Chemical and physical characterization of produced waters from conventional and unconventional fossil fuel resources

► Characterization of produced waters (PWs) is an initial step for determining potential beneficial uses. ► PWs could be an asset rather than a liability and increase water resources. ► Constituents prevalent in the five sources of PWs included chlorides, inorganics (nonmetals, metals, and metalloids), organics and NORM. Characterization of produced waters (PWs) is an initial step for determining potential beneficial uses such as irrigation and surface water discharge at some sites. A meta-analysis of characteristics of five PW sources [i.e. shale gas (SGPWs), conventional natural gas (NGPWs), conventional oil (OPWs), coal-bed methane (CBMPWs), tight gas sands (TGSPWs)] was conducted from peer-reviewed literature, government or industry documents, book chapters, internet sources, analytical records from industry, and analyses of PW samples. This meta-analysis assembled a large dataset to extract information of interest such as differences and similarities in constituent and constituent concentrations across these sources of PWs. The PW data analyzed were comprised of 377 coal-bed methane, 165 oilfield, 137 tight gas sand, 4000 natural gas, and 541 shale gas records. Majority of SGPWs, NGPWs, OPWs, and TGSPWs contain chloride concentrations ranging from saline (>30000mgL−1) to hypersaline (>40000mgL−1), while most CBMPWs were fresh (