How Oil Drilling Works

Oil Rig Information Guide

What is an Oil Rig and what happens there?

An Oil Rig is, essentially, a means of removing the oil from a reservoir and processing that oil for forward delivery to a refinery. The most prominent process is ‘separation’, as there is usually water associated with the oil when it is brought to the surface.

This separation is achieved by the measured use of demulsifying agents, temperature and vessel engineering, in combination with numerous outlying methods.

Essentially, the oil destined for a refinery should be a dry as possible and the water separated from the oil in the process should be as free from oil as possible, as it will become a waste product. On a rig based in the sea, this latter issue is particularly poignant, as the produced water will either be re-injected into the reservoir, or it will be pumped into the sea. There are strict regulations as to how much oil a rig is allowed to put into the sea and, in the UK sector, the DTI (Department of Trade and Industry) regularly inspect all North Sea Operations to ensure they adhere to the regulations.

What does an Oil Rig look like?

Oil Rigs in the North Sea can take on many forms. Some stand on the sea bed, some float and are tethered to the sea bed. Those which are tethered do exhibit movement in response to the sea, but are extremely secure.

They are very functional structures, built to withstand the climate they exist in and, as such, they are not usually particularly pleasing to the eye. Sea rigs will exhibit extensive surface rusting as a result of the sea water.

Who works on the rigs and what do they do?

A rig cannot function without a solid infrastructure of workers, ensuring not only the function of the process itself, but also the welfare of the employees and the general maintenance of the rig.

As a result, there are a number of different groups working on a rig at any one time, including, but not limited to, the following:

• Operations staff (process)• Stewards (housekeeping, laundry, meals etc.)• Drilling team (during drilling operations)• Medic (healthcare)• Services (logistics, storage, materials)• Scaffolders (temporary structures, barriers etc.)• Maintenance (welders, painters, electricians etc.)• Well Services (maintenance of wells)

All employees work together as one large team to ensure that the rig can function self-sufficiently. In addition to the specific roles that core crew members perform, they will also be required to perform an additional or emergency function. This could be as a member of the helideck crew (ensuring the safe landing and takeoff of helicopters), a member of the fireteam or a very specific role, such as a gas tester.

What is the accommodation like?

The accommodation section of a rig is very functional. You will usually find the following, although not all rigs are the same:

• Cabins (bed, Shower, toilet, TV etc)• Galley or mess (dining room)• TV lounge• Smoking TV lounge• Locker room• Health centre• Gym• Sauna• Recreation room (pool, snooker, darts etc.)• Computer room• Music room• Bond (shop)

Usually the only place you are allowed to smoke on a rig is in the accommodation, but there are very strict rules about where you can do this for the safety and comfort of everyone on board.

Is it safe?

Every member of staff/crew has a responsibility to ensure their own safety and the safety of others. The Operating companies are responsible for providing a safe place of work, but, ultimately, it is essential that the team work together to ensure ongoing safety on a rig.

There are regular safety meetings where any unsafe events are discussed, arising on that rig or on any other rigs across the world, to ensure that lessons are learnt and behavior or equipment adjusted accordingly.

There is a weekly ‘muster’, which is an emergency exercise is conducted and all personnel on board react accordingly. This is to ensure that all personnel are fully aware of how to respond in a real emergency situation. It is a little like a fire drill onshore with the obvious added complexities.

All personnel are encouraged to react to any unsafe actions or events that they witness and each rig has a system which allows these to be reported, catalogued and responded to. In extreme situations, personnel are advised to call the platform emergency number or to activate the General Platform Alarm (GPA). Should this happen, the event is responded to in the manner rehearsed in emergency exercises.

All risks are managed in order to keep the risk ALARP (As Low As Reasonably Practicable) by the use of Permit to Work systems and strict Risk Assessment.

If you have never been offshore before and are considering moving into the offshore industry, do you really know if it’s the job for you?

Offshore employment can be demanding; as a rule, work patterns are organised into 12 hour shift patterns and employees usually live on the platform for 2 to 3 weeks at a time(UK North Sea).

All offshore employees are rigorously trained in safety and environmental regulations and are expected to adhere to them at all times, to ensure the safety and protection of the people and the environment around them.

Whilst each operating company works to minimise the risks present on their installations, residual risks will always remain for as long as there is a human factor involved.

If you are the kind of person who does not take well to regulations, rules and authority, then offshore work is not for you.

Before you can even set foot on an offshore installation, you will need the following:

• BOSIET (Basic Offshore Safety Induction and Emergency Training)• UKOOA Medical (Medical approved by the United Kingdom Offshore Operators Association)

BOSIET (Basic Offshore Safety Induction and Emergency Training): The course consists of four modules; Safety Induction, Helicopter Safety and Escape (HUET), Sea Survival and First Aid, Fire Fighting and Self Rescue. The BOSIET is required for cold water areas and includes additional training in the use of survival suits and emergency breathing systems during the HUET module. The courses are OPITO accredited and successful completion results in an internationally recognised certification.

The Difference between BOSIET and T-BOSIETThe difference between T-BOSIET and BOSIET is the T-BOSIET is designed for tropical climates, i.e. warm water such as here in the Arabian Gulf, the Far East, Malaysia etc. The T-BOSIET does not include the cold water element of the full BOSIET course (survival suits and emergency breathing systems are not used during the HUET training) and is therefore more applicably to our clients in this region.

How Oil Drilling Works

Photo courtesy Phillips Petroleum Co.

Offshore oil rigIn January 2001 alone, the United States produced an estimated 181 million barrels of crude oil and imported 273 million barrels from other countries. This oil gets refined into gasoline, kerosene, heating oil and other products. To keep up with our consumption, oil companies must constantly look for new sources of petroleum, as well as improve the production of existing wells.

How does a company go about finding oil and pumping it from the ground? You may have seen images of black crude oil gushing out of the ground, or seen an oil well in movies and television shows like "Giant," "Oklahoma Crude," "Armageddon" and "Beverly Hillbillies." But modern oil production is quite different from the way it's portrayed in the movies.

In this edition of HowStuffWorks, we will examine how modern oil exploration and drilling works. We will

discuss how oil is formed, found and extracted from the ground.

