Slanted-Streamer Acquisition - Broadband Case Studies in Europe / Africa

In 2012, two offshore Africa slanted-streamer acquisition pilot surveys were acquired, as well as one circular acquisition with slanted streamers offshore northern Europe. This technique uses a linear slant streamer in order to produce a sliding notch over offsets. This is an exploration tool as it uses a typical towed-streamer spread with all cables slanted. Receiver deghosting is applied upfront in the processing sequence to narrow the receiver ghost notches. Post deghosting, the processing sequence is similar to any other dataset taking into account the enhancements in both low and high frequencies. We will briefly discuss the acquisition technique and then present the deghosting algorithm. We will then show the results on two case studies in Europe and Africa. The West Africa pilot consisted of three 2D sequences overlapping a large 3D survey acquired in this area. The Europe project consisted of a circular acquisition using slanted streamers. This is currently being processed and we present some preliminary results. The latter gives a combination of full azimuth and broadband data in shallower waters. We will be showing the results of the deghosting up to and including migration and we will be comparing it with the legacy data.