The TFEM (Time-Frequency electromagnetic Sounding) technique has been developed by BGP. It can process the EM signals in Frequency and Time domains jointly to extract resistivity and polarization anomalies of the geological targets. It can be used to study the geoelectric structures and predict the potential hydrocarbon areas. At present, the TFEM technique has been widely used in Saudi Arabia, Oman, Chad, Ethiopia, Niger and Thailand as well as nearly 20 domestic oil fields in China, with the completion of nearly 20,000 km of TFEM sections to date.