B.1.6.1 Introduction

The Chinese drilled the first oil well in the 4th Century but the industry did not start until the mid 19th century when chemists in Scotland, Canada and the US first distilled oil to separate useful constituents such as kerosene, paraffin wax and lubricating oil. The industry increased dramatically and the oil majors were formed in the second half of 19th century with the most famous, Standard Oil, formed in 1865. The Anglo-Persian Oil Company followed in 1907 and these companies and their successors remained very commercially successful through the two World wars.  Influence subsequently moved to the oil producing nations with the formation of OPEC in 1960. Petroleum production peaked in the 1970s and despite subsequent oil gluts and massive price swings the oil and gas thrives as a multi-million dollar industry and continues alongside renewables to provide much of the Worlds energy in the first decades of the 21st century.

B.1.6.2 Offshore Oil Installations

Offshore oil installations are found worldwide and are fixed leg, jack-up or floating semi-submersible structures. The mobile installations, or drilling rigs, are used for exploration, whilst the fixed leg  platforms are used for oil recovery and production.

There are 12,000 offshore oil and gas platforms worldwide and these vary immensely in design and size with many being unmanned, and many with multiple remotely controlled satellite subsea wells. Deep waters are served by FPSOs (Floating production storage and offloading) vessels. Where they are manned installations these complex, compact facilities provide a challenging environment for the workforce, usually up to 150 in number. They work continuous shifts, often 12hrs at a time, for up to three weeks or more.

Oil production requires a chemical processing and heavy engineering plant to be housed in confined spaces, adjacent to administration and living quarters. There is limited communication to the shore, often hundreds of kilometres away, with logistical support provided by supply vessels bringing routine equipment, water and food, with helicopters moving personnel and emergency supplies. In some areas, such as the North Atlantic, west of the Shetland Islands, these installations can be isolated by weather conditions for significant periods of time.

B.1.6.3 Health requirements

In many parts of the World there is specific health legislation, and industry guidance, that relates to the heath of the offshore workforce. These standards, many originally developed for the UK offshore oilfields, 1-19 have often been adopted by the industry in other parts of the globe, as accepted best practice.

Workers are expected to be free of medical conditions that might cause a safety threat to themselves, colleagues or others, and to be in a physical condition such that they can fulfil the critical physical capability aspects of their job. An on-board sick bay manned by a trained medic allows for diagnosis and treatment of intercurrent illness and injuries, the medic in turn is supported by higher level medical advice from doctors available for consultation onshore.

Individuals who are unlikely to return to work in a reasonable period of time, and those who are more seriously ill or injured, are evacuated by helicopter either on routine or emergency flights.

The medic will also supervise the installation’s food and water hygiene and will lead the health education initiatives that are regularly run offshore.


1          United Kingdom Continental Shelf Act 1964.

2          The Offshore Installations (Safety Case) Regulations SI 2005/311

3          Offshore Installations and Pipeline Works (Management and Administration) Regulations 1995

4          Offshore Installations and Pipeline Works (First-Aid) Regulations 1989 SI 1989/1671. London: The Stationery Office, 1989.

5          The Offshore Installations (prevention of Fire and Explosion, and Emergency Response) Regulations 1995. Approved Code of Practice and Guidance L65. London: HSE Books, 1995.

7          Energy Institute. A recommended fitness standard for the oil and gas industry
London: Energy Institute 2010

8          Energy Institute. Fitness assessment manual. London: Energy Institute 2011

9          Energy Institute. Medical standards for fitness to wear respiratory protective equipment. London: Energy Institute 2011

10        Energy Institute. Guidelines for the medical aspects of work for the onshore oil industry. London: Energy Institute. 2011

11        Oil and Gas UK. Guidelines for medical aspects of fitness for offshore workers. Issue 6. London: Oil and Gas UK 2008.

12        Basic offshore safety induction and emergency training and further offshore emergency training. Offshore Petroleum Industry Training Organisation, Aberdeen, 2003.

