“Drop & Pop” 3C Submersed Floating OBN for Cost-Effective Marine Seismic Acquisition

In this paper we present an innovative node design and deployment method that challenges the coupling paradigm. We have designed and tested an autonomous seabed recording system, but instead of placing the unit on the seabed it is tethered to an anchor line and floating. The recording system is composed of two hydrophones separated by 1 meter and a geophone placed in between. The recording of vertical particle velocity is using the natural gimble system. The immersed system sits above the seabed and the positioning is maintained using an “organic anchor”. The vertical stand is ensured by a positive buoyancy of the array using the Archimedes principle. Given the novel design of the 3C recording unit, a “Drop & Pop” deployment is appropriate as it takes advantage of the absence of any coupling requirement. The initial field test has shown some promising results with good quality reflected event and reliable refracted energy being recorded by the geophone sensor out to very long offsets. These preliminary results encourage application of such technology for sparse recording system either for large exploration objective or for reservoir monitoring using combination of 4D FWI and 4D FWM (imaging with multiples).