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THE PROBLEM OF OIL SPILLS
© Nguen T.L.*, Kochegarova N.A.*
Астраханский государственный технический университет, г. Астрахань
An oil spill is a release of a liquid petroleum hydrocarbon into the environment due to human activity, and is a form of pollution. The term often refers to marine oil spills, where oil is released into the ocean or coastal waters. Oil spills include releases of crude oil from tankers, offshore platforms, drilling rigs and wells, as well as spills of refined petroleum products (such as gasoline, diesel) and their by-products, and heavier fuels used by large ships such as bunker fuel, or the spill of any oily white substance refuse or waste oil. Spills may take months or even years to clean up. Oil also enters the marine environment from natural oil seeps. Public attention and regulation has tended to focus most sharply on seagoing oil tankers.
The oil penetrates into the structure of the plumage of birds, reducing its insulating ability, thus making the birds more vulnerable to temperature fluctuations and much less buoyant in the water. It also impairs or disables birds' flight abilities to forage and escape from predators. As they attempt to preen, birds typically ingest oil that covers their feathers, causing kidney damage, altered liver function, and digestive tract irritation. It quickly causes dehydration and metabolic imbalances. Hormonal balance alteration including changes in lutei-nizing protein can also result in some birds exposed to petroleum.
Marine mammals exposed to oil spills are affected in similar ways as sea-birds. Oil coats the fur of marine otters and seals, reducing its insulation abilities and leading to body temperature fluctuations and hypothermia. Ingestion of the oil causes dehydration and impaired digestions. Because oil floats on top of water, less sunlight penetrates into the water, limiting the photosynthesis of marine plants and phytoplankton. This, as well as decreasing the fauna populations, affects the food chain in the ecosystem. There are three kinds of oil-consuming bacteria. Sulfate-reducing bacteria (SRB) and acid-producing bacteria are anaerobic, while general aerobic bacteria (GAB) are aerobic. These bacteria occur naturally and will act to remove oil from an ecosystem, and their biomass will tend to replace other populations in the food chain.
Cleanup and recovery
Cleanup and recovery from an oil spill is difficult and depends upon many factors, including the type of oil spilled, the temperature of the water (affecting evaporation and biodegradation), and the types of shorelines and beaches involved [1].
* Студент кафедры «Химических технологий». Научный руководитель: Кочегарова H.A., старший преподаватель кафедры «Иностранные языки в инженерно-техническом образовании».
* Старший преподаватель кафедры «Иностранные языки в инженерно-техническом образовании».
Pic. 1
Methods for cleaning up include:
- bioremediation: use of microorganisms or biological agents to break down or remove oil;
- bioremediation Accelerator: Oleophilic, hydrophobic chemical, containing no bacteria, which chemically and physically bonds to both soluble and insoluble hydrocarbons. The bioremediation accelerator acts as a herding agent in water and on the surface, floating molecules to the surface of the water, including solubles such as phenols and BTEX, forming gel-like agglomerations. Undetectable levels of hydrocarbons can be obtained in produced water and manageable water columns. By overspraying sheen with bioremediation accelerator, sheen is eliminated within minutes. Whether applied on land or on water, the nutrient-rich emulsion creates a bloom of local, indigenous, pre-existing, hydrocarbon-consuming bacteria. Those specific bacteria break down the hydrocarbons into water and carbon dioxide, with EPA tests showing 98 % of alkanes biodegraded in 28 days; and aromatics being biode-graded 200 times faster than in nature they also sometimes use the hy-drofireboom to clean the oil up by taking it away from most of the oil and burning it;
- controlled burning can effectively reduce the amount of oil in water, if done properly. But it can only be done in low wind, and can cause air pollution;
- watch and wait: in some cases, natural attenuation of oil may be most appropriate, due to the invasive nature of facilitated methods of remediation, particularly in ecologically sensitive areas such as wetlands;
- dredging: for oils dispersed with detergents and other oils denser than water;
- skimming: Requires calm waters;
- solidifying: Solidifiers are composed of dry hydrophobic polymers that both adsorb and absorb. They clean up oil spills by changing the physical state of spilled oil from liquid to a semi-solid or a rubber-like
material that floats on water. Solidifiers are insoluble in water, therefore the removal of the solidified oil is easy and the oil will not leach out. Solidifiers have been proven to be relatively non-toxic to aquatic and wild life and have been proven to suppress harmful vapors commonly associated with hydrocarbons such as Benzene, Methyl Ethyl, Acetone and Naphtha. The reaction time for solidification of oil is controlled by the surf area or size of the polymer as well as the viscosity of the oil. Some solidifier product manufactures claim the solidified oil can be disposed of in landfills, recycled as an additive in asphalt or rubber products, or burned as a low ash fuel. A solidifier called C.I. Agent (manufactured by C.I. Agent Solutions of Louisville, Kentucky) is being used by BP in granular form as well as in Marine and Sheen Booms on Dauphin Island, AL and Fort Morgan, MS to aid in the Deepwater Horizon oil spill cleanup;
- vacuum and centrifuge: oil can be sucked up along with the water, and then a centrifuge can be used to separate the oil from the water - allowing a tanker to be filled with pure oil. Usually, the water is returned to the sea, making the process more efficient, but allowing small amounts of oil to go back as well. This issue has hampered the use of centrifuges due to a United States regulation limiting the amount of oil in water returned to the sea.
