21
History and Terminology
but nonflammable nonhydrocarbon components such as carbon dioxide, nitrogen, and helium are
often present in the minority and are regarded as contaminants.
In addition to the natural gas fund in petroleum reservoirs, there are also those reservoirs in
which natural gas may be the sole occupant. The principal constituent of natural gas is methane,
but other hydrocarbons, such as ethane, propane, and butane, may also be present. Carbon dioxide
is also a common constituent of natural gas. Trace amounts of rare gases, such as helium, may also
occur, and certain natural gas reservoirs are a source of these rare gases. Just as petroleum can vary
in composition, so can natural gas. Differences in natural gas composition occur between different reservoirs, and two wells in the same field may also yield gaseous products that are different in
composition (Speight, 1990).
Natural gas has been known for many centuries, but its initial use was probably more for religious purposes rather than as a fuel. For example, gas wells were an important aspect of religious
life in ancient Persia because of the importance of fire in their religion. In classical times, these
wells were often flared and must have been, to say the least, awe inspiring (Forbes, 1964).
There is also the possibility that the voices of the gods recorded by the ancients were actually
natural gas forcing its way through fissures in the earth’s surface (Scheil and Gauthier, 1920). Gas
wells were also known in Europe in the Middle Ages, and oil was reportedly ejected from the wells,
as in the phenomena observed at the site near the town of Mineo, Sicily. From other such documentations, it can be surmised that the combustible material, or the source of the noises in the earth,
was actually natural gas.
Just as petroleum was used in antiquity, natural gas was also known in antiquity. However, the
use of petroleum has been relatively well documented because of its use in warfare and as a mastic
for walls and roads (Henry, 1873; Abraham, 1945; Forbes, 1958a,b; James and Thorpe, 1994). The
use of natural gas in antiquity is somewhat less well documented, although historical records indicate that the use of natural gas (for other than religious purposes) dates back to about 250 AD when
it was used as a fuel in China. The gas was obtained from shallow wells and was distributed through
a piping system constructed from hollow bamboo stems. There is other fragmentary evidence for
the use of natural gas in certain old texts, but the use is usually inferred since the gas is not named
specifically. However, it is known that natural gas was used on a small scale for heating and lighting
in northern Italy during the early seventeenth century. From this it might be conjectured that natural
gas found some use from the seventeenth century to the present day, recognizing that gas from coal
would be a strong competitor.
Natural gas was first discovered in the United States in Fredonia, New York, in 1821. In the
years following this discovery, natural gas usage was restricted to its environs since the technology
for storage and transportation (bamboo pipes notwithstanding) was not well developed and, at that
time, natural gas had little or no commercial value. In fact, in the 1930s when petroleum refining
was commencing an expansion in technology that is still continuing, natural gas was not considered
a major fuel source and was only produced as an unwanted by-product of crude oil production.
The principal gaseous fuel source at that time (i.e., the 1930s) was the gas produced by the
surface gasification of coal. In fact, each town of any size had a plant for the gasification of coal
(hence the use of the term town gas). Most of the natural gas produced at the petroleum fields
was vented to the air or burned in a flare stack; only a small amount of the natural gas from the
petroleum fields was pipelined to industrial areas for commercial use. It was only in the years after
World War II that natural gas became a popular fuel commodity, leading to the recognition that it
has at the present time.
There are several general definitions that have been applied to natural gas. Thus, lean gas is gas
in which methane is the major constituent. Wet gas contains considerable amounts of the higher
molecular weight hydrocarbons. Sour gas contains hydrogen sulfide, whereas sweet gas contains
very little, if any, hydrogen sulfide. Residue gas is natural gas from which the higher molecular
weight hydrocarbons have been extracted and casing head gas is derived from petroleum but is
separated at the separation facility at the wellhead.
History and Terminology
but nonflammable nonhydrocarbon components such as carbon dioxide, nitrogen, and helium are
often present in the minority and are regarded as contaminants.
In addition to the natural gas fund in petroleum reservoirs, there are also those reservoirs in
which natural gas may be the sole occupant. The principal constituent of natural gas is methane,
but other hydrocarbons, such as ethane, propane, and butane, may also be present. Carbon dioxide
is also a common constituent of natural gas. Trace amounts of rare gases, such as helium, may also
occur, and certain natural gas reservoirs are a source of these rare gases. Just as petroleum can vary
in composition, so can natural gas. Differences in natural gas composition occur between different reservoirs, and two wells in the same field may also yield gaseous products that are different in
composition (Speight, 1990).
Natural gas has been known for many centuries, but its initial use was probably more for religious purposes rather than as a fuel. For example, gas wells were an important aspect of religious
life in ancient Persia because of the importance of fire in their religion. In classical times, these
wells were often flared and must have been, to say the least, awe inspiring (Forbes, 1964).
There is also the possibility that the voices of the gods recorded by the ancients were actually
natural gas forcing its way through fissures in the earth’s surface (Scheil and Gauthier, 1920). Gas
wells were also known in Europe in the Middle Ages, and oil was reportedly ejected from the wells,
as in the phenomena observed at the site near the town of Mineo, Sicily. From other such documentations, it can be surmised that the combustible material, or the source of the noises in the earth,
was actually natural gas.
Just as petroleum was used in antiquity, natural gas was also known in antiquity. However, the
use of petroleum has been relatively well documented because of its use in warfare and as a mastic
for walls and roads (Henry, 1873; Abraham, 1945; Forbes, 1958a,b; James and Thorpe, 1994). The
use of natural gas in antiquity is somewhat less well documented, although historical records indicate that the use of natural gas (for other than religious purposes) dates back to about 250 AD when
it was used as a fuel in China. The gas was obtained from shallow wells and was distributed through
a piping system constructed from hollow bamboo stems. There is other fragmentary evidence for
the use of natural gas in certain old texts, but the use is usually inferred since the gas is not named
specifically. However, it is known that natural gas was used on a small scale for heating and lighting
in northern Italy during the early seventeenth century. From this it might be conjectured that natural
gas found some use from the seventeenth century to the present day, recognizing that gas from coal
would be a strong competitor.
Natural gas was first discovered in the United States in Fredonia, New York, in 1821. In the
years following this discovery, natural gas usage was restricted to its environs since the technology
for storage and transportation (bamboo pipes notwithstanding) was not well developed and, at that
time, natural gas had little or no commercial value. In fact, in the 1930s when petroleum refining
was commencing an expansion in technology that is still continuing, natural gas was not considered
a major fuel source and was only produced as an unwanted by-product of crude oil production.
The principal gaseous fuel source at that time (i.e., the 1930s) was the gas produced by the
surface gasification of coal. In fact, each town of any size had a plant for the gasification of coal
(hence the use of the term town gas). Most of the natural gas produced at the petroleum fields
was vented to the air or burned in a flare stack; only a small amount of the natural gas from the
petroleum fields was pipelined to industrial areas for commercial use. It was only in the years after
World War II that natural gas became a popular fuel commodity, leading to the recognition that it
has at the present time.
There are several general definitions that have been applied to natural gas. Thus, lean gas is gas
in which methane is the major constituent. Wet gas contains considerable amounts of the higher
molecular weight hydrocarbons. Sour gas contains hydrogen sulfide, whereas sweet gas contains
very little, if any, hydrogen sulfide. Residue gas is natural gas from which the higher molecular
weight hydrocarbons have been extracted and casing head gas is derived from petroleum but is
separated at the separation facility at the wellhead.