Patent ID: 7109717

Claim:
A system for real-time monitoring of changes in a sub-seafloor hydrocarbon reservoir over an interval of time during which there may be hydrocarbon extraction, comprising: a controlled source electromagnetic transmitter comprising at least one transmitting antenna for transmitting electromagnetic energy on a plurality occasions over the interval; a plurality of seafloor antennae distributed on the seafloor over an area corresponding to the reservoir, wherein each seafloor antenna comprises a receiver electrode array, each providing a signal responsive to energy from the transmitter on each of the occasions; at least one data logging processor for receiving on each occasion the signal from each of the antennae, the signal characterizing, in part, impedance of the reservoir, and for causing storage, for each occasion, of at least one parameter related to the signals received from the antennae; a clocking device for associating a time with respect to the at least one parameter stored; and an optional comparison process for identifying changes over time in the at least one parameter.