This is the second of the series of energy related blogs. In this post I will discuss natural gas. My main reference for this post is Kenneth S. Deffeyes' Beyond Oil.
A few things should be noted about natural gas:
1. It is produced from the decay of organic material in the absence of air.
2. It is mainly methane, but contains quantities of ethane, butane, propane, nitrogen, and helium.
3. It can be mined for a profit from rock that isn't easily permeable by oil.
Natural gas comes from two sources, "conventional" and "unconventional." Conventional gas comes from standard sources, generally mining of some form or another. Unconventional gas comes from other sources, such as swamp gas or coal beds.
Conventional gas production comes in three varieties. Solution gas is dissolved in oil and comes out of solution when the pressure drops. Basically, when the oil pocket is breached, the gas held in solution separates. A useful analogy would be carbonated beverages. Mining the oil in such pockets is not terribly profitable, but the games comes free. Production of natural gas from these types of mines previously kept gas prices down.
Gas caps form above oil reservoirs when there is more gas than the oil can dissolve. Miners can choose to get the oil first, leaving the gas for later production. Mining from such pockets is more effective at recovering larger percentages of oil, as well. As opposed to the 20-40% from solution gas, mining from gas caps recovers up to 50% of the oil contained therein.
The final conventional production is gas found below the depth where oil is located. Oil is found between 7500-15000 feet. Below that, oil deposits are quite rare. These pockets of gas are very good money makers for miners seeking the fossil fuel.
Unconventional gas production comes from four sources: swamp gas, coal bed gas, basin-center gas, and fractured shales. Swamp gas, as it is called, it produced by a bacteria which converts organic matter into methane gas. This would be the same bacteria which resides in the digestive tract. Some pockets of swamp gas can be commercially viable, but have no attracted the attention of major companies. However, since it is relatively easy to access, such deposits are quite rewarding for smaller countries.
Coal bed gas comes from the coal itself. As the coal is natural material, the decomposition of it produces the natural gas. However, the only reason such deposits exist is the sheer size of the plant matter used in the production of coal. Despite this, coal beds have managed to produce nearly 8% of the United States natural gas production.
Basin center gas is that which has completely permeated the host rock. However, this is not as viable a source of gas as, say, the coal beds. The natural gas is much harder to get and there never seems to be enough to completely saturate less-porous host rocks. By the same token, fractured shale gas can be equally as difficult to come by. More porous rocks like sandstone can become more saturated. However, the fractures in the rock produce wells that can be tapped slowly.
The use of natural gas is nothing new. Homes have stoves that use natural gas. Grills burn propane, a form of liquefied natural gas. Natural gas is also the third largest product used for the generation of electricity, after coal and nuclear power. Overall, it generates just over 600 kilowatt-hours of energy annually in the United States. But natural gas is also used for heating and industrial use. A portion of it also goes to make fertilizers because of the hydrogen that can be produced from natural gas. Since it has come to be used, in large part, for the production of electricity, the reserves of natural gas have been severely depleted.
Another interesting use for natural gas is in the automobile industry. The technology exists to use natural gas as fuel, instead of oil. Overall, these cars would use less than the equivalent of ten gallons of oil. A couple other benefits exist, such as the production of less carbon-dioxide and a high octane rating. (This basically means that it much reach a relatively high temperature before it spontaneously ignites.) However, the gas must be contained under high pressure. That also leads to another issue, that of refueling. The number of refueling stations for natural gas-run vehicles is scant, to say the least. They require specialized equipment, because of the high pressures. But this, in turn, exacerbates the problem. Deffeyes says, "individuals will not buy natural gas-powered vehicles because there are no filling stations; filling stations don't exist because nobody own natural gas powered vehicles" (Deffeyes 58).
As you can see, natural gas has its uses. It heats our homes and office buildings. It produces electricity for our gadgets. It can even be used to run our cars. However, reserves are dropping worldwide. Eventually, we will run out of easily accessable reserves and will need to find other methods to produce natural gas. Whether we will turn to the "unconventional" methods is yet to be known.
Do you have any thoughts on the matter? Is there an alternative for natural gas? Should we be reducing our reliance on this particular fossil fuel? Or should we simply continue as we have been?
