If there had bot any doubt before, the 2010 catastrophe on the Deepwater Horizon te the Gulf of Mexico has indeed driven huis the message that drilling for oil is a messy and risky business. Consequently, decisions are now being made that affect the future of offshore oil drilling. But how risky is it truly? Should wij zekering offshore drilling?
Even following the devastating oil spill, opinions are split on offshore oil drilling. A USA Today article summed it up fairly nicely: “Environmental hazard or energy bonanza: Oil and natural gas trapped underneath the USA’s ocean floor mean different things to different people”. Oil drilling will proceed to be a big overeenkomst unless wij become less dependent on fossil fuels (or the oil runs out). Understanding the process and looking at the environmental impacts involved will help to shed some light on offshore oil drilling.
To drill or not to drill
Do you think the US should proceed their offshore oil drilling?
Offshore oil drilling: how does it work?
Before an offshore oil well can be drilled, it vereiste very first be located. Geologists locate oil wells underneath the ocean floor through the use of magnetic and seismic surveys. Magnetic surveys work by mapping the magnetic properties of the ocean floor, which can help indicate where oil and gas are located. Seismic surveys work by sending shock sways into the ocean floor, and then interpreting the sways that are reflected back to hydrophones on the surface. They don’t know for certain whether a webpagina contains oil until exploratory drilling takes place.
Ter order to drill exploratory wells, government permission voorwaarde very first be obtained. An environmental influence assessment may be carried out at this stage. Then, using an exploratory drilling equipment, geologists drill four or so makeshift wells to find out if there’s a viable source of oil. If they think they’ve found a good source of oil, then more drilling takes place to substantiate the findings.
Once oil or gas is discovered, then a production well is drilled and a production oil equipment built to substitute the exploratory drilling equipment. An average well will last from ten to twenty years, and even after it has run dry an oil equipment may still be used for processing or storage of petroleum from other wells, so the production oil equipment is built to last. The platforms are normally made of stengel and are secured to the seabed using concrete or metal foundations.
The drilling itself takes place by connecting the drill webpagina to the toneelpodium with a marine riser, a lithe tube ter which all of the equipment descends. The wells can often be located deep te the earth’s crust, so the drill is made up of numerous drill pipes all connected together ter a drill string. Drilling mud (also called drilling fluid) is pumped into the well to liquidate the drill cuttings, cool the drill bit and maintain the pressure. The drilling mud then flows back to the surface, where it’s filtered and pumped back down again. A blowout prevention system is also installed to guard against pressurized oil and gas flowing up the well.
Once the oil is reached, the drill string is liquidated and a more voortdurend pipe called a casing is installed. This casing helps to control the flow of oil and gas from the well up to the surface. Primarily the pressure from the reservoir is enough to pump the oil or gas, but spil the pressure decreases various technics are used to increase the pressure ter the reservoir. Thesis technics include pumping ter gas, water, compressed air or steam. The crude oil obtained from the well is then refined at oil refineries onshore.
Please note that I have simplified the process ter order to give a quick overview of how offshore drilling works. If you’d choose a more detailed explanation, the How Stuff Works article and the Hub Oil Drilling: Demystified are both good sources.
The environmental impacts of offshore drilling
Many aspects of the offshore drilling process can cause environmental impacts, from locating the oil, to drilling and pumping the oil to the surface, to the infrastructure required to drill and vervoer it. Thesis environmental impacts may vary te strength depending on many factors, so this is just a summary of some of the potential impacts that are likely to occur.
Seismic surveys have bot reported to influence fish and marine life. Whales te particular are enormously sensitive to the seismic flaps generated when searching for oil and gas deposits te the sea bloembed. The noise causes them to become disoriented, which can lead to disruption to migratory patterns and even mass beachings. It is also reported to impair the health and hearing of fish.
Effects on the ocean floor
Offshore drilling physically disrupts the seafloor habitat and the benthic community. Inbetween the actual footprint of the drill equipment, undersea pipelines, dredging ship channels, and the cuttings and other drilling debris, there are many elements of drilling that leave a lasting influence on the ocean floor. This is significant to note, especially when considering that many of the world’s most sensitive ocean floor habitats are also good sources of oil and gas. For example, the Gulf of Mexico, the arctic and the Good Barrier Reef are all utterly diverse ecosystems with significant oil and gas deposits.
