An introduction of petroleum

Petroleum is a liquid that is found underground. Sometimes we call it oil.Oil can be as thick and black as tar or as thin as water. Petroleum has a lot of energy. We can turn it into different fuels—like gasoline, kerosene, and heating oil. Most plastics and inks are made from petroleum, too. People have burned oil for a long time. Long ago, they didn’t dig for it. They gathered oil that seeped from under the ground into ponds. It floated on the water.

Petroleum is a Fossil Fuel

Long before the dinosaurs, oceans covered most of the Earth. They were filled with tiny sea animals and plants. As the plants and animals died, they sank to the ocean floor. Sand and sediment covered them and turned into sedimentary rock. Millions of years passed. The weight of the rock and heat from the Earth turned them into petroleum and natural gas. Petroleum is called a fossil fuel because it was made from the

remains of plants and animals. The energy in petroleum came from the energy in the plants and animals. That energy came from the sun.

Petroleum is Nonrenewable

The petroleum we use today was made millions of years ago. It took millions of years to form.We can’t make more in a short time. That’s why we call petroleum nonrenewable. The United States doesn’t produce enough oil to meet our needs. We import half the oil we use from other Countries.

We Drill Oil Wells

Petroleum is buried underground in tiny pockets in rocks.We drill oil wells into the rocks to pump out the oil. The typical well is about one mile deep. Texas and Alaska are the states that produce the most oil.

A lot of oil is under the oceans along our shores. Oil rigs that can float are used to reach this oil. Most of these wells are in the Gulf of Mexico. After the oil is pumped to the surface, it is sent to refineries. At the refineries, it is separated into different types of products and made into fuels. Most of the oil is made into gasoline. The oil is moved from one place to another through pipelines and by ships and trucks.

We Use Petroleum Every Day

What would we do without petroleum? Our country would come to a stop. Most of our cars, trucks, and planes are powered by fuel made from oil. Our factories use oil to make plastics and paints, medicines and soaps. We even burn oil to make electricity. We use more petroleum than any other energy source.

Petroleum Can Pollute

Petroleum keeps us going, but it can damage our environment. Burning fuels made from oil can pollute the air. Pollution from cars is a big problem in many parts of the country. Oil companies are making cleaner gasoline and diesel fuel every year. Oil can pollute soil and water, harming the animals that live in the area. Oil companies work hard to drill and ship oil as safely as possible. They try to clean up any oil that spills.

Petroleum Extraction

After an exploration effort has successfully discovered petroleum within an acceptable range of reserve potential, the challenge becomes how to best optimize extraction of recoverable reserves in a manner yielding an acceptable economic return on total cash expenditures required over the life of the project. Surface and subsurface conditions of a discovery have considerable impact on the extraction process, its related costs, and ultimate project success or failure. Technical success is one thing; economic success is another. Real world experience has shown that economic success is by far the more difficult accomplishment, as it is dependent on factors well beyond the means of science and technology.

Petroleum reserves exist as oil or gas within trapping sections of reservoir rock formed by structural and or stratigraphic geologic features. Water is the predominant fluid found in the permeability and porosity of subsurface strata within the earth's crust. Both oil and gas have a low specific gravity relative to water and will thus, float through the more porous sections of reservoir rock from their source area to the surface unless restrained by a trap. Typically, reservoir rock consists of sand, sandstone, limestone, or dolomite. A trap is a reservoir that is overlain by a dense cap rock or a zone of very low or no porosity that restrains migrating hydrocarbon. Petroleum bearing reservoirs can exist from surface seeps to subsurface depths over 4 mi (6.4 km) below sea level. Reservoirs vary from being quite small to covering several thousands of acres, and range in thickness from a few inches to hundreds of feet or more.

The process of evaluating how to best optimize extraction of recoverable reserves begins with a development plan. The development plan considers all available geologic and engineering data to make an initial estimate of reserves in-place, to project recovery efficiencies and optimal recoverable reserve levels under various producing scenarios, and to evaluate development plan alternatives. Development alternatives will include the number of wells to be drilled and completed for production or injection, well spacing and pattern, processing facility requirements, product transportation options, cost projections, project schedules, depletion plans, operational programs, and logistics and economic studies.

