Apr
17
What’s That Shale Gas Stuff?
April 17, 2008 | Leave a Comment
Shale gas is usually one of the best forms of natural gas. Richer in methane than many natural gas sources that have more ethane and propane it’s a desirable fuel. The reason its making news in petroleum circles is that the past few years have seen prices high enough to push the technology for the kind of enhanced recovery that shale gas needs to be economically available. As the technology improves and more service companies offer it the cost to do the enhancements has dropped.
The shale part of the name comes from the kind of rocks called shale where the natural gas is found. There is a lot of it, for decades the drilling and producing of wells has ignored the shale gas. This is because shale rocks are very poor in passages to allow the gas to move to the well hole. Many wells had quick blasts of gas and then nearly nothing after the gas close to the well escaped. With no passages, the well was “dry.”
Shale is a rock that can hold huge amounts of gas, not only in the zones between the particles, but some of the particles are organic that like sponges hold gas, too. When the technique was to drill straight through the gas bearing rock, the hole had very little exposure to rock for the gas to escape.
The new technology is to drill down and then turn the boring of the hole sideways or horizontal so the hole goes through the rock formation sideways. As formations are like stakes of pancakes, a hole through the thin vertical dimension offers little exposed rock. But, boring across the horizontal dimension will expose vastly more rock to the hole.
That’s not the only way to increase the amount of gas that can be raised. Another way is to force special fluids down the hole, forcing open the natural cracks and fissures, and adding new fractures that the special fluid can fill with sand that keeps them pried open.
There is a quiet debate going on about how to rate the reserves of shale gas. With three forms of storage in the rock, one being in the open spaces of between the rock, the second the traps in the pore spaces inside the rock and third the absorbed gas in the organic matter called kerogen there can be a wide range of estimates. This and the march of more technological improvements have outlined a future with a lot of new natural gas coming to market.
Aubrey McClendon, CEO of Chesapeake Energy is an example of the enthusiasm that has taken hold of the natural gas production business. Monday at the University of Tulsa he presented his lecture at the Allen Chapman Activity Center that coincided with the company’s grant of a 5 year $500,000 scholarship and management training program. His comments with the press offered that the new technologies to release the shale gas will change the U.S. economic and fuel strategy. Chesapeake is the nations most active driller and is an important operator in Canada as well. Chesapeake alone produces 5% of the U.S. natural gas supply.
McClendon pointed out that “cracking the code” to release shale gas now contains development costs. This impact allows capital to go farther and profits to increase that go back into more reserve discovery. The results are coming in even now. McClendon offers that the U.S. can count on 5% annual supply increases for the immediate future. He predicts that amount of supply improvement will negate the need to import natural gas and provide enough to consider using the fuel in the transportation sector which would lower oil imports.
Methane, the main component of natural gas is considered by many to be a “Clean Fuel” as it emits one CO2 and two H2O molecules per methane molecule oxidized. The work done for the CO2 emission is markedly better than more dense fuels, but the energy of a given volume is less. It would not be difficult to rig a fill up point at any home or business that has natural gas service now. The issue lies in getting kits to change over a gasoline-fueled vehicle to compressed natural gas.
There is the actual main point that needs served here as well. The reason that the money is granted, the lecture given and the press conference is to offer the young students the opportunity to become part of the natural gas business. Like all of the energy and fuel businesses, be it fossil fuel or biofuel or renewables of any kind, the human resources of skills and talent aren’t adequate now. With all those years of cheap oil and low hiring rates, the pool of young people heading into the energy field has gotten very small. If the world’s developed economies are to loosen the noose of imported fuels – that has to change.
The reality check is the thoughts about the usage. Flowing natural gas into a 20% efficient internal combustion engine isn’t very appealing. On the other hand flowing natural gas into a fuel cell that might 50% efficient would be much more interesting. Methane is the simplest hydrocarbon and offers lots of potential for extracting the heat energy of an oxidation. The prospect that there is much more coming to market is good news, lets just hope that responsible use takes hold before another massive resource gets frittered away in low efficiency applications.
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