Heavy crude oil


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Heavy crude oil

  1. 1. HEAVY CRUDE OIL By: Muneer BashaIntroduction:Heavy crude oil or extra heavy crude oil is any type of crude oil which does not flow easily. Itis referred to as "heavy" because its density or specific gravity is higher than that of lightcrude oil. Heavy crude oil has been defined as any liquid petroleum with an API gravity lessthan 20°. Physical properties that differ between heavy crudes lighter grades include higherviscosity and specific gravity, as well as heavier molecular composition. Extra heavy oil isdefined with a gravity of less than 10° API (i.e. with density greater than 1000 kg/m3 or,equivalently, a specific gravity greater than 1) and a reservoir viscosity of no more than10,000 centipoises. With a specific gravity of greater than 1, extra heavy crude is present as adense non-aqueous phase liquid in ambient conditions.Heavy crude oil is closely related to natural bitumen from oil sands. Some petroleumgeologists categorize bitumen from oil sands as extra heavy crude oil due to the density ofless than 10 °API. Other classifications label this as bitumen differing it from extra-heavy oil.They differ in the degree by which they have been degraded from the original crude oil bybacteria and erosion. Often, bitumen is present as a solid and does not flow at ambientconditions.The largest reserves of heavy crude oil in the world are located north of the Orinoco river inVenezuela, the same amount as the conventional oil reserves of Saudi Arabia, but 30 or morecountries are known to have reserves.Production, transportation, and refining of heavy crude oil present special challengescompared to light crude oil. Generally, a diluent is added at regular distances in a pipelinecarrying heavy crude to facilitate its flow.Economics: Heavy crude oils provide an interesting situation for the economics of petroleumdevelopment. The resources of heavy oil in the world are more than twice those ofconventional light crude oil. In October 2009, the USGS updated the Orinoco deposits(Venezuela) recoverable value to 513 billion barrels (8.16×1010 m3), making this area the oneof the worlds largest recoverable oil deposit. However, recovery rates for heavy oil are oftenlimited from 5-30% of oil in place. The chemical makeup is often the defining variable in 1
  2. 2. recovery rates. Technology utilized for the recovery of heavy oil has steadily increasedrecovery rates.On one hand, due to increased refining costs and high sulfur content for some sources, heavycrudes are often priced at a discount to lighter ones. The increased viscosity and density alsomakes production more difficult (see reservoir engineering). On the other hand, largequantities of heavy crudes have been discovered in the Americas including Canada,Venezuela and California. The relatively shallow depth of heavy oil fields (often less than3000 feet) can contribute to lower production costs; however, these are offset by thedifficulties of production and transport that render conventional production methodsineffective. Specialized techniques are being developed for exploration and production ofheavy oil.Extraction: Production of heavy oil is becoming more common in many countries, with 2008production led by Canada and Venezuela. Methods for extraction include Cold heavy oilproduction with sand, steam assisted gravity drainage, cyclic steam stimulation, vaporextraction, Toe-to-Heel Air Injection (THAI), and open-pit mining for extremely sandy and oil-rich deposits.Environmental Impact: With current production and transportation methods, heavy crudes have a moresevere environmental impact than light ones. With more difficult production comes theemployment of a variety of enhanced oil recovery techniques, including steam flooding andtighter well spacing, often as close as one well per acre. Heavy crudes also carrycontaminants. For example, Orinoco extra heavy oil contains 4.5% sulfur as well as vanadiumand nickel. However, because crude oil is refined before use, generating specific alkanes viacracking and fractional distillation, this comparison is not valid in a practical sense. Heavycrude refining techniques may require more energy input[citation needed] though, so itsenvironmental impact is presently much more significant than that of lighter crude.[citationneeded]With present technology, the extraction and refining of heavy oils and oil sands generates asmuch as three times the total CO2 emissions compared to conventional oil, primarily drivenby the extra energy consumption of the extraction process (which may include burningnatural gas to heat and pressurize the reservoir to stimulate flow). Current research in tobetter production methods seek to reduce this environmental impact. 2