Oil ExplorationOil is a fossil fuel that can be found in many countries around the world. In this section, we will discuss how oil is formed and how geologists find it.

Forming OilOil is formed from the remains of tiny plants and animals (plankton) that died in ancient seas between 10 million and 600 million years ago. After the organisms died, they sank into the sand and mud at the bottom of the sea.

Oil forms from dead organisms in ancient seas.

Over the years, the organisms decayed in the sedimentary layers. In these layers, there was little or no oxygen present. So microorganisms broke the remains into carbon-rich compounds that formed organic layers. The organic material mixed with the sediments, forming fine-grained shale, or source rock. As new sedimentary layers were deposited, they exerted intense pressure and heat on the source rock. The heat and pressure distilled the organic material into crude oil and natural gas. The oil flowed from the source rock and accumulated in thicker, more porous limestone or sandstone, called reservoir rock. Movements in the Earth trapped the oil and natural gas in the reservoir rocks between layers of impermeable rock, or cap rock, such as granite or marble.

Oil reservoir rocks (red) and natural gas (blue) can be trapped by folding (left), faulting (middle) or

pinching out (right).These movements of the Earth include:

Folding - Horizontal movements press inward and move the rock layers upward into a fold or anticline.

Faulting - The layers of rock crack, and one side shifts upward or downward.

Photo courtesy Institute of Petroleum

Close-up of reservoir rock

(oil is in black)

Pinching out - A layer of impermeable rock is squeezed upward into the reservoir rock.

Finding OilThe task of finding oil is assigned to geologists, whether employed directly by an oil company or under contract from a private firm. Their task is to find the right conditions for an oil trap -- the right source rock, reservoir rock and entrapment. Many years ago, geologists interpreted surface features, surface rock and soil types, and perhaps some small core samples obtained by shallow drilling. Modern oil geologists also examine surface rocks and terrain, with the additional help of satellite images. However, they also use a variety of other methods to find oil. They can use sensitive gravity meters to measure tiny changes in the Earth's gravitational field that could indicate flowing oil, as well as sensitive magnetometers to measure tiny changes in the Earth's magnetic field caused by flowing oil. They can detect the smell of hydrocarbons using sensitive electronic noses called sniffers. Finally, and most commonly, they use seismology, creating shock waves that pass through hidden rock layers and interpreting the waves that are reflected back to the surface.

Searching for oil over water using seismologyIn seismic surveys, a shock wave is created by the following:

Compressed-air gun - shoots pulses of air into the water (for exploration over water) Thumper truck - slams heavy plates into the ground (for exploration over land) Explosives - drilled into the ground (for exploration over land) or thrown overboard (for

exploration over water), and detonated

The shock waves travel beneath the surface of the Earth and are reflected back by the various rock layers. The reflections travel at different speeds depending upon the type or density of rock layers through which they must pass. The reflections of the shock waves are detected by sensitive microphones or vibration detectors -- hydrophones over water, seismometers over land. The readings are interpreted by seismologists for signs of oil and gas traps.

Although modern oil-exploration methods are better than previous ones, they still may have only a 10-percent success rate for finding new oil fields. Once a prospective oil strike is found, the location is marked by GPS coordinates on land or by marker buoys on water.

Preparing to DrillOnce the site has been selected, it must be surveyed to determine its boundaries, and environmental impact studies may be done. Lease agreements, titles and right-of way accesses for the land must be

obtained and evaluated legally. For off-shore sites, legal jurisdiction must be determined.

Once the legal issues have been settled, the crew goes about preparing the land:

1. The land is cleared and levelled, and access roads may be built.2. Because water is used in drilling, there must be a source of water nearby. If there is no natural

source, they drill a water well.3. They dig a reserve pit, which is used to dispose of rock cuttings and drilling mud during the drilling

process, and line it with plastic to protect the environment. If the site is an ecologically sensitive area, such as a marsh or wilderness, then the cuttings and mud must be disposed offsite -- trucked away instead of placed in a pit.

Once the land has been prepared, several holes must be dug to make way for the rig and the main hole. A rectangular pit, called a cellar, is dug around the location of the actual drilling hole. The cellar provides a work space around the hole, for the workers and drilling accessories. The crew then begins drilling the main hole, often with a small drill truck rather than the main rig. The first part of the hole is larger and shallower than the main portion, and is lined with a large-diameter conductor pipe. Additional holes are dug off to the side to temporarily store equipment -- when these holes are finished, the rig equipment can be brought in and set up.

Setting Up the RigDepending upon the remoteness of the drill site and its access, equipment may be transported to the site by truck, helicopter or barge. Some rigs are built on ships or barges for work on inland water where there is no foundation to support a rig (as in marshes or lakes). Once the equipment is at the site, the rig is set up. Here are the major systems of a land oil rig:

Anatomy of an oil rig

Power system large diesel engines - burn diesel-fuel oil to provide the main source of power electrical generators - powered by the diesel engines to provide electrical power

Mechanical system - driven by electric motors hoisting system - used for lifting heavy loads; consists of a mechanical winch

(drawworks) with a large steel cable spool, a block-and-tackle pulley and a receiving storage reel for the cable

turntable - part of the drilling apparatus Rotating equipment - used for rotary drilling

swivel - large handle that holds the weight of the drill string; allows the string to rotate and makes a pressure-tight seal on the hole

kelly - four- or six-sided pipe that transfers rotary motion to the turntable and drill string turntable or rotary table - drives the rotating motion using power from electric motors drill string - consists of drill pipe (connected sections of about 30 ft / 10 m) and drill

collars (larger diameter, heavier pipe that fits around the drill pipe and places weight on the drill bit)

drill bit(s) - end of the drill that actually cuts up the rock; comes in many shapes and materials (tungsten carbide steel, diamond) that are specialized for various drilling tasks and rock formations

Casing - large-diameter concrete pipe that lines the drill hole, prevents the hole from collapsing, and allows drilling mud to circulate

