How Drilling for oil offshore is done?

The world produces over 82 million barrels of oil every day, much of it in harsh conditions, miles from shore and safety in the event of an emergency. So how is it done?

Oil has been around for millions of years, located deep below the land or sea where it became trapped under layers of permeable rocks, or slowly seeping to the surface. Although examples of oil drilling were documented in 4th Century China, the fi rst modern oil-gathering structure was built in 1897, and by 1928 mobile rigs consisting of a simple barge with a drill mounted on top had set the scene for a revolution that fuelled Western industrial dominance for the next century.  Over 82 million barrels of oil are produced every single day, a process that usually starts with a range of surveys. These include geographical and geomagnetic surveys and the deep echo sounding or seismic refl ection surveys that pinpoint the likely location of a substantial deposit. Only then – and after the necessary permits have been obtained – can the rigs move in. These multi million-pound structures are positioned by teams of professionals who make the well safe and drill down to its precious commodity.  Today, there are over 40,000 oil fi elds around the world, with most offshore drilling undertaken in the Continental shelf – the sunken perimeter of a continent’s original glacial shape. From the $100 million monsters that plumb the deepest waters in the Gulf of Mexico, to the smaller North Sea structures that nevertheless have to withstand 90-knot winds and 20m waves. Mobile rigs are usually reserved for exploratory work, owned by private contractors and leased to the oil companies who then have limited time to fi nd, tap and process their precious bounty. Larger manned platforms and spars can service up to 30 wellheads, tapping into multiple wells up to 8km from the platform itself.

Life on a platform

Required to work for up to six months a year, oil workers are well compensated for the undeniably hazardous conditions in which they work. Wages are typically higher than in similar engineering disciplines and the larger platforms and spars come complete with facilities more appropriate to a cruise ship than a fl oating factory. These can include private rooms for the 100+ crew, cinemas, 24-hour restaurants and even gyms. Supplies are usually brought in by helicopter or ship, making oil platforms better stocked than most workplaces and signifi cantly more important to the local economies in which they reside. It is estimated that every offshore worker supports up to ten more in local industries such as food, transport or maintenance. However, the dangers are constant and largely unpredictable. Offshore drilling involves not only dealing with highly fl ammable oil and gas – with the added danger of this being pumped out at exceptionally high pressures – but also extreme wind and sea conditions. When danger strikes, support is often miles away by helicopter or ship, and despite the high levels of training and increasingly safe equipment, offshore fatality rates have been on the rise in recent years. In addition to this, workers are often prone to alcoholism or drug abuse to overcome the isolation and gruelling 12-hour shifts. 

Oil rig teamwork

Offshore installation manager

 Also known as the Man in Charge (MIC) the installation manager makes all key production decisions, both before, during and after drilling. He has usually worked his way through the other drill team roles.

Driller

 A highly specialist discipline, the drillers are those who operate the drilling equipment, including making the initial hole in the seabed. The driller is effectively in charge of everything that happens on the rig fl oor.

Derrickman 

So called because of their position at the top of the derrick, derrickmen are usually  working roughnecks responsible for guiding the pipe into the drill as well as operating mud pumps and other such machinery.   

Roughneck

The grunts of the oil business, roughnecks work in teams of three and are mainly responsible for manual work both during and after drilling. They can also be called on to operate other equipment such as mud shakers. 

Tool pusher 

On an offshore rig, tool pushers tend to be department heads in charge of drilling or other essential functions such as engineering or operations. They may also assist with administrative work, such as payroll or benefits. 

THE RIGHT RIG FOR THE JOB

Drill Ships

 Designed for speculative or deep-water mining, these vessels are converted to include a drilling platform in the centre. Drill ships use sophisticated sensors and satellite tracking to keep them moving while lined up to the well. 

Semi-submersibles

 Made up of fl oating pontoons and columns able to sink in the water where they are anchored to the sea fl oor or kept in place by steerable thrusters. Effective at drill depths of up to 1,800m, they’re designed for quick deployment.

 Jack-up

Mobile platforms can be raised above the sea on extendable steel legs. Designed for depths of 500m or less, they are useful for small to midsized deposits and typically only support smaller crews.

 Rig

 An immovable structure of concrete and steel that rests on the seabed with deck space for multiple rigs, crew quarters and production facilities. Their design and expense makes them appropriate for larger offshore deposits. 

Spar 

Perfect for major oil fi elds, such as the North Sea, spars are drilling platforms fi xed to giant, hollow hulls that can descend up to 250m, still above the ocean fl oor and secured by cables.