Natural gas is a naturally occurring mixture of gaseous hydrocarbons consisting primarily of methane in addition to various smaller amounts of other higher alkanes. Low levels of trace gases like carbon dioxide, nitrogen, hydrogen sulfide, and helium are also usually present. Methane is colorless and odorless, and the second largest greenhouse gas contributor to global climate change after carbon dioxide. So odorizers such as mercaptan are commonly added to natural gas supplies for safety so that leaks can be readily detected.
In the United States, fracking began in 1949. According to the Department of Energy (DOE), by 2013 at least two million oil and gas wells in the US had been hydraulically fractured, and that of new wells being drilled, up to 95% are hydraulically fractured. The output from these wells makes up 43% of the oil production and 67% of the natural gas production in the United States. Environmental safety and health concerns about hydraulic fracturing emerged in the 1980s, and are still being debated at the state and federal levels.
Shale gas is an unconventional natural gas that is found trapped within shale formations. Since the 1990s a combination of horizontal drilling and hydraulic fracturing has made large volumes of shale gas more economical to produce, and some analysts expect that shale gas will greatly expand worldwide energy supply.
Well stimulation is a well intervention performed on an oil or gas well to increase production by improving the flow of hydrocarbons from the reservoir into the well bore. It may be done using a well stimulator structure or using off shore ships / drilling vessels, also known as "Well stimulation vessels".
An injection well is a device that places fluid deep underground into porous rock formations, such as sandstone or limestone, or into or below the shallow soil layer. The fluid may be water, wastewater, brine, or water mixed with industrial chemical waste.
The oil and gas industry plays a central role in the economy of the United Kingdom. Oil and gas account for more than three-quarters of the UK's total primary energy needs. Oil provides 97 per cent of the fuel for transport, and gas is a key fuel for heating and electricity generation. Transport, heating and electricity each account for about one-third of the UK's primary energy needs. Oil and gas are also major feedstocks for the petrochemicals industries producing pharmaceuticals, plastics, cosmetics and domestic appliances.
The Fracturing Responsibility and Awareness of Chemicals Act was a 2009 legislative proposal in the United States Congress to define hydraulic fracturing as a federally regulated activity under the Safe Drinking Water Act. The proposed act would have required the energy industry to disclose the chemical additives used in the hydraulic fracturing fluid. The gas industry opposed the legislation.
The inclusion of unconventional shale gas with conventional gas reserves has caused a sharp increase in estimated recoverable natural gas in Canada. Until the 1990s success of hydraulic fracturing in the Barnett Shales of north Texas, shale gas was classed as "unconventional reserves" and was considered too expensive to recover. There are a number of prospective shale gas deposits in various stages of exploration and exploitation across the country, from British Columbia to Nova Scotia.
Fracking is a well stimulation technique involving the fracturing of bedrock formations by a pressurized liquid. The process involves the high-pressure injection of "fracking fluid" into a wellbore to create cracks in the deep-rock formations through which natural gas, petroleum, and brine will flow more freely. When the hydraulic pressure is removed from the well, small grains of hydraulic fracturing proppants hold the fractures open.
Fracking in the United Kingdom started in the late 1970s with fracturing of the conventional oil and gas fields near the North Sea. It was used in about 200 British onshore oil and gas wells from the early 1980s. The technique attracted attention after licences use were awarded for onshore shale gas exploration in 2008. The topic received considerable public debate on environmental grounds, with a 2019 high court ruling ultimately banning the process. The two remaining high-volume fracturing wells were supposed to be plugged and decommissioned in 2022.
Fracking has become a contentious environmental and health issue with Tunisia and France banning the practice and a de facto moratorium in place in Quebec (Canada), and some of the states of the US.
Environmental impact of fracking in the United States has been an issue of public concern, and includes the contamination of ground and surface water, methane emissions, air pollution, migration of gases and fracking chemicals and radionuclides to the surface, the potential mishandling of solid waste, drill cuttings, increased seismicity and associated effects on human and ecosystem health. Research has determined that human health is affected. A number of instances with groundwater contamination have been documented due to well casing failures and illegal disposal practices, including confirmation of chemical, physical, and psychosocial hazards such as pregnancy and birth outcomes, migraine headaches, chronic rhinosinusitis, severe fatigue, asthma exacerbations, and psychological stress. While opponents of water safety regulation claim fracking has never caused any drinking water contamination, adherence to regulation and safety procedures is required to avoid further negative impacts.
The environmental impact of fracking is related to land use and water consumption, air emissions, including methane emissions, brine and fracturing fluid leakage, water contamination, noise pollution, and health. Water and air pollution are the biggest risks to human health from fracking. Research has determined that fracking negatively affects human health and drives climate change.
There are many exemptions for fracking under United States federal law: the oil and gas industries are exempt or excluded from certain sections of a number of the major federal environmental laws. These laws range from protecting clean water and air, to preventing the release of toxic substances and chemicals into the environment: the Clean Air Act, Clean Water Act, Safe Drinking Water Act, National Environmental Policy Act, Resource Conservation and Recovery Act, Emergency Planning and Community Right-to-Know Act, and the Comprehensive Environmental Response, Compensation, and Liability Act, commonly known as Superfund.
Shale gas in the United Kingdom has attracted increasing attention since 2007, when unconventional onshore shale gas production was proposed. The first shale gas well in England was drilled in 1875. As of 2013 a number of wells had been drilled, and favourable tax treatment had been offered to shale gas producers.
The Marcellus natural gas trend is a large geographic area of prolific shale gas extraction from the Marcellus Shale or Marcellus Formation, of Devonian age, in the eastern United States. The shale play encompasses 104,000 square miles and stretches across Pennsylvania and West Virginia, and into eastern Ohio and western New York. In 2012, it was the largest source of natural gas in the United States, and production was still growing rapidly in 2013. The natural gas is trapped in low-permeability shale, and requires the well completion method of hydraulic fracturing to allow the gas to flow to the well bore. The surge in drilling activity in the Marcellus Shale since 2008 has generated both economic benefits and considerable controversy.
Fracking in South Africa is an energy production strategy at early stages of development using high-pressure drilling techniques to release natural gas trapped in shale rock. After initially imposing a moratorium on fracking in April 2011, the South African government lifted the moratorium in September 2012 after an initial investigation by an interdepartmental task team. Several energy companies were subsequently granted exploration licenses. Fracking in South Africa is a current topic of debate, with proponents pointing to substantial economic and energy benefits and opponents voicing concerns about potentially adverse environmental impacts.
Fracking in Canada was first used in Alberta in 1953 to extract hydrocarbons from the giant Pembina oil field, the biggest conventional oil field in Alberta, which would have produced very little oil without fracturing. Since then, over 170,000 oil and gas wells have been fractured in Western Canada. Fracking is a process that stimulates natural gas or oil in wellbores to flow more easily by subjecting hydrocarbon reservoirs to pressure through the injection of fluids or gas at depth causing the rock to fracture or to widen existing cracks.
The Petroleum Act 1998 is an Act of the Parliament of the United Kingdom which consolidated arrangements for the licensing, operation and abandonment of offshore installations and pipelines. As a consolidation Act, it did not change the substantive law, although certain Acts were amended and repealed.
