| OCR Text |
Show I Oil shale burning started on Colorado C-a V -uine MiUcr, president of the Rio v ' Oil Shale Company, announced V 1 (hat tlie company has started f ' the first of three demonstration " r ""Lmd modified in situ retorts on Prototype Oil Shale Tract C-a Blanco County. Colorado. ' retort is about 30 feet square and "-feet high. It is the first of three F :'i nlanned by Rio Blanco in a $140 rV; ;. program to demonstrate the "ercial feasibility of its modified sr ..j technology. The company plans ''irn tw0 additional ""derground ..bythe end of 1981. e. r-: nio Blanco Oil Shale Company, a he ' -j partnership of Gulf Oil Cordon Cor-don and Standard Oil Company y, a) acquired the lease to Tract (f5.; ;", 1974 for $210 million. The I "" acre lease is about 20 air miles rj. stofRangely, Colorado. rjer said the retort was ignited at some 670 feet below the earth's jce A downhole burner was j-red from the surface through a ip, ;veinch vertical casing to the El rd Amixture of natural gas and air - iused for ignition. f ,. Rio Blanco's modified in situ -.logy, some 30 to 40 of the plann- . in' -etort volume is removed by mining brought to the surface. The re- -der of the retort is rubbled with ' entional explosives. The rubbling i wthe necessary permability for fa Wli (iff ignition, the combustion zone of retort burns at between 1,400 and ii Fahrenheit. However, the shale aves the rock at about 900 blijV ::re the flame front arrives. When iatei :Tame front reaches the retorting . ' ; the carbon residue left on the rock mCe e: the shale oil has left serves as the. l the ifarthe burn. P' :( shale oil leaves the rock in the form of a vapor. Once away from the retorting zone, it condenses into liquid and travels down to the bottom of the retort. There it is separated from water and pumped to the surface. Gas produced produc-ed with the shale oil is separated and cleaned through surface processing facilities. The nonpolluting waste gases are vented to the atmosphere. Miller said the burn could take up to nine weeks, depending on the rate of the burn. The rate is controlled :by the use of air and steam. He said the first oil from the retort is expected to be recovered in about a month. Only a total of 1,000 to 2,000 barrels bar-rels of oil is anticipated from the first retort. The oil will be used in various research and testing programs. Miller pointed out that the modified in situ demonstration program is part of Rio Blanco's phased development approach ap-proach which could lead to commercial production of shale oil from Tract C-a by 1987. "We also have a program which could lead to construction of a demonstration surface retort beginning in 1981. In a commercial operation, surface sur-face retorting capability would be needed need-ed for processing the oil shale removed from the mine prior to rubbling." Miller also said Rio Blanco is engaged engag-ed in engineering design and commercial commer-cial planning for an open pit development develop-ment plan. That plan would require surface sur-face retorting of all the mined oil shale. "The merits of the modified in situ and open pit technologies will be assessed assess-ed in the next'two to three years. We would probably not begin any commercial commer-cial construction of either approach before 1983." Rio Blanco currently has some 400 workers, primarily contractors' employees, at Tract C-a. The workforce is not expected to increase significantly over the next two to three years. |
