PRODUCED WATER REPORT

New web resource offers guidance on produced water

 The US Energy Department-sponsored site aims to help operators manage an increasingly costly waste stream. 

David Michael Cohen, Production Engineering Editor

Produced water is the largest-volume waste stream generated by oil and gas production, representing 98% of all E&P waste and 9.5 bbl/bbl oil in the US, according to data compiled by Argonne National Laboratory in 2004.¹ As fields mature, produced water represents increasingly large percentages of fluids brought to surface, due to oil and gas depletion and to water injection used for well stimulation. Management of produced water is a major cost component in oil and gas production. Options are dependent on the applicable state and federal regulations. Developing cost-effective and environmentally sound produced water management strategies is complicated by the wide variance in produced water’s physical and chemical properties, depending on location and type of hydrocarbon produced. To meet these challenges, Argonne National Laboratory, with funding from the US Department of Energy, has developed an interactive online resource providing information on produced water management options and regulatory requirements. The website is scheduled to launch this month.

OVERVIEW

One of the goals of the DOE is to identify and support technologies to make production and use of fossil fuels more efficient and environmentally cleaner. To this end, the agency funded Argonne National Laboratory in 2003 to develop an interactive website to provide information on drilling waste management. Argonne and its partners ChevronTexaco and Marathon developed the Drilling Waste Management Information System (DWMIS-http://web.ead.anl.gov/dwm), which became available to users in June 2004.

The resource has been surprisingly popular for a “niche” site, generating more than 1.7 million hits between its launch and May 2007. A hit is generated whenever any file is served on a website, which can make it an unreliable measure of online traffic. However, more useful statistics are available: During the same time period, more than 421,700 pages were viewed in about 112,400 user sessions on the site, representing about 55,500 unique visitors.² The enthusiastic industry response to DWMIS spurred the DOE in mid-2006 to provide Argonne with additional funding for the development of a comparable information resource specifically to address produced water.

Site architecture and design. The new site, called the Produced Water Management Information System, follows the same format as DWMIS. It has three functional modules:

• A technology description module providing fact sheets on practices and technologies used to manage produced water
• A regulatory module identifying state and federal regulations relating to produced water management
• A technology identifier that asks users well-specific questions to generate a detailed decision tree identifying appropriate produced water management options for the user’s circumstances.

The site’s user interface incorporates Microsoft Access relational database management software and ColdFusion, a software package used to integrate databases and web pages.³ Users can effectively navigate the site without any technical knowledge beyond the use of web browser software.

The online resource will offer internal search using a Verity search engine, which allows Boolean searches (i.e., using AND, OR, NOT, NEAR, etc.) and stemming (e.g., “drill” and “drilling” will return the same results). “Wildcard” operators (“?” to match a single character in a search term, “*” to match one or more characters) are also included. Searches will generate results from all pages except those in the technology identifier module. Advanced search options and a site index are not offered.

TECHNOLOGY DESCRIPTION MODULE

The first module of the website is dedicated to practices and technologies being used for produced water management. Short fact sheets, including figures, photos and some references, offer basic information on each of 25 technologies, Fig. 1.
These fact sheets are organized in three tiers: minimization, recycle/re-use and disposal, Table 1.

Fig. 1. Fact sheets on the new website offer basic information on technologies used to manage produced water, including figures, photos, tables and references. Courtesy of Argonne National Laboratory.

TABLE 1. Produced water management technologies

The first step in managing produced water is often to try to minimize the amount of produced water. Examples of water minimization strategies include packers, plugs and cement jobs to block water from entering the well, and downhole separators to reduce the water in oil or gas brought to surface.

Even after minimization strategies have been implemented successfully, whatever produced water remains must be eliminated either by finding a use for it or by disposal. By far, the most common use of produced water is re-injection into a producing formation to increase recovery. Produced water for re-injection must often be treated to remove components that can harm the formation or piping. The type and amount of treatment needed will depend on the composition of the produced water, which will vary greatly from one reservoir to another.

Other industrial produced water uses may include makeup water for drilling fluid, and boiler makeup water or cooling water for power generation. In areas where water is scarce, produced water may also be treated for agricultural use, such as irrigation or wildlife watering, or for domestic use.

Produced water that remains after all available minimization, re-use and recycle options have been applied must be disposed. Options for disposing produced water include injection into an underground formation, evaporation and discharge. To satisfy regulations for discharge, produced water must be treated for salinity and/or oil and grease, depending on the nature of the body of water receiving the discharge. For example, US Environmental Protection Agency regulations for the Gulf of Mexico require that oil and grease concentration of discharged water average less than 29 ppm, but do not regulate salinity of discharge water.⁴ Technologies for removing salt and other inorganics from produced water include ion exchange, thermal distillation and membrane processes such as reverse osmosis. Technologies to remove organics (i.e., oil and grease) include flotation, adsorption and physical extraction (e.g., using a hydrocyclone or centrifuge).

Content for the technology description module is drawn from a January 2004 white paper on produced water prepared by Argonne for the DOE and from other research conducted by the content team over the past decade. All of the technology description fact sheets were sent to an external review panel composed of industry, service sector, academic and government experts, including several members of the DOE oil and gas environmental staff. However, only two reviewers returned comments on the fact sheets.

