Water purification for UK shale operations
With water still high on the agenda when it comes to environmental concerns relating to fracking, the industry has come up with a plethora of innovative solutions. ElectroPure is a mobile onsite technology developed in Canada and soon to be available in the UK. It helps energy producers remove bacteria, heavy metals and NORM (naturally occurring radioactive materials) from produced and flowback waters, eliminating the use of toxic chemicals, saving water resources and reducing truck movement to the site.
Today we are discussing this innovative solution with Antony Newman of Hydrologic Tech Solutions, the only reseller of the ElectroPure system in the UK.
Monica Thomas (Shale Gas International): Your company provides ElectroPure – a mobile onsite technology that treats contaminated water resulting from hydraulic fracturing operations. Can you briefly explain why there is a need for such technology? What are the elements that need to be removed during the purification process, and why are they problematic?
Antony Newman (Hydrologic Tech Solutions, UK): Well, this is really an opportunity for the triple-bottom-line approach to a problem. As fracking gained in popularity in the mid-2000s, it opened access to commercial levels of production from unconventional tight rock formations not previously thought to be possible. The large volumes of water needed to open the rock must flow back from the well and this requires management. There is an economic cost to managing this flowback when it is trucked off-site for deep well disposal while other trucks source fresh water for the next well frac. There is also social and environmental cost in the form of competing access to water, stewardship of water resources, and nuisance/safety aspects to all the heavy truck traffic. If the water that flows back from one frac can be used in subsequent fracs, there can be environmental, social, and economic wins.
When the water is in contact with the geological formation, it picks up contaminants as it flows back to the surface. Further, bacteria may begin to grow in the water, creating additional contaminants. Some of these contaminants can pose problems with re-use of the water, either by interfering with the friction reducers or gelling agents in a well frac, plugging pores in the rock needed to let gas or oil escape, or by posing health risks to on-site workers. ElectroPure is a proprietary wastewater process train specifically engineered to treat oilfield water for re-use. Heavy metals, bacteria, suspended solids, hydrogen sulphide, and organic matter is removed by ElectroPure so that flowback water may be re-used.
MT: Can you explain the difference between produced and flowback water? What is the difference in terms of chemical make-up or treatment?
AN: Produced water generally refers to formation water originally present in the pores of the rock which flows back to the surface with the oil or gas in a well. Think of it as ancient oceans. Flowback generally refers to the water which is used to hydraulically fracture the rock and then flows back to the surface as the well is brought on-stream. However, since it can take months for a well to flow back the water used in a frac, the convention may be to call flowback produced water after a well has been on production for a number of days. This can vary by State or Province, as each dictates how oil and gas production is recorded. Some unconventional resources do not have material pore water and so these wells technically do not have any produced water.
Produced water has been in contact with the geological formation for millions of years and so it has reached some degree of chemical equilibrium. In contrast, water used in the frack is only in contact with the formation for a short period of time. The flowback also contains some of the sand and residual chemicals that were used in the frac. Treating flowback is challenging because the composition can change dramatically over time, depending on a number of factors.
MT: According to the UK Department of Energy & Climate Change, each fracking operation requires between 10 and 30 million litres of fresh water. How much of that would be fresh water and how much recycled flowback / produced water?
AN: That is a very good question but one that is very difficult to answer! It will depend on how much of the original volume of water used in the frac returns, how quickly it returns, what the chemical composition of the water is over that period, what other sources of water are available, and what the water disposal options are. It is not uncommon for a formation to return less than 60% of the volume of water used in a frac, so make-up water from another source has to be found. Exploration and production companies across the world are evaluating alternative sources of water, such as brackish or brine water which may be found deeper than most potable freshwater aquifers while others are utilizing gray water from municipal waterworks plants. Still others are using produced water from conventional oil and gas production as sources of water. Economics play a dominant role in the evaluation of water sources and we are focusing on making treatment and re-use of water more economically viable by continuously improving the ElectroPure technology.
MT: Following on from the previous question; how big a strain do you think shale exploration will put on the utilities sector in Britain?
AN: I cannot speak on their behalf if you do your research you will find that our utility sector has in place long-term strategies for water and wastewater services. A House of Commons briefing paper, dated September 2015 does cover off a number of points for shale gas exploration including comments around water usage and how it can be managed sustainably.
MT: Hydrologic Tech Solutions is a partner / reseller of the Canadian firm Grounds Effect Company, why do you think this particular solution should be adopted in the UK?
AN: Because ElectroPure is a proven patented solution. A Green, environmentally friendly, chemical free answer in Oil & Gas Solids Control and Wastewater Treatment.
MT: My understanding is that when it comes to fracking operations, the water situation in the UK is rather different from, say, in the U.S. For one, British landowners don’t tend to take their water from wells located on their properties, but rather rely on the utility companies. Can you, perhaps, explain how does this difference impact on fracking operations in the UK?
AN: Water sourcing is only one of the factors that are considered in an overall water management plan. Fresh water can be found in underground aquifers, rivers, lakes, and from precipitation. The availability at any given time of these sources and the cost to access, transport, and store the water is taken into account. Water utilities play a role in supplying water for fracking in many areas of North America and I expect they will play a significant role in the UK. As regulated entities, this will allow the utility companies and the regulators to anticipate the needs of all water users and ensure reliable delivery to all.