In the past, natural gas was either burned or allowed to escape into the atmosphere. Now, technology has been developed to capture the natural gas and either reinject it into the well or compress it into liquid natural gas LNG. LNG is easily transportable and has versatile uses. Extracting Petroleum In some places, petroleum bubbles to the surface of the Earth. In parts of Saudi Arabia and Iraq, for instance, porous rock allows oil to seep to the surface in small ponds. However, most oil is trapped in underground oil reservoirs.
The total amount of petroleum in a reservoir is called oil-in-place. These petroleum liquids may be too difficult, dangerous, or expensive to drill. Drilling can either be developmental, exploratory, or directional. Drilling in an area where oil reserves have already been found is called developmental drilling. Prudhoe Bay, Alaska, has the largest oil reserves in the United States. Developmental drilling in Prudhoe Bay includes new wells and expanding extraction technology.
Drilling where there are no known reserves is called exploratory drilling. McCarthy struck oil 38 times in the s, earning millions of dollars.
Directional drilling involves drilling vertically to a known source of oil, then veering the drill bit at an angle to access additional resources. Accusations of directional drilling led to the first Gulf War in Iraq accused Kuwait of using directional drilling techniques to extract oil from Iraqi oil reservoirs near the Kuwaiti border. Iraq subsequently invaded Kuwait, an act which drew international attention and intervention.
After the war, the border between Iraq and Kuwait was redrawn, with the reservoirs now belonging to Kuwait. Oil Rigs On land, oil can be drilled with an apparatus called an oil rig or drilling rig. Offshore, oil is drilled from an oil platform. Primary Production Most modern wells use an air rotary drilling rig, which can operate 24 hours a day.
In this process, engines power a drill bit. A drill bit is a cutting tool used to create a circular hole. The drill bits used in air rotary drilling rigs are hollow steel, with tungsten rods used to cut the rock.
Petroleum drill bits can be 36 centimeters 14 inches in diameter. As the drill bit rotates and cuts through the earth, small pieces of rock are chipped off. A powerful flow of air is pumped down the center of the hollow drill, and comes out through the bottom of the drill bit. The air then rushes back toward the surface, carrying with it tiny chunks of rock. Geologists on site can study these pieces of pulverized rock to determine the different rock strata the drill encounters.
When the drill hits oil, some of the oil naturally rises from the ground, moving from an area of high pressure to low pressure. It is also one of the most dangerous, and a piece of equipment called a blowout preventer redistributes pressure to stop such a gusher. Pumps are used to extract oil.
Most oil rigs have two sets of pumps: mud pumps and extraction pumps. Mud pumps circulate drilling fluid. The petroleum industry uses a wide variety of extraction pumps. Which pump to use depends on the geography, quality, and position of the oil reservoir.
Submersible pumps, for example, are submerged directly into the fluid. A gas pump, also called a bubble pump, uses compressed air to force the petroleum to the surface or well. One of the most familiar types of extraction pumps is the pumpjack , the upper part of a piston pump. A crank moves the large, hammer-shaped pumpjack up and down. Far below the surface, the motion of the pumpjack moves a hollow piston up and down, constantly carrying petroleum back to the surface or well.
Successful drilling sites can produce oil for about 30 years, although some produce for many more decades. Other methods are necessary to extract this petroleum, a process called secondary recovery. Vacuuming the extra oil out was a method used in the s and early 20th century, but it captured only thinner oil components, and left behind great stores of heavy oil.
Water flooding was discovered by accident. In the s, oil producers in Pennsylvania noticed that abandoned oil wells were accumulating rainwater and groundwater.
The weight of the water in the boreholes forced oil out of the reservoirs and into nearby wells, increasing their production. Oil producers soon began intentionally flooding wells as a way to extract more oil. The most prevalent secondary recovery method today is gas drive.
During this process, a well is intentionally drilled deeper than the oil reservoir. The deeper well hits a natural gas reservoir, and the high-pressure gas rises, forcing the oil out of its reservoir. Oil Platforms Drilling offshore is much more expensive than drilling onshore. It usually uses the same drilling techniques as onshore, but requires a massive structure that can sustain the tremendous strength of ocean waves in stormy seas.
