Page 6 - A Primer of Oilwell Drilling, 7th Edition

his book is an introduction to the art and science of drilling
Toilwells. While this book focuses on well drilling in the oil and 1
Petroleum Extension-The University of Texas at Austin
gas industry, it is important to note that wells can be drilled for a
variety of purposes. Not all wells are used to extract oil and gas from
the earth. Wells are also drilled to produce fresh water for irrigation
and to supply water to cities. Some wells are drilled into deep lay-
ers of rock to dispose of hazardous waste. Greenhouse gases, such Introduction
as carbon dioxide, can be captured and injected into underground
layers for permanent disposal. The same well drilling methods can
be applied to all these uses.
Drilling rigs are large and noisy. They operate numerous pieces
of enormous equipment (fig. 1). The purpose of a drilling rig is only
to drill a hole in the ground. Although the rig is big, the hole it drills
is relatively small. The purpose of the drill hole is to tap an oil or
gas reservoir often thousands of feet or hundreds of metres below
the surface of the earth. The drill hole is usually less than one foot
(30 centimetres) in diameter at final depth.

Figure 1. Drilling rigs are large to
accommodate the size of the drilling
equipment and pipes.

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