История нефти
Добыча нефти ведется человечеством с древних времен. Сначала применялись примитивные способы: сбор нефти с поверхности водоемов, обработка песчаника или известняка, пропитанного нефтью, при помощи колодцев. Но началом развития нефтяной промышленности принято считать время появления механического бурения скважин в 1859 году в США, и сейчас практически вся добываемая в мире нефть извлекается посредством буровых скважин. За сто с лишним лет развития истощились одни месторождения, были открыты другие, повысилась эффективность добычи нефти.
В России первое письменное упоминание о получении нефти появилось в XVI веке. Путешественники описывали, как племена, жившие у берегов реки Ухта на севере Тимано-Печорского района, собирали нефть с поверхности реки и использовали ее в медицинских целях и в качестве масел и смазок. Нефть, собранная с реки Ухта, впервые была доставлена в Москву в 1597 году.
В 1702 году царь Петр I издал указ об учреждении первой регулярной российской газеты "Ведомости". В первом выпуске газеты была опубликована статья о том, как была обнаружена нефть на реке Сок в Поволжье, а в более поздних выпусках была информация о нефтепроявлениях в других районах России. В 1745 году Федор Прядунов получил разрешение начать добычу нефти со дна реки Ухта. Прядунов также построил примитивный нефтеперегонный завод и поставлял некоторые продукты в Москву и Санкт-Петербург.
Нефтепроявления также наблюдались многочисленными путешественниками на Северном Кавказе. Местные жители даже собирали нефть с помощью ведер, вычерпывая ее из скважин глубиной до полутора метров. В 1823 году братья Дубинины открыли нефтеперерабатывающий завод в Моздоке для переработки нефти, собираемой с близлежащего Вознесенского нефтяного месторождения.
Нефте- и газопроявления были зафиксированы в Баку, на западном склоне Каспийского моря арабским путешественником и историком еще в десятом веке. Марко Поло позднее описывал, как люди в Баку использовали нефть в медицинских целях и для проведения богослужений. С XIV века нефть, собираемая в Баку, экспортировалась в другие страны Среднего Востока. Первая нефтяная скважина в мире была пробурена на Биби-Айбатском месторождении вблизи Баку в 1846 году, более чем на десятилетие раньше, чем была пробурена первая скважина в США. Начало современной нефтяной промышленности связывают с этим событием.
текст 3
Read the text below and match the headings to the paragraphs of the text. There is one extra heading.
1. Arrangement of hydrocarbon molecules.
2. What is crude oil?
3. Production of chemical feedstock.
4. Modification of hydrocarbon molecules.
5. Oil formation.
6. Oil and gas products.
7. Different mixtures of hydrocarbons.
FORMATION OF OIL
A) Crude oil is a complex mixture of hydrocarbons with minor proportions of other chemicals such as compounds of sulphur, nitrogen and oxygen. To use the different parts of the mixture they must be separated from each other. This separation is called refining.
B) Crude oils from different parts of the world, or even from different depths in the same oilfield, contain different mixtures of hydrocarbons and other compounds. This is why they vary from light colored volatile liquids to thick, dark oils - so viscous that they are difficult to pump from the ground.
C) Hydrocarbons vary in structure depending on the number of carbon atoms and the way in which the hydrogen atoms combine with them. Hydrocarbons can be arranged as straight chains, branched chains or closed rings. There are two main chemical families of hydrocarbons - the alkanes and the alkenes.
D) As the structure of hydrocarbons varies so much, thousands of synthetic products can be manufactured with many different properties. Hydrocarbons with small molecules make good fuels. Methane (CH4) has the smallest molecules, and is a gas, used for cooking and heating and generating electricity. Gasoline, diesel, aviation fuel and fuel oil are all liquid fuels.
E) Hydrocarbon molecules can be split up into smaller ones, or built up into bigger ones, or altered in shape, or modified by adding other atoms. This is why they are a very useful starting point (called a chemical feedstock) for making other materials. Even the thick black tarry residue left after distillation is useful. It is called bitumen, and is used in tarmac for road surfacing, and for roofing.
F) Oil is formed from the remains of tiny plants and animals (plankton) that died in ancient seas between 10 and 600 million years ago. After the organism died, they sank into the sand and mud at the bottom of the sea. 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.
текст 4
How Oil Becomes Oil
Petroleum (literally rock oil, from the Greek petra- for rock and Latin -oleum for oil) is a general term used to refer to all forms of oil and natural gas that is mined from the earth. What most people concern them with is crude oil, the liquid mixture of naturally occurring hydrocarbons, and natural gas, which is a gaseous mixture of naturally occurring hydrocarbons. Hydrocarbons are complex molecules that are formed from long strings of hydrogen and carbon, such as propane (C3H8) or butane (C4H10).