Circulation system - pumps drilling mud (mixture of water, clay, weighting material and chemicals, used to lift rock cuttings from the drill bit to the surface) under pressure through the kelly, rotary table, drill pipes and drill collars

pump - sucks mud from the mud pits and pumps it to the drilling apparatus

pipes and hoses - connects pump to drilling apparatus mud-return line - returns mud from hole shale shaker - shaker/sieve that separates rock cuttings from the mud shale slide - conveys cuttings to the reserve pit reserve pit - collects rock cuttings separated from the mud mud pits - where drilling mud is mixed and recycled mud-mixing hopper - where new mud is mixed and then sent to the mud pits

Mud circulation in the hole

Drill-mud circulation system

Derrick - support structure that holds the drilling apparatus; tall enough to allow new sections of drill pipe to be added to the drilling apparatus as drilling progresses

Blowout preventer - high-pressure valves (located under the land rig or on the sea floor) that seal the high-pressure drill lines and relieve pressure when necessary to prevent a blowout (uncontrolled gush of gas or oil to the surface, often associated with fire)

The Oil Drilling Process: Drilling:

The crew sets up the rig and starts the drilling operations. First, from the starter hole, they drill a surface hole down to a pre-set depth, which is somewhere above where they think the oil trap is located. There are five basic steps to drilling the surface hole:

1. Place the drill bit, collar and drill pipe in the hole.2. Attach the kelly and turntable and begin drilling.3. As drilling progresses, circulate mud through the pipe and out of the bit

to float the rock cuttings out of the hole.4. Add new sections (joints) of drill pipes as the hole gets deeper.5. Remove (trip out) the drill pipe, collar and bit when the pre-set depth

(anywhere from a few hundred to a couple-thousand feet) is reached.

Once they reach the pre-set depth, they must run and cement the casing -- place casing-pipe sections into the hole to prevent it from collapsing in on itself. The casing pipe has spacers around the outside to keep it centered in the hole.

The casing crew puts the casing pipe in the hole. The cement crew pumps cement down the casing pipe using a bottom plug, a cement slurry, a top plug and drill mud. The pressure from the drill mud causes the cement slurry to move through the casing and fill the space between the outside of the casing and the hole.

Rotary workers trip drill pipe

Finally, the cement is allowed to harden and then tested for such properties as hardness, alignment and a proper seal.

Drilling continues in stages: They drill, then run and cement new casings, then drill again. When the rock cuttings from the mud reveal the oil sand from the reservoir rock, they may have reached the final depth. At this point, they remove the drilling apparatus from the hole and perform several tests to confirm this finding:

Well logging - lowering electrical and gas sensors into the hole to take measurements of the rock formations there

Drill-stem testing - lowering a device into the hole to measure the pressures, which will reveal whether reservoir rock has been reached

Core samples - taking samples of rock to look for characteristics of reservoir rock

Once they have reached the final depth, the crew completes the well to allow oil to flow into the casing in a controlled manner. First, they lower a perforating gun into the well to the production depth. The gun has explosive charges to create holes in the casing through which oil can flow. After the casing has been perforated, they run a small-diameter pipe (tubing) into the hole as a conduit for oil and gas to flow up the well. A device called a packer is run down the outside of the tubing. When the packer is set at the production level, it is expanded to form a seal around the outside of the tubing. Finally, they connect a multi-valved structure called a Christmas tree to the top of the tubing and cement it to the top of the casing. The Christmas tree allows them to control the flow of oil from the well.

Once the well is completed, they must start the flow of oil into the well. For limestone reservoir rock, acid is pumped down the well and out the perforations. The acid dissolves channels in the limestone that lead oil into the well. For sandstone reservoir rock, a specially blended fluid containing proppants (sand, walnut shells, aluminum pellets) is pumped down the well and out the perforations. The pressure from this fluid makes small fractures in the sandstone that allow oil to flow into the well, while the proppants hold these fractures open. Once the oil is flowing, the oil rig is removed from the site and production equipment is set up to extract the oil from the well.

Extracting the OilAfter the rig is removed, a pump is placed on the well head.

New Drilling Technologies

The U.S. Department of Energy and the oil industry are working on new ways to drill oil, including horizontal drilling techniques, to reach oil under ecologically-sensitive areas, and using lasers to drill oil wells.

Blowouts and Fires

In the movies, you see oil gushing (a blowout), and perhaps even a fire, when drillers reach the final depth. These are actually dangerous conditions, and are (hopefully) prevented by the blowout preventer and the pressure of the drilling mud. In most wells, the oil flow must be started by acidizing or fracturing the well.

Pump on an oil wellIn the pump system, an electric motor drives a gear box that moves a lever. The lever pushes and pulls a polishing rod up and down. The polishing rod is attached to a sucker rod, which is attached to a pump. This system forces the pump up and down, creating a suction that draws oil up through the well.

In some cases, the oil may be too heavy to flow. A second hole is then drilled into the reservoir and steam is injected under pressure. The heat from the steam thins the oil in the reservoir, and the pressure helps push it up the well. This process is called enhanced oil recovery.

With all of this oil-drilling technology in use, and new methods in development, the question remains: Will we have enough oil to meet our needs? Current estimates suggest that we have enough oil for about 63 to 95 years to come, based on current and future finds and present demands.

Enhanced oil recovery

Oil and Gas Value Chain

Natural Gas Value Chain

Exploration Production Processing Transportation Marketing

Using technologyto find new

oil resources

Bringing gas tothe surface

Treating gasto be sentto markets

Moving gaswith pipelinesand tankers

Distributingand sellingnatural gas

From Wellhead to Gasoline Pump

Crude Oil Value Chain

Exploration Production Transportation Refining Marketing

Using technologyto find new

oil resources

Bringing oil tothe surface

using naturaland artificial

methods

Moving oil torefineries and

consumers with

tankers, trucksand pipelines

Natural Gas Does More than Heat Our Homes

Let's start with natural gas.Natural gasproduced from beneath the earth's surface is transported by a system ofpipelines to consumers. The gas is burned to produce energy to heat homes, business, and industrial plants. Natural gas is also used to dry clothes and cook food.

Industries use natural gas to provide energy for various manufacturing processes. Automobile plants use natural gas to heat air to dry paint on cars and trucks. Food companies use natural gas to dry products like potato chips and pretzels. Industrial users also burn natural gas to produce steam for various operations.

