THERE can be fewer workplaces which could be deemed to be as high risk in terms of health and safety than working on an oil rig. Thankfully, due to the stringent regulations in place and the expertise of the companies who are involved in the industry, major catastrophes are few and far between.

Working aboard oil rigs requires great attention to all aspects of safety including reducing risk for employees. This work environment is a mixture of a construction site and chemical plant rolled into one – with all the hazards associated with these workplaces and more.

On an oil rig, either off-shore or on land, working at heights, slips, trips and falls, working in enclosed environments, chemical safety, and fire hazards all need to be considered, as does work in confined spaces.

Personal protective equipment and clothing are all important. Training is paramount both in hazard avoidance and what to do if a hazard should occur.

Every piece of equipment on both off-shore and land oil rigs, is identified with a code. This code means that it has been tested and is safe to use from the most recent equipment testing process. Equipment with recent codes is safe to use.

Items like alcohol, matches and lighters should not be taken aboard any oil rigs. Other forbidden items include flammable items, illegal drugs and weapons. 
All luggage is checked before coming aboard an offshore oil rig to ensure the safety of all people onboard. Batteries should be removed from electrical equipment; cellphones should be turned off.

 

Employees who work onshore in oil productions have a basic workday of 8 hours, for 5 days. This differs to oil rigs offshore as they tend to work 7 day weeks and 12 hours a day then they may have 7 days off. Drilling operations will work continuously for 24 hours and or until oil has been discovered and fully pumped then drained. Working offshore the workers will be transported by boat or helicopter to and from the oil rig platform.

The lowdown on oil

Petroleum or crude oil is an oily, flammable liquid that occurs naturally in deposits, most often found beneath the surface of the earth.

Over millions of years, plant and animal remains fall to the floor of shallow seas. As the seas recede, the plant material is covered by sediment layers, such as silt, sand, clay and other plant material. Buried deep beneath layers of rock, the organic material partially decomposes, under an absence of oxygen, into petroleum that eventually seeps into the spaces between rock layers.

As the earth’s tectonic plates move, the rock is bent or warped into folds or it “breaks” along fault lines, allowing the petroleum to collect in pools. Early Man was not unfamiliar with crude oil. In the Middle East escaping petroleum gases burned continuously, giving rise to fire worship.

 

Oil Industry

The oil industry began over five thousand years ago. In the Middle East, oil seeping up through the ground was used in waterproofing boats and baskets, in paints, lighting and even for medication.

Whale oil has been used in more recent times as a source of light. However, the high premium for whale oil decimated whale populations and as their numbers dropped the prices rose further. Many companies and individuals were looking for an alternative and longer lasting source of what would later become known as black gold. Apart from a brief period of coal oil, the answer came with the development of drilling for crude oil.

 

Land oil wells were first and as demand continued to grow exploration companies began to look below the sea bed.

 

Oil Wells

An oil well is a general term for any boring through the Earth’s surface designed to find and produce petroleum oil hydrocarbons. Usually some natural gas is produced along with the oil, and a well designed to produce mainly or only gas may be termed a gas well. The creation and life of a well can be divided up into five segments:

• Planning
• Drilling
• Completion
• Production
• Abandonment

Oil wells come in many varieties. By produced fluid, there can be wells that produce oil, wells that produce oil and natural gas, or wells that only produce natural gas. Another obvious way to classify oil wells is by land or offshore wells. There is very little difference in the well itself. An offshore well targets a reservoir that happens to be underneath an ocean.

Due to logistics, drilling an offshore well is far more costly than an onshore well. By far the most common type is the onshore well. These wells dot the Southern and Central Great Plains, Southwestern United States, and are the most common wells in the Middle East.

 

Drilling Rig


A drilling rig is a machine that creates holes (usually called boreholes) and/or shafts in the ground. Drilling rigs can be massive structures housing equipment used to drill water wells, oil wells, or natural gas extraction wells or they can be small enough to be moved manually by one person. They sample sub-surface mineral deposits, test rock, soil and groundwater physical properties, and to install sub-surface fabrications, such as underground utilities, instrumentation, tunnels or wells. Drilling rigs can be mobile equipment mounted on trucks, tracks or trailers, or more permanent land or marine-based structures (such as oil platforms, commonly called ‘offshore oil rigs’). The term “rig” therefore generally refers to the complex of equipment that is used to penetrate the surface of the earth’s crust.

Emergency response on land rigs

If emergency responders have never been around a drilling operation, they may lack situational awareness of the true hazards to which they are being exposed. Many responders feel the biggest hazard they face on drilling locations is fire. Although this is a real hazard, you cannot overlook the fact the underground formations also contain hydrogen sulfide hazards and overpressurization hazards.

The site has open pits that contain water and drilling fluid (called mud) that, if not noticed, can be a place where the unaware emergency responder may fall in and be unable to get out of because of the slick linings and the weight of his PPE, once it becomes soaked with drilling fluid or oily water.

