Gas depletion
Encyclopedia
Gas depletion is the inescapable result of extracting and consuming natural gas
since it is a nonrenewable natural resource. The number of years of natural gas left is estimated by the ratio of proven natural gas reserves to the current consumption rate.
Like oil production, natural gas production in a given region tends to follow a bell curve
, therefore gas production on a continental level is expected not to cease abruptly, rather it will decline gradually over time. But a key difference in understanding peak gas
compared to peak oil
is that while an individual oil well
's production tends to decline relatively slowly, a gas well's production drops off much more abruptly as pressure in the reservoir is relieved. This could potentially lead to a much sharper decline in gas production at the continental level than has been seen in conventional oil production on those continents that have peaked.
, underlying the city of Fort Worth, which is a highly impermeable formation and difficult to produce by conventional means. Wells drilled horizontally rather than vertically through the formation enabled profitable gas production, and the Barnett Shale now produces 6% of US natural gas. Other shale gas
formations in the lower 48 states are widely distributed, and are known to contain large resources of natural gas.
Natural gas
Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons . It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock for fertilizers.Most natural...
since it is a nonrenewable natural resource. The number of years of natural gas left is estimated by the ratio of proven natural gas reserves to the current consumption rate.
Depletion date
According to the Energy Information Agency, the world in 2005 had about 60 years of natural gas left. However, the relevance of worldwide figures is questioned since unlike oil relatively little gas is shipped across the oceans. If one compares proven North American reserves versus North American consumption, one gets only 11 years.Like oil production, natural gas production in a given region tends to follow a bell curve
Bell curve
Bell curve can refer to:* A Gaussian function, a specific kind of function whose graph is a bell-shaped curve* Normal distribution, whose density function is a Gaussian function...
, therefore gas production on a continental level is expected not to cease abruptly, rather it will decline gradually over time. But a key difference in understanding peak gas
Peak gas
Peak gas is the point in time at which the maximum global natural gas production rate is reached, after which the rate of production enters its terminal decline. Natural gas is a fossil fuel formed from plant matter over the course of millions of years. It is a finite resource and thus considered...
compared to peak oil
Peak oil
Peak oil is the point in time when the maximum rate of global petroleum extraction is reached, after which the rate of production enters terminal decline. This concept is based on the observed production rates of individual oil wells, projected reserves and the combined production rate of a field...
is that while an individual oil well
Oil well
An oil well is a general term for any boring through the earth's surface that is designed to find and acquire petroleum oil hydrocarbons. Usually some natural gas is produced along with the oil. A well that is designed to produce mainly or only gas may be termed a gas well.-History:The earliest...
's production tends to decline relatively slowly, a gas well's production drops off much more abruptly as pressure in the reservoir is relieved. This could potentially lead to a much sharper decline in gas production at the continental level than has been seen in conventional oil production on those continents that have peaked.
Role of New Technology
As new technologies for natural gas production are discovered, the world's ultimate reserves can grow. Although some predictions of ultimate reserve recovery include provisions for new technology, not every magnitude of breakthrough can be accurately accounted for.Example
More than half the increase in US natural gas production from 2006 to 2008 came from Texas, where production rose 15% between the first quarter of 2007 and the first quarter of 2008. This was mostly due to improved technology, which allowed the production of deepwater offshore and "unconventional" resources. An important new development was the horizontal drilling in a geologic formation known as the Barnett ShaleBarnett Shale
The Barnett Shale is a geological formation located in the Bend Arch-Fort Worth Basin. It consists of sedimentary rocks of Mississippian age in Texas...
, underlying the city of Fort Worth, which is a highly impermeable formation and difficult to produce by conventional means. Wells drilled horizontally rather than vertically through the formation enabled profitable gas production, and the Barnett Shale now produces 6% of US natural gas. Other shale gas
Shale gas
Shale gas is natural gas produced from shale. Shale gas has become an increasingly important source of natural gas in the United States over the past decade, and interest has spread to potential gas shales in the rest of the world...
formations in the lower 48 states are widely distributed, and are known to contain large resources of natural gas.