Utility companies use natural gas to produce electricity. Natural gas is burned to produce steam, which drives turbines to generate electricity. So not only does natural gas keep us warm in the winter, it also helps keep us cool in the summer.

Natural gas is also being used as a transportation fuel. Compressed natural gas or CNG is used in government and company car and van fleets.

Oil and gas companies obtain other products from natural gas that help improve our lives. Natural gas contains compounds that are removed before the gas is sent to customers. Three important chemicals are obtained from natural gas: ethane, propane, and butane. Ethane is a raw material in the petrochemical industry. Ethane is processedto make ethylenethat is used to manufacture polyethylene. Polyethylene is a plastic that is used in a variety of products including house wares, insulation, packaging films, and toys. Ethylene is used to manufacture ethylene oxidewhich is a raw material to make ethylene glycol or anti-freeze for car and truck radiators. Ethylene oxide is used to prepare polyester fibers, film and latex paints. Ethylene is combined with chlorine to make vinyl chloride. Vinyl chloride is used to make polyvinyl chlorideor PVC for pipes. Ethylene is a raw material to manufacture vinyl acetate for paints and adhesives. Polystyrene manufactured from ethylene is used to make resinsfor rubber. Ethanol is also produced from ethylene.

Propane and butane from natural are blended to produce LPG for cooking and heating. Propane and butane are also used to manufacture the chemical building blocks: propylene and butylene. Propyleneoxide produced from propylene is used to sterilize medical and food products and to manufacture surfactants. Propylene glycol, made from propylene, is used as a moisturizer in skin care lotions and cream. Propylene glycol is used as industrial antifreeze and as hydraulic and brake fluid. Butylene is an important chemical used in manufacturing products that improve the quality of gasoline. LPG is also being used in transportation.

Natural gas is a raw material to make ammonia for agricultural fertilizer. Carbon black, which is used to reinforce rubber and make ink and batteries, comes from natural gas. Paints use lamp black formed from natural gas for tinting. Sulfur impurities contained in natural gas are removed to obtain raw materials for agricultural chemicals.

Crude Oil Products Keep Us MovingCrude oil is a liquid that comes from reservoirs below the earth's surface. It is called crude oil because it must be processed or "refined" into useable products like gasoline. Crude contains many different compounds with different properties. When these compounds are separated, they produce refined products.

The most important refined product is gasoline. Gasoline is burned in car and truck engines. Gasoline is also the most visible product produced by the oil and gas industry because of the presence of service stations and the importance of the automobile in American life. Think what your day would be like without gasoline.

No way to get to work, school, shopping plazas, movies, amusement parks, and beaches. The partnership between the automobile industry and the oil and gas industry has transformed the American lifestyle and given us greater freedom.

The next most important products from crude oil are home heating oiland dieselfuel. These are the same products except for some minor differences. Home heating oil is used to heat homes. Diesel fuel is used for fuel in truck, bus, train, and ship engines. Diesel fuel is one of the most important fuels in the world's economy because it provides energy to transport products from manufacturers to consumers.

Crude oil is also the source of jet fuel for airlines. Jet fuel allows us to move passengers and freight around the world in a fast and efficient manner. Jet fuel has helped to shrink the earth, allowed us to visit friends and family, and make new acquaintances all over the world.

Residual fueloil

is used for boiler fuel to power industrial plants. These boilers produce steam, heat, and electricity for use in manufacturing processes. Residual fuel is also use as bunker fuel in large ocean-going tankers.

Not only does crude oil provide the fuels that power engines it also produces the lubricants that reduce friction and the wear on the engine parts. Lubricants are used in car and truck motors, airplane engines, railroad engines, and turbines for power plants. Lubricants are also used to make salves, ointments, and cosmetics.

In addition to supplying the fuel used to transport people and products, crude oil also provides the asphalt to pave roads.

Petroleum coke

from crude oil is used to make electrodes to produce aluminum and as a raw material to manufacture steel.

Aromatic compounds from crude oil such as benzene, toluene, and xylene are important chemical building blocks and are used to manufacture plastics, agricultural chemicals and pharmaceuticals.

Offshore Oil Drilling

Not all oil is accessible on land or in shallow waters. You can find some oil deposits buried deep under the ocean floor. Reaching these oil deposits is dangerous, but if done correctly, it can also be rewarding. If things go wrong, however, the results can be deadly both for oil workers and the surrounding environment.

Using sonic equipment, oil companies determine the drilling sites most likely to produce oil. Then they use a mobile offshore drilling unit (MODU) to dig the initial well. Some units are converted into production rigs, meaning they switch from drilling for oil to capturing oil once it's found. Most of the time, the oil company will replace the MODU with a more permanent oil production rig to capture oil.

There are four main types of MODUs:

A submersible MODU usually consists of a barge that rests on the sea floor at depths of around 30 to 35 feet (9.1 to 10.7 meters). On the barge's deck are steel posts that extend above the water line. A drilling platform rests on top of the steel posts. These rigs are typically used in areas with calm water.

A jackup is a rig that sits on top of a floating barge. A ship tows the barge to the drilling site. Once positioned, the jackup can extend legs down to the sea floor. The legs are loaded in such a way that they don't penetrate the floor. Once each leg is secure, the jackup continues to ratchet the legs so that the platform rises above the water level. This keeps the rig safe from tidal motions and waves. Jackups can operate in depths of up to 525 feet (160 meters).

Drill ships are ships that have a drilling rig on the top deck. The drill operates through a hole in the hull. Drill ships can pilot to the drill site and then use a combination of anchors and propellers to correct for drift as the rig drills for oil. They can operate in deep water conditions.

Semisubmersibles float on the surface of the ocean on top of huge, submerged pontoons. Some have propulsion systems, which allow them to navigate to drilling sites under their own power while others require a second vessel to tow them to the right location. Most use several anchors -- up to a dozen -- that help maintain the structure's orientation. Computers control the tension on each anchor chain to correct for drift. Some can convert from drilling rigs to production rigs, reducing the need for a second rig to take its place once oil is found.