REGULATORY MODULE

State and federal regulations form the framework within which operators in the US must choose their produced water management strategies. The regulatory module of the new information resource offers capsule summaries of state and federal regulations related to produced water. Federal regulations are listed by issuing agency, the relevant agencies being the EPA, the US Department of the Interior’s Bureau of Land Management and the Minerals Management Service, also under the Interior Department. External links direct the user to the agency websites.

State regulations can be accessed by clicking on the desired state on a US map or selecting from a drop-down list on the module’s opening page. The user is directed to a state summary page including information about the agencies that regulate produced water management in that state, as well as embedded hyperlinks to the relevant sections of the regulatory text on the agencies’ websites, Fig. 2. In addition, the regulatory module provides contact information-including officers’ names, telephone numbers and addresses-for state and federal regulatory agencies.

Fig. 2. In the website’s regulatory module, summary pages for each state explain regulations concerning produced water and offer links to the full text of those regulations on the websites of the state agencies responsible for their enforcement. Contact information for the relevant agencies is also given. Courtesy of Argonne National Laboratory.

Regulatory information was collected between November 2006 and February 2007 from web-based research and interviews of state and federal regulators. Each agency’s regulatory summary page was sent to the appropriate agency contact for verification before the material was sent to the web team. Comments were received on about two-thirds of the pages. All information and hyperlinks will be checked prior to the site’s launch.

TECHNOLOGY IDENTIFICATION MODULE

Many factors determine the appropriate produced water management practice for any given application, among them location, produced water properties, technical feasibility of practices, cost, infrastructure and equipment requirements and availability, available discharge options and regulatory requirements. To help operators navigate these diverse variables to find the most appropriate option, the new website offers an interactive technology identification module. This module consists of a programmed decision-tree flow chart. For each technology option, the user is asked yes/no questions in four areas:

• Is the technology physically feasible at the site?
• Does the regulatory agency with jurisdiction allow the technology’s use?
• Does company policy prohibit the technology, or is the liability from using the technology considered too great?
• Can the company cost-effectively meet all the requirements of the regulatory agency for using the technology?

If the user’s answers to these questions all support the technology’s use (yes, yes, no, yes), the technology is added to a list of options for the user’s consideration. If any of the answers does not support the technology’s use, it is rejected and the program moves on to the next technology, Fig. 3. Answering the program’s questions may require investigation in the website’s other modules or external information.

Fig. 3. The technology identification module asks the user questions related to his or her specific well in order to determine the most appropriate produced water management options. Courtesy of Argonne National Laboratory.

The produced water website’s technology identification module is based on similar functionality developed for the drilling waste site, but is considerably more complex due to the wider range of variables affecting and options for managing produced water.

PROJECT TEAM

The produced water management site is the work of a content team with expertise in produced water management technologies and regulations and a web development team. John Veil, manager of the Water Policy Program in Argonne’s Environmental Science (EVS) Division, is the author of the content for the technology description and technology identification modules. He has 27 years’ experience in water regulation and policy, and 15 years’ experience specifically in produced water. He has authored or co-authored many papers on produced water for journals, conferences and government agencies and has been invited to speak frequently on produced water in the US and abroad.

Dr. Markus Pruder, a researcher and analyst in the Environmental Health Risk Section of the laboratory’s EVS Division, is the author of the regulatory module content. Pruder has 15 years’ experience in environmental law and regulation, with a focus on water and waste issues for the past seven years. His experience includes conducting, overseeing and reviewing environmental remediation, decontamination and decommissioning at federal hazardous waste sites. Pruder also teaches European Union law at the Georgetown University Law Center.5 Argonne’s Bob Sullivan, Tom Kotek and Pam Richmond comprise the web team, which is responsible for site design and programming.

CONTINUING DEVELOPMENT

It is unclear whether or how often the technology and regulatory information on the produced water website will be updated. Veil said the regulatory module of the drilling waste management site has been successfully kept current so far.

“Our webmaster notifies us every month or so about any links that are no longer active. We research these and update or remove them,” Veil said. “We also occasionally get notices from state agencies that their regulations have been re-codified or re-numbered.”

Veil said keeping the new site current will depend on Argonne receiving ongoing funding from the DOE for oil and gas work.

“FY07 has been a bad funding year,” he said. “It is the first time in over a decade in which we received no new oil and gas funds from DOE. If that trend continues, we will not be able to keep the site updated. However, we are hopeful that some funding will be available.”

At present, there are no plans to include regulations of other countries or international bodies on the website, as the DOE has only funded Argonne to cover US regulations. However, Mr. Veil said that if a third-party source of funding can be found for the site, Argonne may expand the regulatory module to include non-US regulations.   

LITERATURE CITED 

¹ Veil, J. A., Puder, M. G., Elcock, D. and R. J. Redweik, Jr., “A white paper describing produced water from production of crude oil, natural gas, and coal bed methane,” Argonne National Laboratory, January 2004.
² Veil, J., email interview by author, May 9, 2007.
³ Veil, J. et al., “New produced water information resource,” presented at the 17th Produced Water Seminar, Houston, January 17-19, 2007.
⁴ Walsh, J. et al., “Troubleshooting produced water-methods and lessons learned,” World Oil, March 2007, pp. 111.
⁵ EVS staff directory, Argonne National Laboratory website, <http://www.ead.anl.gov/staff/> Accessed May 10, 2007.