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Unconventional Gas Production


Traditionally, conventional natural gas production has centered on sandstone and carbonate rock formations. Increasingly, however, the nation has turned to low-permeability, tight sandstones, gas shales and coal bed methane formations to increase our nation's natural gas reserves.
With DTE Energy's strong technical and operating expertise related to shale formations, we are well positioned to deliver on our nation's growing need for natural gas.
Our DTE Gas Resources subsidiary operates approximately 200 wells in the Fort Worth basin. Located in north central Texas, the Barnett shale formation has emerged as one of the largest and most active gas fields in North America.
Our properties are located in the western expansion of the Barnett shale where gas production is rich with natural gas liquids, which yields a premium to dry gas at current commodity prices.

Conventional vs. Unconventional Gas Production
Unconventional                                                  Conventional
Conventional vs. Unconventional gas drilling illustration

From an investment standpoint, conventional natural gas exploration holds more risk. Gas reservoirs are typically smaller and/or more difficult to locate.
On the other hand, unconventional gas reservoirs can exist over a large area penetrated by older conventional wells, reducing the exploration risk. Horizontal drilling techniques may enhance and extend production of unconventional natural gas.
Unconventional reservoirs exist in a self contained environment where the productive formation may act as source, reservoir and seal. After test wells prove the economic viability of a given area, unconventional resources can be developed on a large scale.

Methods of Mining


a graphic illustrates the underground mining methods and surface mining methods

According to the Kentucky Department of Mines and Minerals, 131.8 million tons of coal was mined in Kentucky in 2000; 62 percent (81 million tons) was from underground mines and 38 percent (50 million tons) was from surface mines. There were 264 active underground mines and 240 active surface mines in Kentucky in 2000.

Underground Mining

Underground modes of access include drift, slope, and shaft mining, and actual mining methods include longwall and room and pillar mining. Drift mines enter horizontally into the side of a hill and mine the coal within the hill. Slope mines usually begin in a valley bottom, and a tunnel slopes down to the coal to be mined. Shaft mines are the deepest mines; a vertical shaft with an elevator is made from the surface down to the coal. In western Kentucky, one shaft mine reaches 1,200 feet below the surface.

In room and pillar mining, the most common type of underground coal mining, coal seams are mined by a "continuous miner" that cuts a network of "rooms" into the seam. As the rooms are cut, the continuous miner simultaneously loads the coal onto a shuttle or ram car where it will eventually be placed on a conveyor belt that will move it to the surface. "Pillars" composed of coal are left behind to support the roof of the mine. Each "room" alternates with a "pillar" of greater width for support. Using this mining method normally results in a reduction in recovery of as much as 60 percent because of coal being left in the ground as pillars. As mining continues, roof bolts are placed in the ceiling to avoid ceiling collapse. Under special circumstances, pillars may sometimes be removed or "pulled" toward the end of mining in a process called "retreat mining." Removing support during retreat mining can lead to roof falls, so the pillars are removed in the opposite direction from which the mine advanced: hence the term "retreat mining."

Longwall mining is another type of underground mining. Mechanized shearers are used to cut and remove the coal at the face of the mine. After the coal is removed, it drops onto a chain conveyor, which moves it to a second conveyor that will ultimately take the coal to the surface. Temporary hydraulic-powered roof supports hold up the roof as the extraction process proceeds. This method of mining has proven to be more efficient than room and pillar mining, with a recovery rate of nearly 75 percent, but the equipment is more expensive than conventional room and pillar equipment, and cannot be used in all geological circumstances. As mining continues,roof bolts are placed in the ceiling to avoid ceiling collapse. In longwall mining, only the main tunnels are bolted. Most of the longwall panel is allowed to collapse behind the shields (which hold the roof as coal is excavated).

Surface Mining

Photo of surface mining equipment

Surface-mining methods include area, contour, mountaintop removal, and auger mining. Area mines are surface mines that remove shallow coal over a broad area where the land is fairly flat. Huge dragline shovels commonly remove rocks overlying the coal (called overburden). After the coal has been removed, the rock is placed back into the pit. Contour mines are surface mines that mine coal in steep, hilly, or mountainous terrain. A wedge of overburden is removed along the coal outcrop on the side of a hill, forming a bench at the level of the coal. After the coal is removed, the overburden is placed back on the bench to return the hill to its natural slope. Mountaintop removal mines are special area mines used where several thick coal seams occur near the top of a mountain. Large quantities of overburden are removed from the top of the mountains, and this material is used to fill in valleys next to the mine. Augur mines are operated on surface-mine benches (before they are covered up); the coal in the side of the hill that can't be reached by contour mining is drilled (or augured) out. Drift, contour, mountaintop removal, and augur mining are more common in the Eastern Kentucky Coal Field, and area, slope, and shaft mining are more common in the Western Kentucky Coal Field.

Laptop of the Future


Imagine if you could roll up your laptop like a newspaper and open it when required, and what if you could turn your laptop into a primary monitor if you wanted to play some awesome video games?

rolltop laptop Rolltop: A Laptop Concept that Can be Rolled and Carried
Well all these are possible with the cool new conceptual ROLL TOP Laptop concept, which is being touted as a Future Designer Laptop. Orkin Design has unveiled this cool new concept with the support of Schlagheck-Design and the device comes with a flexible display which can be rolled and carried wherever you want. This goes beyond the traditional book like laptops which are cumbersome to say the least.

Thanks to its OLED-Display technology and a multi touch screen, it can be used a laptop while it weighs as much as mini notebook. It comes with a 13 inch screen while being used a laptop and when being used as a monitor, you could get a cool 17 inches screen. Power supply, multi media integrated pen and even a holding belt are integrated in the ROLL TOP and it certainly is an all-in-one gadget.
rolltop tablet
If this product is ever manufactured, you could carry your laptop like a newspaper by rolling it up, and making sure that you are not burdened by heavy laptop bags. While this is still a concept, we had written about the coolMicrosoft Courier Tablet which comes with dual screens. You could also read about Cintiq, which allows you to write and draw better than with the help of pen and paper.
rolltop laptop backside