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Infrastructure & Design

Safe and Efficient Operations in Deepwater
- Dr. Zafar Khan, Deputy General Manager – HSE, Leighton Welspun Contractors Pvt Ltd
Oil and gas industry is one of the most favoured industries in the industrial sector as many professionals opt to make a career out of it. However, it is also considered to be one of the most potential high risk areas to work under, as it deals with the exploration and production of flammable liquids. This article mainly discusses and emphasizes safety issues that arise in deep marine conditions as this particular location deals with the exploration and production of petroleum. The article not only strikes out safety issues encountered during the construction phase, but also during the operation phase once an offshore structure has been constructed and installed.

Petroleum which supports most of the daily human activities could be found on both, land as well under the ocean. There are two distinct terms which describe the location of exploration and production of oil and gas, viz, Onshore and Offshore. Onshore can be referred to as a location on land where petroleum is found and then explored, whereas exploration of petroleum in open sea can be termed as an offshore area. An Offshore platform is situated in deep sea wherein water depth could reach more than 2,000 meters.

Construction and operations in deep marine conditions have significant differences when compared to onshore operations or other non-oil and gas projects. Installation of offshore infrastructure also involves numerous equipment’s, tools, labourers and funding. The rent for an accommodation and crane barge for installing a new structural part of existing fixed platforms on an offshore location for a period of 24 hours could cost around USD 100,000. One can only imagine the amount that needs to be spent on a large scale project.

The offshore industry deals with an unusual combination of problems from the safety point of view. They include:
  • High pressure systems up to 300 bar and sometimes to 500 bars;
  • A high (300 tonnes) inventory of explosive and flammable material;
  • Extensive electrical system, often at voltages as high as 6.6 KV;
  • Large scale machinery such as gas turbines, compressors and pumps;
  • All plants placed in a confined space;
  • Living quarters very close to a working plant;
  • Evacuation of personnel difficult if not impractical in the most adverse
  • weather conditions;
  • Installations, all individually designed to meet specific requirements;
  • Installation life of 20 to 30 years;
  • Installation to be modified during their life, to meet changes in field behaviour.
Case Study
The Tragedy of Piper Alpha (1988) could give brief a view about the importance of safety in the offshore industry. Piper Alpha was a North Sea oil production platform operated by Occidental Petroleum (Caledonia) Ltd. The platform began production in 1976, first as an oil platform and then later converted to gas production. An explosion and the resulting oil and gas fires destroyed it on 6 July 1988, killing 167 men, with only 61 survivors. The death toll includes two crewmen of a rescue vessel. Total insured loss was about USD 3.4 billion. At the time of the disaster, the platform accounted for approximately 10 per cent of North Sea oil and gas production, and was the worst offshore oil disaster in terms of lives lost and industry impact.

Identifying Hazards
Safety issues on deep marine construction need to be taken into account by stakeholders, oil company, engineering consultant, installation contractor and other vendors. First step to deal with safety issues is the identification of a hazard. Hazard is anything that has a potential to cause harm (e.g., chemicals, fire, explosion, electricity, a hole in the ground, etc.). Hazards usually occur from machines and processes, emissions, radiations, etc.

Hazards to Humans
During an installation sequence at an offshore site, there are quite a lot hazards that could happen to humans. One of them is skin contact by chemicals which have an immediate destructive effect. However, type of chemicals used during offshore installation or operation has no immediate destructive effect. They are harmful to human skin, but not so destructive and could be prevented. For instance, various types of liquids for topside painting, oils used as lubricant for machines, crude oils, various types of chemical liquids used for operation purpose. But skin damage caused from petroleum products could have fatal effects. It could trigger possible cancerous effects in case of long-term exposure.

Hydro test of piping on topside platform could also have hazardous effects. High-pressure jets by air penetrations into the bloodstream can cause death. In addition, all materials nearby the hydro test area are hazards to humans.

Eye contact by spray, mists, high vapour concentrations and harmful rays can be classified as hazards. Grinding activities during installation phase is one of the sources of small particles that could hurt someone’s eye. Moreover, fire from welding activities is also harmful to a worker as the glow emitted due to the welding process is of high intensity and could damage the retina.

Hazards from Machines and Processes
Hazards from machines and processes on deep marine construction condition usually occur from cranes and welding machines. Welding machines are situated on topside platforms; they could be positioned at cellar, sub-cellar, or top deck. These welding machines run on high electricity voltage and flammable fuels. Since all these locations are near to heavy working locations, there is a possibility that a worker may come in contact with a welding machine which is in operation. Furthermore, once the platform has been commissioned and operated, there would be another hazard which arises from processes itself. Improper installation and lack of maintenance of all parts of infrastructure for supporting the processes would be hazardous.