In general, petroleum is extracted by drilling wells from an appropriate surface configuration into the hydrocarbon-bearing reservoir or reservoirs. Wells are designed to contain and control all fluid flow at all times throughout drilling and producing operations. The number of wells required is dependent on a combination of technical and economic factors used to determine the most likely range of recoverable reserves relative to a range of potential investment alternatives.

The complexity and cost of drilling wells and installing all necessary equipment to produce reserves can vary significantly. The development of an onshore shallow gas reservoir located among other established fields may be comparatively low cost and nominally complex. A deep oil or gas reservoir located in 4,000+ ft (1,219+ m) of water depth located miles away from other existing producing fields will push the limits of emerging technology at extreme costs. Individual wells in deepwater can and have cost in excess of 50 million dollars to drill, complete, and connect to a producing system. Onshore developments may permit the phasing of facility investments as wells are drilled and production established to minimize economic risk. However, offshore projects may require 65% or more of the total planned investments to be made before production start up, and impose significant economic risk.

Once production begins, the performance of each well and reservoir is monitored and a variety of engineering techniques are used to progressively refine reserve recovery estimates over the producing life of the field. The total recoverable reserves are not known with complete certainty until the field has produced to depletion or its economic limit and abandonment.

The ultimate recovery of original in-place volumes may be as high as one-third for oil and 80% or more for gas. There are three phases of recovering reserves. Primary recovery occurs as wells produce because of natural energy from expansion of gas and water within the producing formation, pushing fluids into the well bore and lifting them to the surface. Secondary recovery occurs as artificial energy is applied to lift fluids to surface. This may be accomplished by injecting gas down a hole to lift fluids to the surface, installation of a sub-surface pump, or injecting gas or water into the formation itself. Secondary recovery is done when well, reservoir, facility, and economic conditions permit. Tertiary recovery occurs when means of increasing fluid mobility in oil reservoirs within the reservoir are introduced in addition to secondary techniques. This may be accomplished by introducing additional heat into the formation to lower the viscosity (thin the oil) and improve its ability to flow to the well bore. Heat may be introduced by either injecting steam in a "steam flood" or injecting oxygen to enable the ignition and combustion of oil within the reservoir in a "fire flood." Such methods are undertaken only in a few unique situations where technical, environmental and economic conditions permit. Most gas reserves are produced during the primary recovery phase. Secondary recovery has significantly contributed to increasing oil recoveries.

Future of petroleum production

Future of petroleum production
 Consumption in the twentieth and twenty-first centuries has been abundantly pushed by automobile growth; the 1985–2003 oil glut even fuelled the sales of low economy vehicles in OE CD countries. In 2008, the economic crisis seems to have some impact on the sales of such vehicles; still, the 2008 oil consumption shows a small increase. The BRIC countries might also kick in, as China briefly was the first automobile market in December 2009. The immediate outlook still hints upwards. In the long term, uncertainties linger; the OPEC believes that the OE CD countries will push low consumption policies at some point in the future; when that happens, it will definitely curb oil sales, and both OPEC and EIA kept lowering their 2020 consumption estimates during the past 5 years. Oil products are more and more in competition with alternative sources, mainly coal and natural gas, both cheaper sources.

US oil production and imports, 1920–2005.

Production will also face an increasingly complex situation; while OPEC countries still have large reserves at low production prices, newly found reservoirs often lead to higher prices; offshore giants such as Tupi, Guara and Tiber demand high investments and ever-increasing technological abilities. Subsalt reservoirs such as Tupi were unknown in the twentieth century, mainly because the industry was unable to probe them. Enhanced oil Recovery (EOR) techniques (example: DaQing, China) will continue to play a major role in increasing the world's recoverable oil
.

Peak oil

Peak Oil is the scientific projection that future petroleum production (whether for individual oil wells, entire oil fields, whole countries, or worldwide production) will eventually peak and then decline at a similar rate to the rate of increase before the peak as these reserves are exhausted. The peak of oil discoveries was in 1965, and oil production per year has surpassed oil discoveries every year since 1980.

