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Prepared by: J. Daniel Arthur, P.E. and Bruce G. Langhus, Ph.D. June 2008. Emerging National Produced Water Issues. Prepared for: U.S. Department of Energy Office of Fossil Energy National Energy Technology Laboratory. Presentation Outline. Why Produced Water? Issues Barriers Summary
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Prepared by: J. Daniel Arthur, P.E. and Bruce G. Langhus, Ph.D. June 2008 Emerging National Produced Water Issues Prepared for: U.S. Department of Energy Office of Fossil Energy National Energy Technology Laboratory
Presentation Outline Why Produced Water? Issues Barriers Summary Current and Emerging Issues of Significance PW Treatment Implementation Issues Management and Sustainability DOE Sponsored CBNG Field Tour of Chinese Contingency by ALL Consulting San Juan Basin (Colorado)
Realities of Produced Water U.S. on-shore O&G - over 18 billion bbls/yr. 756 billion gallons - 2,320,000 acre-feet Enough to supply 4.5 million families for a year PW lifting and disposal is the single biggest operating cost for U.S. on-shore operators – causes premature abandonment of marginal producers Produced water permits are limiting the pace of development for coal bed methane and gas shales Environmental effects demand technology solutions for production to continue in a growing number of areas
Why Does PW Matter? Water production in the US and worldwide is surging in production rates along with oil production rates Global warming phenomenon is creating extreme weather patterns, including severe droughts in many areas Produced water, although often poor in quality, offers a drought resistant source of groundwater that must otherwise be disposed of – generally via injection or discharge In the 1930s, severe drought caused massive dust storms and charged an event that changed the way of life in the mid-continent (the DUST BOWL)
Emerging Considerations Regional droughts Arid and semi-arid regions Conflicts over municipal vs. industrial use Major aquifers drying up Aquifer/Underground Storage Climate change?
Water: A growing Concern Issues such as Global Warming, Peak Oil, Peak Coal, Alternative Energy Development, etc. have become household discussion points In the US today, as has been the case throughout history, severe droughts have plagued many areas Lack of water can change our landscape, cause exodus from an area, and impede industrial development
Bureau of Reclamation Access to adequate supplies of fresh water is becoming an increasingly critical issue in many parts of the world. In arid and semi-arid regions of the southwestern U.S., diminishing water supplies and extended periods of drought have generated an interest in non-traditional water resources, and the development of new technologies to exploit them. New Mexico has limited supplies of fresh water, but very large reserves of saline groundwater. As conventional water supplies become locally depleted, desalinated groundwater may become an important alternative source of fresh water for many communities. (ref: New Mexico Brackish Groundwater Assessment Workshop)
Barriers to Energy Development Management of produced water is becoming a more sensitive issue both onshore and offshore Managing produced water can be challenging, costly, and potentially create a roadblock to oil & gas development Wasting and excessive depletion of water resources will no longer be an issue that can simply be ignored Required sustainable management of produced water continues to develop Each platform also discharges hundreds of thousands of gallons of produced water every day, according to the MMS. Produced water typically contains benzene, arsenic, lead, naphthalene, zinc and toluene, and can contain radioactive pollutants. All major field research programs on produced water have detected petroleum hydrocarbons, toxic metals and radium in the water column down-current from the discharge. Source: NRDC
Surging Water Production Conventional Oil & Gas Aging oil fields Dewatering plays CBNG Powder River Basin San Juan Basin Illinois Basin Green River Basin Oil Shales Tight Sand Plays Developing Unconventional plays Shale Gas Barnett Fayetteville Woodford Chattanooga Haynesville Marcellus Utica Lewis Mancos An Atrium Shale outcrop at the Paxton Quarry in northern Michigan Courtesy: Gas Research Institute
Water Statistical Tracking Tracking water production, disposal and use statistics varies significantly by state – with minimal data tracked in many states Tracking produced water quality data varies greatly, with many historical statistics based on estimates Disposition of produced water usage is not consistently tracked and although tracking water statistical information is required on federal lands, reported data is not consistently managed or analyzed Expansion of data systems is critical to moving sustainable produced water management forward
Why Produced Water?Summary Costs of PW management cause pre-mature abandonment and make some planned projects uneconomic Produced Water issues are limiting domestic production Protecting the environment is essential for both the public and industry Produced water is a tremendous potential asset in semi-arid or drought stricken regions DOE has the opportunity to turn this waste stream into a resource
Treating Produced Water Many existing water treatment technologies have not been fully customized and/or optimized for use by the energy industry Variations in water quality and production volumes/duration (often representing considerable variations!) Size, motion resistance, explosion resistant, etc. Easily scalable, environmentally elegant, remote use, customizable to conditions (e.g., power, chemicals, etc.) Power demands lead to climate change concerns and add to costs
