from DairyNet Website

 

New electric drilling techniques can overcome many of the stumbling blocks encountered by traditional boring methods. Researchers at the Los Alamos National Laboratory (Los Alamos, NM) are using electricity for a new type of soil penetration -- rock melting. This technology, called Subterrene, works especially well for environmental drilling in poorly consolidated soils in which conventional rotary equipment has difficulty. It also has excellent insulation capabilities for cables, wires, and pipes and can be used to anchor structures.

The Subterrene makes vertical or horizontal holes in rocks and soils by using an electrical resistance heater operating at about 2800 degrees Fahrenheit. The melted rock is chilled into glass to form a dense, strong, firmly attached hole-lining which can be used to contain contaminants, to stabilize structures, or to insulate pipes, cables or wires. The device requires no lubricants or casings, nor does it use chemicals, detergents, plastics or metals. Moreover, it minimizes the remobilization of in situ waste.

 

Other advantages:

  • All in one. The three major facets of excavation -- rock fracturing, debris removal, and wall stabilization -- are all accomplished in a single integrated process.

     

  • Precision. The Subterrene can make lined holes of precise diameter, useful for anchoring structures such as bridges, TV towers, and transmission line towers. This also means that holes for anchoring pipeline supports can be made quickly in difficult terrain, such as Alaska permafrost.

     

  • Coring capabilities. Geophysical prospectors like to extract undisturbed core samples to identify rock layers. A coring subterrene penetrator can extract a sample which remains thermally unaltered at the center.

"The technology is ideal for environmental drilling, for sensor placement, and for remediation," says Jim Blacic, technical support at Los Alamos. The process can be used where you want to prevent spread of contaminants or as insulation for conduits for telecommunications. The Subterrene is also great for making holes in hot rocks. Because the action of the device depends on melting, the rocks high initial temperature reduces the power needed to form the hole. This enhances the penetration rate, making the Subterrene a super idea.
 


Not Yet Off the Ground


Blacic believes his new technology, still in research and development, holds great promise for a number of sectors, including the electric utility industry. Transmission lines for electric power are currently laid in trenches. Maintenance work cannot be done without disrupting the environment. The Subterrene would drive horizontal holes for utility emplantments with minimal disturbance to ground surface. This would mean efficient, high-capacity underground transmission lines that allow easier, cleaner and faster maintenance. Oil service companies are also looking at the Subterrene's potential as a stabilizer for weak zones during oil and gas drilling.

Where does the technology go from here? Blacic says it depends on the level of support. Some applications are closer than others. For shallow drilling of poorly consolidated soil, commercialization will probably occur within a few years, he says.
 


Electric Drilling, Soviet-Style


One method, developed by the former Soviet Union, simply uses electricity as a fuel source for drilling. According to a report by Russian scientists, translated and published in Oil & Gas Journal, electro drilling has three inherent advantages over turbo, rotary, and positive displacement motor systems. These advantages are applicable to electricity in the broad sense:

  • Inexpensive. Electricity is relatively cheap and convenient for long-distance transmission.
     

  • Adaptable. Electricity can be easily and efficiently transformed into other kinds of energy, permitting the use of automated technologies and remote control.

     

  • Constant. It can maintain a constant high power by compensating for transmission power losses through voltage increases.

Though electro-drilling has not caught on in the U.S., the Soviets have been using it for years as an alternative to rotary, turbo, and positive displacement motor systems. The first electric downhole motor was developed in the Soviet Union in the late 1930s. Research was disrupted during World War II, then resumed in 1947. Despite many incidences of improved drilling performance, users found some disadvantages and inconsistencies, including lengthy down time, poor longevity, pressure loss, and limitations regarding size of the drill (large) and direction (down only).

 

Improvements in the past 30 years remedied these problems and considerably increased the reliability and flexibility of electro drilling. Russian scientists believe the technique will find wide applications in the coal industry, mining, underground railway construction, trenchless pipe laying and other areas.

For more information on rock melting, contact Jim Blacic at Los Alamos at 505/667-4318 or visit www-emtd.lanl.gov

 

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