Expected Results The Dragon Trail experiment would be a valuable contribution to the Plowshare Program. It should show: 1. The amount of increase in gas productivity ex- 2. The extent of fracturing beyond the chimney. 4. The extent to which the area around the well- 5. The permeability of the fracture system. 6. That nuclear stimulation is both technically and commercially feasible. The area proposed for the test, as well as most of the surrounding acreage, is Government owned. Successful testing of nuclear stimulation in this area could lead to further development of the Mancos B zone on a commercial basis. This tightly held gas is not currently available since production rates are too low to justify development. Nuclear Explosive Effects A schematic drawing of what happens when a contained nuclear device is exploded is presented in Figure 1. This shows the sequence of events which is expected to result when an explosive is detonated in the Mancos formation. Of most significance to the oil and gas industry is the formation of the nuclear chimney and the associated fracturing outside the chimney. These fractures should extend several radii beyond the cavity. It is the number and extent of these fractures which will govern the rate of gas production into the new wellbore. In normal oil or gas production, a 5% or 7-inch hole is drilled into the reservoir. The pressure in the well is reduced and the higher pressure in the reservoir forces gas or oil to flow into the wellbore. Restriction to flow is concentrated at the interface between the wellbore and the reservoir. Once a nuclear device is fired in the reservoir the restriction occurs between the fractured area and the virgin reservoir. At this interface there is a much larger area for flow than adjacent to a conventional wellbore, and, consequently, a much smaller restriction to flow. The effectiveness of nuclear stimulation will be a function of the number of fractures and the distance that these fractures extend out into the reservoir. Site Location The site of the proposed 40 kiloton Dragon Trail shot is in Rio Blanco County, Colorado. The location is shown in Figure 2. The topographic features in the site area are shown in Figure 3. The location is in an unpopulated area with the nearest habitation several miles from the site. The nearest town is Rangely, Colorado, about 17 miles north of ground zero. The land proposed for the test is Government owned and currently under lease to Continental Oil Company. Royalties resulting from successful application of nuclear stimulation would go to the U. S. Government. 98 179 O-68-24 |