The flux of radionuclides in flowback fluid from shale gas exploitation

Abstract

This study considers the flux of radioactivity in flowback fluid from shale gas development in three areas: the Carboniferous, Bowland Shale, UK; the Silurian Shale, Poland; and the Carboniferous Barnett Shale, USA. The radioactive flux from these basins was estimated, given estimates of the number of wells developed or to be developed, the flowback volume per well and the concentration of K (potassium) and Ra (radium) in the flowback water. For comparative purposes, the range of concentration was itself considered within four scenarios for the concentration range of radioactive measured in each shale gas basin, the groundwater of the each shale gas basin, global groundwater and local surface water. The study found that (i) for the Barnett Shale and the Silurian Shale, Poland, the 1 % exceedance flux in flowback water was between seven and eight times that would be expected from local groundwater. However, for the Bowland Shale, UK, the 1 % exceedance flux (the flux that would only be expected to be exceeded 1 % of the time, i.e. a reasonable worst case scenario) in flowback water was 500 times that expected from local groundwater. (ii) In no scenario was the 1 % exceedance exposure greater than 1 mSv—the allowable annual exposure allowed for in the UK. (iii) The radioactive flux of per energy produced was lower for shale gas than for conventional oil and gas production, nuclear power production and electricity generated through burning coal.Electronic supplementary materialThe online version of this article (doi:10.1007/s11356-014-3118-y) contains supplementary material, which is available to authorized users.

Evolution of water chemistry during Marcellus Shale gas development: A case study in West Virginia

“…Data from Hayes (2009) NORM in flowback and are derived from the radioactive decay of 238 U and 232 Th, which commonly occur in sandstones and shales in hydrocarbon reservoirs (Kraemer and Reid, 1984;Neff et al, 2011;Watler et al, 2012). Radium is more soluble than the largely immobile uranium and thorium isotopes and are soluble in pore water and HF fluid (Almond et al, 2014). Radium has been documented in formation waters in many sedimentary basins (Rowan et al, 2011;Dresel and Rose, 2010), and it has been measured in the water co-produced with gas and oil from Devonian (Marcellus) age rocks in the Northern Appalachian Basin.…”

Wastewater from hydraulic fracturing in the UK: assessing the viability and cost of management

“…NORM contaminated waste streams generated by the conventional hydrocarbon industry can be re-injected into the source formation onshore or offshore to provide pressure support to enhance reservoir recovery, or can be diluted and dispersed offshore into the marine environment within set limits. 35,36 As previously mentioned, the capacity and legality of re-injection of FP waters in the UK is uncertain. Additionally, the dilution and dispersion of pre-treated FP waters high in NORMs directly to the offshore environment will not be feasible due to limitations on marine contamination enforced by The OSPAR Treaty (2007) as outlined in Section B.44, UK NORM Waste Management Strategy.…”

Shale Gas: A Review of the Economic, Environmental, and Social Sustainability

“…[122] However, the concentration of NORMs in flowback water is lower than in other sources (e.g.,i nt he medical and mining sectors)a nd is normally not considered to be hazardous to human health. [126] Nevertheless,b ecause the composition and concentration of NORMs depend on the mineralogy of the shale formation, it is important to understand the relationships between different groups of elements to the mineralogy;this allowsmore accurate predictions of water contamination associated with shale gas extraction. [127] Water contamination associated with flowback water can occur if it is treated in ac onventional wastewatert reatment plant.T his is because the chemicals used in fracturing fluid, as well as the high levels of bromide andt otal dissolved solids in produced water, are not normally handledi nc onventional wastewater treatmentp lants.T his could result in chemical reactionsb etween the chemical components and disinfectant agent in the treatment plant,l eading to the formation of unwanted disinfectant byproducts and an overload of existingi nfrastructure as the quantity and chemical content of the wastewater exceed existingp rocessing capacity and capability.…”