Recycling hydraulic fracturing wastewater

Water management can significantly add to the cost and environmental footprint of oil production and innovations in water management can provide significant economic and environmental gains. New treatment technologies make recycling of water for hydraulic fracturing possible.

Methods for recycling wastewater

Methods for recycling fracking water include anaerobic and aerobic biologic treatment; clarification; filtration; electrocoagulation; blending (directly diluting wastewater with freshwater); and evaporation.

Anaerobic

Generally, anaerobic treatments on wastewater are implemented on concentrated wastewater. Anaerobic sludge contains a variety of microorganisms that cooperate to convert organic material to biogas via hydrolysis and acidification. Biogas typically consists of 70% methane (CH4) and 30% carbon dioxide (CO2) with residual fractions of other gases (e.g. H2 and H2S). The methane can be used as an energy source. Anaerobic reactors can be implemented in a variety of ways. (The figure shows a contact reactor and an upflow reactor. The sludge is mixed with wastewater in the reactor, then separated in the sedimentation tank and returned to the reactor. In the anaerobic upflow reactor, the influent is introduced at the bottom of the vertical reactor. The primarily grain-shaped sludge forms a blanket in the reactor, with the most compact sludge grains at the bottom and the lighter grains and heavier sludge floccules above it. Light sludge floccules are released by the upward flow, but can potentially be collected in a sedimentation tank. Biogas is collected and disposed of at the top of the reactor, separately from the partially purified water and the sludge.

Benefits of wastewater recycling

Factors driving the conservation of water include the limitations in sources of fresh water in areas with a high rate of development, attractive economics of recycling compared with tanker truck transportation costs, minimization of road traffic to reduce environmental impacts, and water disposal costs.

Prevalence of wastewater recycling

After stimulation treatment, water used to fracture the well, in amounts as large as 50%, can rise back to the surface, along with the initial production, as flowback water. Flowback and produced waters, both part of the production stream, must be separated from the formation. In most cases, flowback and produced water are disposed into an injection well, put in evaporation ponds, or treated and disposed of according to government regulations. Water management can significantly add to the cost and environmental footprint of oil production and innovations in water management can provide significant economic and environmental gains. New treatment technologies make recycling of water recovered from hydraulic fracturing possible. Methods for recycling fracking water include anaerobic and aerobic biologic treatment, clarification, filtration, electrocoagulation, blending (directly diluting wastewater with freshwater), and evaporation. Recycling of produced water and fracture flowback water for reuse in hydraulic fracturing is on the rise in the development of unconventional resource plays. Factors driving the conservation of water include the limitations in sources of fresh water in areas with a high rate of development, attractive economics of recycling compared with tanker truck transportation costs, minimization of road traffic to reduce environmental impacts, and water disposal costs.

Noteworthy papers in OnePetro

Campin, D. 2013. Environmental Regulation of Hydraulic Fracturing in Queensland. Presented at the SPE Annual Technical Conference and Exhibition, 30 September-2 October, New Orleans. SPE-166146-MS. http://dx.doi.org/10.2118/166146-MS.

Edwards, J., Tudor, R., Jones, D. 2009. Benefits of Quality Hydrocarbon Fracturing Fluid Recycling. Presented at the Canadian International Petroleum Conference, Calgary, 16-18 June. PETSOC-2009-056-EA. http://dx.doi.org/10.2118/2009-056-EA.

Elliott, A.S., Suri, N.K., An, D., et al. 2014. Analysis of Microbes in Hydraulic Fracturing of Montney Tight Gas Formations in Western Canada. Presented at the SPE/CSUR Unconventional Resources Conference – Canada, Calgary, 30 September–2 October. SPE-171651-MS. http://dx.doi.org/10.2118/171651-MS.

Ely, J.W., Fraim, M., Horn, A.D., et al. 2011. Game Changing Technology For Treating And Recycling Frac Water. SPE Annual Technical Conference and Exhibition, Denver, 30 October-2 November SPE-145454-MS. http://dx.doi.org/10.2118/145454-MS.

Hallock, J.K., Roell, R.L., Eichelberger, P.B., et al. 2013. Innovative Friction Reducer Provides Improved Performance and Greater Flexibility in Recycling Highly Mineralized Produced Brines. Presented at the SPE Unconventional Resources Conference-USA, 10-12 April, The Woodlands, Texas, USA. SPE-164535-MS. http://dx.doi.org/10.2118/164535-MS.

Lord, P., Weston, M., Fontenelle, L.K., Haggstrom, J. 2013. Recycling Water: Case Studies in Designing Fracturing Fluids Using Flowback, Produced, and Nontraditional Water Sources. Presented at the SPE Latin-American and Caribbean Heath, Safety, Environment and Social Responsibility Conference, Lima, Peru, 26-27 June. SPE-165641-MS. http://dx.doi.org/10.2118/165641-MS.

Pierce, D., Bertrand, K., Cretiu-Vasiliu, C. 2010. Water Recycling helps with Sustainability. SPE Asia Pacific Oil and Gas Conference and Exhibition, Brisbane, Queensland, Australia. 18-20 October, SPE-134137-MS. http://dx.doi.org/10.2118/134137-MS.

Robinson, R., Kolla, H.S., Jackson, L. 2013. Friction Reducers as Water Management Aids in Hydraulic Fracturing. Presented at the SPE Production and Operations Symposium, 23-26 March, Oklahoma City, Oklahoma, USA. SPE-164493-MS. http://dx.doi.org/10.2118/164493-MS.

Satya Gupta, D.V., Hlidek, B.T. 2010. Frac-Fluid Recycling and Water Conservation: A Case History. SPE Prod & Oper 25 (01): 65 – 69. SPE-119478-PA. http://dx.doi.org/10.2118/119478-PA.

Schumacher, J.P., Malachosky, E., Lantero, D.M. et al. 1991. Minimization and Recycling of Drilling Waste on the Alaskan North Slope. J of Pet Technol 43 (06): 722 – 729. SPE-20428-PA. http://dx.doi.org/10.2118/20428-PA.

External links

Boschee, P. 2014.Produced and Flowback Water Recycling and Reuse. http://www.halliburton.com/public/multichem/contents/Papers_and_Articles/web/Feb-2014-Oil-Gas-Facilities-Article.pdf.

Easton, J. 2014. Fracking Wastewater Management. Waterworld. http://www.waterworld.com/articles/wwi/print/volume-28/issue-5/regional-spotlight-us-caribbean/fracking-wastewater-management.html.

Energy from Shale. 2015. America's Energy Environment. http://www.energyfromshale.org/americas-energy/environment.

Energy from Shale. 2015. Wastewater Management. http://www.energyfromshale.org/articles/wastewater-management.

Environmental Protection Agency. 2015. The Hydraulic Fracturing Water Cycle. http://www2.epa.gov/hfstudy/hydraulic-fracturing-water-cycle.

FracFocus. 2015. Fracturing Fluid Management. http://fracfocus.org/hydraulic-fracturing-how-it-works/drilling-risks-safeguards.

Fuquay, J. 2013. Recycling of fracking water is still rare, but it’s growing. Columbus Dispatch 27 May. http://www.dispatch.com/content/stories/business/2013/05/27/recycling-of-fracking-water-is-still-rare-but-its-growing.html.

Scott, J. 2014. Eagle Ford water recycling thrives following change in Texas Railroad Commission rules. Oil & Gas Journal 13 August 2013. http://www.ogj.com/articles/uogr/print/volume-2/issue-4/eagle-ford-water-recycling-thrives-following-change-in-texas-railroad-commission-rules.html.

See also

Hydraulic fracturing

Water for hydraulic fracturing