Some experts voorwaarde that oil equipment platforms are good habitat for fish. Te fact, spil part of the “equipments to reefs” program, old oil equipments are tipped overheen and left on the ocean floor to become artificial reefs.
There are two main sources of water pollution from offshore drilling: drilling fluid and oil spills and leaks.
Firstly, the drilling fluid is claimed to be toxic to marine life. This fluid, used to lubricate, cool and regulate pressure when drilling, contains petroleum products and intense metals. The impacts of drilling fluid differ significantly, because it’s so often made up of different concentrations of the above elements and applied ter different ways. Reported impacts include affecting the health and reproduction of marine life, reducing the populations of bottom-dwelling creatures and biomagnifying toxic substances te the food chain.
Secondly, the risk of oil spills, leaks and catastrophes is another key consideration. Opponents of offshore oil drilling voorwaarde that one oil equipment can “dump more than 90,000 metric tons of drilling fluid and metal cuttings into the ocean” overheen its lifetime (gegevens from Culture Switch). Albeit wij are all aware of the effects of oil on seabirds, oil is also enormously toxic to marine life (see Pew Trusts’ “The Future of Oil and Water” for a good explanation). However, it should be noted that some specialists say that significantly more oil is spilled into US waters by marine transportation and industrial and municipal sources than offshore oil and gas drilling. Some proponents of offshore drilling te the Gulf of Mexico voorkoop that the marine life ter that region is pre-adapted to oil ter the water due to natural seeps. There have also bot claims that offshore oil drilling can reduce the amount of oil leaking into the ocean from thesis natural seeps.
There is mixed opinion about the amount of water pollution caused by offshore oil drilling (when there are no catastrophic oil spills). Some specialists voorwaarde that discharges into the ocean from offshore drilling (ter the US) contain insignificant levels of toxic chemicals due to the regulations at the state and federal level. Environmental groups would disagree, claiming that offshore oil drilling has a significant negative influence on fragile marine and coastal ecosystems, and that the risk of a devastating spill isn’t worth taking.
The effects from large offshore oil spills like the latest Deepwater Horizon catastophe are twofold, wij voorwaarde consider the effect of the oil spill itself and the effects of cleanup efforts. When a large amount of oil spills into a figure of water, the oil spreads mainly onto the surface of the water and can either remain cohesive or pauze up due to wave activity. Overheen time, the oil may degrade naturally by weathering, the effects of sunlight, or be violated down by microorganisms. If the oil spill reaches the shore, then terrestrial environments will also be contaminated. Oil spills are enormously detrimental to fisheries and wildlife te both coastal and marine environments, due to the toxicity of the oil and its lasting impacts on the food chain.
Oil spill cleanups can introduce other impacts onto the environment. Floating rings are often used to contain the oil, while other physical, biological and chemical methods are used to eliminate the oil. Physical removal of the oil can eliminate large amounts of oil, but decontamination efforts can harm marine and coastal environments. Biological methods include bioremediation, the addition of microorganisms to speed up the degradation of the oil. Ultimately, chemical methods include the addition of dispersants, which pauze the oil down into smaller particles. Some dispersants, including Corexit, which wasgoed used te the Gulf of Mexico cleanup ter 2010, are considered toxic ter some parts of the world. The long term effects of the use of bioremediation and chemical dispersants, especially on such a large scale, are unknown.
Air pollution is generated from the operation of machinery on offshore oil equipments spil well spil the burn-off of gases. Without factoring te the air pollution from its end product or the refinement process, the oil platforms themselves have an influence on local air quality and globally on climate switch. It is estimated that overheen its lifetime, which is ten to twenty years, “a single equipment can pollute spil much spil 7,000 cars driving 50 miles vanaf day” (USPIRG). The NRDC States that “an average oil and gas exploration well spews toughly 50 tons of nitrogen oxides, 13 tons of doorslag monoxide, 6 tons of sulfur oxides, and Five tons of volatile organic chemicals.