13         UK Civil Aviation Authority.  Safety review of offshore public transport helicopter operations in support of the exploitation of oil and gas. CAP1145 report   20 February 2014. 

14        Minimum Industry Safety Training Standard (MIST) Revision 1 Amendment 2. Standard code: 5301. Offshore Petroleum Industry Training Organisation, Aberdeen, 2017.

15        UK Offshore Operators Association. Industry guidelines for first aid and medical equipment on offshore installations. London: UK Offshore Operators Association, 2000.

16        Oil and Gas UK. The management of competence and training in emergency response for offshore installations. London: Oil and gas UK, 2010. Oil & Gas UK.

17        Equality Act (Offshore Work) Order 2010 HMSO, 2010.

18        Energy Institute. Guidance on Health Surveillance Energy Institute. London 2010

19        UK Offshore Operators Association. Environmental health guidelines for offshore installations, Issue 3. London: UK Offshore Operators Association, 1996.

B.1.6.4 Platform Supply Vessels

Platform Supply Vessels or Offshore Support Vessels are critical purpose built vessels that sustain the demands of the offshore energy production, construction and maintenance projects. They are typically 50-100m in length with a crew of up to 351,2 and are specifically designed as logistical support to oilfield operations. They fulfil many roles including the delivery of materials, plant, tools and equipment, general supplies and containered food, carried above deck, with bunkered fluids such as Diesel fuel, drilling mud, chemicals, or potable water, below decks.  These vessels fulfil a vital necessity in the support of oilfield operations on the high seas.

In some areas they are also the principle method of transportation of the crew. Some vessels have a firefighting capability and are equipped with fire monitors for fighting platform fires. Others are equipped with oil containment and recovery equipment to assist in the clean-up of an oil spill at sea.

These vessels are also used for the removal of installation waste and rubbish, anchor handling and may also be used to stand off platforms providing a search and rescue function.

The crew remain on board for 4-6 weeks usually on a 12hr rota. Accommodation may involve shared bathroom facilities, with common mess and entertainment facilities.

Crew members are expected to fulfil the normal criteria for seafarers’ medical standards,3  and in addition, to maintain a level of fitness that reflects the heavy manual tasks associated with the duties of loading and unloading these vessels whilst at sea in inclement conditions.

Platform Supply Vessels do not normally have a dedicated medic on board, but may have an advanced first aider, with the crew trained in first aid. Medically trained personnel may be included where the vessel has increased Persons On Board in remote operations.

B.1.6.5 Diving Support Vessels

Diving support vessels (DSV) are specifically designed and equipped with professional diving equipment for effective diving operations in harsh environments. This often includes full saturation diving facilities with an underwater bell and on board decompression facilities. DSVs are used for underwater diving operations carried out below and around oil production platforms and their related facilities. They are used for the inspection, maintenance and underwater repair of production platforms and related installations in open waters below the surface. They are also used in pipeline maintenance, construction and well intervention. Further information on diving can be found in Ch 3.2.8.


1          Marine Insight.    www.marineinsight.com

2          Wartsila Encyclopaedia of Marine technology.        www.wartsila.com/encyclopedia

3          UK Government Maritime and Coastguard  Agency.     https://www.gov.uk/guidance/seafarers-medical-certification-guidance

4          Offshore Fleet  www.offshore-fleet.com

B.1.6.6 Relationship between operators and contractors

Whilst the licence owners of the oil field will be represented as the Operator of the oil installations with core production and maintenance crew, many of the offshore skills will be represented by contractor crewmembers. This allows for the changing operations involved and certain roles may be sub contracted by the contractor. This includes construction operators, scaffolders, crane drivers etc.

Platform supply vessels and diving support vessels will be hired on contract for defined periods which reflect daily offshore activity and longer term general economic variation. They may be owned by the same parent company or a contractor.

The staffing of both rigs and vessels with operator staff, contractor, sub-contractor and even sub sub contractor staff can be difficult in terms of employment contracts, schedules, the willingness of crew to seek health care on board and evacuation if necessary and for cohesiveness of the crew on board.