We often hear statements suggesting that by ramping up shale gas production, the U.S. can raise total natural gas production and solve many of its energy problems, including adding quite a number of natural gas vehicles, and replacing a large share of coal fired electricity generation.
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While there is the possibility that shale gas will allow U.S. natural gas supplies to increase for a few years (or even 10 or 15 years), natural gas is only about one-fourth of U.S. fossil fuel use, so it would be very difficult to ramp it up enough to meet all of these needs.
One issue is whether a rise in shale gas will mostly offset other reductions in natural gas supply. In Annual Energy Outlook 2011, EIA forecasts that shale gas production will increase from 23% of US natural gas production in 2010 to 46% of U.S. natural gas production by 2035, but that these increases will mostly offset decreases elsewhere.
Even with this huge increase in shale gas production, the EIA only sees US natural gas production increasing by an average of 0.8% per year between 2011 and 2035, and US natural gas consumption increasing by an average of 0.6% per year per year to 2035–not enough to make a very big dent in our overall energy needs.
Click here to see why we simply cannot rely on natural gas →
This post originally appeared at The Oil Drum.
A person can see how irregular the natural gas supply pattern has been in Figure 2. Figure 3, below, shows US natural gas production by itself. The irregularity of production over the years and the fact that current production is not much above 1970, makes a person wonder if the optimistic forecasts are really accurate.
One factor that may have may have depressed production was price controls from 1954 until 1978, but even without price controls, there has not been much of an upward trend in production until recently.
In the absence of shale gas, EIA's forecast for U.S. natural gas production would be a decline over the next 25 years.
EIA is forecasting an increase in shale gas, but to a significant extent it would act to offset a decline in other production. Note that historical shale gas production on Figure 1 is very small, but the EIA is forecasting a very large increase for this sector.
If declines in other production have been optimistically estimated, then it is possible that there may be a decline in total production, even if the shale gas estimate is correct.
Figure 1. EIA Figure from the Early Release Overview of Annual Energy Release 2011. (Upper caption is EIA's.)
The production of Canada, the U.S.'s largest source of imports, is declining as its own use is rising.
Figure 4 suggests that at least part of the need for additional shale gas production is simply to offset declines in Canadian production. If Canada uses more natural gas in its oil operations, this could exert additional downward pressure on exports in future years.
Figure 4. Canadian Natural Gas Production, Consumption, and Exports from Energy Export Databrowser.
If Texas experience serves as an example, shale production starts dropping fairly quickly after it starts.
Texas is the home of Barnett Shale, the first of the big shale resource plays. Data for the state of Texas indicates that 2009 production was down from the 2008 level, and an estimate I made for 2010 using data through November suggests it will be down even further in 2010.
Based on Figure 6, It appears that Barnett Shale production reached a peak (of approximately 2 trillion cubic feet per year) in 2008, and has been declining since. According to Art Berman, initial plans were based on the assumption that the quality of reserves was uniformly excellent throughout the area, but as drilling proceeded, it became increasingly clear that there were only two sweet spots, and drilling contracted into those areas.
Figure 6. Texas natural gas marketed production based on EIA data. 2010 estimated based on Jan-Nov actual data.
Shale gas drillers appear to need higher prices than are currently available to make production of shale gas profitable.
A big reason why natural gas looks so attractive now is its low price, but it is doubtful these low prices can last. Art Berman has shown that a well head price of over $7 per thousand cubic feet is needed for shale gas drillers to make a profit.
He has also pointed out that estimates of well profitability are based on optimistic views of how long individual wells will be economic. If wells are taken offline more quickly than assumed, this will further raise the needed price. (I came to a similar conclusion using a different approach here also).
In the recent past, prices have been more in the $4 per thousand cubic price range, but over the long term, prices have been very volatile.
Many who are expecting that natural gas use to grow are assuming that prices will stay low. It is doubtful this can happen. Prices will need to be much higher for shale gas production to grow greatly.
Figure 7. Monthly average wellhead natural gas prices based on EIA data, adjusted to current cost level using US Urban CPI.
High (and volatile) prices tend to depress natural gas consumption for industrial use and for heating buildings.
Industrial use of natural gas has not been rising over the long term; it was higher in 1973 than it is currently. Industrial use rose to a peak in 1997, but when prices started becoming volatile, it dropped again. Natural gas for residential and commercial use is primarily for heating, hot water, and cooking.
Its use has remained quite level over the years, reflecting increased efficiency of furnaces, better insulation, and growth in electrical substitutes (such as heat pumps). The only area of natural gas consumption showing real growth has been electrical use of natural gas.
Much of the enthusiasm for new uses for natural gas seems to be driven by its current low price. When this price starts rising again, past history suggests that enthusiasm may wane. Higher use for electrical consumption may continue regardless of price, but a low price makes it more attractive for this use too.
At some point, even electrical use may decline with high price. There is considerable evidence that high oil prices send the economy into recession. There is good reason to believe that very high natural gas prices might have a similar effect.
Figure 8. US Natural Gas Consumption by Sector, based on EIA data.
The amount of oil and coal consumption that needs to be replaced is huge in relationship to natural gas consumption.
Figure 9 shows that natural gas amounts to only a little more than a quarter of total US fossil fuel consumption. Trying to ramp its production up to replace coal, and to offset declines in oil availability would seem to be an extra-ordinarily difficult task. Natural gas production would need to be more than doubled--something no one is expecting.
Figure 9. US historical fossil fuel consumption, based on BP data.
With traditional gas drilling, most drilling seems to be in relatively unpopulated areas. Shale gas operations include more populated areas, leading to more chance of water pollution.
Many people are concerned about the possibility of harmful environmental effects from fracking, especially if it is done close to the source of New York City water supplies. At this point, there is a six month ban on fracking of horizontal wells in New York. The EPA is also doing an analysis of the safety of fracking. It is not expected to be completed until 2012, however.
There is also an issue of whether fracking permits significant fugitive emissions of methane that could result in shale gas's overall global warming potential being far higher than that of natural gas from conventional sources. The EPA has a technical support document on its website, suggesting that this might be the case. This is a summary graphic from that paper.
Figure 10. Summary Emissions factors from EPA Technical Paper.