Barents Drilling Results Reflected in EM Data

There is a lot of drilling activity in Norway's favorite frontier area this year, though not all of it is positive. This week Statoil declared its latest Gemini prospect non-commercial. Our EM team was not surprised at the outcome.

Recent Barents Sea drilling results show close correlation with EM responses.

PGS acquired towed streamer EM data simultaneously with seismic in the Wisting area in 2015. This image shows a resistivity plot, superimposed on an initial interpretation of the structure. Wisting, to the south, is characterized by a strong anomaly of high resistivity, while Gemini North 7325/4-1 indicates a much weaker response, barely distinguishable from the background.The prospect may have looked promising on the seismic, but the EM doesn't back it up.  

The weaker EM anomaly indicates a much lower hydrocarbon content, in line with the drilling result.

Resistivity map through the main reservoir interval. The weaker Gemini EM anomaly indicates a much lower hydrocarbon content, in line with the non-commercial drilling result.Resistivity map through the main reservoir interval Wisting and Gemini North. The weaker Gemini EM anomaly indicates a much lower hydrocarbon content, in line with the non-commercial drilling result.

Historically, successful wells in the Barents Sea have been shown to have a high EM response. Complementary data adds new layers of understanding. While seismic is the best measure of lithology, EM is more sensitive to changes in fluids. Correlating velocity, acoustic impedance and resistivity improves drilling results.

PGS is expanding its EM data library with new Barents Sea projects in the Harstad Basin and has an extensive MultiClient EM library in the BSSE. Contact em@pgs.com to find out more.