Bench-Scale Investigation of Treatment Technologies for Flowback Fluids from Shale Gas Fracturing

This paper presents the results of the investigation of flowback fluids treatment from shale gas fracturing by bed sorption, reverse osmosis, and electrocoagulation. It was found that the bed sorption experiment with 1:3 ratio of vermiculite:zeolite was effective at improving the quality of the flowback fluid sample with an overall reduction in Na+ level of 7.50%, EC of 2.40%, and Cl- of 1.31%. The two membrane in series configuration combined with the ClO2 pretreatment achieved a 92 % salt rejection concurrent with a 93 and 90% of Cl- and Na+ reduction in the permeate. For the flowback sample containing guar in the matrix, electrocoagulation operated in batch mode yielded decrease in turbidity ranging from 43 to 98%, TSS from 54 to 86%, and COD from 61 to 76%. Management options and priority risk index for disposal options were also ascertained. Key words: hydraulic fracturing, flowback, salinity, reverse osmosis, bed sorption, electrocoagulation