Towed Streamer EM data from Barents Sea, Norway

The measured Towed Streamer EM data from a survey in the Barents Sea, undertaken in the Norwegian sector are inverted as a series of unconstrained 2.5D inversion. We show that unconstrained anisotropic 2.5D inversion of the EM data in complex geological settings can produce resistivity models that are consistent with both interpreted log and seismic data, and known discoveries. We consider three cases from the surveys acquired over Skrugard, Caurus and Norvarg areas of Barents Sea. We have compared the results of unconstrained inversion to publically available log data at Skrugard discovery. Not only is the overall depth trend recovered, but the main variation of the resistivity is captured as well as, in some intervals, comparable average interval resistivity. We also show example resistivity and apparent anisotropy sections, while the resistivity section highlights that the sub-surface resistivity is complex, the somewhat simpler anisotropy section reveals an anisotropy anomaly that is co-incident with both the lateral, and depth, extent of Skrugard. The apparent anisotropy corresponds fairly well with Caurus and Norvarg anomalies. However, finding structural outline from the vertical resistivity alone is challenging by unconstrained inversion