Hubbert applied his theory to accurately predict the peak of U.S. oil production at a date between 1966 and 1970. This prediction was based on data available at the time of his publication in 1956. In the same paper, Hubbert predicts world peak oil in "half a century" after his publication, which would be 2006.

It is difficult to predict the oil peak in any given region, due to the lack of knowledge and/or transparency in accounting of global oil reserves. The scientist and researchers from Oxford University argue that official figures are inflated because OPEC members over-reported reserves in the 1980s when competing for global market share. Based on available production data, proponents have previously predicted the peak for the world to be in years 1989, 1995, or 1995–2000. Some of these predictions date from before the recession of the early 1980s, and the consequent reduction in global consumption, the effect of which was to delay the date of any peak by several years. Just as the 1971 U.S. peak in oil production was only clearly recognized after the fact, a peak in world production will be difficult to discern until production clearly drops off. The peak is also a moving target as it is now measured as "liquids", which includes synthetic fuels, instead of just conventional oil.

                                                                                     Global Peak Oil forecast

The International Energy Agency (IEA) says production of conventional crude oil peaked in 2006. Since virtually all economic sectors rely heavily on petroleum, peak oil could lead to a "partial or complete failure of markets or, simply an orderly transition to 100 per cent renewable energy, within as short as a decade.

Empirical equations for thermal properties

Empirical equations for thermal properties

Heat of combustion

At a constant volume the heat of combustion of a petroleum product can be approximated as follows:

.

where  is measured in cal/gram and d is the specific gravity at 60 °F (16 °C).

Thermal conductivity

The thermal conductivity of petroleum based liquids can be modeled as follows:

0.547

where K is measured in BTU · hr⁻¹ft⁻² , t is measured in °F and d is the specific gravity at 60 °F (16 °C).

Specific heat

The specific heat of a petroleum oils can be modeled as follows:

,

where c is measured in BTU/lbm-°F, t is the temperature in Fahrenheit and d is the specific gravity at 60 °F (16 °C).

In units of kcal/(kg·°C), the formula is:

,

where the temperature t is in Celsius and d is the specific gravity at 15 °C.

Latent heat of vaporization

The latent heat of vaporization can be modeled under atmospheric conditions as follows:

,

where L is measured in BTU/lbm, t is measured in °F and d is the specific gravity at 60 °F (16 °C).

In units of kcal/kg, the formula is:

,

where the temperature t is in Celsius and d is the specific gravity at 15 °C.

Oil extraction and recovery

Oil extraction and recovery

Primary recovery

During the primary recovery stage, reservoir drive comes from a number of natural mechanisms. These include: natural water displacing oil downward into the well, expansion of the natural gas at the top of the reservoir, expansion of gas initially dissolved in the crude oil, and gravity drainage resulting from the movement of oil within the reservoir from the upper to the lower parts where the wells are located. Recovery factor during the primary recovery stage is typically 5-15%.

While the underground pressure in the oil reservoir is sufficient to force the oil to the surface, all that is necessary is to place a complex arrangement of valves (the Christmas tree) on the well head to connect the well to a pipeline network for storage and processing.

Secondary recovery

Over the lifetime of the well the pressure will fall, and at some point there will be insufficient underground pressure to force the oil to the surface. After natural reservoir drive diminishes, secondary recovery methods are applied. They rely on the supply of external energy into the reservoir in the form of injecting fluids to increase reservoir pressure, hence replacing or increasing the natural reservoir drive with an artificial drive. Sometimes pumps, such as beam pumps and electrical submersible pumps (ESPs), are used to bring the oil to the surface. Other secondary recovery techniques increase the reservoir's pressure by water injection, natural gas reinjection and gas lift, which injects air, carbon dioxide or some other gas into the bottom of an active well, reducing the overall density of fluid in the wellbore. Typical recovery factor from water-flood operations is about 30%, depending on the properties of oil and the characteristics of the reservoir rock. On average, the recovery factor after primary and secondary oil recovery operations is between 35 and 45%.

