AsshaleexploitationisstillinitsinfancyoutsideNorthAmericamuchresearcheffortisbeingchannelledintovariousaspectsofgeochemicalcharacterizationofshalestoidentifythemostprospectivebasins,formationsandmaptheirpetroleumgenerationcapabilitiesacrosslocal,regionalandbasin-widescales.Themeasurementoftotalorganiccarbon,distinguishingandcategorizingthekerogentypesintermsoil-proneversusgas-prone,andusingvitrinitereflectanceandRock-Evaldatatoestimatethermalmaturityarestandardpracticeintheindustryandappliedtosamplesfrommostwellboresdrilled.Itisthetrendsofstableisotopesratios,particularlythoseofcarbon,thewetnessratio(C1/∑(C2+C3)),andcertainchemicalbiomarkersthathaveprovedtobemostinformativeaboutthestatusofshalesasapetroleumsystem.Thesedatamakeitpossibletoidentifyproduction'sweet-spots',discriminateoil-,gas-liquid-andgas-proneshalesfromkerogencompositionsandthermalmaturities.Rolloversandreversalsofethaneandpropanecarbonisotoperatiosareparticularlyindicativeofhighthermalmaturityexposureofanorganic-richshale.Comparisonsofhopane,streraneandterpanebiomarkerswithvitrinitereflectance(Ro)measurementsofthermalmaturityhighlightdiscrepanciessuggestingthatRoisnotalwaysareliableindicatorofthermalmaturity.Majorandtraceelementinorganicgeochemistrydataandratiosprovidesusefulinformationregardingprovenance,paleoenvironments,andstratigraphic-layerdiscrimination.Thisreviewconsidersthedatameasurement,analysisandinterpretationoftechniquesassociatedwithkerogentyping,thermalmaturity,stableandnon-stableisotopicratiosforrocksandgasesderivedfromthem,productionsweet-spotidentification,geochemicalbiomarkersandinorganicchemicalindicators.Italsohighlightsuncertaintiesanddiscrepanciesobservedintheirpracticalapplication,andthenumerousoutstandingquestionsassociatedwiththem.
