Oil shale or tar sands is extracted under nonthermally destructive conditions with a solvent liquid containing a compound having the general formula. These systems use large hydraulic and electrically powered shovels to dig up tar sands and load them into. Conocophilips uses a heating method to extract bitumen from tar sands. Exchanging oil sands expansion for renewable energy growth in canada. As with the extraction and use of any fossil fuel, negative environmental effects arise as a result of the extraction, upgrading, and processing of bitumen from the oil sands. Water is a crucial component of all oil and gas production methods. Shale oil extraction methods are more flexible than traditional oil well drilling. Mining in the boreal tar sands global forest atlas.
Despite improvements in certain methods of producing alternative. Methods of extraction which do not involve strip mining are even worse for the environment. Each grain of sand is covered by a film of water, which is then surrounded by a slick of heavy oil bitumen. In next weeks article i will conclude the series on the athabasca oil sands by examining the logistical issues of getting the oil sands to market, including the impact of the keystone xl decision regardless of which way it goes. The carbon intensity of oil sands development poses other environmental health questions. Oil sands is sand containing bitumen often referred to as tar sand, because the bitumen or oil resembles black, sticky tar.
Tar sands tar sands are grains of sand or, in some cases, porous carbonate rocks that are intimately. The extraction of bitumenderived crude oil follows several steps. The cost of production and energy return of oil sands. Oil sands also contain fine solids and clays, typically in the range of 10 to 30% by weight. For surface mining, areas are first cleared of trees, bogs are drained. Sand and rock material which contains crude bitumen a heavy, viscous form of crude oil. Extraction of oil from the tar sands of ofosu and environs, edo state, midwestern nigeria. These oil sands, hosted primarily in the mcmurray formation, consist of a mixture of crude bitumen a semisolid rocklike form of crude oil, silica sand, clay minerals, and water. It is composed of sand, claw, water, and bitumen, which is an oil that is black and viscous.
How tar sands oil is produced high oil prices and technological advances have made it economically viable to ramp up oil production from. This is achieved through a simple waterbased gravity separation process, most of which. Unconventional oil and gas have already made a dent in international energy linkages by reducing us energy import dependency. Environmental impacts of oil sands the environmental impact of the oil sands is an issue that has been extremely divisive. Oil sands are either loose sands or partially consolidated sandstone containing a naturally occurring mixture of sand, clay, and water, soaked with a dense and extremely viscous form of petroleum technically referred to as bitumen. Steam assisted gravity drainage sagd is currently the most widely used insitu recovery method.
A key area of controversy over mining in the boreal region is the exploitation of tar or oil sands, which are areas with sand or sandstone saturated with bitumen, a viscous form of petroleum, which can be mined and processed to produce oil. In the united states, shale gas takes a prominent role in the. February 2016 the future of the canadian oil sands. In spite of these problems, liquid fuels derived from oil shale can become important alternatives to petroleum, when the world economic situation particularly the price of crude oil becomes favorable. Ghg emission factors for high carbon intensity crude oils. The athabasca tar sands also known as oil sands are a very large source of heavy, viscous oil, known as bitumen, located in alberta, canada. Unconventional oil is petroleum produced or extracted using techniques other than the conventional method. It is taken to an extraction plant, where a hot water process can. Natural gas is a relatively clean fossil fuel and ing finances gas extraction. The initial drilling only accounts for 40% of the total cost. Oil sands extraction and processing natural resources canada. Currently, 20% of oil sands reserves are accessible via mining techniques. These sands can be mined, and then processed, to remove the bitumen.
Canadas tar sands are the worlds most expensive major source of oil in the world. This method requires the use of large hydraulic shovels to dig up tar sands and load them onto trucks carrying up to 320 tons per load. Tar sands extraction methods would shift away from destructive stripmining methods toward the even more carbonintensive in. Currently, 80% of oil sands reserves are accessible via insitu techniques. This resource requires special extraction methods to get it out of the ground and into a state where it is fluid enough for transportation by pipeline. The extraction and refining of oil sands produces 3070% more greenhouse gas emissions than conventional oil production, according to estimates by alex farrell and adam brandt published in the october 2007 issue of climatic change. Common extraction methods include surface miningwhere the extraction site is excavatedand insitu mining, where steam is used to liquefy bitumen deep underground. Oil sands or tar sands or bituminous sands refer to a mixture of sand, water, clay, and bitumen which we have seen refers to the heaviest of hydrocarbon mixtures found in crude petroleum. A study on solvent extraction of bitumen from nigerian tar sands using toluene was investigated 5.
Bitumen is so viscous that at room temperature it acts much like cold molasses. The bitumen extraction from nigerian tar sand using dense. Tar sands are extracted by either surface open pit mining or insitu extraction. Openpit mining is the most common form of tar sands extraction. New methods introduced in the 1990s considerably improved the efficiency of tar sands mining, thus reducing the cost.
The method used to extract bitumen from the oil sands depends on the depth of the deposit. Doc renme, an early oil entrepreneur built a tar extraction plant on asphalt ridge using a hot water separation process. The pipeline would transport oil from the alberta tar sands in. The purpose of extraction is to recover the bitumen portion, while rejecting the heavy solids. The potential effects of this technique raise concerns. The overall economics of oil extraction is that there is money in it both for extraction companies and their investors. Oil sands, tar sands, crude bitumen, or more technically bituminous sands, are a type of unconventional petroleum deposit. The second way is to heat the bitumen causing the viscosity to decrease allowing it to flow into a well, which is then accessible to the oil and gas company. Extracted oil sands crude can then be refined into gasoline and other hydrocarbon products. Once the oil sand is crushed, hot water is added so it can be pumped to the extraction plant. Beginning on 20 august 2011, bill mckibben is leading what may be the largest green civil disobedience campaign in a generation, against the proposed construction of the 1,600mile long keystone xl pipeline. Growth potential of a unique resource amidst regulation, egress, cost, and price uncertainty 5 preface this research was conceived with two central objectives. Tar sands oil is so thick that it cant be extracted by traditional methods. Extension of the methodology developed in phase i to.
