Minimizing the Impact on Water Resources with Oil and Gas Hydrofracturing
Water has always been a part of modern oil and gas drilling operations. Every well needs water-based drilling fluids, or “mud,” circulating in the well bore to cool the drill bit and carry the cuttings to the surface, and often, more water than oil flows from the producing geological formations.
The discovery of immense natural gas reserves locked in impermeable shale formations throughout the United States has greatly increased the water intensity of drilling operations, typically in areas where access to water supplies and waste treatment facilities – are limited.
The growing use of hydraulic fracturing – a technology that dates to the 1940s – is simultaneously creating an awareness about water supplies, as well as water reuse and proper disposal, according to Brady Hays, Director of Strategic Business Development for Black & Veatch’s global water business.
“Water is part of the oil and gas drillers’ supply chain, but its a non-core competency,” Hays said. “As unconventional oil and gas from onshore deposits become more of an allocation in the portfolios of companies, their biggest risk – outside of commodity price risk – is the water and corporate social responsibility (CSR) risk.”
CSR plays a large role because the hydraulic fracturing of a well takes thousands of trucks of water. “These trucks are driving around the small communities 24/7,” Hays said. Companies are looking for ways to get the trucks off the road, as well as ensuring there is no harm to water resources.
Black & Veatch can help drilling companies manage their water supplies and ensure all environmental measures are in place in order to minimize the impact on water resources and stay in good standing in the community.
“With the growing adoption of horizontal drilling and hydraulic fracturing technologies, along with the changing regulatory environment, exploration and production companies are paying close attention to the management services that Black & Veatch can provide,” Hays said. “Oil and gas developers are considering partners early in the planning process who can integrate various operations to improve cost efficiencies and regulatory permitting. This encompasses gas processing, power generation and distribution, water supply and disposal management, air quality and communications,” he noted.
ALTERNATIVES TO TRUCKING
At least one drilling company in Pennsylvania is using abandoned mine water for drilling and fracking. It has also received approval to use water from a storm water erosion control basin that would otherwise need to be sent to a treatment plant. It is currently requesting permission to use treatment plant effluent for drilling and fracking.
These alternate sources reduce the volume that needs to be drawn from freshwater sources and trucked to the drill sites.
On the other side of the country, QEP Resources, which has large operations on the Pinedale Anticline in western Wyoming, initially tapped deep saline aquifers for its water supply when it first began operations, rather than pull from rivers or streams. The recovered water from the drilling operations and the produced water from the gas wells are sent to large storage and evaporation ponds, from which the water can be withdrawn and reused. The company no longer has to drill for water.
“Now we’re pretty much self-sustaining with continually recycling the water we already have, plus the water that we produce out of the gas wells,” said Paul Matheny, Rockies Region Vice President for QEP Resources, which is based in Denver.
Matheny noted that fracking is becoming so common that it is getting hard to call it unconventional.
“These days most natural gas and most oil wells have to be hydraulically fractured,” Matheny said. “You can still call it unconventional oil and gas, but it’s pretty typical.”
It all points to the increasing nexus of water and oil and gas drilling.
MINIMIZING IMPACTS IN THE MARCELLUS SHALE
The area of the Marcellus Shale has especially thrust hydrofracking into the spotlight, even though the amount of water used for fracturing is less than for agriculture and power generation, said Lee Fuller, Regulatory Affairs Vice President for the Independent Petroleum Association of America.
The Marcellus formation underlies a swath of the eastern United States from New York to West Virginia. The heart of the resource is smack in the midst of the Susquehanna River Basin in Pennsylvania, a major watershed.
Susan Obleski, a spokeswoman for the Susquehanna River Basin Commission, a tri-state federal compact agency charged with managing the water resources of the basin, says that the amount of water used in each hydrofracturing event totals about 4.3 million gallons, of which 3.8 million gallons is freshwater that is trucked to the site. About 8 to 10 percent of the water returns to the surface as flowback, and the vast majority of that volume is recycled.
The commission is looking at various ways to reduce the amount of freshwater used in the hydrofracturing activities, she said. It has so far issued one approval for a drilling company to use the effluent of a municipal wastewater treatment plant, and has incentives in place for drillers to use the polluted water from abandoned mine drainage, which would otherwise flow into the regions waterways.
The commission also has in place a new policy to streamline the importation of flowback water from other watersheds to encourage the reuse of water from nearby sources, helping alleviate truck traffic. For example, some drill sites in the western part of the Susquehanna River Basin are close-by drilling operations located in the adjacent Ohio River Basin. Since this inter-basin water transfer can be done over relatively short distances, it helps reduce the impact of trucking operations.
Story by Sam Glasser, Black & Veatch