Water is an essential component of deep shale natural gas and oil development during both the drilling and hydraulic fracturing processes. Chesapeake uses water for drilling, where a mixture of clay and water is used to carry rock cuttings to the surface, as well as to cool and lubricate the drillbit. Drilling a typical Chesapeake deep shale natural gas and oil well requires between 65,000 and 600,000 gallons of water.
Water is also used in hydraulic fracturing where a mixture of water and sand is injected into the formation at a high pressure to create small cracks in the rock allowing gas and oil to freely flow to the surface. Hydraulic fracturing of a typical Chesapeake horizontal deep shale natural gas or oil well requires an average of 4.5 million gallons per well.
Chesapeake utilizes several sources of water in deep shale gas and oil exploration including rivers, creeks, lakes, discharge water from industrial or city wastewater treatment plants, groundwater and the re-use of fracturing water. The company often works directly with local officials to arrange water purchases from a municipality when drilling inside city limits. This water is typically transported via temporary pipelines or trucked to drilling locations for storage prior to use in tanks or impoundments. The overall mix of water sources used depends on the region and the availability of sources near drilling sites.
The largest water users are municipalities (public water supply), power generation, industrial users and agriculture. However, the magnitude of these uses varies widely from region to region. For example, in the Barnett Shale area of Texas, municipal uses account for more than 80% of water use, with agriculture accounting for about 8%. In the Marcellus Shale area of the Appalachian Basin, power generation accounts for more than 70% of water consumption, while agriculture accounts for approximately one-tenth of one percent (0.1%). Use of this water in natural gas and oil operations is a one-time use, and does not represent a long-term commitment of the resource. Other water users typically consume water for years, decades or even longer.
How Much Is 4.5 Million Gallons?
The 4.5 million gallons of water needed to drill and fracture a typical deep shale gas or oil well is equivalent to the amount of water consumed by:
- New York City in approximately 6.3 minutes
- A 1,000 megawatt coal-fired power plant in 10.8 hours
- A golf course in 22.5 days
- 6.75 acres of corn in a season