Offshore drilling platforms are some of the largest manmade structures in the world. They often include housing accommodations for people who work on the platform, as well as docking facilities and a helicopter landing pad to transport workers.
The platform can either be tethered to the ocean floor and float, or can be a rigid structure that is fixed to the bottom of the ocean, sea, or lake with concrete or steel legs. More than 70 people work on the platform, in three-week shifts. The platform is meters feet tall and is anchored to the ocean floor.
About , tons of solid ballast were added to give it additional stability. The platform can store up to 1. In total, Hibernia weighs 1. However, the platform is still vulnerable to the crushing weight and strength of icebergs. Its edges are serrated and sharp to withstand the impact of sea ice or icebergs. Oil platforms can cause enormous environmental disasters.
Problems with the drilling equipment can cause the oil to explode out of the well and into the ocean. Repairing the well hundreds of meters below the ocean is extremely difficult, expensive, and slow.
Millions of barrels of oil can spill into the ocean before the well is plugged. When oil spills in the ocean, it floats on the water and wreaks havoc on the animal population. One of its most devastating effects is on birds. Oil destroys the waterproofing abilities of feathers, and birds are not insulated against the cold ocean water.
Thousands can die of hypothermia. Fish and marine mammals, too, are threatened by oil spills. The dark shadows cast by oil spills can look like food. A massive oil platform in the Gulf of Mexico, the Deepwater Horizon , exploded in This was the largest accidental marine oil spill in history.
Eleven platform workers died, and more than 4 million barrels of oil gushed into the Gulf of Mexico. More than 40, barrels flowed into the ocean every day. Eight national parks were threatened, the economies of communities along the Gulf Coast were threatened as the tourism and fishing industries declined, and more than 6, animals died. Rigs to Reefs Offshore oil platforms can also act as artificial reefs. They provide a surface substrate for algae, coral, oysters, and barnacles.
This artificial reef can attract fish and marine mammals, and create a thriving ecosystem. Until the s, oil platforms were deconstructed and removed from the oceans, and the metal was sold as scrap.
Now, oil platforms are either toppled by underwater explosion , removed and towed to a new location, or partially deconstructed. This allows the marine life to continue flourishing on the artificial reef that had provided habitats for decades. The environmental impact of the Rigs-to-Reefs Program is still being studied. Oil platforms left underwater can pose dangers to ships and divers. Fishing boats have had their nets caught in the platforms, and there are concerns about safety regulations of the abandoned structures.
Environmentalists argue that oil companies should be held accountable to the commitment they originally agreed upon, which was to restore the seabed to its original condition.
By leaving the platforms in the ocean, oil companies are excused from fulfilling this agreement, and there is concern this could set a precedent for other companies that want to dispose of their metal or machinery in the oceans. Petroleum and the Environment: Bitumen and the Boreal Forest Crude oil does not always have to be extracted through deep drilling.
If it does not encounter rocky obstacles underground, it can seep all the way to the surface and bubble above ground. Unfortunately, because bitumen contains high amounts of sulfur and heavy metals, extracting and refining it is both costly and harmful to the environment.
Gloppy and unrefined straight from the earth. The oil man's black gold. Gasoline and diesel fuel to power our transport. Heating oil to warm our homes. And other petroleum products such as naphta, waxes, and lubricating oils that ultimately become a part of almost every product we produce and consume.
But where does it come from? We answer that, and 5 other things you should know about crude oil. Dead critters, plenty of pressure, a lot of heat, and hundreds of thousands of years in time. Crude oil is formed from the remains of dead organisms diatoms such as algae and zooplankton that existed millions of years ago in a marine environment. These organisms were the dominant forms of life on earth at the time.
As they lived these organisms absorbed energy from the sun and stored it as carbon molecules within their bodies. Once they died their remains sank to the bottom of the oceans or riverbeds and were buried in layers of sand, mud and rock.
