Two members of Colorado's congressional delegation have proposed legislation on the subject of hydraulic fracturing of oil and gas wells. (Their public comments and quotes refer to "fracking." The generally accepted spelling, as recognized by the petroleum industry, the oilfield service companies and other knowledgeable groups, is "fraccing.")
Hydraulic fracturing of oil and gas wells is a commonly used completion method that employs the use of water and other fluids and materials injected into "tight" (low permeability) hydrocarbon reservoirs. The "frac" fluids are injected under high pressures that exceed the reservoirs' naturally occurring pressure and fracture the rock creating high permeability channels that allow oil or gas to flow to the well bore and to be produced at the surface. In most cases, sand or other fine grained material known as "proppants" may be pumped along with the frac fluids to prop open the created fractures enhancing the effectiveness of the treatment. Frac treatments are more common in natural gas wells than oil wells. The trillions of cubic feet (TCF) of natural gas reserves that have been developed in the past decade from previously nonproductive reservoirs such as "tight sands" and "gas shales" would not be possible without frac technology. Oil field service companies like Halliburton and Schlumberger who provide fraccing services carefully guard the specific chemicals added to their frac fluids as proprietary information. Most state oil and gas regulatory bodies, Colorado's oil and Gas Conservation Commission included, require that these chemicals be reported while agreeing to keep that information confidential excepting cases of emergency.
Fresh water aquifers containing water used for either human or animal consumption or for agricultural irrigation occur within a few hundred feet of the surface. With the exception of shallow coal bed methane (CBM) gas wells at depths of less than 1000 feet, oil and natural gas wells, particularly those requiring fracture treatments, are several thousand feet deeper. Without exception, the intervening strata contain impermeable rock layers that form seals to fluid migration. (Without seals, hydrocarbons and/or water could not be "trapped" in their reservoirs.) These vertical seals effectively isolate the zones subject to fraccing from any shallow potable water reservoirs. CBM gas reservoirs are a different story. Due to their shallow nature, they may well be intercalated with potable or at least usable water supplies. Shallow water reservoirs may, in fact, be "contaminated" by CBM gas or the water contained in coal beds through natural fractures and joints.
(The completion process for a CBM gas well actually requires that the reservoir be "de-watered" before commercial amounts of methane gas can be produced. The de-watering process, over an entire field area, may produce millions of gallons of brackish water that is not suitable for drinking or irrigation. This produced water is a greater threat to surface waters in streams, lakes and reservoirs than to aquifers. Operators are carefully regulated as to the handling or disposal of CBM water.)
US representative Diana DeGette, D-Colorado District 1,with co-sponsor, Representative Jared Polis, D-Colorado District 2, has recently introduced legislation and is conducting hearings aimed at regulating hydraulic fracturing of wells by placing it under federal jurisdiction through the Safe Drinking Water Act legislation of the 1990s. During both the Clinton and George W. Bush administrations, the EPA as well as several state regulatory bodies conducted investigations of hydraulic fracturing operations and frac fluids. No verifiable instances of frac water contamination of drinking water supplies were found. Proposed legislation requiring Federal oversight and permitting was defeated. (Only the State of Alabama adopted new regulations specifically for frac fluids. Significantly, those regulations pertain primarily, although not exclusively, to fracture treatment of CBM wells.) Under DeGette's newly proposed regulations, operators and service companies would be required to make their proprietary additives matters of public record. Every new well would require a permit issued through the EPA in addition to any federal, state or local permits currently required.
Representative John Salazar, D-Colorado District 3, who formerly supported some aspects of this legislation, now has apparently retreated from that position. Salazar references operators' concerns with being able to profitably produce natural gas with the imposition of another level of bureaucracy and its consequent costs in time and money. Representative Salazar's district encompasses the vast bulk of Colorado's natural gas producing areas including the prolific San Juan Basin in southwest Colorado and the "tight sand", huge reserve Piceance Basin in northwest Colorado.
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