  3. 3. In a 2009 report, the National Toxics Network, citing data provided by the Carbon DioxideInformation Analysis Center of the government of the United States and the CanadianAssociation of Petroleum Producers (CAPP), found that heavy oils can have higher CO2emissions per ton than coal. Emissions were lower than coal on a "per unit of energyproduced" basis, at about 84% of those for coal (0.078/0.093) and thus higher on this basis ofCO2 emissions, than conventional oil.Environmental Research Web has reported that "because of the energy needed for extractionand processing, petroleum from Canadian oil tar sands has higher life cycle emission" versusconventional fossil fuels; "up to 25% more."Geological Origin: Most geologists agree that crude becomes "heavy" as a result of biodegradation, inwhich lighter ends are preferentially consumed by bacterial activity in the reservoir, leavingheavier hydrocarbons behind. This hypothesis leans heavily on the techniques of petroleumgeochemistry. Poor geologic reservoir sealing exposes the hydrocarbon to surfacecontaminants, including organic life (such as bacteria) and contributes to this process.Heavy oils can be found in shallow, young reservoirs, with rocks from the Pleistocene,Pliocene, and Miocene (younger than 25 million years). In some cases, it can also be found inolder Cretaceous, Mississippian, and Devonian reservoirs. These reservoirs tend to be poorlysealed, resulting in heavy oil and oil-sands.Chemical Properties: Heavy oil is asphaltic and contains asphaltenes and resins. It is "heavy" (dense andviscous) due to the high ratio of aromatics and naphthenes to paraffins (linear alkanes) andhigh amounts of NSOs (nitrogen, sulfur, oxygen and heavy metals). Heavy oil has a higherpercentage of compounds with over 60 carbon atoms and hence a high boiling point andmolecular weight. For example, the viscosity of Venezuelas Orinoco extra-heavy crude oil liesin the range 1000–5000 cP (1–5 Pa·s), while Canadian extra-heavy crude has a viscosity in therange 5000–10,000 cP (5–10 Pa·s), about the same as molasses, and higher (up to 100,000 cPor 100 Pa·s for the most viscous commercially exploitable deposits).A definition from theChevron Phillips Chemical company is as follows:The "heaviness" of heavy oil is primarily the result of a relatively high proportion of a mixedbag of complex, high molecular weight, non-paraffinic compounds and a low proportion ofvolatile, low molecular weight compounds. Heavy oils typically contain very little paraffin andmay or may not contain high levels of asphaltenes. 3
  4. 4. There are two main types of heavy crude oil: Those that have over 1% sulfur (high sulfur crude oils), with aromatics andasphaltenes, and these are mostly found in North America (Canada (Alberta, Saskatchewan),United States (California), Mexico), South America (Venezuela, Colombia and Ecuador) andthe Middle East (Kuwait, Saudi Arabia).Those that have less than 1% sulfur (low sulfur crude oils), with aromatics, naphthenes andresins, and these are mostly found in Western Africa (Chad), Central Africa (Angola) and EastAfrica (Madagascar).Companies and organizations:Major petroleumcompaniesSuper majors BP Chevron ConocoPhillips ExxonMobil Royal Dutch Shell TotalNational oilcompanies ADNOC CNOOC CNPC Iraq National Oil Company Indian Oil Corporation Kuwait Petroleum Corporation Nigerian National Petroleum Corporation NIOC ONGC Orlen PDVSA Pemex Pertamina Petrobras 4
  5. 5. Petronas Qatar Petroleum Rosneft Saudi Aramco Sonangol SonatrachOther: Anadarko Apache BG Group Cenovus Energy Devon Eni GalpEnergia Gazprom Hess Husky Energy Imperial Oil Lukoil Marathon Oil Nippon Oil Occidental OMV PetroChina Reliance Industries Repsol YPF Sinopec Statoil Suncor Energy Surgutneftegas TNK-BPMajor services companies: AMEC Baker Hughes 5
  6. 6. CGGVeritas CH2M HILL China Oilfield Services Enbridge Ensco GE Oil & Gas Halliburton NaftiranIntertrade National Oilwell Varco Petrofac Saipem Schlumberger Snam Technip TransCanada Transocean Weatherford Wood GroupOther: International Association of Oil & Gas Producers International Energy Agency International Petroleum Exchange OPEC Society of Petroleum Engineers World Petroleum CouncilData: Natural gas Consumption Production Reserves Imports Exports Price 6
  7. 7. Petroleum Consumption Production Reserves Imports Exports Price (Price of gasoline and diesel)Exploration andproduction:Exploration: Core sampling Geophysics Integrated asset modelling Petroleum engineering Reservoir simulation Seismic to simulation Petroleum geology Petrophysics Reflection seismology (Seismic inversion) Seismic sourceDrilling: Blowouts Completion (Squeeze job) Differential sticking Directional drilling (Geosteering) Drilling engineering Drilling fluid Drilling fluid invasion Drill stem test Lost circulation Measurement 7
