Electromagnetic data collection goes 3-D
2009 R&D 100 Winner
To map the oceanic subsurface, researchers at Lawrence Berkeley National Laboratory, Berkeley, Calif., combined computing power and controlled source electromagnetics (CSEM) to create the EMGeo: ElectroMagnetic Geological Mapper to create the first commercially available technology for full 3-D geophysical imaging of industrial-sized EM data.
CSEM is a key emergent way to quantify hydrocarbons and utilizes low-frequency EM energy (less than 1 Hz) to map variations in the subsurface electrical resistivity of oil and gas prospects. To conduct CSEM measurements, scientists use a deep-towed transmitter to excite low-frequency electromagnetic signals measured on the sea floor by electric and magnetic field sensors/detectors, with the largest transmitter-detector separations exceeding 15 km. EMGeo analyzes the data under a 3-D imaging framework, incorporating computationally optimized modeling grids and different levels of computational parallelism. At a time when efficient use of resources must accompany energy production, the EMGeo offers a means of offshore hydrocarbon mapping. It can provide fluid information about hydrocarbon reservoirs, distinguishing oil or gas from brine.
3-D geophysical imaging technology