A few things should be noted about natural gas:
1. It is produced from the decay of organic material in the absence of air.
2. It is mainly methane, but contains quantities of ethane, butane, propane, nitrogen, and helium.
3. It can be mined for a profit from rock that isn't easily permeable by oil.
Natural gas comes from two sources, "conventional" and "unconventional." Conventional gas comes from standard sources, generally mining of some form or another. Unconventional gas comes from other sources, such as swamp gas or coal beds.
Conventional gas production comes in three varieties. Solution gas is dissolved in oil and comes out of solution when the pressure drops. Basically, when the oil pocket is breached, the gas held in solution separates. A useful analogy would be carbonated beverages. Mining the oil in such pockets is not terribly profitable, but the games comes free. Production of natural gas from these types of mines previously kept gas prices down.
Gas caps form above oil reservoirs when there is more gas than the oil can dissolve. Miners can choose to get the oil first, leaving the gas for later production. Mining from such pockets is more effective at recovering larger percentages of oil, as well. As opposed to the 20-40% from solution gas, mining from gas caps recovers up to 50% of the oil contained therein.
The final conventional production is gas found below the depth where oil is located. Oil is found between 7500-15000 feet. Below that, oil deposits are quite rare. These pockets of gas are very good money makers for miners seeking the fossil fuel.
Unconventional gas production comes from four sources: swamp gas, coal bed gas, basin-center gas, and fractured shales. Swamp gas, as it is called, it produced by a bacteria which converts organic matter into methane gas. This would be the same bacteria which resides in the digestive tract. Some pockets of swamp gas can be commercially viable, but have no attracted the attention of major companies. However, since it is relatively easy to access, such deposits are quite rewarding for smaller countries.
Coal bed gas comes from the coal itself. As the coal is natural material, the decomposition of it produces the natural gas. However, the only reason such deposits exist is the sheer size of the plant matter used in the production of coal. Despite this, coal beds have managed to produce nearly 8% of the United States natural gas production.
Basin center gas is that which has completely permeated the host rock. However, this is not as viable a source of gas as, say, the coal beds. The natural gas is much harder to get and there never seems to be enough to completely saturate less-porous host rocks. By the same token, fractured shale gas can be equally as difficult to come by. More porous rocks like sandstone can become more saturated. However, the fractures in the rock produce wells that can be tapped slowly.
The use of natural gas is nothing new. Homes have stoves that use natural gas. Grills burn propane, a form of liquefied natural gas. Natural gas is also the third largest product used for the generation of electricity, after coal and nuclear power. Overall, it generates just over 600 kilowatt-hours of energy annually in the United States. But natural gas is also used for heating and industrial use. A portion of it also goes to make fertilizers because of the hydrogen that can be produced from natural gas. Since it has come to be used, in large part, for the production of electricity, the reserves of natural gas have been severely depleted.
Another interesting use for natural gas is in the automobile industry. The technology exists to use natural gas as fuel, instead of oil. Overall, these cars would use less than the equivalent of ten gallons of oil. A couple other benefits exist, such as the production of less carbon-dioxide and a high octane rating. (This basically means that it much reach a relatively high temperature before it spontaneously ignites.) However, the gas must be contained under high pressure. That also leads to another issue, that of refueling. The number of refueling stations for natural gas-run vehicles is scant, to say the least. They require specialized equipment, because of the high pressures. But this, in turn, exacerbates the problem. Deffeyes says, "individuals will not buy natural gas-powered vehicles because there are no filling stations; filling stations don't exist because nobody own natural gas powered vehicles" (Deffeyes 58).
As you can see, natural gas has its uses. It heats our homes and office buildings. It produces electricity for our gadgets. It can even be used to run our cars. However, reserves are dropping worldwide. Eventually, we will run out of easily accessable reserves and will need to find other methods to produce natural gas. Whether we will turn to the "unconventional" methods is yet to be known.
Do you have any thoughts on the matter? Is there an alternative for natural gas? Should we be reducing our reliance on this particular fossil fuel? Or should we simply continue as we have been?
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