Petroleum is the final product that we get out of the ground. But how does it get there? Petroleum begins as living animals, microscopic organisms (like diatoms or plankton) that live in the oceans. When these organisms die, their bodies sink and collect on the ocean floor. These organisms live all over the oceans and their bodies fall and collect on the ocean bottoms all over the world. When the organic matter becomes buried and begin to decompose, they are referred to as kerogen. Despite the apparent abundance of dead organisms raining down on the ocean bottoms, there are specific conditions that must be met for these organisms to be transformed into petroleum.
First, the area that the kerogen collects must be a restricted basin, a depression where sediment can accumulate and where there is poor water circulation. When the oxygen is gone, the decomposition stops and the remaining matter are preserved. The kerogen must be buried under sediment where it will be altered through high temperatures and high pressures. As the heat and pressure breaks down the kerogen, the hydrocarbon chains are freed. Long chains of hydrocarbon are oil; shorter chains are gas, generally methane (CH4) and condensates such as ethane, propane and butane. As the heat and pressure continues, the longer chains will continue to break into shorter chains. If the process continues long enough, all that will remain will be methane.
Compaction of the sediment, and the expansion of the kerogen as it is transformed into petroleum cause it to be forced out of the rock it was created in (the source rock) and into nearby sediments. If these sediments are porous enough (have microscopic holes) and permeable enough (allowing for the flow of liquids), then the petroleum will migrate through the rock. Since gas and oil are lighter than water, they can travel through water-saturated rock. Eventually the oil will stop migrating as it meets rock that is not porous or permeable, and will collect in a trap. It is these petroleum traps that geologists search for and that the oil companies drill into to recover the oil.
Despite the simplicity, there are several conditions that must occur, otherwise, no oil will be made.
First, there needs to be a source rock that contains the organic matter to be converted into petroleum. This source rock is generally shale or other mudstones. There must be a reservoir rock, usually sandstone or limestone that is porous and permeable where the oil can be stored and transported. There needs to be a trap, something that is non-porous and non-permeable that will hold the petroleum in the reservoir and prevent it from migrating further. Finally, there needs to be enough heat and pressure to sufficiently cook the oil and gas out of the kerogen. If anyone of these conditions is not met, then petroleum cannot be formed.
The important step in the process is the trap. Something needs to block or trap the petroleum so it will accumulate into a large enough deposit for geologists to be able to locate it. Petroleum traps come in several varieties, in various sizes and can be made through structural processes (like folds and faults), or by sedimentary processes.
Structural traps work by folding or breaking the reservoir rock and placing it adjacent to an impermeable rock layer, like shale. There are three types of structural traps. One of the most common is a trap from the folding of the rocks. Anticlines bend the reservoir rock and create a pocket at the apex of the fold where the petroleum cannot migrate. Normal and thrust faults can result in petroleum traps by breaking the reservoir rock and moving it so that it is against an impermeable rock layer.
The other way to trap petroleum is through stratigraphic traps. The diagram shows five different types of stratigraphic traps. The differences between these and structural traps is that these traps occur by the nature of how the sediment was deposited and not whether it was broken or folded. The first two, sandstone lenses and sandstone pinch-outs, are the result of the changes in deposition of the sediment. Thick layers of mud are covered by thinner layers of sand from migrating shoreline, or by the sand deposited by large rivers. As sea level changes or rivers migrate, the different sand and mud layers are interwoven creating lenses or pinch-outs. These sand layers allow the petroleum to accumulate and the mudrock layers trap the petroleum.
Unconformities can create traps by burying truncated sandstone or limestone layers with layers of mudstone.
Finally, salt domes can push up through buried sediment and deform the overlying layers of rock. This causes folds and fractures to form in the rock, trapping the oil salt domes are the primary places where the oil is found.
The words to be memorized:
abundance – распространённость
to adjacent – смежный, прилегающий
apex – вершина
to cook – подвергаться тепловой обработке
compaction – уплотнение
decompose – decomposition – разлагаться - разложение
depression – впадина
expansion – распространение (на большую площадь)
fold – складка
fracture – разлом, трещина
to interweave – перемешивать, вкраплять
kerogen – кероген
lens – чечевицеобразная залежь, линза
to migrate – мигрировать, перемещаться
mudstone – аргиллит
pocket – карман
to pinch out – выклиниваться
to preserve – сохранять
restricted basin – ограниченный бассейн
recover oil – добывать нефть
truncated – срезанный, эродированный
thrust fault – сброс
unconformity – несогласованное напластование
текст 5
Read and translate the text "Physical and Chemical Properties of Oil". Tell about the main properties of oil and its characteristic features, based on the information from the text.