The MODU's job is to drill down into the ocean's floor to find oil deposits. The part of the drill that extends below the deck and through the water is called the riser. The riser allows for drilling fluids to move between the floor and the rig. Engineers lower a drill string -- a series of pipes designed to drill down to the oil deposit -- through the riser.

At the sea floor is the blowout preventer (BOP). The blowout preventer has a pair of hydraulically-powered clamps that can close off the pipe leading up to the rig in the case of a blowout. As the rig drills down, engineers must add more pipe to the drill string. Each section of pipe is about 30 feet long (9.1 meters).

To add stability to the well, the engineers use metal casings, much as they do with land-based oil rigs. These casings help keep the well from collapsing in on itself. Each casing is lined with cement walls. Casings get narrower as the well gets deeper. Oil companies use progressively smaller drill bits as the well's depth increases. At each annulus -- the spot where a narrower casing joins with a wider one -- engineers use a liner hanger O-ring to seal the two sections together.

When the MODU hits oil, engineers must seal the well to prepare it for a production rig. The engineers will use a pair of plugs to seal off the well bore. The bottom plug sits near the oil deposit. Drilling mud or

seawater provides the pressure to hold the plug in place while the engineers place a top plug to cap the oil well. Then the well is ready for a production rig to take over. Offshore production rigs work in a similar way to land-based oil rigs.

With all of this oil-drilling technology in use, and new methods in development, the question remains: Will we have enough oil to meet our needs? Current estimates suggest that we have enough oil for about 63 to 95 years to come, based on current and future finds and present demands.

Lots More Information

Related Articles

Oil Shale Quiz How Oil Refining Works How Gas Prices Work How Gasoline Works How Earthquakes Work How Volcanoes Work What is the Strategic Petroleum Reserve? What is the difference between gasoline, kerosene, diesel fuel, etc.? How much gasoline does the United States consume in one year?

More Great Links

Chevron: A Petroleum Prospecting Primer Oil & Gas in California - comic-book style tutorial for kids Oil and Gas Online American Petroleum Institute California Department of Conservation: Division of Oil, Gas, & Geothermal Resources

Sources

Australian Institute of Petroleum. "Offshore Oil Drilling." Earth Science Australia. (June 21, 2010) http://earthsci.org/mineral/energy/gasexpl/offshore.html

Diamond Offshore. "Offshore Drilling Basics." (June 22, 2010) http://www.diamondoffshore.com/ourCompany/ourcompany_offshorebasics.php

OPEC is the acronym for the Organization of Petroleum Exporting Countries.

The Organization of the Petroleum Exporting Countries (OPEC) was founded in Baghdad, Iraq, with the signing of an agreement in September 1960 by five countries namely Islamic Republic of Iran, Iraq, Kuwait, Saudi Arabia and Venezuela. They were to become the Founder Members of the Organization.

These countries were later joined by Qatar (1961), Indonesia (1962), Libya (1962), the United Arab Emirates (1967), Algeria (1969), Nigeria (1971), Ecuador (1973), Gabon (1975) and Angola (2007).

Oilfield Products are the result of the oil exploration, drilling and research that are conducted in the oil field and refinery. Products of oil fields are also located on the continental shelf.

Oil Drilling Terms

To follow along with The Cutters as they set up and work their oil wells, here's a quick guide to some what you'll see and hear.

Crown block:

This is the stationary section of the block and tackle system at the top of the derrick. It contains the pulleys through with the steel wire or cable is threaded and is opposite the travelling block. Together with the traveling block it pulls the heavy pipes into place.

Derrick:

A derrick is the support structure that holds the drilling apparatus. It’s built tall to accommodate new sections of drill pipe to be added into the drilling apparatus as the drilling progresses and pushes pipe in the system into the ground.

Traveling Block/Hoisting System:

This is used for lifting heavy loads such as extra lengths of pipe. It consists of a winch or drawworks with a steel cable spool (called a drilling line), a block-and-tackle pulley, and a receiving storage reel for the cable.

Drilling line:

The steel cable or wire that is part of the block-and-tackle system that manipulates the traveling block and pipe that moves into the drill hole.

Standpipe:

A few sections of pipe joined together.

Kelly:

A four or six-sided pipe that transfers rotary motion to the turntable and drill string.

Drill String:

Consists of drill pipe (connected sections of about 30 feet) and drill collars (larger, heavier pipe that fits around the drill pipe and puts weight on the drill bit)

Rotary Turntable:

This drives the rotating motion of the pipe and drill.

Drawworks:

The drawworks reels the drilling line in and out in a controlled fashion. The drilling line is reeled over the crown and traveling block to gain mechanical advantage in a "block and tackle" or "pulley" fashion. This movement of the drilling line is what causes the pipe and drillbit to be lowered into or raised out of the wellbore.

Blowout Preventers:

An important part of the rig, these are high pressure valves located under the rig that seal the high pressure drilling lines and relieve pressure to prevent blowouts or uncontrolled releases of oil or gas on the surface that could ignite.

Casing hood:

surface casing is to isolate freshwater zones so that they are not contaminated during drilling and completion.

Mud Pit:

Where the drilling mud is mixed and recycled.

Shale Shaker:

Separates the rock cuttings from the mud.

Mud Pump:

Sucks up the mud from the mud pit and pumps it into the drilling apparatus.

Spare Pipe:

Extra lengths of pipe put ready to be put in place in the rig to further push the drilling bit down into the rock.

Drill Bits:

This is at the end of the pipe. It’s the drill that cuts up the rock as the pipes push downward. It can be made of different materials depending on the type of rock and process involved. Two examples are diamond bits, or tungsten carbide steel.

Casing:

A large concrete pipe that lines the drilling hold that prevents the hole from collapsing. It also allows the drilling mud to circulate, and prevents any outside water from the water table from rushing in and collapsing the drilling hole.

List of components of oil drilling rigs

Offshore drilling rigs have similar elements, but are configured with a number of different drilling systems to suit drilling in the marine environment.

The equipment associated with a rig is to some extent dependent on the type of rig but typically includes at least some of the items listed below.

