23rd February 2021
Speaker: Per Eivind Dhelie, Chief Geophysicist, Lundin Energy Norway AS
Topic: Using wide tow Quad point sources for high resolution seismic and accurate AVO measurements in the Barents Sea
A seismic acquisition and image project was undertaken by Lundin Energy Norway and Licence co-venturer Spirit Energy and was acquired by Shearwater in the 3rd quarter 2019 in the Greater Wisting Area of the Barents Sea. It involved very specific and clear goals stated upfront. Redesigning the towing configuration was of paramount importance so as to obtain close to zero offsets. The sources were re-designed and re-built into four sources comprising small efficient point sources. The acquisition adopted a multisensor recording system to allow for full deghosting.
The new seismic, named ‘HalfSeis’ (Lundin Energy AS), has provided the interpretation team with a much improved image dataset: enabling the reservoir architecture to be structurally mapped with confidence in turn leading to high resolution maps of multiple target levels including ‘top and base’ reservoir. Of particular interest was the need to identify fault reactivation caused through either younger Tertiary episodes or by ice rebound and its impact on fault compartment retention of hydrocarbons. The new data will be used for shallow hazard gas detection and hence it does away with the need for further 2D site survey acquisition. The dataset represents a significant uplift in the reliability of AVO attributes and hence it greatly enhances the identification of hydrocarbon filled shallow targets.