The Oil Shale Industry's Water Problems

Abstract

MARCH, 1968 Abstract This paper presents an analysis of the water budget of the oil shale industry in Colorado. Particular reference is given to restrictions on supply imposed by the Mexican Water Treaty and interstate compacts, and by commitments already made against that restricted supply. It is concluded that the uncommitted residue will be inadequate for the oil shale industry's projected requirements, and must be supplemented by acquisition of existing water right and curtailment of competing uses. Introduction Various water supply problems will confront the oil shale industry as it develops in Colorado, Utah and Wyoming. These three states are in the Colorado River basin, and the problem of finding a water supply will bring this new industry into contact with the mysteries of several compacts, statutes and treaties. These have the effect of restricting the quantity of water available for consumption in those states to a substantially smaller quantity than that physically available. Many had not realized the magnitude of the future water demands of the oil shale industry until a speech was made on this subject by Raymond D. Sloan. Later, Reistle and Sloan stated the supply and demand equation for shale oil. This equation really controls the potential demand for water for this new industry. Energy Requirements On the demand side, the energy requirements of the United States are increasing at a rate that doubles every 20 to 25 years. On the supply side, natural gas and petroleum are currently supplying 70 percent of our energy, compared with 55 percent in 1950. The U. S. is consuming 11 million B/D of petroleum products, and this is expected to increase to 18 million B/D by 1980. To meet this demand, the oil industry must develop reserves on the order of 89 billion bbl by 1985. This is almost three times the existing known domestic reserve of 31 billion bbl. If the industry does not succeed in this, we will become primarily dependent on imports. This total of required reserves, to be achieved in less than 20 years, represents more liquid energy than the U. S. has consumed in the past 100 years. Even after taking into account various offsetting factors, such as the likelihood of increases in drilling costs and the law of diminishing returns on discovering significant new oil and gas fields, and on the other hand, the probability that nuclear energy and other new sources will supply an increasing share of the total demand, the conclusion nevertheless appears inescapable: synthetic liquid fuels will become a major domestic source of energy well within two decades. In this regard, the statistics of the domestic oil shale reserves are impressive. The nation's oil shale reserves cover about 16,500 sq miles in northwestern Colorado, the Uintah basin in northeastern Utah and the Green River basin of southwestern Wyoming. Estimates will be restricted to the richer portion of the shales in Colorado, which average 25 gal of oil per ton. Estimates also will be based on only the presently known technology of mining, retorting and upgrading. Restricted in this fashion, the estimate of the recoverable reserve in Colorado is 280 billion bbl of oil. This is nearly 10 times our presently known domestic reserve of liquid petroleum. Getting the oil out of the shale at prices competitive with other sources of energy is another matter. But experts forecast that large-scale production of oil from shale at competitive costs can be expected in the early 1970's, and that this will amount to at least 2 million B/D in the 1980's. This will be about 10 percent of the total domestic oil production projected for that time. Water Requirements As is generally the case, the resulting water problems fall into two categories: quantity and quality. As to quantity, Sloan estimated that the production of 2 million B/D of oil from oil shale will require the consumption of about 1.2 times that amount of water in processing, retorting and upgrading. This works out to about 112,000 acre-ft/year. If the oil is refined locally, this requirement will increase to 200,000 acre-ft annually. If in situ methods of retorting were used, this total quantity might be more than doubled. And these are only the direct uses of the industry. In addition, the population and related activities which will develop around the new industry will consume large quantities of water. Assuming an associated population of 500,000 to 1 million, as much as 200,000 acre-ft of water must be added annually for indirect uses. Thus, a total water requirement on the order of 500,000 acre-ft in terms of consumption may be required. Considerably more water than this must be diverted since consumption, by definition, is the difference between the quantity diverted and the quantity returned to the stream. This demand will mature well before the turn of the century. Therefore, it will coincide with the predicted onset of basin-wide water shortages. These troubles may be expected about the last decade of this century. JPT P. 237ˆ