Natural gas production from low permeability shale formations (shale gas) has recently become economically viable due to technological advancements in horizontal drilling and hydraulic fracturing. Shale gas is present in numerous and large "basins" around the world, including across the United States, and has been largely untapped due to the very "tight" nature of shale rock. With horizontal drilling and hydraulic fracturing, previously inaccessible natural gas is made to flow through newly formed fractures in the shale to production wells.
As a result of this technology, natural gas is now one of the world’s fastest growing energy sources. The development of unconventional sources, such as coal seam gas, will grow dramatically due to vast basins in the United States, and Europe. These reserves are being tapped with new techniques for detection, hydraulic stimulation and extraction.
Leveraging any natural resource requires responsible environmental management. Development includes many protective measures, with special concern for water resources and water quality. There is considerable debate about environmental concerns related to produced water. Our industry has a role to identify and apply robust, reliable and efficient scientific and engineering methods to help protect water supplies and the environment.
Water management is one of the biggest operating issues for resource developers. While well development may require 4-5 million gallons of water per horizontal well, more liquid is produced throughout the gas well’s lifecycle containing constituents at concentrations much higher than in surface water—all of which requires management through treatment and beneficial use. To protect fresh water resources and control treatment costs, resource developers are seeking innovative treatment and reuse options.
This paper provides detailed information and context from case studies including references of relevance to the gas field produced water characteristics of representative Europe and American gas fields.