While many examples and practices are drawn from experience in the us, this note is intended to be relevant to a global audience. On the base of elastic toughness cement slurry system. Common clay and shale are composed mainly of illite or chlorite, but also may contain kaolin and montmorillonite. New methods to calculate water saturation in shale and. Shale oil extraction methods are more flexible than traditional oil well drilling.
Production decline analysis of tight gas and shale gas wells with this method typically results in a bestfit value of greater than unity for the decline exponent parameter. A challenge to preventing pollution is that shale gas extractions varies widely in this regard, even between different wells in the same project. This period has been mainly referred to as the shale gas boom or revolution and the growth of natural gas production in the united states through shale gas extraction has led. However, the opportunity shale gas brings also brings many ques tions yet unanswered, not least about its extraction method of hydraulic fracturing or fracking. Directional drilling and hydraulicfracturing technologies are dramatically increasing natural gas extraction. Shale oil production methods above ground retorting mining of ore well known technology large environmental impact popcorn effect large open mines emissions insitu conversion underground conversion research in progress lower environmental impact not commercially proven. Hydraulic fracturing, or fracking for short, is a technique that makes it possible to extract natural gas. The resulting oil can be used immediately as a fuel or upgraded to meet refinery feedstock specifications by adding hydrogen and removing impurities such as sulfur and nitrogen. Eia data show domestic natural gas production increased 24.
Shale oil is an unconventional oil produced from oil shale rock fragments by pyrolysis, hydrogenation, or thermal dissolution. Exploration and development technology of fuling shale gas. The extraction and use of shale gas can considerably affect the environment through the leaking of extraction chemicals and waste into water supplies, contamination of the water table and the surface soil as well the leaking of greenhouse gases during extraction. Shale gas extraction explained many believe the us is on the brink of a new industrial age, as it benefits from a recent energy boom.
Most domestic clay is mined by openpit methods using various types of equipment, including. In aquifers overlying the marcellus and utica shale formations of northeastern pennsylvania and upstate new york, we document systematic evidence for methane contamination of drinking water associated with shale gas extraction. The extraction and use of shale gas can affect the environment through the leaking of extraction chemicals and waste into water supplies, the leaking of greenhouse gases during extraction, and the pollution caused by the improper processing of natural gas. Shale gas exploration and production key issues and. Shale drilling site in pennsylvania photo helge hansen statoil. Examining growth in shale gas production may shed further light on the downward trend in natural gas prices. The volume of produced water has increased in recent years as exploration of the marcellus shale has generated wastewater in addition to. The us energy information administration eia estimates the global. In particular, water saturation has significant effects on shale rthe eservoir how to cite this paper. The oldest and the most common extraction method involves pyrolysis also known as retorting or destructive distillation. The gas industry claims that because shale and tight gas extraction involves deeper rock layers, they are safer than gas extraction from shallow coal seams.
What is shale gas, how is it extracted through fracking. Shale gas is natural gas produced from shale formations that typically function as both the reservoir and the source rocks for the natural gas. The in situ combustion process is used for extracting shale oil from far below the surface. Natural gas producers use the same methods to access shale gas as they do to reach shale oil horizontal drilling and hydraulic fracturing. Currently, most of the worlds shaleoil is coming from the. In some cases, this fast expansion has resulted in natural gas drilling and.
Another major technology often employed in producing natural gas from shale is horizontal drilling see. Shale gas formations are unconventional reservoirs i. In this publication, we examine the current conditions and outlook for the shale gas production. Yet there is still a great deal of confusion about the workings of the gas and oil industry and therefore about the risks of these new developments in shale gas extraction. Eia adds new play production data to shale gas and tight. Shale gas extraction and its methods have gained a lot of attention in the community and in the media, and have already generated a lot of controversy. Sand pumped in with the fluids often water helps to keep the fractures open. The differences between oil shale, shale oil, and shale gas. This is the same procedure as that used in shale gas production. Australia is undoubtedly one of the most resourceful countries in the world. In terms of chemical makeup, shale gas is typically a dry gas composed primarily of methane 6095% vv, but some formations do produce wet gas. This booklet gives some basic information to use as a starting point to become fully informed about shale gas extraction and hydraulic fracture stimulation, also commonly known as.
