The oil and gas industry is experiencing a period of change and economic uncertainty. Its continued viability is dependent on being able to make the most of the resources at its disposal. Structurally conformable 2D to 3D interpolation is a technology that maximizes the potential of existing 2D data and minimizes the financial risks associated with acquiring new 3D data. Two case studies are outlined. Case study 1 is offshore North East Greenland, an area consisting of complex, terminating unconformities and which is inaccessible to 3D streamers, which has been mapped in 3D using SCI. Case study 2 is offshore Mid Norway, where a vast library of vintage 2D and 3D datasets have been utilized to create one continuous 3D volume, again with SCI. These case studies demonstrate the versatility and the validity of SCI technology.
Presentation Date: Wednesday, September 27, 2017
Start Time: 11:00 AM
Location: Exhibit Hall C/D
Presentation Type: POSTER
Conventional marine seismic data is affected by the interference from ghosts on both the source and receiver sides. The natural diversity provided by propagation directions, depth variations and imperfect reflections at the sea surface means the notches are not as deep as they often appear after stack. For a flat streamer, the apparent time delay between the main signal and its ghost is angle dependent, and deterministic de-ghosting in the τ-p domain can reduce the effect of ghosts and retrieve the original wavelet spectrum. For a linearly-slanting streamer, further to the angle-dependant time shift a lateral separation occurs in the angle dimension. The amplitude and phase discrepancies around the notch frequencies caused by the variations in depths and effective refection coefficients can be reduced by using a stochastic search for the optimum set of de-ghosting parameters. A deconvolution process stabilized by averaging over a large number of traces in common–slowness panels may be used to address the remaining spectral defects.