In China it has become common to integrate several geophysical techniques when exploring for reservoirs in complex geologic areas. Conventional seismic cannot provide a good image below igneous rock, salt domes, and/or complex and deeply dipping structures, and it has major limitations in determining if a reservoir trap contains hydrocarbons and in mapping the range and scope of a hydrocarbon-bearing reservoir. EM techniques, on the other hand, have recently progressed to the point that they can solve specific E&P problems. EM instrumentation has improved and many new methods have been developed (e.g., high-power time-frequency and borehole-to-surface methods). Processing and interpretation techniques (e.g., joint inversion, constrained inversion, and comprehensive and integrated interpretation) also have improved.