3D inversion of towed streamer EM data — A model study of the Harding field and comparison to 3D CSEM inversion

A towed streamer electromagnetic (EM) system capable of simultaneous seismic and CSEM data acquisition has been developed and tested in the North Sea. The towed EM data are processed and delivered as a time-domain impulse response. In this paper, we use 3D modeling and inversion to investigate the ability of the towed EM system to detect and characterize the Harding field, a typical North Sea-type target. The 3D model of the Harding field itself was constructed from dynamic reservoir simulations. We have compared our 3D inversion of time-domain towed streamer EM data with 3D inversion of conventional frequencydomain CSEM data. We observe similarities in the recovered models. Obviating the need for ocean bottom receivers, the towed-streamer EM system enables CSEM data to be acquired simultaneously with seismic over very large areas in frontier and mature basins for higher production rates and relatively lower cost than conventional CSEM.