High Resolution Mirror Imaging of 4D OBC Data at Valhall
R. Milne, E.J. Kjos, A. Dawson and M. Ortin
Event name: Third EAGE Workshop on Permanent Reservoir Monitoring 2015
Session: PRM Technology - Deeper Dimensions
Publication date: 16 March 2015
Info: Extended abstract, PDF ( 6.14Mb )
Price: € 20
The specifications of the permanent OBC (LoFS) array at Valhall were designed to produce time-lapse images of the reservoir at 2.5km depth. Advances in processing technology have been leveraged to re-process the data from several legacy LoFS surveys in order to produce high resolution images of the overburden, beyond the original specification of the array. Inclusion of the down-going arrivals into the workflow improves shallow coverage to provide a near-continuous image of the sea bed. Processing of the down-going arrivals in a 4D sense provides high resolution time-lapse images much shallower than was previously achievable. Analysis of LoFS recordings of an ultra-high resolution site survey demonstrate that the array can be reliably used to record frequencies up to 500Hz.