Over millions of years, the remains were buried deeper and deeper under more sediment and organic materials. The enormous pressure, high temperatures, and lack of oxygen transformed the organic matter into a waxy substance called kerogen. With even more heat, pressure, and time the kerogen undergoes a process called catagenesis which transforms the kerogen into hydrocarbons. Different combinations of pressure, heat, and the original composition of organic material will determine the type of hydrocarbon formed.
In this case, the hydrocarbons form crude oil. Other examples are asphalt if the temperature is lower, and natural gas if the temperature is higher. After the oil is formed it moves through tiny pores in the surrounding rock from an area of high pressure to low pressure, this is often upwards.
Some oil might make it all the way to the surface where it pools, in other cases the oil will get trapped under impermeable layers of rock or clay where it will form underground reservoirs. Oil seemingly keeps getting deeper and deeper. Rising Sea Level. Oil formation Oil or petroleum is a readily combustable fossil fuel that is composed mainly of carbon and hydrogen , and is thus known as a hydrocarbon. Process of oil and natural gas formation. May 11, Formation of Oil [Online]. January 7, Oil Formation [Online].
Energy, Environment and Climate , 2nd ed. New York, U. Earth: Portrait of a Planet , 3rd ed. New York, NY, U. Toronto, ON, Canada. And Venezuelans are beginning to excavate the solid tarry deposits of the Oronoco sludge belt, which contains as much as 1 trillion barrels of oil. Tapping it and converting it to liquid fuels a process nobody has fully mastered yet could yield a supply lasting a millennium.
This parade of unending innovation makes any worries about impending oil shortages sound unduly pessimistic. Still, not everyone is buying the idea. Sure, we can figure out new ways to extract oil and other fuels, argues Campbell, but the payoff for such technology is a long way off. As he sees it, the age of oil abundance may soon come to a close.
The oil runs out. Already, the massive oil discoveries of the s — from Alaska to the North Sea — are nearing their crest of production. Worse still, he argues, the number of oil finds peaked in the s.
Today, one new barrel of oil is found for every four produced. At that point, boosting production among the countries in the Middle East can fill the gap — leaving the world vulnerable once more to an oil embargo. This spring, Saudi Arabia, Iran, Mexico, Algeria, and Norway banded together to shore up prices by slight cuts in oil production. Campbell argues that these countries could eventually gain a greater control of the market and impose whatever price they please.
But they could easily double. An oil-devouring economy has not been good for the planet. The so-called greenhouse gases — mainly water vapor and carbon dioxide — make the planet warm and habitable by trapping solar heat as it radiates back off the Earth.
When humans burn hydrocarbons, or fossil fuels, the carbon reacts with oxygen. The result: more heat-trapping carbon dioxide in the air. Since the beginning of industrialization around , the levels of carbon dioxide have increased from parts per million to about today, says Pieter Tans, of the National Oceanic and Atmospheric Administration.
No one can precisely predict the effects of this addition to the atmosphere, but global warming, rising sea levels and changing climates are among the troubling possibilities. As more fuels are burned, the problem may become more obvious. Environmentalists once hoped for oil shortages to cut carbon dioxide emissions, but that no longer seems likely.
Only voluntary restrictions or, more likely, taxes on fossil-fuel consumption and incentives for developing alternative fuels will reduce emissions. The Kyoto Conference — a world meeting on fossil-fuel use — produced an agreement by a handful of highly industrialized countries to reduce carbon emissions to levels by What it did not produce was how exactly this was to be achieved. Of course, some see encouraging growth in renewable energy sources such as solar, wind, and even geothermal power.
And if oil prices start to rise, these alternatives could eventually become competitive with conventional energy sources. Indeed, the perfect solution already exists: a carbon-free fuel cell that strips combustible hydrogen from a molecule like water or alcohol and yields only water when it is burned. But the cost of the technology remains prohibitive. And in a world swimming in oil, few companies and governments bother to spend big on alternative fuel technologies.
Even if they did, the addiction to cheap oil would most likely persist. The world is wired for oil.
0コメント