List of items

Simple diagram of a drilling rig and its basic operation

1. Mud tank 2. Shale shakers 3. Suction line (mud pump)4. Mud pump 5. Motor or power source6. Vibrating hose 7. Draw-works 8. Standpipe 9. Kelly hose

10. Goose-neck 11. Traveling block 12. Drill line 13. Crown block 14. Derrick 15. Monkey board 16. Stand (of drill pipe)17. Pipe rack (floor)18. Swivel (On newer rigs this may be replaced by a top drive)19. Kelly drive 20. Rotary table 21. Drill floor 22. Bell nipple 23. Blowout preventer (BOP) Annular type24. Blowout preventer (BOP) Pipe ram & blind ram25. Drill string 26. Drill bit 27. Casing head or Wellhead28. Flow line

Explanation

Bell nipple (#22) is a section of large diameter pipe fitted to the top of the blowout preventers that the flow line attaches to via a side outlet, to allow the drilling mud to flow back to the mud tanks.

Blowout preventers (BOPs) (#23 and #24) are devices installed at the wellhead to prevent fluids and gases from unintentionally escaping from the wellbore. #23 is the annular (often referred to as Hydril named after a manufacturer), and #24 is the pipe rams and blind rams.

Casing head (#27) is a large metal flange welded or screwed onto the top of the conductor pipe (also known as drive-pipe) or the casing and is used to bolt the surface equipment such as the blowout preventers (for well drilling) or the Christmas tree (oil well) (for well production).

Centrifuge (not pictured) is an industrial version of the device that separates fine silt and sand from the drilling fluid. It is typically mounted on top or just off of the mud tanks.

Crown block (#13) is the stationary end of the block and tackle. Degasser (not pictured) is a device that separates air and/or gas from the drilling fluid. It is typically mounted

on top of the mud tanks. Derrick (#14) is the support structure for the equipment used to lower and raise the drill string into and out

of the wellbore. Desander / desilter (not pictured) contains a set of hydrocyclones that separate sand and silt from the

drilling fluid. Typically mounted on top of the mud tanks. Draw-works (#7) is the mechanical section that contains the spool, whose main function is to reel in/out the

drill line to raise/lower the traveling block. Drill Bit (#26) is a device attached to the end of the drill string that breaks apart the rock being drilled. It

contains jets through which the drilling fluid exits. Drill floor (#21) is the area on the rig where the tools are located to make the connections of the drill pipe,

bottom hole assembly, tools and bit. It is considered the main area where work is performed. Drill line (#12) is thick, stranded metal cable threaded through the two blocks (traveling and crown) to raise

and lower the drill string. Drill pipe (#16) is a joint of hollow tubing used to connect the surface equipment to the bottom hole

assembly (BHA) and acts as a conduit for the drilling fluid. In the diagram, these are stands of drill pipe which are 2 or 3 joints of drill pipe connected and stood in the derrick vertically, usually to save time while tripping pipe.

Drill string (#25) is an assembled collection of drill pipe, heavy weight drill pipe, drill collars and any of a whole assortment of tools, connected and run into the wellbore to facilitate the drilling of a well. The collection is referred to singularly as the drill string.

Elevators (not pictured) are hinged devices that is used to latch to the drill pipe or casing to facilitate the lowering or lifting (of pipe or casing) into or out of the wellbore.

Flow line (#28) is large diameter pipe that is attached to the bell nipple and extends to the shale shakers to facilitate the flow of drilling fluid back to the mud tanks.

Goose-neck (#10) is a thick metal elbow connected to the swivel and standpipe that supports the weight of and provides a downward angle for the kelly hose to hang from.

Kelly drive (#19) is a square, hexagonal or octagonal shaped tubing that is inserted through and is an integral part of the rotary table that moves freely vertically while the rotary table turns it.

Kelly hose (#9) is a flexible, high pressure hose that connects the standpipe to the kelly (or more specifically to the gooseneck on the swivel above the kelly) and allows free vertical movement of the kelly, while facilitating the flow of the drilling fluid through the system and down the drill string.

Monkey board (#15) is the catwalk along the side of the derrick (usually about 35 or 40 feet above the "floor"). The monkey board is where the derrick man works while "tripping" pipe.

Mud motor (not pictured) is a hydraulically powered device positioned just above the drill bit used to spin the bit independently from the rest of the drill string.

Mud pump (#4) is a reciprocal type of pump used to circulate drilling fluid through the system. Mud tank (#1) is often called mud pits and stores drilling fluid until it is required down the wellbore. Pipe rack (#17) is a part of the drill floor (#21) where the stands of drill pipe are stood upright. It is typically

made of a metal frame structure with large wooden beams situated within it. The wood helps to protect the end of the drill pipe.

Rotary table (#20) rotates, along with its constituent parts, the kelly and kelly bushing, the drill string and the attached tools and bit.

Shale shaker (#2) separates drill cuttings from the drilling fluid before it is pumped back down the wellbore. Stand (#16) is a section of 2 or 3 joints of drill pipe connected and stood upright in the derrick. When they

are pulled out of the hole, instead of laying down each joint of drill pipe, 2 or 3 joints are left connected and stood in the derrick to save time.

Standpipe (#8) is a thick metal tubing, situated vertically along the derrick, that facilitates the flow of drilling fluid and has attached to it and supports one end of the kelly hose.

Suction line (#3) is an intake line for the mud pump to draw drilling fluid from the mud tanks. Swivel (#18) is the top end of the kelly that allows the rotation of the drill string without twisting the block. Traveling block (#11) is the moving end of the block and tackle. Together, they give a significant mechanical

advantage for lifting. Vibrating hose (#6) is a flexible, high pressure hose (similar to the kelly hose) that connects the mud pump to

the stand pipe. It is called the vibrating hose because it tends to vibrate and shake (sometimes violently) due to its close proximity to the mud pumps.

The Work on Oil Rig Jobs in UK

Usually derrickem on the oil rig jobs in UK are required to work about 20-25 meters above the offshore oil rig floor on

a little oil rig platform, which is attached to the derrick (derrick is the mast, which supports the equipment for the drilling

process). Derrickmen on oil rig jobs in UK usually are supervised by the driller and assistant driller on the offshore oil

rig platform, and their main duties include the following:

handle and stack sections of the offshore oil rig pipe in UK

derrickmen as oil rig jobs in UK maintain the derrick

operate the lifting and hoisting machinery to position the drill

control and maintain mud pumps on the offshore oil rig platform, and supervise mud pump operators.

