Energy Policy Act of 2005 (Ultra-deepwater and Unconventional Resources Program)
Pretreatment and Water Management for Frac Water Reuse and Salt Production
GE Global Research
STW Resources, Inc.
Two significant barriers to the development of many shale gas plays are water availability for drilling and hydrofracturing and disposal options for the water coproduced with gas (“frac flowback water”). In this project, GE Global Research will develop technology that enables recycle of nearly all the frac flowback water as well as production of a salable salt by-product.
In most frac water recycling processes the recovered wastewater is collected and distilled, producing pure water for recycle and a concentrated brine or dried mixed salts for disposal as waste. A key objective of this project is to develop a pretreatment process (prior to evaporation) such that the resulting salt produced from the evaporator has commercial value, perhaps as road salt.
Under the leadership of Dr. James Silva, Principal Investigator, this project will combine system and cost models with lab-scale experiments to determine the most cost-effective pretreatment options and water management strategies. To produce a salable salt product, it is necessary to selectively remove ionic species, particularly multi-valent ions, from the frac flowback water. The pretreatment technologies to be evaluated include lime softening, ion exchange, and nano-filtration.
The key deliverables of this project are the specification and verification of a pretreatment process that enables cost-effective production of salable salt and recycled water from recovered hydrofacturing water. In addition, a water management strategy will be defined to optimally stage and integrate multiple wells. The chief benefits are greatly reduced fresh water consumption, up to 50% less water traffic on roads, and reduced risk associated with long-term contamination of salt-water disposal wells.
GE will work closely with STW Resources, Inc, a partner with expertise in water reclamation in the oil and gas field. STW and GE have installed one of the first water reclamation projects in the shale gas arena. GE Global Research will provide the required cost share for this project.
Principal Investigator: James Silva