/ENF/169 and Operations Notice 82. 

Temporary accommodation

18 Temporary accommodation, for example using containers, should meet all the goals of the regulations.

Completion, decommissioning and dismantling

19 Regulation 12(2) requires that while there are persons on a fixed installation which is being completed at the place where it is to be operated, the dutyholder shall ensure that schedule 1 is complied with, to such an extent as is reasonably practicable in the circumstances. A lower standard of compliance may therefore be acceptable during these activities.

20 It should normally be feasible to have the cabin accommodation operating to its usual standard during these activities. Any reduction in occupancy standards should be critically examined. Additional temporary accommodation or a flotel may be needed.

21 The completion date of the installation should be agreed in writing with the dutyholder, as this is the date on which the full requirements of schedule 1 will apply. It should not extend past the date hydrocarbons are first brought onto the installation or of the first well drilling operation.

Normally unattended installations (NUIs)

22 There is no specific mention of emergency accommodation in the regulations. Accommodation is needed if the nature, scale, and duration of operations so require, and should meet paragraphs 59 to 61 of schedule 1. Guidance on typical scenarios for NUIs can be found in SPC/ENF/169 and Operations Notice 82.


23 DCR covers the lifecycle of a well, from planning to abandonment, and applies to wells on the UKCS and land wells in the UK. It applies to all wells drilled for the exploration or exploitation of oil, gas and coalbed methane. A well includes all downhole components and equipment forming the pressure envelope. Any  equipment controlling the well pressure is covered, downhole and on top of the well, including blow-out preventers and Xmas trees. Well control equipment downstream that can be isolated from the well by valves is excluded. Examples of where the well may be deemed to end are: above the top blow-out preventer in the BOP stack outside the choke and kill valves, downstream of the swab and production wing valves of a Xmas tree, and at the top of the stuffing box of a wireline BOP.

General duty (regulation 13)

24 The regulations require the dutyholder to ensure the integrity of a well, from design to abandonment. The dutyholder is the well operator, defined as the person appointed by the concession owner for overall responsibility for organising and supervising all operations in respect of a well. If no one is appointed, the concession owner is the well operator. The license operator will normally retain responsibility for the wells in a field, and will be the well operator.

Assessment of conditions (regulation 14)

25 The well operator is required to assess the subsurface conditions before the well is designed. This includes an assessment of the geological sequence and pressure conditions and the identification of subsurface hazards. The latter include conditions that may inhibit dealing with a well control incident, such as loss zones or where stuck pipe may occur. The requirement continues throughout the drilling of the well. The well design should be amended if well conditions prove sufficiently different from those anticipated.

Materials (regulation 16)

26 All parts of a well should be composed of suitable material. Materials should conform to recognised industry standards, including the cement slurry sealing well casings.

Well control (regulation 17)

27 The regulations incorporate parts of the Extractive Industries (Borehole) Directive regarding the supply and use of blow-out preventers. There is a duty to provide suitable well control equipment for all operations on a well, and to deploy it where conditions require. The duty to ensure the equipment is provided is on the well operator, and includes specifying pressure, temperature and other service requirements of the equipment.

28 The duty to deploy it is on the installation dutyholder. Deployment means both installation of the equipment and its use to control an influx from the well. For well operations from a well intervention vessel, which is not an offshore installation, the well operator is responsible for both provision and deployment.

Arrangements for examination (regulation 18)

29 The objective of the examination scheme is to provide confidence that the well is designed, drilled, completed, operated, maintained, suspended and abandoned in accordance with appropriate standards and drilling practices, to reduce the potential for unplanned hydrocarbon releases. Enforcement action should be considered where this objective is not achieved. Potential causes should be investigated, including the independence and competence of persons (ICPs) carrying out the examination. Where the lack of independence, as defined in the regulation, is a significant factor, enforcement may be appropriate. Apart from the duty of co-operation in regulation 20, ICPs have no duties under these regulations.

Provision of information (regulation 19)

30 Operators are required to submit reports on specified well operations at intervals agreed by HSE. In the event of no agreement, weekly reports are required. Enforcement action is only appropriate where there are blatant and persistent breaches of this requirement.

Information, instruction, training and supervision (regulation 21)

31 This regulation places a duty on the operator of a fixed installation and the owner of a mobile installation to ensure that those engaged in well operations are adequately informed, supervised and trained for the job they are doing. These requirements complement the employers' duties under the HSW Act and the Management of Health and Safety at Work Regulations 1999. For well intervention vessels the well operator is the duty holder.

Further information

33 Further information can be obtained from OSD 2.4 Legal and Operational Strategy team

Updated 11.02.11