Offshore oil rig jobs in UK – as a driller, you will supervise the team that is responsible for the drilling process as oil

rig jobs in UK, and you will control the rate of drilling process. The offshore oil rig driller work in this highly skilled role

would include:

control the operations on the offshore oil rig platform

oversee assembly of the oil drilling tools and facilities on the pipe, and connect sections of the offshore oil drill

pipe

operate and control the machinery, which raises and lowers the offshore oil drill

keep records of the offshore drilling process

make sure that the entire team of oil rig workers in UK follows health and safety rules.

"Drilling rig operators"

A

Aban Offshore Aker Drilling Atwood Oceanics Awilco Offshore

B

Baker Hughes Baker Hughes INTEQ

C

Caspian Drilling Company Challenger LTD China Oilfield Services

D

Diamond Offshore Drilling

E

Eastern Drilling Ensco plc

E cont.

Eurasia Drilling Company Limited

F

Fred. Olsen Energy

G

GlobalSantaFe Corporation Grup Servicii Petroliere

H

Halliburton Hornbeck Offshore Services

K

KCA DEUTAG

M

Maersk Drilling Major Drilling Group

International

N

National Iranian Drilling Company

Noble Corporation

O

Ocean Rig

O cont.

Odfjell Drilling

P

Petrojack Pride International

R

Rowan Companies

S

Schlumberger Scorpion Offshore Seadrill Sevan Marine Smedvig Songa Offshore

T

Transocean

"Drilling rigs"

A

Aban Pearl

B

Byford Dolphin

D

Deepwater Horizon Deepwater Nautilus Development Driller III

G

GSF Development Driller II GSP Atlas GSP Jupiter GSP Orizont

G cont.

GSP Prometeu GSP Saturn

K

Kolskaya (jack-up rig)

M

Mr. Louie

O

Ocean Ranger Odyssey (launch platform) Offshore drilling

P

Petrobras 36

S

Scarabeo 8

S cont.

Scarabeo 9 Sea Gem Sea Quest Songa Mercur

T

Thunder Horse PDQ Transocean John Shaw Transocean Marianas

V

Vermilion Block 380 platform

Drilling rigAll the drilling machinery and devices that are used to excavate and extract oil from the ground.

Mud injection hose Flexible hose that introduces the drilling mud into the swivel.

anticline Geologic stratum that results from the convex folding of rock formations; large pools of oil often accumulate in it.

impervious rock Layer of impermeable rock that covers and protects the oil deposit; it prevents hydrocarbons from migrating into other rocks.

oil Flammable, relatively viscous oily liquid that is used as an energy source; it is made up of various hydrocarbons resulting from the decomposition of plant life over millions of year.

gas Mixture of gaseous hydrocarbons (mainly methane) that are found in underground deposits, which sometimes also contain crude oil; it is used mainly as a fuel.

engine Device converting the combustion of fuel and air into mechanical energy.

substructure Metal infrastructure that supports the derrick, engines and auxiliary equipment.

vibrating mudscreen Perforated vibrating tray that is used to filter mud as it exits the well to remove debris and recycle the mud.

lifting hook Steel part that is attached to the traveling block; it is used to support the swivel and the drill pipes.

derrick Metal structure erected over an oil well; tools for drilling through rock are raised and lowered through it.

crown block Mechanical device that is mounted on top of the derrick; it has several pulleys and, with the traveling block, it supports the drill pipes.

mud pump Device that circulates the mud in the drilling rig.

mud pit Basin that contains mud (a mixture of water, clay and chemical products) used mainly to cool and lubricate the bit and to remove debris.

drilling drawworks Device that consists of a cylinder on which hoisting cables are wound; it is used to lower the drill pipes and bit into the well and to lift them out.

swivel Piece attached to the lifting hook and the kelly; it is used to introduce mud into the drill pipe to cool and lubricate the bit.

traveling block Movable mechanical device with pulleys; it is attached by cable to the crown block and fitted with a lifting hook.

drill pipe Hollow steel rods that are joined together according to the depth of the excavation; their rotation activates the bit.

drill collar Heavy steel tube immediately above the bit that applies a certain weight to the bit to help it cut into the rock.

bit Rotating drill bit with toothed steel or diamond wheels; it bores into rock to break it up and drill a hole.

rotary system Drilling device in which a kelly is attached to a rotary table; with the help of powerful motors, it transmits the rotative movement to the kellys.

rotary table Circular table that is moved by powerful motors; it transmits its rotative movement to the drill pipes by means of the kelly.

kelly Special square rod that is screwed to the top of the drill pipes and driven by the rotary table.

Figure 37.11 Example of a typical mud circulating system on a drilling rig

Fig. 1. Schematic of the circulating system: The drill bit, drill collar, annulus, drill pipe, kelly and swivel are depicted in the upper right. Drilling mud flows through the mud return line (center) upon its return to the surface from the hole to the shale shaker (upper left), then to the adjacent desander, desilter and degasser back to the mud tank (upper left). Mud passes through the suction line, and the mud pump (center) circulates the mud through the discharge line (above), the stand pipe (upper right) through the rotary hose (right) and the swivel (lower right), back to the kelly and into the drill pipe.

DRILLING EQUIPMENTDrilling Equipment refers to the components and ingredients that are used for the purpose of Drilling oil. It is the job of geologists to locate oil with the help of necessary Equipment that are used in an oil trap. The task of the geologists is to locate a Drilling resource such as the right kind of rock, entrapment or reservoir rock.

Some time back, it was the task of the geologists to come up with the features of the surface, the rock as well as the types of the soil. Equipment is used with the help of core samples that are obtained through shallow drilling procedures. Drilling rigs are used for the extraction of oil. According to the modern oil geologists, they can now examine the terrain and the surface rocks with the help of satellite images.