Tertiary recovery

Tertiary, or enhanced oil recovery methods increase the mobility of the oil in order to increase extraction. Thermally enhanced oil recovery methods (TEOR) are tertiary recovery techniques that heat the oil, thus reducing its viscosity and making it easier to extract. Steam injection is the most common form of TEOR, and is often done with a cogeneration plant. In this type of cogeneration plant, a gas turbine is used to generate electricity and the waste heat is used to produce steam, which is then injected into the reservoir. This form of recovery is used extensively to increase oil extraction in the San Joaquin Valley, which has very heavy oil, yet accounts for 10% of the United States' oil extraction. In-situ burning is another form of TEOR, but instead of steam, some of the oil is burned to heat the surrounding oil.

Occasionally, surfactants (detergents) are injected to alter the surface tension between the water and oil in the reservoir, mobilizing oil which would otherwise remain in the reservoir as residual oil.

Another method to reduce viscosity is carbon dioxide flooding.

Tertiary recovery allows another 5% to 15% of the reservoir's oil to be recovered.

                

                Steam is injected into many oil fields where the oil is thicker and heavier than normal crude oil

Tertiary recovery begins when secondary oil recovery isn't enough to continue adequate extraction, but only when the oil can still be extracted profitably. This depends on the cost of the extraction method and the current price of crude oil. When prices are high, previously unprofitable wells are brought back into use and when they are low, extraction is curtailed.

Microbial treatments is another tertiary recovery method. Special blends of the microbes are used to treat and break down the hydrocarbon chain in oil thus making the oil easy to recover as well as being more economic versus other conventional methods. In some states, such as Texas, there are tax incentives for using these microbes in what is called a secondary tertiary recovery. Very few companies supply these, however companies like Bio Tech, Inc. have proven very successful in waterfloods across Texas

Locating the oil field

Locating the oil field

Geologists use seismic surveys to search for geological structures that may form oil reservoirs. The "classic" method includes making an underground explosion nearby and observing the seismic response that provides information about the geological structures under the ground . However, "passive" methods that extract information from naturally-occurring seismic waves are also known.

Other instruments such as gravimeters and magnetometers are also sometimes used in the search for petroleum. Extracting crude oil normally starts with drilling wells into the underground reservoir. When an oil well has been tapped, a geologist (known on the rig as the "mudlogger") will note its presence. Such a "mudlogger" is known to be sitting on the rig. Historically, in the USA, some oil fields existed where the oil rose naturally to the surface, but most of these fields have long since been used up, except in certain places in Alaska. Often many wells (called multilateral wells) are drilled into the same reservoir, to ensure that the extraction rate will be economically viable. Also, some wells (secondary wells) may be used to pump water, steam, acids or various gas mixtures into the reservoir to raise or maintain the reservoir pressure, and so maintain an economic extraction rate

Extraction of petroleum

Extraction of petroleum

The extraction of petroleum is the process by which usable petroleum is extracted and removed from the earth.

                               Extracting the oil from sea

Oil extraction is simply the removal of oil from the reservoir (oil pool). Oil is often recovered as a water-in-oil emulsion, and specialty chemicals called demulsifiers are used to separate the oil from water. Oil extraction is costly and sometimes environmentally damaging, although Dr. John Hunt of the Woods Hole Oceanographic Institution pointed out in a 1981 paper that over 70 per cent of the reserves in the world are associated with visible macroseepages, and many oil fields are found due to natural seeps. Offshore exploration and extraction of oil disturbs the surrounding marine environment.

Oil spills

Oil spills

Crude oil and refined fuel spills from tanker ship accidents have damaged natural ecosystems in Alaska, the Gulf of Mexico, theGalapagos Islands, France and many other places.

The quantity of oil spilled during accidents has ranged from a few hundred tons to several hundred thousand tons (e.g., Deepwater Horizon Oil Spill, Atlantic Empress, Amoco Cadiz). Smaller spills have already proven to have a great impact on ecosystems, such as the Exxon Valdez oil spill

Oil spills at sea are generally much more damaging than those on land, since they can spread for hundreds of nautical miles in a thin oil slick which can cover beaches with a thin coating of oil. This can kill sea birds, mammals, shellfish and other organisms it coats. Oil spills on land are more readily containable if a makeshift earth dam can be rapidly bulldozed around the spill site before most of the oil escapes, and land animals can avoid the oil more easily.

