HOW IT WORKS

Prof. Nielson founded Ramex Corp., where he developed the idea for practical application. A vertical hole is bored into the shale and a heater is lowered to a depth of some 50 feet (or more if necessary). The hole is sealed at the top around the gas delivery pipe, which becomes the only possible exit for the produced gas. A gas-fueled heater is lowered into the hole to heat the shale for 2-3 weeks before it starts producing. As shown in the figure, the heat transfer takes place horizontally, with very little going up or down. The gas arises in the kerogen globules out to a distance of 50 ft, and perhaps 100 ft from the heater; the corresponding volume is ex-pected to produce for 5 years, though the daily harvested quantity will decline over that period. The gas forms at very low pressure and is sucked out of the production volume through the delivery pipe by a vacuum system.

A pilot project of two small units, conducted by Ramex, went into operation in the Green River formation of Wyoming in June, and the first round of results became available last month. With an energy gain of 5 (the energy invested amounts to 20% of the energy made available), the test project produced a flow of 75,000 cubic ft per day. The heating value was 550 BTU/1,000 cft in low-grade shale (6-10 gallons of oil per ton of shale), and 800 - 850 BTU per 1,000 cft in medium-grade shale (25 gal/ton).

[DIAGRAM]

The big question is cost. In the test, which suffered from diseconomies of its small size, it was about 60›/1,000 cft, or about three times the cost of natural gas from a well. However, with economies of size, and stripped of other disadvantages of a first test, the process may well become competitive.

Western shale, which has a carbonate base, will not produce as much energy as the silicate-based Eastern (Devonian) shale. The chemical reactions in the latter are more advantageous, so that shale of the same quality (kerogen concentration) will produce gas with a higher heating value. In the tar sands of Canada, Dr Nielson con-cludes from his laboratory tests, it would rise to 1,340 BTU, or more than double that of the shale in Wyoming's Green River basin.

I am a layman in oil shale, but as far as I can tell, the simplicity of the process (compared with retorting) has an excellent chance to make it competitive. What seems, in any case, certain is that unlike other energy schemes which are inherently limited (e.g., by the diluteness of the solar influx), this is a source of concentrated energy with cost the only as yet undecided issue. If it proves economical, its potential is very impressive: its resource base is enormous (second only to the world's uranium reserves) not only in North America, but in many other parts of the world.

There is even a possibility that the process could extract the energy of coal, leaving most of its polluting characteristics in the ground. It could be applied to coal in a two step process: the coal would first be coked in situ, and a second step would produce gas from coke and oxygen.

That, however, is another matter. But for unlocking the vast reserves of energy in America's oil shale, this could turn out to be a breakthrough.

[Source: Video Tape by Ramex Corp. (302 Pointer Trail W., Van Buren, AR 72956), and interview with its Chairman D.L. Walker. A general press release by Ramex is planned for the near future.]