  8. 8. Tracers Underbalanced drilling Well loggingProduction:Agreements o Concessions o Production sharing agreementsArtificial lift o Pumpjack o Submersible pump (ESP) o Gas liftDownstreamEnhanced oil recovery (EOR) o Steam injection o Gas reinjection Midstream Petroleum product Pipeline transport Refining Upstream Water injection Well intervention XTHistory: 1967 Oil Embargo 1973 oil crisis 1979 energy crisis 1980s oil glut 2000s energy crisis Founders 8
  9. 9. History of petroleum Nationalization Seven Sisters Standard Oil Oil market timelinesProvinces and fields List of natural gas fields List of oil fields East Texas Gulf of Mexico Niger Delta North Sea Persian Gulf Prudhoe Bay Oil Field Russia Venezuela Western Canadian Sedimentary BasinOther Acronymns Peak oil o Mitigation o Timing People Petrocurrency Petrodollar Petroeuro Shale gas Swing producer Unconventional oilHeavy crude oil: o Oil sands o Oil shale 9
  10. 10. What is Crude Oil?Crude oil, commonly known as petroleum, is a liquid found within the Earth comprised ofhydrocarbons, organic compounds and small amounts of metal. While hydrocarbons areusually the primary component of crude oil, their composition can vary from 50%-97%depending on the type of crude oil and how it is extracted. Organic compounds like nitrogen,oxygen, and sulfur typically make-up between 6%-10% of crude oil while metals such ascopper, nickel, vanadium and iron account for less than 1% of the total composition.Crude Oil Formation: Crude oil is created through the heating and compression of organic materials overa long period of time. Most of the oil we extract today comes from the remains of prehistoricalgae and zooplankton whose remains settled on the bottom of an Ocean or Lake. Over timethis organic material combined with mud and was then heated to high temperatures from thepressure created by heavy layers of sediment. This process, known as diagenesis, changes thechemical composition first into a waxy compound called kerogen and then, with increasedheat, into a liquid through a process called catagenesis.Crude Oil Extraction: The most common method of crude oil extraction is drilling. Geologists will firstidentify a section of land they believe has oil flowing beneath it. There are a number of waysthis can be accomplished, the most frequently used methods are satellite imagery, gravitymeters, and magnetometers. Once a steady stream of oil is found, underground the drillingcan begin.Drilling is not an overly complicated process however a standard method has been developedto provide maximum efficiency. The first step of the process involves drilling into the groundin the exact location where the oil is located. Once a steady flow has been identified at aparticular depth beneath the ground a perforating gun is lowered into the well. A perforatinggun has explosive charges within it that allow for oil to flow through holes in the casing. Oncethe casing is properly perforated a tube is run into the hole allowing the oil and gas to flow upthe well. To seal the tubing a device called a packer is run along the outside of the tube. Thelast step involves the placement of a structure called a Christmas tree which allows oilworkers to control the flow of oil from the well. 10
  11. 11. Oil Sands: Oil can also be extracted from oil sands, often called tar sands. Oils sands aretypically sand or clay mixed with water and a very viscous form of crude oil known asbitumen. The extraction process for oil sands is quite different from drilling due to the highviscosity of this extra-heavy oil. Rather than using drills, crude oil is extracted from oil sandsthrough strip mining or a variety of other techniques used to reduce the viscosity of the oil.This process can be far more expensive than traditional drilling and is found in highabundance only in Canada and Venezuela. As oil demand continues to rise, and reservesbecome depleted, oil sands could provide one of the last viable methods for extracting crudeoil from the Earth.Worldwide Oil Production: While just about every country in the world depends on oil, not all countriesproduce it. The top five oil producing countries are: Saudi Arabia, Russia, United States, Iran,and China. It is important to note that the term production here refers to crude oil extractedfrom oil reserves. The top five oil consuming countries are: United States, China, Japan,Russia, and Germany.At the current rate of consumption it is estimated that worldwide reserves will becomeextinguished by 2039. Scientists and engineers are working hard to find ways of moreefficiently extracting and processing crude oil to delay what could become a global energycrisis. 11