                                                                          Kelp after an oil spill

Control of oil spills is difficult, requires ad hoc methods, and often a large amount of manpower. The dropping of bombs and incendiary devices from aircraft on the Torrey Canyon wreck produced poor results; modern techniques would include pumping the oil from the wreck, like in the Prestige oil spill or the Erika oil spill.

Though crude oil is predominantly composed of various hydrocarbons, certain nitrogen heterocylic compounds, such as pyridine,picoline, and quinoline are reported as contaminants associated with crude oil, as well as facilities processing oil shale or coal, and have also been found at legacy wood treatment sites. These compounds have a very high water solubility, and thus tend to dissolve and move with water. Certain naturally occurring bacteria, such as Micrococcus, Arthrobacter, and Rhodococcus and have been shown to degrade these contaminants.

Global warming

Global warming

When burned, petroleum releases carbon dioxide; a greenhouse gas. Along with the burning of coal, petroleum combustion is the largest contributor to the increase in atmospheric CO2. Atmospheric CO2 has risen steadily since the industrial revolution to current levels of over 380ppmv, from the 180 – 300ppmv of the prior 800 thousand years, driving global warming.The unbridled use of petroleum could potentially cause a runaway greenhouse effect on Earth

Petroleum industry

Petroleum industry

The petroleum industry is involved in the global processes of exploration, extraction, refining, transporting (often with oil tankers andpipelines), and marketing petroleum products. The largest volume products of the industry are fuel oil and petrol. Petroleum is also the raw material for many chemical products, including pharmaceuticals, solvents, fertilizers, pesticides, and plastics. The industry is usually divided into three major components: upstream, midstream and downstream. Midstream operations are usually included in the downstream category.

Petroleum is vital to many industries, and is of importance to the maintenance of industrialized civilization itself, and thus is critical concern to many nations. Oil accounts for a large percentage of the world's energy consumption, ranging from a low of 32 per cent for Europe and Asia, up to a high of 53 per cent for the Middle East. Other geographic regions' consumption patterns are as follows: South and Central America (44%), Africa (41%), and North America (40%). The world at large consumes 30 billion barrels (4.8 km³) of oil per year, and the top oil consumers largely consist of developed nations. In fact, 24 per cent of the oil consumed in 2004 went to the United States alone, though by 2007 this had dropped to 21 per cent of world oil consumed.

In the US, in the states of Arizona, California, Hawaii, Nevada, Oregon and Washington, the Western States Petroleum Association (WSPA) represents companies responsible for producing, distributing, refining, transporting and marketing petroleum. This non-profit trade association was founded in 1907, and is the oldest petroleum trade association in the United States

Unconventional oil reservoirs

Oil-eating bacteria biodegrade oil that has escaped to the surface. Oil sands are reservoirs of partially biodegraded oil still in the process of escaping and being biodegraded, but they contain so much migrating oil that, although most of it has escaped, vast amounts are still present—more than can be found in conventional oil reservoirs. The lighter fractions of the crude oil are destroyed first, resulting in reservoirs containing an extremely heavy form of crude oil, called crude bitumen in Canada, or extra-heavy crude oil in Venezuela. These two countries have the world's largest deposits of oil sands.

On the other hand, oil shales are source rocks that have not been exposed to heat or pressure long enough to convert their trapped hydrocarbons into crude oil. Technically speaking, oil shales are not always shales and do not contain oil, but are fined-grain sedimentary rocks containing an insoluble organic solid called kerogen. The kerogen in the rock can be converted into crude oil using heat and pressure to simulate natural processes. The method has been known for centuries and was patented in 1694 under British Crown Patent No. 330 covering, "A way to extract and make great quantities of pitch, tar, and oil out of a sort of stone." Although oil shales are found in many countries, the United States has the world's largest deposits