Table 2 Summary of the fluids and particles used in hydraulic fracturing fluid in Australia (© Copyright, Economides & Martin 2007; Golder Associates 2010b; DEHP 2012b; APLNG 2011; AGL 2011; Santos 2011; QGC 2011; Arrow Energy 2012b). Injected Purpose Products used CAS Notes substance number Fractures the Bore water, farm pond water or 7732-18-5 Volume of coal when groundwater previously extracted water required injected under from coal seams is often used is ~0.2 to high pressure 1.3 ML per well (USEPA 2011) Proppant Keeps the Sand 99439-28-8 The latest fractures open technology Resin-coated sand None or once the high advances in proprietary Ceramics pressure fluid proppants 66402-68-4 Bauxite (aluminium ore) is removed include high 90669-62-8 strength ceramics and sintered bauxite Acid Dissolves Hydrochloric acid 7647-01-0 Not all wells calcite in the require this Muriatic acid 75-00-3 coal prior to treatment Acetic acid 64-19-7 fracturing because coal seams do not always contain calcite Gelling Increases the Guar gum None or Not all hydraulic agent viscosity of the proprietary fracturing uses Starches to allow a gel; gel-free or 9005-25-8 Cellulose derivatives more proppant fracturing is Clay 9004-34-6 Polydimethyldiallylammonium to be carried termed stabilisers chloride 26062-79-3 into fractures ‘slickwater’ (Claytrol) Tetramethylammonium chloride 75-57-0 (Claytreat 3C) Crosslinker Increase the Borate salt 1330-43-4 There are viscosity of different Ethyl glycol 107-21-1 gelling agents crosslinkers for Isopropanol 67-63-0 different gelling Disodium octaborate tetrahydrate agents Boric acid 52869-79-1 Boric oxide 1303-86-2
Table 2 Summary of the fluids and particles used in hydraulic fracturing fluid in Australia (© Copyright, Economides & Martin 2007; Golder Associates 2010b; DEHP 2012b; APLNG 2011; AGL 2011; Santos 2011; QGC 2011; Arrow Energy 2012b). Injected substance Purpose Products used CAS number Notes Fractures the coal when injected under high pressure Bore water, farm pond water or groundwater previously extracted from coal seams is often used 7732-18-5 Volume of water required is ~0.2 to 1.3 ML per well (USEPA 2011) Proppant Keeps the fractures open once the high pressure fluid is removed Sand Resin-coated sand Ceramics Bauxite (aluminium ore) 99439-28-8 None or proprietary 66402-68-4 90669-62-8 The latest technology advances in proppants include high strength ceramics and sintered bauxite Acid Dissolves calcite in the coal prior to fracturing Hydrochloric acid Muriatic acid Acetic acid 7647-01-0 75-00-3 64-19-7 Not all wells require this treatment because coal seams do not always contain calcite Gelling agent or Clay stabilisers Increases the viscosity of the to allow more proppant to be carried into fractures Guar gum Starches Cellulose derivatives Polydimethyldiallylammonium chloride (Claytrol) Tetramethylammonium chloride (Claytreat 3C) None or proprietary 9005-25-8 9004-34-6 26062-79-3 75-57-0 Not all hydraulic fracturing uses a gel; gel-free fracturing is termed ‘slickwater’ Crosslinker Increase the viscosity of gelling agents Borate salt Ethyl glycol Isopropanol Disodium octaborate tetrahydrate Boric acid Boric oxide 1330-43-4 107-21-1 67-63-0 52869-79-1 1303-86-2 There are different crosslinkers for different gelling agents
background-review-hydraulic-fracturing_0.docx