Extracting bitumen from tar sandsand refining it into products like gasolineis significantly costlier and more difficult than extracting and refining liquid oil. Crude oil from oil sands will constitute a substantial share of future global oil demand. Oil sands recovery processes include extraction and separation system to separate the bitumen from the clay, sand and water that make up the. Some loss methods are used to recover bitumen that lies too deep beneath the surface for mining greater than 75 metres underground. One way is by mining on the surface less than 100 meters deep. Tar sands oil sands petroleum 27 68 extraction production, refining usdoe 2006, p 5759. Industry and governments across the globe are investing in unconventional oil sources due to the increasing scarcity of conventional oil reserves. A variety of treatment methods are currently available to oil sands producers and new methods are put into practice as more research is. However, there are concerns about certain extraction methods, namely hydraulic fracturing of shale. A hot water extraction process for extracting bitumen from tar sands is taught wherein the tar sand is conditioned using an alkali metal bicarbonate, an alkali metal carbonate and a liquid hydrocarbon. The process of oil sands basically consists of extraction either by openpit mining or insitu, upgrading and refining. Climate impacts of the keystone xl tar sands pipeline pdf. Tar sands contain about 1015% bitumen, the remainder being sand or other inorganic.
Laramie energy technology center letc from 1971 through 1982 to develop technology for future recovery of oil from u. The carbon emissions from tar shale and tar sands would initiate a continual. Coaa glossary nov14 07 construction industry institute. Pulverization of the tar sands followed by agglomeration in a mechanical shaker resulted in spherical agglomerates having higher bitumen contents than the mined tar sand. Oil sands slurry produced in the slurry preparation plant spp contains about 5055% sand and less than 10% bitumen. Tar sands bitumen that is extracted and upgraded to produce synthetic crude has been. Then the water is recycled so it can be used for steam again. Us4396491a solvent extraction of oil shale or tar sands. Tar sands extraction process geopetrol equipment ltd. Formal cooperation between state, federal, and private interests for coring and resource characterization is a possible option. Throughout the world, considerable oil reserves are locked in the form of tar sands, also called bitumen sands. Oil sands are actually found all over the world, and are sometimes referred to as tar sands or bituminous sands.
Tar sands 7% bitumen by weight from the tar sands and oil shale contain relatively low concentrations of hydrocarbons. Seismic refraction survey of tar sands deposits in ijebu. Since most of the tar sand leases containing petroleum in tar form are under considerable overburden. There are two primary extraction methods for tar sands. Determine the feasibility of in situ recovery methods applied to tar sand deposits. The ecological footprint left behind by both extraction methods is astonishing. By 2017, insitu extraction will be how most tar sands. Tar sands are extracted in alberta and transported via pipelines. Environmental consequences of oil production from oil sands. The athabasca oil sands, also known as the athabasca tar sands, are large deposits of bitumen or extremely heavy crude oil, located in northeastern alberta, canada roughly centred on the boomtown of fort mcmurray. There are two ways in which we can obtain the tar sands in order to create oil.
There are two ways to extract bitumen from the oil sands. For deposits that are deep below the surface, bitumen is extracted insitu or in place. The sands are bonded firmly together by graintograin contact. Tar sands extraction and processing tar sands deposits near the surface can be recovered by open pit mining techniques. Pdf an overview of oil sand tar sand extraction and processing. They expose the bitumen to steam so the product is softened and this allows it to be pumped to the processor. Pulverization of the tar sands followed by agglomeration in a mechanical shaker resulted in spherical agglomerates having higher bitumen contents than the mined tar. The first step is the extraction of the heavy oil from the rock. Tar sands are produced from a different feedstock than conventional crude also called. If the deposit is near the surface, the oil sands is mined and sent to a bitumen processing plant. The conditioning step replaces the step of conditioning using caustic soda previously used in tar sand extraction. Chapter 10 synthetic fuels, oil shale and tar sands.
Oil sands deposits account for a third of globally proven oil reserves, underlie large natural forested areas, and have extraction methods requiring large volumes of freshwater. Tar sands impact on climate change skeptical science. Tar sands impact on climate change posted on 23 august 2011 by dana1981. A source of calcium andor magnesium ions can also be added. Environmental impacts of oil sands energy education. The present invention is directed toward a tar sands extraction process and, in particular, a hot water extraction process for tar sands and a conditioning agent for use therein. Exchanging oil sands expansion for renewable energy growth. Pdf an overview of oil sand tar sand extraction and. Extraction of oil from the tar sands of ofosu and environs. Tar sands also called oil sands are a mixture of sand, clay, water, and bitumen. Tar sands extraction destroys vast swaths of forests and wetlands and the habitat of. Large shovels scoop the oil sand into trucks which then move it to crushers where the large clumps of earth are processed. The alberta tar sands operation is one of the most prolific sources of air pollution in north america, often exceeding the total emissions from canadas largest city, according to canadian scientists. A typical oil sands deposit in alberta contains on average about 10% bitumen, 5% water and 85% solids, mostly in the form of coarse silica sand.