The rig itself presents hazards from its moving parts, trip hazards, and fall from height hazards, etc. Many drilling rigs have been modified from their original design to allow for quicker set-up time. These modifications often come in the form of removing handrails and chains that protect drilling rig workers from fall hazards.

The health and safety professional should make regular site audits of the location to ensure the rig is not modified in a manner that exposes employees and emergency responders to undue hazards. It is important that safety be stressed to emergency response organizations and that site safety awareness training be offered at no charge to emergency response organizations that have the potential to respond to an energy exploration company’s drilling location.

Along with the exploration company’s contingency planning process, it also is required to contact the people who live nearby who could be affected if a release of natural gas or poisonous hydrogen sulfide were to occur.

 

Oil at sea

The first oil well structures to be built in open waters were in the Gulf of Mexico. They were in water depths of up to 100m and constructed of a piled jacket formation, in which a framed template has piles driven through it to pin the structure to the sea bed. To this, a support frame was added the working parts of the rig such as the deck and accommodation. These structures were the fore-runners for the massive platforms that now stand in very deep water and in many locations around the world.

 

Blowouts

Blowouts are easily the most dangerous and destructive potential disasters in the world of oil drilling. Not only can they lead to serious injury and even death, but they can also cause massive, debilitating production shut-downs and can have a negative effect on future production from the lost well.

Blowouts can also cause severe ecological damage. As with any potential disaster, prevention is the first step in avoiding an otherwise costly and dangerous situation. These preventative measures are called, collectively, Well Control.

 

“A clearer phrase [than Well Control] might be Blowout Prevention,” said Barry Cooper of Well Control School, an organization, which has offered well control training programs to the oil and gas industry for more than 25 years. “Blowout Prevention is simply the training and understanding of how to prevent this from happening.”

Blowout prevention is a very broad term that can encompass anything from the precautionary methods used on rigs to prevent “kicks” — the unexpected and undesired flow of formation fluids into a well — from developing, to the use of sophisticated devices called Blowout Preventers (or BOPs) designed to close off a well in the face of a looming blowout.

 

Be prepared

The first stage of blowout prevention is preparedness. Most countries and corporations require certification in well control practices from all drilling employees, a policy that underscores the potential danger of a blowout.

 

To prevent kicks, drilling operators must use “drilling mud,” otherwise known as drilling fluid, a viscous mud-like substance that comes in varying densities, to balance the tremendous upward pressure of the formation fluids surging up the well. The downward pressure of the drilling fluid is called bottomhole pressure. Drilling fluid engineers must be vigilant and careful to ensure that the pressures reach equilibrium, a tedious but vitally important task.

“The working [drilling] fluid in a well is considered the primary barrier against blowouts,” explained Cooper. “Theoretically, if the formation pressure is greater than the bottomhole pressure, formation fluids could enter a well and, if uncontrolled, develop into a blowout.”

 

Blowout Preventers

Should a kick develop, though, there are several fail-safes in place. These heavy, specialized devices are called Blowout Preventers (BOPs). BOPs are essentially large valves on the surface of the well that quickly shut off the well as a last-ditch precaution to prevent a kick from becoming a blowout. Often, different types of BOPs are used in an arrangement configuration, called a “BOP stack.”

 

BOPs come in two main types: annular preventers and ram preventers. Ram preventers move two opposing rods horizontally across the top of the well. Ram blocks on the ends of the shafts create a seal around the pipe. Ram blocks come in various sizes and designs to cope with specific drilling operations.

Annular preventers use an elastomer packer squeezed across the annulus (the void in the well through which drilling fluid is circulated) in a smooth upward-and-inward motion to cork the well and prevent upward movement in the wellbore.

 

Annular preventers are usually the preventer of choice because the packer will form a seal around any diameter tubular or wireline that may be in the well at the time a kick is taken. However, both types are usually employed in stacks, highlighting the seriousness with which safety is taken where blowouts are concerned.

 

It is vitally important to recognize and address the situation as quickly and safely as possible, and then act accordingly. The great challenge for the crew is recognizing a developing well control incident and taking appropriate action.

 

Case study – Deepwater Horizon

There has been a lot of debate about the giant oil spill in the Gulf of Mexico in May 2010, which was caused by the fire and explosion on a Transocean offshore drilling rig, the Deepwater Horizon.  The blowout preventer seems to have failed.

While drilling for oil or gas the rig drills into pockets of oil, gas embedded in layers of rock that have been sealed off from the surface for millions of years. During that time natural gas has built up to an incredible pressure. Normally these high pressures are dealt with by keeping the hole full of heavy fluid or drilling mud that contains the mineral barite. When the weight of the drilling fluid or mud cannot hold back this pressure, an oil rig blowout can occur if quick action is not taken.

BP executives appeared before a House Energy Committee meeting when it was revealed that a combination of factors led to the failure of the BOP or blow out preventer device. A dead battery in a device called a “deadman trigger” as well as a leaking hydraulic house were both possibly part of the cause of the failure of the BOP to activate.

Operators on the surface tried to activate a device that initiated the “blind ram