The Commonwealth of Australia is committed to providing web accessible content wherever possible. If you are having difficulties with accessing this document please call the Department of the Environment and Energy on 1800 803 772 (free call). Reports in this series The full set of technical reports in this series and the partner agency responsible for each is listed Technical report number Title Authoring agency Reviewing existing literature 1 Literature review: Summary report NICNAS 2 Literature review: Human health implications NICNAS 3 Literature review: Environmental risks posed by chemicals used coal seam gas operations Department of the Environment and Energy 4 Literature review: Hydraulic fracture growth and well integrity 5 Literature review: Geogenic contaminants associated with coal seam gas operations 6 Literature review: Identification of potential pathways to shallow groundwater of fluids associated with hydraulic fracturing Identifying chemicals used in coal seam gas extraction 7 Identification of chemicals associated with coal seam gas extraction in Australia NICNAS Modelling how people and the environment could come into contact with chemicals during coal seam gas extraction 8 Human and environmental exposure conceptualisation: Soil to shallow groundwater pathways 9 Environmental exposure conceptualisation: Surface to surface pathways Department of the Environment and Energy 10 Human and environmental exposure assessment: Soil to shallow groundwater pathways – A study of predicted environmental concentrations Assessing risks to workers and the public 11 Chemicals of low concern for health based on an initial assessment of hazards NICNAS 12 Human health hazards of chemicals associated with coal seam gas extraction in Australia NICNAS 13 Human health risks associated with surface handling of chemicals used in coal seam gas extraction in Australia NICNAS Assessing risks to the environment
limit for fracture height if fracture and well path are not aligned. Production logging Provides only information about zone or perforation contributing to production in applications. ^ # ^ ^ ^ ^ ^ ^ Wellbore imaging logging Run only in open hole. Provides fracture orientation only near the wellbore. ^ # ^ # # # ^ ^ Downhole video Run mostly in cased holes and provides information only about zones and perforation contributing to production. May have open hole applications. ^ # ^ ^ ^ ^ ^ ^ Model based Net-pressure fracture analysis Results depend on model assumptions and reservoir description. Requires “calibration” with direct observations. # # ^ # ^ ^ # # Well testing Results depend on model assumptions. Requires accurate permeability and reservoir pressure estimates. # ^ ^ # ^ ^ ^ # Production analysis Results dependent on model assumptions. Requires accurate permeability and reservoir pressure estimates. # ^ ^ # ^ ^ ^ # Note: * Techniques can be determined; # techniques may be determined; ^ techniques that cannot be determined
naturally occurring. Most of that which is not naturally occurring can be avoided through best-practice well completion. Two accounts of grey sediment temporally associated with HF activities apparently not investigated. of thousands of CSG wells. None of these three cases is inconsistent with historical, natural behaviour of groundwater in the region nor have they been tied to CSG operations. same aquifer so that drawdown (up to 200 ft or 60 m) causes wells to dry up. Methane contamination occurs but does not seem to be as widespread (report does not mention historical methane contamination). stemmed from CSG activities. But acknowledged soap contamination does show that drilling fluids can escape to the aquifer. Source: US EPA (2004), unless otherwise Table 4.2 Summary of producing US basins from which the EPA registered few or no resident complaints Piceance Basin Uinta Basin Northern Appalachian Basin Western Interior Coal Region Raton Basin Number of wells in operation (ca. year 2000) Not reported 1255 Not reported 377 Not reported Production (year 2000) 1.2 Bcf/y (34 million m3/y) 76 Bcf/y (2.2 billion m3/y) 1.41 Bcf/y (40 million m3/y) 6.5 Bcf/y (185 million m3/y) 31 Bcf/y (880 million m3/y) Size 7225 mi2 (19 billion m3) 14 450 mi2 (37 billion m3) 43 700 mi2 (113 billion m3) 87 000 mi2 (225 billion m3) 2200 mi2 (6 billion m3) Depth of wells Two-thirds of wells >5000 ft (1500 m), nearly all >4000 ft (1200 m) 1200-4400 ft (370-1340 m) Most <1000 ft (<300 m) 600-3700 ft (180-1130 m) 500-4100 ft (150-1250 m) (based on typical reported overburden