Many of the external pressures that drive the increasing
demands for water also play influential roles in the growing demand for energy.
Both are fundamentally driven by (and drivers of) social
development and economic growth, and both are strongly influenced by economic forces, increasing living standards, technological development and government policy.
Market forces have tended to play a much more important role with respect to energy sector development.
Water is crucial for energy
Water is used in the extractive industries for producing fuels such as coal, uranium, oil and gas. Water is an input for energy crops such as corn and sugar cane for ethanol and biomass for fuel pellets.
Water is also crucial for cooling purposes in most power plants
and the driving force for hydroelectric and steam turbines. In some places, water is used for transporting fuels, such as waterways throughout Europe and many parts of Asia that float barges carrying coal from mines to power plants.
In other places water is used to permit coal slurry to be transported from coal mines to power plants through pipelines. Energy accounts for a significant fraction of a country’s water use (both consumptive and non-consumptive).
In developing countries, 10% to 20% of withdrawals are used
to meet industrial needs, including energy.
In some developed countries, where a smaller fraction is used for agriculture, more than 50% of water withdrawals are used for power plant cooling alone.
Coal mining uses large volumes of water for various processes , and discharges to natural water bodies may be contaminated, while underground operations may disrupt and contaminate aquifers.
For conventional oil and gas production, water injection (sometimes referred to as water flooding) is used to pressurize fields, increasing productivity.
Oil and gas extraction yields high volumes of ‘produced water’, which is water that comes out of the well along with the oil and
gas. Produced water usually has very high salinity and is
difficult to treat.
Underground injection into saline aquifers is one disposal method, although the water can also be treated and reused. In many cases, the volume of produced water far exceeds the volume of fuel
produced.
Water is used as a process input and a feedstock for process steam at refineries to upgrade crude into higher
value products.
Typical volumes of water needed end-to end
(from extraction through refining) for petroleum based fuels are 7–15 litres water per litre fuel.
For natural gas, the volumes of water are approximately 20–50 litres water per barrel equivalent of oil.
Unconventional oil and gas production is generally more water intensive than conventional oil and gas production. For oil sands production in Canada and heavy oil production in Venezuela, water is used to make steam to reduce the viscosity of the fuel, easing production.
Water is also a critical input for hydraulic fracturing, or ‘fracking"
For hydraulic fracturing, typical water injection volumes
are 8–30 million litres per well. Approximately 250 tonnes of proppant, such as sand, is injected to hold the cracks open to increase the gas flows.
The typical composition of fracking fluids is 98% sand and water and 2% chemicals (acids, surfactants, becides and scaling inhibitors), which are added to increase productivity.
As producers become more water efficient, using less water per well, the relative proportion of chemicals increases. A significant
fraction of the injected fluid comes back out of the wells
as waste water (including drilling mud's, flow back water
and produced water).
The volume of produced water that is returned varies greatly, depending on the geological characteristics of the formation; it can be as low as 15% and as high as 300% of the injected volume.
The water intensive process produces large volumes of waste water with high salinity and potential for containing naturally occurring radioactive materials.
Further risks to water quality can occur from storage pits that are not properly lined (allowing the waste water to trickle down
into the groundwater), from spills by trucks that carry the waste water, or by injection into waterways from waste water treatment plants that do not adequately treat the produced water.
There is disruptive clean technologies that enhance water efficiency in the oil recovery process. These innovative technologies need to be promoted and implemented because they are emerging.
One amazing example is:
Titan Oil Recovery, they utilize a patented state of the art Microbially enhanced oil recovery (MEOR) technology.
Proven:
Over 100% Average Production Increase for 300 plus well applications on 30 oil fields.
100% Success Rate on Injector Well Applications.
Click: Titan Oil Recovery
Source: United Nations
Click: Cleantech Grants
Joshua Daniel Mosshart BIO
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