Abstract: The system and method for real-time monitoring of a hydrocarbon reservoir (4) during extraction include an electro-magnetic source assembly (16) for transmitting a first plurality of electromagnetic fields. A plurality of seafloor antennae (30a-30d) is distributed over an area of the seafloor (8) corresponding to the reservoir (4), where each antenna (30a-30d) comprises a receiver electrode array (30a-30d) adapted for receiving a second plurality of electromagnetic fields and generating signals corresponding to the detected fields. A data logging processor receives the signals over time and stores data corresponding to the signals. Different combinations of the receiver electrode are used in combination with transmitter antennae for measuring vertical, radial and/or azimuthal fields. Transmission and detection of the fields can be performed continuously or at timed intervals during hydrocarbon extraction to estimate the rate and efficiency of extraction.

Abstract: A system for mapping electrical conductivity of the seafloor incorporates a plurality of data logging units, where each unit (100) is an assembly adapted for deployment at a location on the seafloor for measurement of horizontal electric and magnetic fields. Rigidly attached and extending vertically from the unit assembly is a vertically-oriented substantially rigid arm (158) having a pair of vertically-displaced electrodes (160, 162) disposed on the arm to create a vertically-oriented dipole antenna. The electrodes are in electrical communication with an amplifier located within the assembly which generates an amplified signal which is then provided to a data logging processor also located within the assembly. The processor collects time series of amplified electric field and magnetic signals over a predetermined period of time.