Methods and systems for characterizing a wellbore extending into a geologic structure comprising a reservoir of subterranean hydrocarbons comprising: providing a first fluid composition comprising a base metal into the first wellbore; wherein corrosion of the base metal in the first wellbore results in electrochemical oxidation of the base metal and electrochemical reduction of a reducible species that generates a gaseous product; providing at least one sensor in proximity to the first wellbore; and receiving a signal detected by the sensor at a monitoring unit, wherein the sensor senses a signal resulting from corrosion of the base metal; wherein the signal is used to determine information relating to the characteristics of the first wellbore and extraction of hydrocarbons therefrom.