Hazards from Emissions
Machines and engineered process plants produce waste streams, these are unwanted emissions. The unwanted emissions are burnt out before they are released to the air. Carbon monoxide (CO) emitted from welding machines, power machines, cranes, and other machinery is released in the air and often finds its way and enters the work area, which could lead to an unwanted hazard. During installation of structural parts of offshore platforms, welding cannot be avoided. As a consequence, Non Destructive Test (NDT) is also required. For particular joints, NDT has to be performed using X-ray or radiography method. Radiation of from that activity is classified as a hazardous emission. In addition, water pollutants generated as a result of human activities on the accommodation barge could also have hazardous effects on human health. Hence, unwanted wastes from food have to be collected properly, and not disposed directly into the sea. Other emission that occurs during construction and operation on deep marine condition is noise emission in the form unwanted sound produced by working machinery and plant. It could be continuous, intermittent, or erratic, depending on the source. Noise could cause hearing damage. Ability for communication could be also affected by noise; therefore important consideration needs to be taken into account for designing control rooms or cabins.

Hazards from Circumstances
The latent energies are hazardous, which if released could pose danger to life and limb. Potential energy is one of the latent energies, for example, people or loads falling from a height. Riggers, during installation stage on deep marine condition are people who have the highest risks with regards to this hazard. They have to climb to a particular height for assisting the crane operator during moving and placing of an object from one point to another. Moreover, lifted objects are those which have latent energies and all workers standing up on lifting region have risks. Other latent energy is kinetic energy release. It could be due to explosions, release of moving components due to failure of pressure vessels, components of engines and vehicles, etc.

Dangers from electrical energy could be occurred due to live components, insulation problems, or residual stored energy. Competent engineers who have already worked for this field have to ensure that all electricity sources are well maintained and well controlled during installation phase, as well as during operation stage of platform and construction of smaller parts on topside.

Fire, is a common hazard which could break out in all areas, could also occur in deep marine conditions. Fire could occur due to the presence of three components which are heat, fuel, and oxygen; therefore, fire could be prevented by separating or insulating each of these components. Fuels used on deep marine condition could be painting liquids, LPG, fuels for machines, and others.

The presence of too many equipment’s, tools, machines, raw materials, structural parts, and the limitation of space on the platform, work and transportation barges, could create an entrapment for the worker. In such a scenario, a situation involving fire / gas release or explosion could prove fatal. Hence, design engineers should be careful during carrying out designing process of these platforms and design a proper layout for positioning all areas involved during installation or operation phase of a platform.

Weather conditions
Sometimes due to bad weather, workers have to leave their work incomplete. This condition leads to a potential hazard. For example, jobs for constructing scaffolding in rehabilitation work at topside area. A Scaffolder has to put specific tag on his incomplete job when he has to leave his work site. The tag could be a sign that the scaffolding structure could not be completed due to work stoppage. On the following day, other workers will notice the tag on the scaffolding and carry out work activities accordingly

Safety Integration
Knowing or identifying hazards have already been presented in this article. This section mainly discusses how to deal with the resulting risks. Which are:
  1. Alter designs to avoid a hazard;
  2. Provide facilities to reduce risk from a hazard by design;
  3. Develop procedures to protect exposed persons;
  4. Provide means for personnel protection.
Safety integration is the provision in a design to provide risk control of hazards. In an ideal condition, hazards could be minimized by a design in accordance with the hierarchy. In a particular condition, for instance, in offshore industry which deals with petroleum (flammable) materials, fire and explosion could not be avoided, but risk of fire and explosion will be specific to a particular area of a platform. The designer who designs the layout of a particular platform has to consider these hazards. In addition, computerized control room, CCTV control centre and storage tanks with flammable fluid could also be situated far away from process areas. Since the control room has to be situated close to high risk areas, the designer could design fire and blast proof control rooms. It could also be equipped with suitable hazard control devices.

Safety Culture
It has been widely known that people could not be changed and that therefore the work conditions have to be changed accordingly. However, there is still a possibility to engineer systems that could reduce the risk of human error and experience has shown that this is not enough. Worker’s attitude has to be changed. A safety culture has to be created. All stakeholders involved in deep marine industry have to establish controlled safety policies. Those include, Oil Company as the operator of the offshore field, consulting firm which designs everything and contractors who install the infrastructure. Safety policies for each those parties could be different; therefore, a meeting / coordination need to be held before the project commences.

Conclusion
Working in deep marine condition involves a lot of things to be considered, especially the aspect of safety. Enforcement of safety in deep marine condition has to be started from the project design phase, installation or construction and during the operation stage. First thing that has to be performed is identifying the hazards and risks. Once the possible hazards and risks have been identified, the next action that needs to be performed is to establish safety integration among the stakeholders of the project. It could be done by reinforcing safety culture and establishing safety policies.