Gas producers have made great strides in managing the costs and environmental challenges of sourcing freshwater for hydraulic fracturing as well as treating, recycling, and disposing of water streams collected from the completion and operation of unconventional gas wells. Operators have participated in recent industry surveys and projects that have improved understanding about how developers obtain and use water in drilling and well completions as well as how they plan to reuse and manage water in the future. This considerable progress has typically been the result of collaboration among gas producers, water management solution providers (e.g., engineering firms, equipment vendors, consulting organizations, and research organizations), and other key stakeholders.

Working together

A good example of industry cooperation is the work being done by the Barnett Shale Water Conservation and Management Committee (BSWCMC), an organization of 14 developer companies that have, since 2006, collaborated to identify best management practices and develop treatment processes and decision tools for the low-cost, environmentally acceptable management of brines associated with shale gas well completions in the Barnett Shale region of Texas.

This well completion site uses hydraulic fracturing in the Barnett Shale. (Image courtesy of Devon Energy)

One of the first accomplishments of the committee was the generation of a water use report describing current and projected water use needs. The committee provided this information to state agencies such as the Texas Water Development Board and to the general public. Disseminating information helped to relieve public concern about the industry’s water consumption by comparing its use with the more demanding water needs of other industrial and recreational users.

The committee was also among the first to see the opportunity to reuse flowback water in frac jobs. A “Frac Job Expert Panel” was convened to discuss the characteristics of flowback water and the minimum quality of water required to successfully complete a well, which led to criteria for flowback water treatment.

The committee also invited vendors to participate in cooperative discussions and obtained information about potential water recycling technologies. Several companies have shared information from field demonstrations of key water reuse processes such as the mechanical vapor recompression process. As a result, the committee has identified processes that have proven capable of successfully treating early frac flowback water for reuse by the industry.

The BSWCMC collaborative model was replicated in Appalachia and later rolled into the Marcellus Shale Coalition (MSC). The MSC, a rapidly growing organization of shale gas developers and associate members that came together in 2008, is committed to responsibly developing natural gas from the Marcellus Shale region in Pennsylvania and to enhancing the Commonwealth’s economy.

The mechanical vapor recompression “Nomad” process allows early flowback frac water to be reused. (Image courtesy of GTI)

One success story from the collaborative work of the MSC is a recently completed project in which 17 members provided samples of water supplies and flowback waters from 19 locations in West Virginia and Pennsylvania. Analysis was performed on more than 300 constituents in accordance with a purposefully designed integrated plan reviewed by industry and the state Department of Environmental Protection (DEP) in Pennsylvania and West Virginia. This report, completed by Gas Technology Institute (GTI) and submitted by the MSC to the Pennsylvania DEP for review and comment represents one of the most comprehensive coordinated efforts that has ever been conducted to characterize flowback and produced waters associated with unconventional gas production.

The road ahead

Looking forward, shale gas developers throughout the US continue to face challenges that require even greater levels of innovation. Perceived environmental risks associated with completion and production activity continue to be raised by state regulators. Pressure to eliminate controlled discharges of brines to publicly owned treatment works coupled with the lack of Class II disposal well capacity for brine injection highlight the need for water reuse systems that minimize brine flows to disposal. This is certainly the case in the Appalachian region. The need to reduce truck traffic, carbon footprint, and environmental impact add even more urgency to the need for innovations that achieve a higher degree of water reuse at reasonable costs.

Clearly, more cost-effective alternative solutions are needed.

Fortunately, a suite of technologies that can handle the challenge at a certain cost are currently available, and many new advances are in development. Industry R&D collaborations are exploring the potential of novel processes that can control soluble organics and microbial films. Other processes are also being explored that leverage new technology to separate total dissolved solids from wastewater more efficiently and cost-effectively while recovering water streams suitable for reuse in performing future well completions.

One current project, funded in part by the Research Partnership to Secure Energy for America (RPSEA), is pursuing technology that has the potential to improve water conservation and reuse for shale gas developers in the Barnett and Appalachian shale plays. This collaborative project is evaluating advanced commercially available processes employed for water reuse while pursuing the development of several leading-edge technologies. The effort assesses novel coatings with special surface chemistry properties to reduce fouling and improve the performance and cost of membrane separation processes (including nanofiltration and reverse osmosis) in flowback water demineralization.

In addition, electrodialysis optimized to maintain good conductivity throughout the process holds considerable potential for achieving strategic separations of brine salts at substantially reduced inputs of electrical energy. And satellite imaging, digital mapping, and information mining from existing databases and industry sources allow the identification and evaluation of alternate sources of water that do not compete with community water supplies.

In parallel with these efforts, considerable progress is being made among Barnett Shale commercial firms in incorporating new heat exchanger materials into thermal distillation units to improve energy efficiencies, fouling resistance, and ease of maintenance.

Funding from public sources such as RPSEA and the Department of Energy enhances cooperation by bringing scientists and engineers as well as owners and operators together to collaborate on projects leading to innovative improvements in water management. Many of these projects would otherwise be outside the risk profile or budget of any single company or organization.

A different path

Not all innovative solutions, however, are gaining traction in the industry. Some are too expensive or have not yet established their value to the industry, some are not fully understood by the industry or appear to be solutions looking for a problem, and others are in early stages of development and have not yet received industry attention. Interviews conducted by GTI with producers, water management solution providers, and other stakeholders have identified four commonalities that suggest a consortia approach as a preferred and efficient structure to address the challenging issues.

1. Accurate intelligence-sharing to help minimize costs and reduce commercial risk.

2. A higher level of collaborative dialog and engagement in a structured manner.

3. Joining strategic partners who bring complementary parts of a solution.

4. A supportive regulatory environment.

A higher level of collaboration that addresses these elements will require more “joined-up conversations” between industry, those who can provide solutions, and those who bring unique perspectives to the issue. Increased collaboration can be expected to yield tangible benefits, including water management savings for developers, reduced uncertainties for solution providers, and greater levels of confidence in a production industry that is committed to sound water management solutions on both economic and environmental grounds.

Clearly, collaboration is the key to aligning the industry on the best water management strategies, the best technologies, the best vendors, and the best possible outcomes.

The broader intent is that water use is prevented from ever becoming an obstacle to the sustainable development of one of the world’s most abundant, affordable, and clean-burning sources of energy.