Equipment used includes:
- booms: large floating barriers that round up oil and lift the oil off the water;
- skimmers: skim the oil;
- sorbents: large absorbents that absorb oil;
- chemical and biological agents: helps to break down the oil;
- vacuums: remove oil from beaches and water surface;
- shovels and other road equipments: typically used to clean up oil on beaches.
Pic. 2
Shoreline type
Shoreline type is classified by rank depending on how easy would be cleanup, how long the oil would persist, and how sensitive the shoreline is. The floating oil slicks put the shoreline at particular risk when they eventually come ashore, covering the substrate with oil. The differing substrates between shoreline types vary in their response to oiling, and influence the type of cleanup that will be required to effectively decontaminate the shoreline. In 1995, the US National Oceanic and Atmospheric Administration extended ESI maps to lakes, rivers, and estuary shoreline types. The productivity of the shoreline habitat is taken into account when determining ESI ranking [2]. Mangroves and marshes tend to have higher ESI rankings due to the potentially long-lasting and damaging effects of both the oil contamination and cleanup actions. Impermeable and exposed surfaces with high wave action are ranked lower due to the reflecting waves keeping oil from coming onshore, and the speed at which natural processes will remove the oil.
Pic. 3
Estimating the volume of a spill
By observing the thickness of the film of oil and its appearance on the surface of the water, it is possible to estimate the quantity of oil spilled. If the surface area of the spill is also known, the total volume of the oil can be calculated. Oil spill model systems are used by industry and government to assist in planning and emergency decision making. There is a worldwide oil spill modeling (WOSM) program. Tracking the scope of an oil spill may also involve verifying that hydrocarbons collected during an ongoing spill are derived from the active spill or some other source. This can involve sophisticated analytical chemistry focused on finger printing an oil source based on the complex mixture of substances present. Largely, these will be various hydrocarbons, among the most useful being polyaromatic hydrocarbons. In addition, both oxygen and nitrogen heterocyclic hydrocarbons, such as parent and alkyl homologues of carbazole, quinoline, and pyridine, are present in many crude oils. As a result,
these compounds have great potential to supplement the existing suite of hydrocarbons targets to fine tune source tracking of petroleum spills. Such analysis can also be used to follow weathering and degradation of crude spills.
Список литературы:
1. www.en.wikipedia.org/wiki/Environmental_issues_with_petroleum#Oil_ spills.
2. www.en.wikipedia.org/wiki/Oil_spill.
A NEW FORMULA FOR SUCCESS IN OIL AND GAS SEARCHING
© Хаирмашев T.C.*, Муратова A.C.4
Астраханский государственный технический университет, г. Астрахань
Petroleum and gas exploration today is an expensive, high-risk operation. An unacceptable - and unnecessary - number of dry holes is still being drilled. One must improve exploration accuracy and optimize development programs. The combination and full integration of geology with geophysics and geochemistry - the new 3G strategy - is leading to additional discoveries and more accurate wells.
Searching for oil and gas deep underground is more and more exciting. Sifting through all the clues and data must be thoroughly and carefully considered. And even then it might be the very smallest molecule of evidence, sometimes the very smallest molecules are the key to guarantee success.
Observing visible oil seeps at the surface builds huge confidence that hydrocarbons are present in a basin or block area. In organic chemistry, a hydrocarbon is an organic compound consisting entirely of hydrogen and carbon. The majority of hydrocarbons found naturally occur in crude oil, where decomposed organic matter provides an abundance of carbon and hydrogen which, when bonded, can catenate to form seemingly limitless chains [1, 3]. Historically, parts of many North American basins were first targeted because of these visible surface macroseeps. However, macroseeps reveal only part of the seepage spectrum story and fail to offer strong location clues since they escape along larger fault conduits. But hydrocarbon microseeps of light hydrocarbon gases are being used to more accurately locate oil and gas reservoirs at depth. These
* Студент кафедры «Машины и оборудование нефтегазовых промыслов». Научный руководитель: Муратова A.C., старший преподаватель кафедры «Иностранные языки в инженерно-техническом образовании».
* Старший преподаватель кафедры «Иностранные языки в инженерно-техническом образовании».