What is PW Treatment? General Types of Treatment De-Oiling (e.g., platform discharge) De-Sanding (e.g., prior to re-injection) Pollutant Reduction/Removal (including temperature stabilization) (e.g., for beneficial use) Ion Exchange Produced Water Treatment System (Montana)
Design Considerations Influent water quality characterization Produced Water characteristics: WSOs, Solids, Temperature Produced Oil properties (API gravity, Oil-in-water droplet size distribution) Temporal Variability / Dynamic (hourly & over life of facility) Produced water flow rate Oil-in-water concentration Solids concentration and particle size in produced water Effluent water quality treatment specifications Overboard discharge Environmental Protection Discharge Limitations (Oil-in-Water, Toxicity, etc.) Produced Water Re-Injection (PWRI) Equipment Operability (pumps, flow lines, screens) Sustainable Injectivity (formation plugging) Beneficial Uses/CO2 Sequestration
PWT Technology Review De-Sanding / Solids Filtration Gravity separation De-Sanding (Solid/Liquid) Hydrocyclones Media filtration (sand filter / dual media filter / deep bed filter) Physical barrier (cartridge / sock) Membrane Separation (MF) Freeze/Thaw De-Oiling Gravity separation Coalescence enhanced gravity separation De-Oiling (Liquid/Liquid) Hydrocyclones Gas Flotation Electro-Coagulation Absorption (Organoclay, etc.) Walnut Shell Media Filtration Membrane Separation (ceramic, vibrating)
PWT Technology Review Polishing - soluble pollutant removal Absorption (Activated Carbon, Organoclay, etc.) Aeration & sedimentation (for iron removal) Partitioning Manipulation (enticing soluble pollutants into oil phase prior to De-Oiling) Solvent Extraction Biological treatment (membrane bio-reactor, fixed film, etc.) Oxidation Membrane Separation (UF & NF) Polishing - salinity reduction Membrane Separation (RO) Ion Exchange Electrodialysis (ED) Evaporation (Freeze/Thaw, ponds, etc.) Thermal distillation Freeze/Thaw Polishing - salinity reduction & soluble pollutant removal Membrane Separation (RO) Constructed Wetlands
Actual PW Treatment A single Water Treatment Technology is usually not a complete solution Often, treatment in stages is necessary Often, pre-treatment is necessary to protect and enable downstream processes Real systems have variations in flow rate, water quality, and ancillary env. issues Real systems are subject to abuse, neglect and operating errors Often, treatment processes will concentrate pollutants into a smaller volume of water (often 5% - 35%), which will have highly concentrated pollutants, and will still require disposal or management. For Example: 1,000 bbl PW 400 bbl waste Treatment & 600 bbl finish Wtr
Water Treatment Challenges Minimizing concentrated waste stream associated with desalination Capturing gas entrained in water produced Minimizing power consumption and chemical requirements Customizing technologies for off-shore and remote onshore applications Tools to properly choose water management and treatment alternatives (including economics and regulatory requirements) Innumerable variations can make this process extremely challenging! And more...
Potential Water Resource in Arid Regions Local water supply to ranchers and farmers (Northern PRB) Community water supply as drinking water or gray water (Gillette, WY) Regional water supply to augment river flow (North Platte River)
Produced Water and Energy Production Produced water as cooling water at coal-fired plants Produced water as dust control at coal mines Produced water as cooling water for nuclear plants Produced water as pumped water energy storage at wind farms and PV projects
Produced water as growth medium for algal biodiesel and cellulosic biomass (CYCLO-1 algae grew by 2.8 to 3.0 doublings per day in 15,000 to 30,000 mg/L water; DOE, 1998) Recovery of waste heat from produced water stream prior to disposal (Co-Produced Geothermal) Produced Water and Energy Production, Cont’d
Produced Water and Global GCC Coordination of water withdrawal from unconventional gas reservoirs with disposal of CO2 Produced water disposal into deep reservoirs in conjunction with CO2 disposal and sequestration Use to enhance wildlife habitat and facilitate terrestrial CO2 Sequestration First RBDMS well coverage map of Arkansas (ALL/DOE/AOGCC)
Produced Water and Other Environmental Issues Detoxifying produced water prior to offshore discharge Disposal of treatment brine Reducing volumes of water produced Water shut-off, downhole separation, etc. Ownership of produced water Ownership of pore-space for disposal and migration of injected wastewater Numerous wildlife and GCC issues (onshore and offshore)
Research Needs Identification of barriers and delineation of significance and future needs and applications of produced water Implications of produced water management to green house gases Planning and interaction between coal mines and coal bed methane production and associated management of coal seam waters Water treatment and beneficial uses of produced water Geospatial tools and techniques that can be used to aid in identification and planning for water management Tools to facilitate assessing water management alternatives on a geospatial basis given local or regional criteria and economics Environmental risk analysis and human health risk analysis methods and standards to aid in evaluating risks and environmental impacts Training, technology transfer, technology development, identification and understanding of needs... ...to name a few