Drilling Equipment of other types is also used for finding and locating the oil. They are used with the help of sensitive gravity meters that can detect the tiniest of changes in the Drilling according to the gravitational pull of the earth. Equipment like this helps in the flow of the oil, and changes in the magnetic field of the earth (resulted by the oil flow) that can be detected by the sensitive magnetometers.

This is Equipment that is able to detect the smell of hydro carbons with the help of sensitive electronic noses that are known as sniffers. In the end, it can be said that the Drilling parts make use of seismology by the creation of shock waves which can pass through hidden rock layers and making sense of the series of waves which are reflected to the surface of the earth.

Equipment Used for Purposes of Oil Extraction

Drilling Equipment takes into account a variety of equipment. The major parts of the Equipment for Drilling are the following: crown and crown block situated at the apex of the rig, traveling block, draw works, sand pipe, engine, fuel or water tanks, swivel, rotary hose, turn table, pipe rack, conductor pipe, bore hole, bit, drill pipe, mud pit and mud pump. Drilling parts take into consideration all of the above components. Drilling parts need to be moved to the locations in trucks which are specially provided for the purpose. The drill job is done with the help of a rig that is leveled over the main boring hole.

The Drilling Equipment comprises of the mast or derrick that is hauled over the sub structure and other Equipment such as the engines, pumps, and the hoisting and rotating Equipment that are aligned together and connected. Drilling constituents like the drill collars and drill pipe are stretched out on the racks. The parts of the rig are laid out for the people to hoist them up when they are required. The components are connected to the drill bit or are attached to the string for Drilling purposes.

Equipment that is used for Drilling is also known as oilfield parts that can perform seismic surveys as well as shock waves that are created with the help of the following gears:

Compressed air guns that shoot pulses or columns of air into the water for explorations over the water The thumper trucks are used for Drilling by slamming heavy palates into the ground for exploration over the

land Explosives that are inserted into the ground by Drilling for exploration over the land or taking it over board for

exploration over water and detonatedWhat a Drilling Equipment does is that it makes the shock waves travel to the heart of the earth and these are reflected back to the surface by the different layers of rocks. The reflections travel at varying speed depending on the density or category of layers of rock through which they pass. The shock waves are reflected and picked up by the audio sensitive vibration detectors or microphones: in the land, the Drilling parts consist of seismometers, while those on the water are done by the Drilling hydrophones. Seismologists interpret the readings for signs of gas or petroleum traps and oil. Equipment can perform the task of oil exploration and can only be somewhat successful, about 10 per cent.

Once a Drilling oil strike is chanced upon by the Equipment, the location is marked out by the GPS coordinates on land or on water (by marker buoys). Equipment is also used for filling up the tanks with additives. The Drilling mud uses parts for storing on location for usage. The Drilling mud which is also known as fluids are some of the components of the oil Rig and these are used in the rig operations. They are inspected by the Drilling inspectors who are provided with developed parts. The Drilling parts perform the function with maximum capacity and aid in the construction of a drill.

Equipment for Drilling must be made on sedimentary rocks that are porous in nature and even have qualities of permeability. They are the ones that make Drilling easier as well as effectively trap the hydro carbons in a relatively smaller area. The parts of an oil pump are needed for the Drilling job when a geologist gets an idea of the conditions that can occur. The Drilling Equipment is usually used with the surface owners for helping them gain access to the property. When the Equipment Drilling well comes up with the oil, the company may gain accessibility to the land for a number of years, with the help of a land Drilling contract. When a part of the drill is used, it is related to the location of the site as well as the type of Equipment used.

Equipment when used in the right manner must depend on the selection of the site and this is something that is generally based on geological evidence and it indicates the possible accumulation of petroleum gas. The

Equipment of rigs is provided by the Drilling Company that sees to the fact that the Equipment is well functional as well as effective. The Drilling of oil requires a charter that has to be granted from the owner of the land man before the operations take place.

Oil Drilling is a procedure that requires expert usage of the Equipment by the members of the crew. The crew drills a hole from the starter and drills a hole from the depth that is preset for Drilling. The Drilling of oil with the help of oil Equipment that is a process involves a number of steps. Some of them are:

The Drilling bit is placed in the hole along with the collar and Drilling pipeThe turn table and the Kelly are attached for Drilling with the EquipmentThe oil Equipment helps circulate the mud through the pipe and out of the bit for floating the rock cuttings outside the holeNew sections or joints in Drilling are added in the pipes as the hole gets deeperThe pipe is removed or tripped out along with the other Equipment like the bit and the collar once the preset depth is attained any where from several hundred to a couple of thousand feet

The oil parts must operate and cement the casing when the pre fixed depth is reached. The Drilling gear must be placed on the casing pipe sections into the hole for preventing the Equipment from collapsing on itself. The exterior of the casing pipe has spacers for focusing on the hole. The casing crew inserts the Equipment like the casing pipe in the hole. The casing pipe is pumped down by the cement crew with the help of a top plug, cement slurry, and drill mud. Pressure from the Drilling mud causes the cement slurry to move through the casing to fill in the space between the outside of the hole.

The Drilling Equipment allows the cement to harden and once it is done, it is tested for various kinds of properties such as alignment, rigidity and the right kind of seal. The oil drill is prepared by first determining the site which must be then surveyed for checking out the boundaries for Drilling. After the settlement of the legal formalities, the crew moves ahead with the Equipment for preparing the land. The land is cleared and leveled for the process to take place. Since water is an important constituent, there must be a water body or source of water in the vicinity. If there is none, a well is drilled.

A reserve pit is dug for the oil drilling purposes for the disposal of the rock cuttings and Drilling of mud for bordering it with plastic for ensuring the protection of the environment. If the area in question is ecologically sensitive, like a wilderness space or marsh, make sure to dispose of the rock cuttings away from the site in a truck, instead of placing them in a pit.

After preparing the land, several holes need to be dug for making room for the rig as well as the main hole. A cellar, which is also rectangular in shape, is dug around the location of the real drill hole. The cellar is actually a place of work for the workers as well as is made for housing the drills and accessories. Once the main hole is drilled, it is lined with a conductor pipe that is large in diameter for oil extraction.