An analysis of policy, pollutants and protests abstract australia is undoubtedly one. In this regard, important developments have occurred in the united states of america since the mid2000s. Video explaining shale gas and hydraulic fracturing fracking. Eia recently updated its methodology and production volume estimates for u. In the future, shale gas production is expected to increase, while every other extraction method likely will remain steady or decline. Methane contamination of drinking water accompanying gas. Growth in extraction of oil and natural gas from shale and similar geologic formationsoften referred to as the shale revolutionis arguably the most consequential energy development in the. An analysis of policy, pollutants and protests abstract. What shale oil exploration and production methods are used. In this process, oil shale is heated in the absence of oxygen until its kerogen decomposes into condensable shale oil vapors and noncondensable combustible oil shale gas.
But according to a european commission report there is an overall high risk of ground and surface water contamination resulting from fracking. The result often is physically unrealistic in that cumulative production becomes unbounded as time increases. For minimal amounts of h2s in a gas stream, scavengers can be a. After 2007, the role of shale gas expanded, while extraction from all other sources shrank. Industry claims the public outcry against the new technology is not grounded in science. The most common method of extracting shale oil is by surface mining. Shale gas production casing sealing repair technology and shale gas casing safety entry technology,the success rate of onetime down to scheduled well depth is 100% on the 15003000m horizontal section length.
Raw shale oil extracted from oil shale can be used as fuel oil. Fracking for shale gas production sachverstandigenrat. Doe has a legacy of helping pioneer technologies and processes to improve shale and other unconventional gas extraction, as well as enhance environmental protection. The main difference between tight gas and shale gas, however, is that tight gas can be found in low permeability sedimentary rocks, such as sandstones, while shale gas rocks are usually impermeable 2 royal dutch shell plc. Shale is a laminated sedimentary rock that is formed by the consolidation of clay, mud, or silt. Gas extracted from shale deposits through horizontal drilling and hydraulic fracture. Shale oil exploration and production methods info shale. Furthermore, some leakage of methane is possible during shale gas extraction, and so careful monitoring and checks are required. It involves injection of highly pressurized water with proppant e.
Kpmg global energy institute shale gas a global perspective. Here we look at the major components of hydraulic fracturing, its environmental implications, and its impact on the us and global economies. Shale gas is the term often used to describe both tight gas and shale gas resources. But all shale gas is not the same, and gas processing requirements for shale gas can vary from area to area. The us story and its implications, global energy center senior fellow ellen scholl looks at the factors which enabled the rise of oil and gas production from shale deposits, focusing on the developments which have transpired in texas. An overview of hydraulic fracturing and other formation. Why resource estimates produced with different methods should be different. Shale gas could increase global natural gas resources by approximately 40%.
Natural gas production from shale formations finegrained sedimentary rocks with relatively low permeability that can be rich sources of petroleum and natural gas is one of the most rapidlygrowing trends in u. Environmental safeguards on shale gas production needed as china begins development. For more information about shale oil and gas and fracking, visit the govuk website. Shale oil and gas are exactly the same product as oil and natural gas from conventional extraction. Composition variety complicates processing plans for us shale gas by. The initial drilling only accounts for 40% of the total cost. Shale gas, which is mostly methane can be found in any sedimentary basin, but special methods of extraction is needed. Doe research continues to search for innovative solutions to shale exploration, development, production and environmental protection challenges. These processes convert the organic matter within the rock into synthetic oil and gas. Drilling, extraction, processing, transmission, transportation, storage and distribution are all part of unconventional gas industry operations. Scribd is the worlds largest social reading and publishing site. Composition variety complicates processing plans for us. This typically involves injecting pressurized fluids to stimulate or fracture shale formations and release the natural gas. While shale gas emits lower levels of greenhouse gases when combusted than coal, there are concerns that shale gas extraction could undermine climate change commitments if it replaces the use of renewables.
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