7
Introduction
or produced, which may grow to 12 barrels of water as “enhanced oil and gas recovery methods” become more important.
Chapter 2 illustrates the growing importance of water in raw fuel productions by
examining the use of water in four specific cases: (1) the role of underground water
and produced water in the recovery of oil and gas, and in particular an increased
water usage for the recovery of coal bed methane and gas from geopressurized
zones; (2) an increased use of water in enhanced oil recovery methods; (3) an important role of water in the newly developed and promising method called “fracking” in
the recovery of unconventional gas (shale gas and tight gas); and (4) the use of water
in mining, preparation, and extraction of coal, tar sands and heavy oils, uranium,
and oil shale. The large expansion of tar sand industry will particularly enhance the
use of water.
The four cases examined are the basis of existing and all future growth and
diversification of raw fuel industries. While the large use of water for cases 1 and 4
described earlier is already known, it is the expanded use of water for all cases
that will increase the importance of water in raw fuel production industries. As the
existing oil wells age, the recovery of last remains from the oil wells will require
more and more use of enhanced oil recovery methods. These methods use a number
of techniques such as surfactant, polymer, alkaline flooding, and steam injection,
which involve water or steam. In the case of unconventional oil recovery, pressurized steam is often used. Steam combustion is also used to increase fluidity of
trapped oils.
The recoveries of unconventional gas such as shale gas, tight gas, and coal bed
methane are the game changers in the natural gas industries.
Water has been used as a material for creating underground fractures in various
geological structures to recover unconventional gas. This process is called fracking,
and it opens up the tight geological structures by the injection of a high-pressure
water in the ground either horizontally or at an angle. The fracking process increases
the porosity of the tight geological structures and therefore releases the trapped gas.
The pressurized water also contains additives (e.g., surfactants) and other chemicals.
New unconventional gas industry will thus use significantly more water than old
conventional natural gas industry. Chapter 2 briefly examines these and other relevant issues.
1.2.2 ChAPTer 3: WATer AS energy CArrier
Water also plays a benign but vital role in the recovery of various forms of energy.
Chapter 3 illustrates this with four important applications of water and steam to
recover energy: (1) nuclear reactor, (2) geothermal sources, (3) solar energy, and
(4) thermal energy generated from the combustion of various types of fuels. In each
case, water or steam plays a vital role in converting energy and carrying the thermal
energy to generate electricity and heat.
Water has always been an effective “energy carrier.” For example, in a nuclear reactor, water carries energy generated by the nuclear fission process in the form of steam
(thermal energy) to convert it into electrical energy. Water also plays a role of reactor
moderator, ensuring safety. More than 80% of current nuclear reactors use water as an