Deepwater drilling, or deep well drilling, is the process of creating holes in the

Earth's crust Earth's crust is its thick outer shell of rock, referring to less than one percent of the planet's radius and volume. It is the top component of the lithosphere, a solidified division of Earth's layers that includes the crust and the upper ...

using a

drilling rig A drilling rig is an integrated system that Drilling, drills wells, such as oil or water wells, or holes for piling and other construction purposes, into the earth's subsurface. Drilling rigs can be massive structures housing equipment used to ...

for

oil extraction Petroleum is a fossil fuel that can be drawn from beneath the Earth's surface. Reservoirs of petroleum are formed through the mixture of plants, algae, and sediments in shallow seas under high pressure. Petroleum is mostly recovered from oil ...

under the deep sea. There are approximately 3400 deepwater wells in the

Gulf of Mexico The Gulf of Mexico () is an oceanic basin and a marginal sea of the Atlantic Ocean, mostly surrounded by the North American continent. It is bounded on the northeast, north, and northwest by the Gulf Coast of the United States; on the southw ...

with depths greater than 150 meters. Deepwater drilling has not been technologically or economically feasible for many years, but with rising oil prices, more companies are investing in this sector. Major investors include

Halliburton Halliburton Company is an American multinational corporation and the world's second-largest oil service company which is responsible for most of the world's fracking operations. It employs approximately 55,000 people through its hundreds of su ...

, Diamond Offshore,

Transocean Transocean Ltd. is an American drilling company. It is the world's largest offshore drilling contractor based on revenue and is based in Steinhausen, Switzerland. The company has offices in 20 countries, including Canada, the United States, ...

, Geoservices, and

Schlumberger Schlumberger (), doing business as SLB, is a global multinational oilfield services company. Founded in France in 1926, the company is now incorporated as Schlumberger NV in Willemstad, Curaçao, with principal executive offices in Houston ...

. The deepwater gas and oil market has been back on the rise since the 2010 ''

Deepwater Horizon ''Deepwater Horizon'' was an ultra-deepwater, Dynamic positioning, dynamically positioned, Semi-submersible platform, semi-submersible offshore drilling Oil platform, rig owned by Transocean and operated by the BP company. On 20 April 2010, ...

'' disaster, with total expenditures of around

US$ The United States dollar (Currency symbol, symbol: Dollar sign, $; ISO 4217, currency code: USD) is the official currency of the United States and International use of the U.S. dollar, several other countries. The Coinage Act of 1792 introdu ...

35 billion per year in the market and total global

capital expenditure Capital expenditure or capital expense (abbreviated capex, CAPEX, or CapEx) is the money an organization or corporate entity spends to buy, maintain, or improve its fixed assets, such as buildings, vehicles, equipment, or land. It is considered ...

s of US$167 billion in the past four years. Industry analysis by business intelligence company Visiongain estimated in 2011 that total expenditures in global deepwater infrastructure would reach US$145 billion. A

HowStuffWorks HowStuffWorks is an American commercial infotainment website founded by professor and author Marshall Brain, to provide its target audience an insight into the way many things work. The site uses various media to explain complex concepts, term ...

article explains how and why deepwater drilling is practiced: In the

Deepwater Horizon oil spill The ''Deepwater Horizon'' oil spill was an environmental disaster off the coast of the United States in the Gulf of Mexico, on the BP-operated Macondo Prospect. It is considered the largest marine oil spill in the history of the petroleum in ...

of 2010, a large explosion occurred, killing workers and spilling oil into the Gulf of Mexico while a BP oil rig was drilling in deep waters.

Types of deepwater drilling facilities

Drilling in deep waters can be performed by two main types of mobile deepwater drilling rigs:

semi-submersible Semi-submersible may refer to a self-propelled vessel, such as: *Heavy-lift ship, which partially submerge to allow their cargo (another ship) to float into place for transport *Narco-submarine, some of which remained partially on the surface *S ...

drilling rigs and

drillship A drillship is a merchant vessel designed for use in exploratory offshore drilling of new oil and gas wells or for scientific drilling purposes. In recent years the vessels have been used in deepwater and ultra-deepwater applications, equipped ...

s. Drilling can also be performed from a fixed-position installation such as a fixed platform, or a floating platform, such as a spar platform, a

tension-leg platform __NOTOC__ A tension-leg platform (TLP) or extended tension leg platform (ETLP) is a vertically geotechnical engineering#Floating-moored structures, moored floating structure normally used for the offshore production of crude oil, oil or natural g ...

, or a semi-submersible production platform. # Fixed Platform – A Fixed Platform consists of a tall, (usually) steel structure that supports a deck. Because the Fixed Platform is anchored to the sea floor, it is very costly to build. This type of platform can be installed in water depth up to . # Jack-Up Rig – Jack-up rigs are mobile units with a floating hull that can be moved around; once they arrived at the desired location, the legs are lowered to the seafloor and locked into place. Then the platform is raised up out of the water. That makes this type of rig safer to work on because weather and waves are not an issue. # Compliant Tower Platform – A compliant tower is a particular type of fixed platform. Both are anchored to the seafloor, and both workplaces are above the water surface. However, the compliant tower is taller and narrower and can operate up to 1 kilometer (3,000 feet) water depth. # Semi-Submersible Production Platform – This platform is buoyant, meaning the bulk of it is floating above the surface. However, the well head is typically located on the seafloor, so extra precautions must be taken to prevent a leak. A contributing cause to the oil spill disaster of 2010 was a failure of the leak-preventing system. These rigs can operate anywhere from below the surface. # Tension-Leg Platform – The Tension-leg Platform consists of a floating structure, held in place by tendons that run down to the seafloor. These rigs drill smaller deposits in narrower areas, meaning this is a low-cost way to get a little oil, which attracts many companies. These rigs can drill anywhere from below the surface. # Subsea System – Subsea Systems are actually wellheads, which sit on the seafloor and extract oil straight from the ground. They use pipes to force the oil back up to the surface, and can siphon oil to nearby platform rigs, a ship overhead, a local production hub, or even a faraway onshore site. This makes the Subsea system very versatile and a popular choice for companies. # Spar Platform – Spar Platforms use a large cylinder to support the floating deck from the seafloor. On average, about 90% of the Spar Platform's structure is underwater. Most Spar Platforms are used up to depths of 1 kilometer (3,000 feet), but new technology can extend them to function up to below the surface. That makes it one of the deepest drilling rigs in use today.

2010 ''Deepwater Horizon'' oil spill

On 20 April 2010, a BP deepwater oil rig (

) exploded, killing 11 and releasing 750,000 cubic meters (200 million gallons) of oil into the Gulf of Mexico. With those numbers, many scientists consider this disaster to be one of the worst environmental disasters in the history of the US. A large number of animal deaths have resulted from the release of the oil. A Center study estimates that over 82,000 birds, about 6,000 sea turtles, and nearly 26,000 marine mammals were killed from either the initial explosion or the oil spill. Deepwater wellbore integrity has become an increasingly important point in the field of petroleum engineering.

References

External articles

*
Deepwater Drilling
How It Works , Chevron , Video. chevron.com. *

Ultra Deep Water Oil Drilling
. science.howstuffworks.com. * Rigzone �
Deepwater Gulf of Mexico Drilling Activity to Keep Rising
rigzone.com. April 24, 2013. {{portalbar, Energy, Oceans Chinese inventions Petroleum production Petroleum industry

Types of deepwater drilling facilities

2010 ''Deepwater Horizon'' oil spill

See also

References

External articles